KR102289947B1 - Method and apparatus for managing allocation and usage of radio resource, method and apparatus for transmitting data through unlicensed band channel, and method and apparatus for managing access of radio resource - Google Patents

Abstract

A method is provided for a transmitter to transmit first data having periodicity through a channel of an unlicensed band. The transmitter adjusts at least one of a transmission time of the first data and a clear channel assessment (CCA) time of the channel in order to occupy the channel. The transmitter determines whether the channel can be occupied by performing CCA on the channel at the CCA time point. In addition, when the transmitter can occupy the channel, the transmitter transmits the first data through the channel at the time of transmission of the first data.

Description

A method and apparatus for managing radio resource allocation and use, a method and apparatus for transmitting data through a channel of an unlicensed band, and a method and apparatus for managing access to radio resources AND APPARATUS FOR TRANSMITTING DATA THROUGH UNLICENSED BAND CHANNEL, AND METHOD AND APPARATUS FOR MANAGING ACCESS OF RADIO RESOURCE}

The present invention relates to a method and apparatus for managing the allocation and use of radio resources. In addition, the present invention relates to a method and apparatus for managing and controlling efficient data transmission through management of access to radio resources in a mobile radio access system.

As the number of mobile Internet users through mobile communication systems increases, mobile communication operators are searching for efficient ways to increase the capacity of mobile communication systems. The most efficient and intuitive method is to increase bandwidth by additionally securing licensed band frequencies for mobile communication systems. However, while the licensed band frequency has the advantage of providing efficient mobile communication services through exclusive use of the frequency, the cost of licensing and using the frequency is high, and the licensed band frequency allocated for the mobile communication system is limited. It has the disadvantage of being Accordingly, mobile communication service providers and manufacturers are considering a method of providing a mobile communication service using an unlicensed band frequency, which has relatively many available frequency bands and is inexpensive.

Communication systems installed in unlicensed band frequencies have the following limitations. The communication system installed in the unlicensed band frequency has a limit in which transmission power is limited in order to minimize the impact that may have on other systems sharing the unlicensed band frequency. Specifically, when the licensed band system and the unlicensed band system are installed in the same place, according to the unlicensed band system, unlike the licensed band system, a coverage hole may occur.

The communication system installed in the unlicensed band frequency has a limit in which the unlicensed band frequency must be used discontinuously or opportunistically for fair coexistence with the adjacent unlicensed band system. For this reason, transmission reliability of a control channel and a common channel used in a mobile communication system may be lowered.

Due to the limitations of the unlicensed band system, a scenario in which a licensed band system and an unlicensed band system are installed/operated in a complementary form, rather than a standalone system using only the unlicensed band, is being reviewed. In this scenario, control functions that require reliability, such as terminal control and mobility management, are performed by a system operating in a licensed band frequency, and traffic functions such as wireless transmission speed increase and wireless traffic load balancing are supplemented by the unlicensed band system. is operated with

A system or carrier operating in a licensed band frequency performs a control function and a traffic function, and a system or carrier operating in an unlicensed band frequency performs a traffic function. This operation is implemented through a carrier aggregation (CA) operation. Taking the carrier aggregation configuration of 3rd Generation Partnership Project (3GPP) Long Term Evolution (LTE) as an example, the carrier aggregation method between the unlicensed band Frequency Division Duplex (FDD) carrier and the licensed band LTE and the unlicensed band TDD in which both uplink and downlink operate (Time Division Duplex) There may be a carrier aggregation scheme between the carrier and the licensed band LTE.

The unlicensed band cellular system has the advantage of being able to provide a mobile communication service with guaranteed quality of service by utilizing abundant low-cost frequency resources and advanced interference control technology. However, the unlicensed band cellular system requires a new coexistence technology and interference control technology in order to secure these advantages in the coexistence with other unlicensed band systems and various regulations required in the unlicensed band.

Meanwhile, when two or more homogeneous or heterogeneous systems (or devices) simultaneously transmit data in a wireless access system, the receiving device may not properly receive data due to interference. For example, it is assumed that the first transmitting device transmits data to the first receiving device and the second transmitting device simultaneously transmits data to the second receiving device. When the first receiving device receives data from the first transmitting device, interference may occur due to the data received from the second transmitting device. Similarly, when the second receiving device receives data from the second transmitting device, interference may occur due to the data received from the first transmitting device. Due to such interference, the first receiving device and the second receiving device may not properly receive data.

In order to solve this problem, there is a need for a method for each device to efficiently access resources. In particular, in a band (eg, unlicensed band, TV White Space, etc.) that uses a shared frequency, a frequency access management method based on frequency regulations for operation in the corresponding frequency is required.

An object of the present invention is to provide a method and apparatus for efficiently allocating and using radio resources.

Another object of the present invention is to provide a method and apparatus for efficiently managing allocation and use of radio resources.

Another object of the present invention is to provide a method and apparatus for efficiently managing and controlling radio transmission by managing the allocation and use of radio resources.

In addition, the problem to be solved by the present invention is to provide a method and apparatus for efficiently accessing radio resources.

According to an embodiment of the present invention, there is provided a method in which a transmitter transmits first data having periodicity through a channel of an unlicensed band. The transmission method of the transmitter may include: adjusting at least one of a transmission time of the first data and a clear channel assessment (CCA) time of the channel in order to occupy the channel; determining whether the channel can be occupied by performing CCA on the channel at the CCA time point; and when the channel can be occupied, transmitting the first data through the channel at the time of transmission of the first data.

The adjusting includes adjusting a transmission offset for the transmission time of the first data so that the transmission time of the first data does not overlap with the time when another device transmits periodic data through the channel. may include steps.

The determining may include continuously performing CCA on the channel until the channel can be occupied, regardless of a transmission offset for a transmission time point of the first data.

The transmitting may include transmitting the first data at a time point at which the channel can be occupied, not at a time point at which the first data is scheduled to be transmitted; and notifying a receiver to receive the first data that the first data was transmitted at a time other than the predetermined time.

In the adjusting step, when the first data is not transmitted within the previous transmission period for the first data, the time is advanced by a predetermined value from the time at which CCA is started within the previous transmission period. It may include the step of setting the CCA time point.

In the step of setting the CCA time point, the first duration between the transmission time of the first data determined by the transmission offset for the first data and the time at which the CCA is terminated and the first duration for the transmission of the first data When the sum of the two periods exceeds the limited occupancy time for the channel, the method may include setting the CCA time point as the CCA start time point within the previous transmission period.

In the transmitting step, when the channel can be occupied, from the time when CCA is terminated to the time of transmission of the first data, a special signal for preventing occupation of the channel by another device It may include transmitting through the channel.

In the transmission method of the transmitter, when the first data is successfully transmitted through the channel, the transmission of the first data is determined by a transmission offset of the first data within a next transmission period for the first data. The method may further include setting a CCA time point for the next transmission period so that the CCA is terminated before the transmission time point.

The transmitter may be a base station, and the first data may be a discovery signal (DRS).

The transmitter may be a terminal, and the first data may be an uplink signal transmitted to a base station.

According to another embodiment of the present invention, there is provided a method in which a transmitter transmits first data having periodicity and second data having aperiodicity through a channel of an unlicensed band. In the transmission method of the transmitter, a first clear channel assessment (CCA) for transmission of the first data, a second CCA for transmission of the second data, and the second 2 coordinating at least one of the transmission of data; and when the channel is occupied through at least one of the first CCA and the second CCA, transmitting the first data through the channel at a first time point determined by a transmission offset of the first data. includes

The transmitting method of the transmitter may further include, before the adjusting, transmitting the second data through the channel when the channel is occupied through the second CCA.

The adjusting may include early terminating the transmission of the second data in order to secure a duration during which the first CCA is performed.

The adjusting may include omitting the first CCA when the channel is occupied through the second CCA.

The transmitting may include transmitting the first data and the second data using the channel occupied through the second CCA.

The adjusting may include omitting the second CCA when the channel is occupied through the first CCA.

The transmitting may include transmitting the second data after transmitting the first data using the channel occupied through the first CCA.

The adjusting may include delaying the time of the second CCA after the time when the first data is transmitted when the time interval between the time at which the second data is to be transmitted and the first time is less than or equal to a predetermined value. may include steps.

According to another embodiment of the present invention, there is provided a method in which a transmitter transmits first data having periodicity and second data having aperiodicity through a channel of an unlicensed band. In the transmission method of the transmitter, a first duration during which clear channel assessment (CCA) for transmission of the first data is performed, the second so as to increase the possibility of occupancy of a channel for transmission of the first data. adjusting at least one of a second period during which CCA for data transmission is performed, and a transmission period length of the first data; performing CCA during the first period; and when the channel is occupied through CCA, transmitting the first data using the channel.

The adjusting may include: reducing at least one of the number of CCA unit times and the length of the CCA unit time for the first period; and determining the first period by multiplying the number of CCA unit times by the length of the CCA unit time.

The adjusting may include a first range that is a range of values that the number of CCA unit times for the first period can have, and a second range that is a range of values that the number of CCA unit times for the second period can have. 2 to set less than the range; and determining the first period by multiplying the number of CCA unit times selected within the first range by the length of the CCA unit time for the first period.

The adjusting may include a first in a range of values that the number of CCA unit times for the first period can have when the first data is not transmitted within a previous transmission period for the first data. reducing or maintaining the range and increasing a second range, which is a range of values that the number of CCA unit times for the second period can have; selecting a number of CCA unit times for the first period within the first range; and determining the first period by multiplying the selected number of CCA unit times by the length of the CCA unit time for the first period.

The adjusting may include reducing a transmission period length of the first data when the first data cannot be transmitted within a previous transmission period for the first data.

According to an embodiment of the present invention, for radio resource allocation in a mobile radio access system, a relatively less reliable unlicensed band frequency may be operated simultaneously with a licensed band frequency.

In addition, according to an embodiment of the present invention, it is possible to transmit uplink data through a reliable licensed band frequency. Through this, a reliable service can be provided.

In addition, according to an embodiment of the present invention, when the transmitting device performs radio resource access, the receiving device performs radio resource access, or the receiving device helps the transmitting device for data transmission of the transmitting device, the mobile radio Devices in the access system can efficiently access radio resources.

In addition, according to an embodiment of the present invention, operations such as selection and management of a channel for data transmission can be efficiently performed.

1 is a diagram illustrating a problem of resource allocation that occurs due to CCA (Clear Channel Assessment) for channel occupation when a frequency of an unlicensed band is operated.
2A, 2B, and 2C are diagrams illustrating a License Assisted Access (LAA) deployment scenario according to an embodiment of the present invention.
3A, 3B, 3C, and 3D are diagrams illustrating a method of allocating resources and a method of transmitting data when a licensed band carrier and an unlicensed band carrier are aggregated according to an embodiment of the present invention.
4A and 4B are diagrams illustrating a method of activating and deactivating a carrier when a licensed band carrier and an unlicensed band carrier are aggregated according to an embodiment of the present invention.
5A, 5B, 5C, 5D, and 5E are diagrams illustrating a frame structure according to carrier aggregation between licensed band carriers and unlicensed band carriers according to an embodiment of the present invention.
6 is a diagram illustrating a method of allocating resources using an Enhanced Physical Downlink Control Channel (EPDCCH) when a Frame Based Equipment (FBE) method is used according to an embodiment of the present invention.
7 is a diagram illustrating a method of allocating resources using an EPDCCH when a Load Based Equipment (LBE) method is used according to another embodiment of the present invention.
8 is a diagram illustrating a method of allocating resources using an EPDCCH according to another embodiment of the present invention.
9 is a diagram illustrating a method of allocating resources using an EPDCCH according to another embodiment of the present invention.
10 is a diagram illustrating a method of allocating resources for a multi-subframe according to an embodiment of the present invention.
11 is a diagram illustrating a method of allocating resources for a multi-subframe according to another embodiment of the present invention.
12 is a diagram illustrating a method of allocating resources for a multi-subframe according to another embodiment of the present invention.
13A, 13B, and 13C are diagrams illustrating a partial subframe transmission method.
14 is a diagram illustrating a method of configuring a PDSCH in an unlicensed band.
15 is a diagram illustrating the structure of a partial subframe configured in the COT of UCC after CCA.
16 is a diagram illustrating a partial subframe structure further including an EPDCCH.
17A, 17B, and 17C are diagrams illustrating resource grids corresponding to subframes belonging to COT of UCC.
18A and 18B are diagrams illustrating a partial subframe including a reference signal region when data is transmitted in a part of a subframe after CCA.
19 is a diagram illustrating a partial subframe including an RS region when data is transmitted in a part of the last subframe within a range in which the maximum COT is not exceeded.
20 is a diagram illustrating a first subframe, an intermediate subframe, and a last subframe of an occupied channel.
21 is a diagram illustrating a case in which the PDCCH+PDSCH region of the first subframe after CCA has a time slot length and the PDCCH+PDSCH region of the last subframe has a normal subframe length (1 TTI length).
22 is a diagram illustrating a case in which the PDCCH+PDSCH region of the first subframe after CCA has a normal subframe length (1 TTI length) and the PDCCH+PDSCH region of the last subframe has a time slot length.
23 is a diagram illustrating a case in which a PDCCH+PDSCH region of a first subframe among subframes of an occupied channel has a time slot length, and a PDCCH+PDSCH region of the remaining subframes has a normal subframe length (1 TTI length). .
24 shows that the PDCCH+PDSCH region of the first subframe among the subframes of the occupied channel has a time slot length or a normal subframe length (1 TTI length), and the PDCCH+PDSCH region of the remaining subframes has a normal subframe length (1). It is a diagram showing the case of having a TTI length).
25 and 26 are diagrams illustrating a case in which a PDCCH+PDSCH region of a subframe belonging to an occupied channel has a Downlink Pilot Time Slot (DwPTS) length or a normal subframe length (1 TTI length).
27 is a diagram showing the configuration of a base station according to an embodiment of the present invention.
28 is a diagram showing the configuration of a terminal according to an embodiment of the present invention.
29 is a diagram illustrating a format and a transmission period of a discovery signal (DRS) periodically transmitted by a base station.
30 is a diagram illustrating a method of transmitting a DRS while complying with the unlicensed band frequency regulation.
31 is a diagram illustrating a method of accessing a resource through clear channel assessment (CCA) to which the unlicensed band frequency regulation is applied.
32 is a diagram illustrating a channel search procedure according to an embodiment of the present invention.
33A, 33B, 33C, 33D, 33E, and 33F are diagrams illustrating a channel search method according to an embodiment of the present invention.
34 is a diagram illustrating a data transmission procedure by channel state evaluation according to an embodiment of the present invention.
35 is a diagram illustrating a situation in which signal arrival areas of a transmitting apparatus and a receiving apparatus are different.
36 is a diagram illustrating a method of periodically transmitting data by changing a data transmission time point according to an embodiment of the present invention.
37 is a diagram illustrating a method of transmitting periodic data by changing a CCA time point according to another embodiment of the present invention.
38A, 38B, 38C, 38D, and 38E are diagrams illustrating a method of transmitting periodic data and aperiodic data by changing a CCA time point according to another embodiment of the present invention.
39A and 39B are diagrams illustrating a frame structure for cellular operation in an unlicensed band frequency according to an embodiment of the present invention.
40 is a diagram illustrating a special signal for periodic data transmission according to an embodiment of the present invention.
41 is a diagram illustrating a section in which a special signal is required.
42 is a diagram illustrating a method of using a reference signal as a special signal according to an embodiment of the present invention.
43 is a diagram illustrating a special signal for a subframe in which a synchronization signal is transmitted, according to another embodiment of the present invention.
44A, 44B, and 44C are diagrams illustrating a method of transmitting a special signal in a partial region of a subframe according to another embodiment of the present invention.
45 is a diagram illustrating a configuration of a transmitting apparatus according to an embodiment of the present invention.
46 is a diagram showing the configuration of a receiving apparatus according to an embodiment of the present invention.

Hereinafter, with reference to the accompanying drawings, embodiments of the present invention will be described in detail so that those of ordinary skill in the art to which the present invention pertains can easily implement them. However, the present invention may be embodied in many different forms and is not limited to the embodiments described herein. And in order to clearly explain the present invention in the drawings, parts irrelevant to the description are omitted, and similar reference numerals are attached to similar parts throughout the specification.

Throughout the specification, a terminal is a mobile terminal (MT), a mobile station (MS), an advanced mobile station (AMS), a high reliability mobile station (HR-MS) ), a subscriber station (subscriber station, SS), a portable subscriber station, an access terminal (AT), user equipment (UE), and the like, and may refer to a terminal, MT, MS, It may include all or some of the functions of AMS, HR-MS, SS, portable subscriber station, AT, UE, etc.

In addition, the base station (base station, BS), an advanced base station (advanced base station, ABS), a high reliability base station (high reliability base station, HR-BS), a Node B (node B), an advanced node B (evolved node B) , eNodeB), access point (AP), radio access station (radio access station, RAS), base transceiver station (BTS), MMR (mobile multihop relay)-BS, a repeater serving as a base station ( relay station, RS), a high reliability relay station (HR-RS) serving as a base station, may refer to a repeater, a small base station, a macro base station, etc., BS, ABS, HR-BS, Node B, It may include all or part of the functions of eNodeB, AP, RAS, BTS, MMR-BS, RS, HR-RS, repeater, small base station, macro base station, and the like.

1. How to manage radio resource allocation and usage

Hereinafter, for convenience of description, a carrier operating in a licensed band in an environment in which carriers (or channels) are aggregated is referred to as a Licensed Component Carrier (LCC), and a carrier operating in an unlicensed band is referred to as an Unlicensed Component Carrier (UCC). In addition, hereinafter, for convenience of description, a carrier operated by a primary cell (PCell) among LCCs is referred to as a primary LCC (P-LCC), and a carrier operated by a secondary cell (SCell) among LCCs. is called S-LCC (Secondary LCC). On the other hand, the case in which UCC can be operated by the PCell is a case in which UCC and LCC differ only in frequency bands. In this case, the operation method of the UCC may be the same as or similar to the operation method of the LCC. Hereinafter, it is assumed that the UCC is operated only by the SCell or is operated as a limited PCell. Meanwhile, a plurality of UCCs may be configured in one SCell or may be operated by one SCell, but hereinafter, for convenience of description, it is assumed that one UCC is used. Of course, a method for a case in which one UCC is used may be applied identically or similarly even when a plurality of UCCs are used.

1 is a diagram illustrating a problem of resource allocation that occurs due to CCA (Clear Channel Assessment) for channel occupation when a frequency of an unlicensed band is operated. In FIG. 1, it is assumed that the frequency of the unlicensed band is operated by carrier aggregation as a secondary carrier or SCell for the frequency of the licensed band. Specifically, in (a) of FIG. 1, a case in which a base station schedules a Physical Downlink Shared Channel (PDSCH) of a UCC (cross-carrier scheduling) using a Physical Downlink Control Channel (PDCCH) of an LCC is exemplified. In (b) of FIG. 1, a case in which the base station schedules the PDSCH of the UCC (self-carrier scheduling) using the PDCCH of the UCC is exemplified.

The base station performs CCA to access the unlicensed band channel, which is an auxiliary carrier, according to the regulation of the unlicensed band frequency. As illustrated in (a) and (b) of FIG. 1, although the base station occupies the channel through CCA, due to the characteristics of the LTE system in which resource allocation and transmission are performed in subframe units, the CCA execution time and the PDCCH transmission time are delayed. Overlapping, it may not be possible to allocate resources normally.

In particular, due to the characteristics of the unlicensed band, devices operating in the unlicensed band can occupy and use the channel. In this case, there is a coexistence constraint between devices operating in the unlicensed band and an operation constraint in the unlicensed band. Therefore, there is a need for a carrier aggregation technology in consideration of the characteristics of a licensed band and an unlicensed band and an operation method accordingly.

1.1. license/ unlicensed Basic Operation for Data Transmission Over Band

Since the data transmission operation using the licensed/unlicensed band can be basically performed through the LCC and the UCC, data transmission or reception through the LCC or the UCC should be possible between the base station and the terminal. In particular, in the case of the terminal, it is possible to receive data through the UCC as well as data transmission/reception through the LCC. When the terminal initially accesses the base station, when changing a cell (handover), or when attempting to exchange data through an unlicensed band, the base station and the terminal exchange capabilities of the terminal.

The terminal may have at least one of the following five capabilities and perform data exchange.

- Data transmission/reception is possible only through the licensed band

- Simultaneous data transmission through licensed/unlicensed bands

- Cannot simultaneously transmit data through licensed/unlicensed bands (e.g., data is transmitted through licensed bands at a certain moment in time, and data through unlicensed bands at other moments)

- Simultaneous data reception through licensed/unlicensed bands

- Cannot simultaneously receive data through licensed/unlicensed bands (e.g., data is received through licensed bands at a certain moment in time, and data through unlicensed bands at other moments)

As another method of exchanging the capability of the terminal, when the terminal changes the cell, the device storing the capability of the terminal (eg, a base station providing a service of the previous cell, or an apparatus managing the base station) in a new cell There is a method of transmitting the capability of a terminal to a base station providing a service. According to this method, capability exchange between the base station and the terminal can be omitted.

In addition, the base station exchanges with the terminal a channel capable of data transmission/reception among several channels (frequency) of the unlicensed band, and allows the terminal to transmit data through a channel in which transmission/reception is impossible or difficult to transmit/receive during data service. It can be prevented from doing so, and the UE can be prevented from performing operations for data service (eg, handover, cell search, channel quality measurement/reporting, etc.). Specifically, when the base station informs the terminal of the serviceable channel among the channels in the unlicensed band, the terminal can measure the quality of the serviceable channel and report it to the base station. Through this, the base station can select and service a channel suitable for data service to the terminal. In this case, the base station and the terminal may continuously transmit data through data aggregation for adding a new carrier or carrier change for changing to a selected channel (or adding or deleting a previous channel). If a serviceable channel to the terminal is a carrier managed by a base station other than the current base station, the terminal may change to a cell that manages the corresponding carrier and continuously receive the data service.

1.2. license/ unlicensed Arrangements for data transmission over the band ( deployment ) scenario

2A, 2B, and 2C are diagrams illustrating a License Assisted Access (LAA) deployment scenario according to an embodiment of the present invention. 2B and 2C illustrate a case in which a PCell and a low power SCell (eg, a small cell) are connected through an ideal backhaul. However, even when the PCell and the low power SCell are connected through a non-ideal backhaul, the PCell and the low power SCell are the LAA deployment scenario 2a illustrated in FIGS. 2B and 2C , It can be installed similarly to 2b, 3a, 3b.

2A illustrates LAA deployment scenarios 1a and 1b. In LAA deployment scenario 1a, low-power PCells or low-power SCells are installed outdoors. In LAA deployment scenario 1b, low-power PCells or low-power SCells are installed indoors. In LAA deployment scenarios 1a and 1b, the low-power PCell or SCell may use licensed band frequencies (F1, F2) or unlicensed band frequencies (F3).

2b illustrates LAA deployment scenarios 2a and 2b. In LAA deployment scenario 2a, low-power SCells are installed outdoors, and in LAA deployment scenario 2b, low-power SCells are installed indoors. In LAA deployment scenarios 2a and 2b, the SCell may use the same frequency as the licensed band frequency (F1) used by the PCell, use a different licensed band frequency (F2), or use an unlicensed band frequency (F3).

2C illustrates LAA deployment scenarios 3a and 3b. In LAA deployment scenario 3a, low-power SCells are installed outdoors, and in LAA deployment scenario 3b, low-power SCells are installed indoors. In LAA deployment scenarios 3a and 3b, the SCell may use an unlicensed band frequency (F3) different from the licensed band frequency (F1) used by the PCell.

1.3. license / unlicensed for data transmission over the band LCC and UCC operation

Table 1 below shows the operation methods of LCC and UCC according to the LAA deployment scenario.

LCC, UCC operation according to the LAA deployment scenario of FIGS. 2A, 2B, and 2C LAA Deployment scenario Indoor/Outdoor Relevant LTE CA scenarios Carrier configures co-located Note Scenario1a Outdoor (small cell scenario 2a) LTE CA scenarios 2,3 in low power cell Low power Cell (L+U) LCC and UCC are co-located - LTE CA is configured in low power cell
- PCell and SCell are configured in a single low power cell (co-located PCell and SCell)
- UCC is configured to SCell
- P-LCC is configured to PCell
- if S-LCC is configured (P-LCC+S-LCC+UCC), S-LCC is configured in to SCell Scenario1b Indoor (small cell scenario 2b) Scenario2a Outdoor (small cell scenario 2a) - LTE CA scenarios 4,5 between PCell and SCell with IB
- LTE CA scenarios 2,3 in low power SCell PCell (L)+low power SCell (L+U) with IB S-LCC and UCC are co-located - LTE CA is configured in PCell and low power SCell with ideal backhaul (non-co-located PCell and SCell)
- S-LCC and UCC are configured in a single low power SCell Scenario2b Indoor (small cell scenario 2b) Scenario3a Outdoor (small cell scenario 2a) - LTE CA scenarios 4,5 between PCell and SCell with IB PCell (L)+low power SCell (U) with IB (P-)LCC and UCC are non-co-located - CA is configured in PCell and low power SCell with ideal backhaul (non-co-located PCell and SCell)
- LCC is only configured in a PCell
- UCC is only configured in a single low power SCell Scenario3b Indoor (small cell scenario 2b)

In LAA deployment scenarios 1a, 2a, and 3a, UCC is used by devices (eg, base stations) that are installed and operated outdoors. In LAA deployment scenarios 1b, 2b, and 3b, UCC is used by devices (eg, base stations) installed and operated indoors.

LAA deployment scenarios 1a and 1b are scenarios in which PCell and SCell are installed and operated overlappingly. LAA deployment scenarios 2a, 2b, 3a, and 3b are scenarios in which PCell and SCell are installed and operated without overlapping, and PCell and SCell are connected through an ideal backhaul.

In LAA deployment scenarios 1a and 1b, PCell and SCell are installed and operated overlapping in the same place (the installation place is different only whether it is outdoor or indoor), so LCC and UCC are set in the same device. If two or more LCCs exist and are configured, at least one LCC among the two or more LCCs may be configured in the PCell, and at least one of the remaining LCCs may be configured in the SCell or not configured in the SCell.

LAA deployment scenarios 2a and 2b show a case where LCC and UCC are configured and operated in the SCell. If the PCell and the SCell are connected through a non-ideal backhaul, the LCC may be configured as a pSCell (primary SCell or special SCell).

LAA deployment scenarios 3a and 3b show a case in which only UCC is configured and operated in the SCell.

3A, 3B, 3C, and 3D show a method of allocating resources and transmitting data when a licensed band carrier (LCC) and an unlicensed band carrier (UCC) are aggregated according to an embodiment of the present invention. A drawing showing the method. Specifically, FIGS. 3A, 3B, 3C, and 3D show downlink/uplink resource allocation and transmission methods according to LCC and UCC. The embodiment of the present invention uses a term or method operated/used in LTE CA unless otherwise specified. These terms or methods may be replaced with terms or methods operated/used for the same or similar purpose as the LTE CA in other mobile radio access systems or mobile communication systems.

As described above, due to the limitation of the unlicensed band, the unlicensed band may be usefully used for downlink data services. However, for downlink data transmitted from the base station to the terminal, the terminal transmits reliable uplink data (eg, hybrid automatic retransmit request (HARQ) ACK (acknowledge)/negative acknowledge (NACK), CQI (Channel Quality Indicator)) to the base station. In this case, the terminal can transmit reliable uplink data to the base station through more reliable P-LCC (LCC on PCell) than UCC. Or, if the base station and the terminal want to change the service operation channel during operation of the unlicensed band, if the terminal searches for a channel of a different unlicensed band than the currently operated channel, the state of the channel (eg, channel identifier and channel use, In order to report interference or power strength when using the channel) to the base station, the terminal may transmit (report) the channel status to the base station through P-LCC, which is more reliable than UCC. To this end, the base station may indicate (or allocate, schedule) resource allocation information of uplink/downlink data by using a resource allocation method and a resource transmission method as shown in Table 2 below.

Scenario for downlink / uplink resource allocation and transmission method according to LCC and UCC LAA scheduling alternative DL(Downlink) service UL(Uplink) service LCC (DL) UCC (DL) UL relevant LCC DL UL relevant UCC DL Scenario 1 DL-self scheduling (scheduled by LCC) DL-self scheduling (scheduled by UCC) indicated by LCC indicated by UCC Scenario 2 DL-self scheduling (scheduled by LCC) DL cross-carrier scheduling (scheduled by LCC) indicated by LCC indicated by LCC Scenario 3 DL cross-carrier scheduling (scheduled by UCC) DL cross-carrier scheduling (scheduled by LCC) indicated by UCC indicated by LCC Scenario 4 DL cross-carrier scheduling (scheduled by UCC) DL-self scheduling (scheduled by UCC) indicated by UCC indicated by UCC

3A illustrates an LAA scheduling scenario 1 (LAA scheduling alternative 1). Self-carrier scheduling is performed for each of the downlink P-LCC and the downlink UCC, and uplink feedback (eg, HARQ ACK/NACK, CQI) is transmitted through a PUCCH (Physical Uplink Control Channel) of the uplink P-LCC. . Specifically, the resource allocation information of the downlink data allocated to the LCC and the resource allocation information of the uplink data for the downlink data service include resource allocation information such as the resource allocation information channel (eg, PDCCH, EPDCCH, etc.) of the same LCC. It is indicated through a channel indicating information; hereinafter, PDCCH will be described as an example). Resource allocation information of downlink data allocated to UCC and resource allocation information of uplink data for downlink data service are indicated through the PDCCH of the same UCC. In addition, unless otherwise specified, the resource indicated by the resource allocation information may be at least one of an uplink resource and a downlink resource, the uplink resource is transmitted through a PUSCH (or PUCCH), and the downlink resource is a PDSCH An embodiment of the present invention will be described on the assumption that it is transmitted through In addition, a PUSCH (or PUCCH) or an uplink resource may be applied to a part described as a PDSCH or a downlink resource below.

3B illustrates an LAA scheduling scenario 2 (LAA scheduling alternative 2). Self-carrier scheduling is performed for downlink P-LCC, and cross-carrier scheduling by P-LCC is performed for downlink UCC. Uplink feedback (eg, HARQ ACK/NACK, CQI) is transmitted through the PUCCH of the uplink P-LCC. Specifically, resource allocation information of downlink data allocated to the LCC and resource allocation information of uplink data for a downlink data service are indicated through the PDCCH, which is a resource allocation information channel of the LCC. Resource allocation information of downlink data allocated to UCC and resource allocation information of uplink data for downlink data service are indicated through PDCCH of LCC.

3C illustrates an LAA scheduling scenario 3 (LAA scheduling alternative 3). Cross-carrier scheduling by UCC is performed for downlink P-LCC, and cross-carrier scheduling by P-LCC is performed for downlink UCC. Uplink feedback (eg, HARQ ACK/NACK, CQI) is transmitted through the PUCCH of the uplink P-LCC. Specifically, resource allocation information of downlink data allocated to LCC and resource allocation information of uplink data for downlink data service are indicated through PDCCH, which is a resource allocation information channel of UCC. Resource allocation information of downlink data allocated to UCC and resource allocation information of uplink data for downlink data service are indicated through PDCCH of LCC.

3D illustrates an LAA scheduling scenario 4 (LAA scheduling alternative 4). Cross-carrier scheduling by UCC is performed for downlink P-LCC, and self-scheduling is performed for downlink UCC. Uplink feedback (eg, HARQ ACK/NACK, CQI) is transmitted through the PUCCH of the uplink P-LCC. Specifically, resource allocation information of downlink data allocated to LCC and resource allocation information of uplink data for downlink data service are indicated through PDCCH, which is a resource allocation information channel of UCC. Resource allocation information of downlink data allocated to UCC and resource allocation information of uplink data for downlink data service are indicated through PDCCH of UCC.

4A and 4B show a method of activating or deactivating an unlicensed band carrier in a licensed band service for operating the scenarios shown in FIGS. 3A to 3D and Table 2; Specifically, FIG. 4A shows a method of activating an unlicensed band carrier in an environment in which a licensed band carrier (LCC) and an unlicensed band carrier (UCC) are aggregated, and FIG. 4B shows a method of deactivating an unlicensed band carrier. 4A and 4B illustrate a case in which activation and deactivation of an unlicensed band is controlled through a licensed band, but this is only an example. Of course, activation and deactivation of the unlicensed band may be controlled through another unlicensed band (eg, when downlink data is transmitted through another unlicensed band).

According to the above-described scenario, control for activation/deactivation is performed through a licensed band. Specifically, as illustrated in FIG. 4A , the base station transmits an activation command for the UCC to the terminal through the LCC at time n. When the terminal receives the activation command from the base station, the terminal measures the channel state of the UCC indicated by the activation command (or Activation CE (control element)). When the UE measures the channel state of the UCC, it reports a measurement result (eg, a CSI (Channel State Information) report) to the base station through the LCC. Here, CSI includes CQI, Precoding Matrix Indicator (PMI), Rank Indicator (RI), Procedure Transaction Identity (PTI), and the like. In addition, HARQ ACK/NACK for data reception may be transmitted through the LCC. On the other hand, the UCC corresponding to the activation command is a time _{point (n+k 1} ) and k _{when k 1} (however, 8 (ms) ≤ _{k 1} or a predetermined time or more) elapses from the time point (n) at which the activation command is transmitted. ₂ (provided that k ₂ ≤ 34 (ms) _, k ₂ ≤ 24 (ms), or a predetermined time or less) is activated between _{time points (n+k 2 ).} After UCC is activated, the base station transmits downlink data to the terminal through the activated UCC.

As illustrated in FIG. 4B , the UCC may be deactivated by control through the LCC. Specifically, the base station transmits a deactivation command (or deactivation CE) for the UCC to the terminal through the LCC at time n. The UE does not need to receive a downlink channel (eg, PDCCH, PDSCH, EPDCCH, etc.) for UCC indicated by the deactivation command, and there is no need to measure the channel state of the UCC indicated by the deactivation command. On the other hand, the UCC corresponding to the deactivation command is a time _{point (n+k 1} ) or sCellDeactivationTimer _{when k 1} (however, k ₁ ≤8 (ms) or less than a predetermined time) elapses from the time point (n) at which the deactivation command is transmitted. It is deactivated when the timer expires. Here, the sCellDeactivationTimer timer is started at the time point n when the activation command is transmitted in FIG. 4A .

On the other hand, when the carrier is changed similarly to the carrier activation/deactivation method, the carrier may be managed in the following way. Specifically, the base station may deactivate the previous carrier (Deactivation CE) and then activate the new carrier (Activation CE). Alternatively, the base station may activate a new carrier (Activation CE) and then deactivate the previous carrier (Deactivation CE). Alternatively, the base station may perform activation of a new carrier (Activation CE) and deactivation of a previous carrier (Deactivation CE) at the same time. For example, when the base station performs activation and deactivation at the same time, if the value mapped to the previously activated carrier is reset from 1 to 0, the activated carrier is deactivated, and the previously set value for activation/deactivation is If it is set from 0 to 1, the carrier is activated, and if the value set for activation/deactivation remains unchanged as 1, the activated carrier can be continuously used. Also, if the value set for activation/deactivation is 0 and is maintained without change, the base station does not activate the deactivated carrier.

1.4. unlicensed Resolving coexistence and interference in the band

In order to solve interference that occurs when devices of the same/heterogeneous system operating in the unlicensed band coexist, the following method may be used.

1.4.1. How to choose an efficient channel

In order to prevent multiple devices from using the same channel within the unlicensed band, each device selects a channel from idle channels (channels judged not to be used by other devices) when selecting an operating channel or interference measured by a base station or a terminal. Based on , the device may select a channel having the least interference among channels as an operating channel.

1.4.2. How to use resources efficiently on the same channel

The device may access the resource through the resource access availability determination method (CCA) presented in the unlicensed band operation regulation (Regulatory requirement).

Alternatively, the device may prevent other devices from using the resource during service. Specifically, by providing a continuous service while the device occupies the channel for the service, it is possible to prevent other devices from occupying the corresponding channel. Alternatively, when a device does not provide a data service while occupying a channel, a reference signal or data for energy detection of another device may be transmitted in order to prevent another device from occupying the corresponding channel. .

Alternatively, the device may service only a specific section and allow other devices to service the remaining section. For example, the device can service only in the DL section of the TDD frame. Alternatively, the device may divide the channel into a DTX (Discontinuous Transmission) on/off period and serve only in the DTX on period. Alternatively, the device may reuse a value configured for a Multicast Broadcast Single Frequency Network (MBSFN) and serve only in a section not configured as an MBSFN. Alternatively, the device may allow other devices to service in the MBSFN-configured section, or, conversely, may serve itself only in the MBSFN-configured section. Alternatively, the device may operate so that the section set to MBSFN and the section not set to MBSFN service one or more methods simultaneously by setting different settings for each section set to MBSFN and section not set to MBSFN. Alternatively, the device may use an ABS (Almost Blank Subframe) (service only in a specific subframe) scheme for Inter-Cell Interference Coordination (ICIC). In addition, the device may operate so that the divided sections provide the same or similar service by setting the same or different settings for each divided section as described above.

1.5. unlicensed Resource allocation and resource use for band operation

Meanwhile, FIGS. 5A, 5B, 5C, 5D, and 5E show a frame structure in which a licensed band carrier (LCC) and an unlicensed band carrier (UCC) are aggregated according to an embodiment of the present invention.

5A shows a frame structure for each carrier according to aggregation between LCC-FDD (licensed band carrier operated by FDD) and UCC-FDD (unlicensed band carrier operated by FDD).

Figure 5b shows a frame structure for each carrier according to the aggregation between LCC-FDD and UCC-TDD (unlicensed band carrier operated as TDD). 5B illustrates a case in which DL/UL configuration 1 is applied to UCC-TDD.

5c shows a frame structure for each carrier according to aggregation between LCC-TDD (licensed band carrier operated by TDD) and UCC-TDD. 5c illustrates a case in which DL/UL configuration 1 is applied to LCC-TDD and UCC-TDD.

5D shows a frame structure for each carrier according to aggregation between LCC-TDD and UCC-FDD. 5D illustrates a case in which DL/UL configuration 1 is applied to LCC-TDD.

5e shows a frame structure for each carrier according to aggregation between LCC-TDD and UCC-TDD. FIG. 5E illustrates a case in which DL/UL configuration 1 is applied to LCC-TDD and DL/UL configuration 3 is applied to UCC-TDD.

On the other hand, when the carrier aggregation of FIGS. 5D and 5E is performed according to the scenario described in FIGS. 3 and 2, the subframe of the licensed band is the uplink subframe and the subframe of the unlicensed band is the downlink subframe (SD1) , DL cross-carrier scheduling for allocating UCC resources through LCC cannot be used. A method for enabling DL cross-carrier scheduling is needed. One of the methods for enabling DL cross-carrier scheduling is, as illustrated in FIG. 5A , the same frame structure (eg, LCC-FDD+UCC-FDD, or LCC-TDD+UCC- to which the same DL/UL configuration is applied). TDD) is a method of carrier aggregation of licensed and unlicensed bands. Another one of the methods for enabling DL cross-carrier scheduling is when the UCC provides a downlink service at a time point corresponding to the uplink subframe of the LCC-TDD with a different DL/UL configuration, the downlink sub of the corresponding UCC. This is a method of setting the frame not to be serviced (subframe muting). Another one of the methods for enabling DL cross-carrier scheduling is a method of using aggregation between LCC-FDD and UCC-TDD, as illustrated in FIG. 5B . Another one of the methods for enabling DL cross-carrier scheduling is a method of applying the same DL/UL configuration to LCC-TDD and UCC-TDD, as illustrated in FIG. 5C . As illustrated in FIGS. 5B and 5C , an LCC that performs scheduling on a carrier that additionally serves the UCC may be configured as at least a downlink carrier. As another method, there is a method in which the UCC performs self-carrier scheduling on the same carrier in a section where cross-carrier scheduling from LCC to UCC is impossible. As another method, when some subframes (sections) within the channel occupancy time are sections in which cross-carrier scheduling is impossible, there is a method in which the UCC performs self-carrier scheduling during all channel occupancy times.

Table 3 below shows another embodiment of a resource allocation method for each subframe according to carrier aggregation between LCC and UCC.

Scenario for downlink/uplink resource allocation method for each subframe according to LCC and UCC scenarios subframe Note P-LCC UCC Scenario 1 DL DL - either cross-carrier scheduling from P-LCC or Self-scheduling on UCC Scenario 2 DL UL - self-scheduling only in P-LCC
- no cross-carrier scheduling from P-LCC (No scheduling UCC) Scenario 3 UL DL - self-scheduling only in UCC
- no cross-carrier scheduling from P-LCC (No scheduling LCC) Scenario 4 UL UL - schedules neither LCC nor UCC

As in Scenario 1 of Table 3, when the subframe of P-LCC is a DL subframe and the subframe of UCC is a DL subframe, DL cross-carrier scheduling for allocating UCC resources through P-LCC or UCC It is possible to apply DL self-carrier scheduling for allocating UCC resources through .

However, as in Scenario 3 of Table 3, when the P-LCC subframe is a UL subframe and the UCC subframe is a DL subframe to provide downlink data service, DL cross-carrier scheduling by P-LCC is not applicable. In this case, for resource allocation, instead of DL cross-carrier scheduling, DL self-carrier scheduling for allocating UCC resources through UCC may be used.

As shown in Scenario 2 and Scenario 4 in Table 3, since the UCC subframe is a UL subframe, the UCC does not provide a DL service regardless of whether the P-LCC subframe is a DL subframe or a UL subframe. However, if the LCC is a DL subframe at the time point nk at which the uplink resource is allocated to the current subframe n, the uplink resource may be allocated by cross-carrier scheduling, and the uplink resource may be allocated to the current subframe n. When the UCC is a DL subframe at the time of allocation nk, uplink resources may be allocated by self-carrier scheduling. On the other hand, as described above, when the LCC is a UL subframe at time nk, resource allocation based on cross-carrier scheduling is restricted not to be performed, or cross at time nkm (here, m is a predetermined value) in a DL subframe. Resource allocation based on carrier scheduling may be performed.

1.6. unlicensed Band resource occupancy behavior ( CCA ) resource allocation considering characteristics

A method of solving the problem as illustrated in FIG. 1 will be described in detail with reference to FIGS. 6 to 12 . 6 to 11, T _Frame is represents the frame time, T _Occupancy represents the channel occupancy time, T _Idle represents the channel idle time, and T _CCA represents the CCA time.

6 and 7 show a method of indicating data allocation information through a PDCCH and an Enhanced Physical Downlink Control Channel (EPDCCH) when resources of an unlicensed band are allocated. Specifically, FIG. 6 is a diagram illustrating a method of allocating resources using an Enhanced Physical Downlink Control Channel (EPDCCH) when a Frame Based Equipment (FBE) method is used. FIG. 6(a) shows a case where cross-carrier scheduling is performed, and FIG. 6(b) shows a case where self-carrier scheduling is performed. 7 is a diagram illustrating a method of allocating resources using an EPDCCH when a Load Based Equipment (LBE) method is used. The CCA illustrated in FIG. 7 is a CCA performed in the LBE method, and extended CCA may be performed in addition to the initial CCA. FIG. 7A shows a case in which cross-carrier scheduling is performed, and FIG. 7B shows a case in which self-carrier scheduling is performed.

8 is a diagram illustrating another method of allocating resources using an EPDCCH. Specifically, in the embodiment of FIG. 8, the base station performs cross-carrier scheduling at the CCA time point, and performs self-carrier scheduling during the channel occupancy time thereafter. Meanwhile, the CCA illustrated in FIG. 8 is a CCA performed in the FBE method or the LBE method, and in particular, when the LBE method is used, extended CCA may be performed.

9 is a diagram illustrating another method of allocating resources using an EPDCCH. Specifically, in the embodiment of FIG. 9 , the base station performs cross-carrier scheduling at the CCA time point, and performs self-carrier scheduling during the channel occupancy time thereafter. On the other hand, the CCA time illustrated in FIG. 9 is a PDCCH transmission time. The CCA illustrated in FIG. 9 is a CCA performed in the FBE method or the LBE method, and in particular, when the LBE method is used, extended CCA may be performed.

As illustrated in FIGS. 6 (a) and 7 (a), when resources are allocated through the cross-carrier scheduling method, the base station transmits the PDCCH through the licensed band carrier (LCC), and the unlicensed band carrier It indicates (indicate) the EPDCCH of (UCC). Alternatively, instead of the method in which the base station directly indicates the EPDCCH through the PDDCH, the EPDCCH is pre-defined (or pre-configured), so that the terminal is pre-defined (configured) by the base station without an indication from the base station (instruction through the PDCCH). In anticipation of EPDCCH transmission through , an operation for receiving a predefined (configured) resource may be performed (hereinafter, 'receiving method through a predefined EPDCCH'). Meanwhile, the EPDCCH indicates data transmission (PDSCH). In this case, even if the end time of CCA overlaps with the PDCCH transmission time at the time CCA is performed, if CCA is terminated before the EPDCCH transmission time, the base station may transmit the PDCCH through the LCC, and the terminal may receive the PDCCH and It is possible to prepare to receive the EPDCCH and PDSCH of the UCC expected to be transmitted.

A case in which the channel cannot be occupied (or used) because the channel is being used by another device as a result of the base station performing CCA for the UCC will be described. Since the base station cannot transmit data (eg, PDCCH, EPDCCH, PDSCH, etc.) through UCC, in the first subframe after CCA, the base station transmits only PDCCH through LCC and data (eg, EPDCCH, PDSCH, etc.) through UCC ) is not transmitted. Until the base station starts the next CCA, the PDCCH does not include information indicating the EPDCCH or resource allocation (PDSCH, PUSCH) of the corresponding UCC. On the other hand, in the reception method through the predefined EPDCCH, the terminal determines that the channel is occupied (or used) by the serving base station at least when the EPDCCH is properly received, and the operation for receiving the PDSCH from the resource indicated by the EPDCCH , and if the EPDCCH is not properly received, it may be determined that the channel is being used by another device.

A case in which a channel is available as a result of the base station performing CCA and thus occupying/using the channel will be described. The base station transmits the PDCCH through the LCC during the channel occupancy time (T _Occupancy ) after the CCA to indicate the EPDCCH transmitted through the UCC. The EPDCCH transmitted through the UCC indicates the PDSCH including data (PDSCH) allocation information of the corresponding subframe. On the other hand, in the reception method through the predefined EPDCCH, the terminal determines that the channel is occupied (or used) by the serving base station at least when the EPDCCH is properly received, and the operation for receiving the PDSCH from the resource indicated by the EPDCCH , and if the EPDCCH is not properly received, it may be determined that the channel is being used by another device.

On the other hand, when this method is applied, data transmission is not performed through the UCC during the time (eg, at least 1 OFDM symbol, at most 4 OFDM symbols) corresponding to the PDCCH transmitted through the LCC. In order to prevent the channel from being used, the base station may transmit a reservation signal. Through this, the other device determines that the corresponding channel is busy or occupied (Busy or Occupied) as a result of the CCA. For this, the following methods may be used.

The base station may include the PDCCH information transmitted through the LCC in the reservation signal and transmit the reservation signal. Through this, the PDCCH including the same information may be transmitted through the LCC and the UCC.

Alternatively, as illustrated in (b) of FIG. 6 , the base station may terminate CCA prior to PDCCH transmission in order to perform self-carrier scheduling for UCC. Through this, the base station can allocate UCC resources. Meanwhile, when the base station allocates UCC resources using self-carrier scheduling, the EPDCCH may be omitted and resource allocation information (eg, PDSCH) may be directly indicated through the PDCCH.

Alternatively, as illustrated in FIG. 8 , the base station allocates UCC resources by performing cross-carrier scheduling through LCC at the point in time when CCA is made, and in subsequent subframes or after that, channel occupancy time (T _Occupancy ) During the time, self-carrier scheduling through UCC may be performed to allocate UCC resources. Meanwhile, when the base station allocates UCC resources using self-carrier scheduling, the EPDCCH may be omitted and resource allocation information (eg, PDSCH) may be directly indicated through the PDCCH. Meanwhile, as illustrated in FIG. 9 , the CCA time may be defined as a time at which the PDCCH is transmitted instead of being defined as a time before PDCCH transmission (before the subframe). According to the embodiment of FIG. 9 , resource use efficiency for the last subframe SFL1 of the _{channel occupancy time T Occupancy may be improved.}

Alternatively, the base station may transmit a reservation signal when the channel is idle. Upon receiving the reservation signal, the terminal may determine that the corresponding channel is occupied (or used) by its serving base station, and may perform an operation for data reception (receiving PDCCH, EPDCCH, PDSCH, etc.).

On the other hand, when the base station needs to inform the terminal of the CCA result, the method illustrated in FIG. 8 may be used. The UE determines the UCC expected to transmit data through the PDCCH of the LCC, and prepares for data reception for the corresponding UCC. In this case, the UE may know that CCA for the corresponding UCC has been made, and may recognize that data transmission through the corresponding UCC may be possible. If, as a result of CCA, the corresponding channel is occupied (or used), the base station transmits the EPDCCH and the PDSCH through the UCC. If, as a result of CCA, the corresponding channel is occupied (or used) by another device, the base station cannot transmit data such as EPDCCH and PDSCH through the corresponding UCC, so the terminal cannot successfully receive data. A terminal that has not succeeded in data reception may recognize the CCA result, that is, that the channel is being used by another device (that the channel is busy or occupied). Even if the base station wants to allocate/transmit resources by changing the UCC, the carrier can be changed to a new UCC through carrier identification information (including information on the old UCC and information on the new UCC) included in the PDCCH. there is. The base station may select a carrier to be newly changed, transmit and receive data, search for and measure a channel, and the like.

10 to 12 are diagrams illustrating a method of allocating resources for a multi-subframe or a multi-transmission time interval (TTI) according to an embodiment of the present invention. Specifically, FIG. 10(a) shows a case where cross-carrier scheduling is performed, and FIG. 10(b) shows a case where self-carrier scheduling is performed. 11A illustrates a case in which cross-carrier scheduling is performed, and FIG. 11B illustrates a case in which self-carrier scheduling is performed. 12 (a) and (b) show a case in which cross-carrier scheduling is performed.

In FIG. 10, when the base station determines that the channel can be occupied (or used) as a result of the CCA, a method of performing scheduling for the _{channel occupancy time T Occupancy in the first subframe SFF1 after CCA is illustrated.} The base station may omit PDCCH transmission from the second subframe to the last (or predetermined) subframe after CCA. That is, the base station can allocate and use resources by performing scheduling on a plurality of subframes belonging _{to the UCC channel occupancy time T Occupancy in one subframe SFF1 .}

On the other hand, as illustrated in FIG. 11 , the base station allocates a resource region for reservation signal transmission in a subframe after the first subframe (SFF2) among subframes belonging to the _{UCC channel occupancy time (T Occupancy) for EPDCCH transmission.} can also be used. That is, the difference between the embodiment of FIG. 10 and the embodiment of FIG. 11 lies in the extent to which the base station uses the EPDCCH region of the UCC.

On the other hand, as illustrated in (b) of FIG. 12, the base station transmits data (PDSCH) in the remaining region except for the EPDCCH region among the resource regions of the subframes (subframes i to i+3) belonging to the channel occupancy time of the UCC. can also be transmitted. Alternatively, as illustrated in (a) of FIG. 12 , the base station may transmit only the data (PDSCH) without the EPDCCH region among the resource regions of the subframes (subframes i to i+3) belonging to the channel occupancy time of the UCC. That is, the difference between the embodiment of Fig. 11 and the embodiment of Fig. 12 lies in the extent to which the base station uses the PDSCH region of the UCC.

1.7. less than 1ms Short subframe configuration and transmission

According to the regulation of unlicensed band frequencies, CCA is basically performed for channel access/occupancy/use for data transmission. It is difficult to perform CCA according to the subframe unit, which is the basic operation unit of LTE. In addition, transmission of data according to a subframe within a channel occupation time (COT) causes a waste of occupied resources by a maximum of 1/COT.

To this end, as illustrated in FIGS. 13A, 13B, and 13C , partial subframe transmission may be supported. 13A, 13B, and 13C are diagrams illustrating a partial subframe transmission method. 13A, 13B, and 13C, Ext-CCA indicates extended CCA, initial signal indicates the aforementioned reservation signal, T _CCA indicates CCA time, and T _{ext - CCA} is extended CCA time , and T _RSV represents a reservation signal transmission time. T _{RSV _ TOTAL} is a channel reservation time, and is T _CCA + T _{ext - CCA} + T _RSV . T _TX represents the data transmission time, and T _COT represents the channel occupancy time. T _COT is T _TX + T _RSV . T _CCA1 is T _CCA + T _{ext - CCA} am.

Specifically, in FIG. 13A , a fractional subframe that enables data transmission in sections FS1 and FS2 shorter than 1 ms is exemplified.

FIG. 13B exemplifies a super TTI subframe that enables data transmission in sections SS1 and SS2 in which a section shorter than 1 ms and an adjacent 1 ms subframe are added to the shorter section.

13C illustrates a floating subframe that enables data transmission by reconfiguring subframes FLS1, FLS2, ..., FLS3 in 1ms units after the CCA end time. That is, each of the data transmission areas FLS1, FLS2, ..., FLS3 has a length of 1 ms.

Therefore, in order to apply cellular technology to the unlicensed band and efficiently use the operation and occupied resources according to the unlicensed band frequency regulation, a scheduling method or HARQ retransmission method supported in LTE is illustrated in FIGS. 13a, 13b, and 13c. Considering partial subframe transmission, it needs to be supported.

Meanwhile, in LTE, TTI, which is a subframe unit, includes (E)PDCCH and PDSCH. For data transmitted from the base station to the terminal, resource allocation is performed in units of resource blocks (RBs). For an RB indicated by Downlink Control Information (DCI) transmitted during resource allocation, a Modulation and Coding Scheme (MCS) applied to data transmission and a Transport Block Size (TBS) according to the MCS are determined. However, CCA is performed in order to comply with regulations for operation of unlicensed band frequencies, and the start and end of CCA may not be performed at the start and end time of the subframe. Therefore, when the above-described partial subframe is supported, PDSCH transmission and EPDCCH transmission may be performed in any orthogonal frequency division multiplexing (OFDM) symbol in the subframe instead of the start and end times according to the LTE standard.

Meanwhile, in 3GPP LTE, the TTI is configured in units of 1 ms, and the TTI includes a PDCCH and a PDSCH for data transmission, and an EPDCCH is additionally included according to the configuration. In particular, since the unlicensed band carrier operates as an auxiliary carrier, according to the scheduling method (eg, cross-carrier scheduling) of the base station, the UE expects only the PDSCH in the unlicensed band, and may receive and decode only the PDSCH. On the other hand, only the entire frame or a partial frame only in TTI having one length (same length) of partial subframe lengths (length shorter than 1 TTI length of 3GPP, eg, 0.5 ms or 1 slot unit length) according to an embodiment of the present invention The configuration and transmission method of a partial subframe according to an embodiment of the present invention may also be applied to this configured system. A frame of such a system may be composed of a subframe having a length corresponding to the TTI (having a length shorter than 1 ms) of the corresponding system among the first partial subframe and the last partial subframe described below.

14 shows a method (method M10, method M11) of configuring a PDSCH in an unlicensed band in which cross-carrier scheduling is configured.

As illustrated in (b) of FIG. 14 , method M11 is a method in which the PDSCH region does not include a region corresponding to the PDCCH. Specifically, the method M11 is a method that can be applied based on the existing LTE standard. For example, the PDSCH is transmitted in the remaining regions except for the region corresponding to the PDCCH (eg, OFDM symbols 0 to 3) among the resource regions of the intermediate subframe belonging to the COT of the UCC. Method M11 may be used while minimizing standard change (eg, TBS redefinition) for PDSCH. However, according to method M11, since other unlicensed band operating devices can perform channel access to the area corresponding to the PDCCH, a coexistence method such as a channel access suppression method is required.

As illustrated in (a) of FIG. 14 , method M10 is a method in which the PDSCH region includes a region corresponding to the PDCCH. For example, the PDSCH region of the middle subframe belonging to the COT of UCC has a 1ms TTI length. Method M10 may be applied to a cross-carrier scheduling scheme, and may block channel access of other unlicensed band operating devices to a region corresponding to the PDCCH. Therefore, the base station can use up to the area corresponding to the PDCCH as the PDSCH area. However, for this purpose, it may be necessary to redefine the TBS.

On the other hand, when partial subframe transmission is supported, due to the characteristics of CCA, the base station may not be able to access and use the OFDM symbol in which the PDCCH is transmitted. 15 is a diagram illustrating the structure of a partial subframe configured in the COT of UCC after CCA.

As illustrated in FIG. 15 , the PDCCH+PDSCH region of each of the first subframe and the last subframe among subframes belonging to the COT of UCC may consist of partial subframes. In the present specification, the PDCCH+PDSCH region may include the PDCCH region and the PDSCH region or may include only the PDSCH region. The PDCCH and the PDSCH may be configured by the following methods (method M20, method M21, method M22, method M23, method M24, method M25, method M26). In addition, unless otherwise specified, when the PDCCH and the PDSCH are simultaneously included in a subframe, it is assumed that self-carrier scheduling in which the PDCCH of the corresponding subframe indicates resource allocation information of the PDSCH is performed.

Method M20 illustrated in (a) and (x) of FIG. 15 is a method in which both a partial subframe (having a length less than 1 ms) and a normal subframe (having a length of 1 ms) include a PDCCH and a PDSCH am. For example, as illustrated in (a) and (x) of FIG. 15 , each of the first subframe and the last subframe belonging to the COT of UCC is a partial subframe, and includes a PDCCH and a PDSCH. An intermediate subframe belonging to the COT of UCC is a normal subframe, and includes a PDCCH and a PDSCH. Method M20 may be applied to a typical subframe structure of LTE. In order to use the method M20, definitions for related operations such as PDCCH region, PDSCH region, and TBS definition of the UE according to the structure of the partial subframe are required. Meanwhile, according to method M20, it is possible to reuse the last subframe belonging to the COT of the UCC in a Downlink Pilot Time Slot (DwPTS) structure of the TDD.

Method M21 illustrated in (b) and (y) of FIG. 15 is a method in which, when partial subframes and normal subframes are consecutively, the PDCCH is included in the previous subframe but the PDCCH is not included in the following subframe. am. For example, as illustrated in (b) and (y) of FIG. 15 , the first subframe belonging to the COT of UCC is a partial subframe and the second subframe is a normal subframe, so the first subframe that is the previous subframe includes the PDCCH and the PDSCH, and the second subframe, which is the following subframe, includes only the PDSCH. In order to use method M21, definitions for related operations such as PDCCH region, PDSCH region, and TBS definition of the UE according to the structure of the partial subframe are required, and the PDCCH of the previous subframe (eg, the first subframe) is the same sub It may be configured (operated) to indicate resource allocation information of the PDSCH of a frame (eg, the first subframe) and the PDSCH of the next subframe (eg, the second subframe), respectively. On the other hand, in the method M21, since successive partial subframes and normal subframes can be configured as one TTI, a relatively large TBS definition or a higher coding rate can be used, and the previous subframe (eg, The PDCCH of the first subframe) may be configured (operated) to indicate resource allocation information of a PDSCH configured with one TTI.

Method M22 illustrated in (c) and (y) of FIG. 15 is a method in which the PDCCH is not included in the partial subframe. For example, as illustrated in (c) and (y) of FIG. 15 , each of the first subframe and the last subframe belonging to the COT of the UCC is a partial subframe and includes only the PDSCH. Since the method M22 can be applied to a typical subframe structure of LTE, it is possible to minimize the specification change. However, according to method M22, the base station cannot apply self-carrier scheduling to the occupied channels of the first partial subframe and the last partial subframe belonging to the COT, and apply cross-carrier scheduling or so that resources are not used (eg, partial sub-frames). Frame resources are not allocated) and can be set (operated).

Method M23 illustrated in (a) and (y) of FIG. 15 is a method in which the last partial subframe includes only the PDSCH and the remaining subframes include the PDCCH and the PDSCH among subframes belonging to the COT of the UCC. For example, as illustrated in (a) and (y) of FIG. 15 , the first subframe belonging to the COT of UCC is a partial subframe and includes PDCCH and PDSCH, and the middle subframe is a general subframe and includes PDCCH and It includes the PDSCH, and the last subframe is a partial subframe and includes only the PDSCH. In order to use method M23, definitions for related operations such as PDCCH region, PDSCH region, and TBS definition of the UE according to the structure of the partial subframe are required, and the PDCCH of the previous subframe is the same as the PDSCH of the subframe and the next subframe It may be configured (operated) to indicate the resource allocation information of the PDSCH respectively. On the other hand, in the method M23, since a sequential subframe (eg, the last subframe) and a normal subframe (eg, a subframe before the last subframe) can be configured as one TTI, a relatively large TBS definition or higher The coding rate may be used, and the PDCCH of the previous subframe may be configured (operated) to indicate resource allocation information of the PDSCH (last subframe + previous subframe of the last subframe) configured with one TTI.

Method M24 illustrated in (c) and (x) of FIG. 15 is a method in which the first partial subframe includes only the PDSCH and the remaining subframes include the PDCCH and the PDSCH among subframes belonging to the COT of the UCC. For example, as illustrated in (c) and (x) of FIG. 15 , the first subframe belonging to the COT of UCC is a partial subframe and includes only PDSCH, and the middle subframe is a normal subframe, and PDCCH and PDSCH and the last subframe is a partial subframe and includes a PDCCH and a PDSCH. In order to use the method M24, definitions for related operations such as PDCCH region, PDSCH region, and TBS definition of the UE according to the structure of the partial subframe are required. Self-carrier scheduling cannot be applied to the first subframe, cross-carrier scheduling may be applied, or resources may be set (operated) not to be used. On the other hand, in the method M24, since the consecutive partial subframes and the normal subframes (eg, the first two subframes or the last two subframes belonging to COT) can be configured as one TTI, a relatively large TBS definition or higher coding The rate may be used, and the corresponding resource allocation information may be set (operated) to be indicated through the PDCCH of a subframe configured with one TTI.

Method M25 illustrated in (d) and (z) of FIG. 15 is a method in which the subframe of the unlicensed band includes only the PDSCH. For example, as illustrated in (d) and (z) of FIG. 15 , both the partial subframe and the normal subframe belonging to the COT of the UCC include only the PDSCH. Method M25 may be used when cross-carrier scheduling is configured. Meanwhile, according to the method M25, a relative PDCCH load may be applied in a licensed band.

In the method M26 illustrated in (b) and (x) of FIG. 15, both the partial subframe and the normal subframe belonging to the COT of the UCC include the PDCCH and the PDSCH, but the partial subframe and the normal subframe are consecutive. This is a method in which the following subframe includes only the PDSCH. For example, as illustrated in (b) and (x) of FIG. 15 , the first subframe belonging to the COT of UCC is a partial subframe and the second subframe is a normal subframe, so the first subframe that is the previous subframe includes the PDCCH and the PDSCH, and the second subframe, which is the following subframe, includes only the PDSCH. Configuration (operation) so that the PDCCH of the previous subframe (eg, the first subframe) indicates the resource allocation information of the PDSCH of the same subframe (eg, the first subframe) and the PDSCH of the next subframe (eg, the second subframe) can be The remaining subframes include a PDCCH and a PDSCH.

Meanwhile, FIG. 16 is a diagram illustrating a partial subframe structure further including an EPDCCH as well as a PDCCH and a PDSCH. As illustrated in FIG. 16 , among the subframes belonging to the COT of UCC, the first subframe and the last subframe are composed of partial subframes, and the remaining subframes are composed of normal subframes. In the following methods (method M30, method M31, method M32), a PDCCH, a PDSCH, and an EPDCCH may be configured. Unless otherwise stated, if the PDCCH and the PDSCH are simultaneously included in a subframe, it is assumed that the PDCCH of the corresponding subframe indicates the resource allocation information of the PDSCH or that the EPDCCH indicates the resource allocation information of the PDSCH is performed. do.

Method M30 illustrated in (f1), (f2), (m1), (m2), (m5), (11), (12), and (15) of FIG. 16 is OFDM in which the EPDCCH region is the same as the PDSCH region. A method to have a symbol length. Specifically, among subframes belonging to the COT of UCC, the first subframe is configured as one of (f1) and (f2) of FIG. 16, and the middle subframe is one of (m1), (m2), and (m5). is configured as one, and the last subframe is configured as one of (11), (12), and (15). Method M30 is a method applicable to the LTE standard. In order for the method M30 to be used, it is necessary to define the partial subframes illustrated in (f1), (f2), (11), (12), and (15) of FIG. 16, and (m2) of FIG. A definition for the configuration (configuration from OFDM symbol 0) is additionally needed. On the other hand, when the subframe is configured as illustrated in (m5) and (15) of FIG. 16, there is a need for a method of preventing other license-exempt band operating devices from accessing a channel in an area in which a PDCCH is not transmitted.

Method M31 exemplified in (f2) to (f4), (m2) to (m5), (12) to (15) of FIG. 16 , the EPDCCH region is the OFDM symbol j times (eg, regardless of the length of the PDSCH) j = 0,1,2,3,4) is a method constructed from. Specifically, among the subframes belonging to the COT of UCC, the first subframe is configured as one of (f2) to (f4) of FIG. 16, and the middle subframe is configured as one of (m2) to (m5), and , the last subframe is configured as one of (l2) to (l5). When the OFDM symbol length of the EPDCCH region is set to be the same as that of the PDSCH region, the OFDM symbol length of the EPDCCH region according to method M31 may be the same as the OFDM symbol length of the EPDCCH region according to method M30. However, when the OFDM symbol length of the EPDCCH region is set differently from the PDSCH region, definition (or configuration) of the length of the corresponding EPDCCH region is required, which is indicated by the base station to the UE (eg, RRC signaling, MAC CE, L1 signaling). and the like) may be one or a combination of two or more. It is also possible to apply method M31 when there is no PDSCH. On the other hand, in order to prevent other non-licensed band operating devices from accessing a channel in an area where the PDCCH is not transmitted, the EPDCCH may be configured (operated) from OFDM symbol 0.

In the method M32 illustrated in (f2), (f3), (l2), and (l3) of FIG. 16, the EPDCCH region is the first ODFM symbol j times of the partial subframe (=0,1,2,3,4) how it is constructed from Specifically, among the subframes belonging to the COT of UCC, the first subframe is configured as one of (f2) and (f3) of FIG. 16, and the last subframe is configured as one of (12) and (13) , the middle subframe is configured as one of (m1) to (m5). Similar to method M31, method M32 requires definition (or setting) of the length of the EPDCCH region when the OFDM symbol length of the EPDCCH region is different from the PDSCH region, which is indicated by the base station to the terminal (eg, RRC signaling, MAC CE, L1 signaling, etc. may be one or a combination of two or more). Method M32 may be applied even when there is no PDSCH. On the other hand, the method M32 may suppress the channel access of other unlicensed band operating devices within the partial subframe.

In the method M33 illustrated in (f1), (f4), (m1), (m4), (m5), (11), (14), and (15) of FIG. 16 , the EPDCCH region is a PDCCH region among OFDM symbols. This is a method configured from the first OFDM symbol among the remaining OFDM symbols except for the OFDM symbol that can be set to . Specifically, among subframes belonging to the COT of UCC, the first subframe is configured as one of (f1) and (f4) of FIG. 16, and the middle subframe is one of (m1), (m4), and (m5). is configured as one, and the last subframe is configured as one of (11), (14), and (15). On the other hand, method M33 can be applied to the LTE standard, but in order for method M33 to be used, when the OFDM length of the EPDCCH region is different from the PDSCH region (eg, (f4), (m4), and (l4) in FIG. 16) A definition is required, which may be indicated (eg, one or a combination of two or more such as RRC signaling, MAC CE, L1 signaling, etc.) from the base station to the terminal.

1.7.1. for data transmission of subframes RE (Resource Element) and TBS

14 to 16, according to the configuration of the first subframe and the last subframe belonging to the COT of the unlicensed band, the subframe is a general subframe defined in 3GPP LTE or a partial subframe composed of some OFDM symbols. It is configured and may include a PDSCH, a PDCCH, and an EPDCCH. On the other hand, a system in which the entire frame or a partial frame is configured with only a part of the subframes from the first subframe to the last subframe according to an embodiment of the present invention (eg, 1 TTI is shorter than 1 ms defined by 3GPP (eg, 0.5ms, or 1 slot size) in a system in which the entire section or a partial section is configured only with subframes having a size of 0.5ms, or a system in which a frame is configured only with the first subframe or the last subframe illustrated in FIGS. 14 to 16), the present invention RE configuration according to the embodiment (eg, a frame consisting of only subframes illustrated in FIGS. 17A to 17C , or a subframe consisting of a specific number of OFDM symbols illustrated in Table 4) and a subframe structure according to the RE configuration and TBS size may be applied.

17A, 17B, and 17C are diagrams illustrating DL resource grids corresponding to the partial subframe and the normal subframe illustrated in FIG. 13A .

Specifically, as illustrated in FIG. 17A , the resource block Rb1a in the resource grid for the first subframe among the subframes belonging to the COT of the UCC corresponds to the period FS1.

As illustrated in FIG. 17B , the resource block Rb1b in the resource grid for the middle subframe among the subframes belonging to the COT of the UCC corresponds to the period FS3.

As illustrated in FIG. 17C , the resource block Rb1c in the resource grid for the last subframe among subframes belonging to the COT of the UCC corresponds to the period FS2.

Since the resource grid shown in FIGS. 17A, 17B, and 17C conforms to the LTE standard, a detailed description of the resource grid is omitted.

1.7.1.1. TBS Determination method (Method M40)

Method M40 is a method of obtaining an available RE for data transmission according to the number of OFDM symbols constituting a subframe, and obtaining a TBS based on the obtained RE.

Table 4 below shows examples of available REs for data transmission obtained based on the number of OFDM symbols constituting a subframe.

Embodiment of RE for partial subframe in COT idx l _DataStart l _DataEnd

the number of OFDM symbols

the number of REs

Note First TTI of COT
0 0 13 14 152(=14*12-16) No partial subframe in the whole subframe One One 13 13 144(=13*12-12) 2 2 13 12 132(=12*12-12) 3 3 13 11 120(=11*12-12) TBS Determination Criteria for Current Standards 4 4 13 10 108 (=10*12-12) 5 5 13 9 100(=9*12-8) 6 6 13 8 88(=8*12-8) 7 7 13 7 76(=7*12-8) 8 8 13 6 68(=6*12-4) 9 9 13 5 56(=5*12-4) 10 10 13 4 44(=4*12-4) 11 11 13 3 32(=3*12-4) 12 12 13 2 24(=2*12-0) 13 13 13 One 12(=1*12-0) Last TTI of COT
14 0 0 One 8(=1*12-4) 15 0 One 2 20(=2*12-4) 16 0 2 3 32(=3*12-4) 17 0 3 4 44(=4*12-4) 18 0 4 5 52(=5*12-8) 19 0 5 6 64(=6*12-8) 20 0 6 7 76(=7*12-8) 21 0 7 8 84(=8*12-12) 22 0 8 9 96(=9*12-12) 23 0 9 10 108 (=10*12-12) 24 0 10 11 120(=11*12-12) 25 0 11 12 132(=12*12-16) 26 0 12 13 144(=13*12-16) 27 0 13 14 152(=14*12-16) Same as Idx0

Specifically, the TBS included in a partial subframe (eg, partial PDSCH or partial EPDCCH) within one subframe may be calculated by Equation 1 below.

은 방법 M40에 따른 TBS를 나타내고,

는 I_TBS와 N_PRB에 따른 TBS(표준 규격 TS 36.213에 정의)를 나타낸다. In Equation 1,

represents TBS according to method M40,

denotes TBS (defined in standard TS 36.213) according to _{I TBS} and N _PRB.

이다. 여기서,

는 PDSCH 내에 포함되는 RS(CRS, CSI-RS 등)를 이용해 TBS을 구하기 위해서, 제외되는 RE의 개수를 나타낸다.In Equation 1,

am. here,

indicates the number of REs excluded in order to obtain TBS using RS (CRS, CSI-RS, etc.) included in the PDSCH.

이고, 하나의 서브프레임을 구성하는 OFDM 심볼들의 개수를 나타낸다. 여기서,

는 서브프레임의 종료와 시작을 나타내는 OFDM 심볼 인덱스이다.

and indicates the number of OFDM symbols constituting one subframe. here,

is an OFDM symbol index indicating the end and start of a subframe.

이다.In Equation 1,

am.

는 하나의 RB 내의 부반송파들의 개수이고,

는 부분 서브프레임 내의 CRS(Cell-specific Reference Signal)의 개수를 나타낸다. 만약, 3GPP LTE에서 정의되는 TBS가 그대로 이용되고,

이 11(

)이라면,

= 12이고,

는 0, 4, 8, 12, 또는 16이다.

is the number of subcarriers in one RB,

denotes the number of cell-specific reference signals (CRS) in a partial subframe. If the TBS defined in 3GPP LTE is used as it is,

this 11(

), if

= 12,

is 0, 4, 8, 12, or 16.

는 데이터 전송에 사용되지 않는 RE의 개수에 따라 변경될 수 있다.In the above formula,

may be changed according to the number of REs not used for data transmission.

는 데이터 전송에 사용되지 않는 RE의 개수에 따라 변경될 수 있다.In the above formula,

may be changed according to the number of REs not used for data transmission.

은 하향링크 슬롯 내의 OFDM 심볼의 개수(예, 7개)이다.

is the number (eg, 7) of OFDM symbols in a downlink slot.

는 PDCCH를 위한 OFDM 심볼의 개수이다.

is the number of OFDM symbols for the PDCCH.

On the other hand, in the case of a super TTI subframe (eg, super TTI subframe (SS1, SS2) of FIG. 13B ) consisting of two subframes (eg, partial subframe + normal subframe), Equation 2 below and Similarly, method M40 obtains the TBS for each constituent subframe of the super TTI subframe, and then obtains the total TBS.

은 슈퍼 TTI 서브프레임의 TBS를 나타낸다.In Equation 2,

denotes the TBS of the super TTI subframe.

은 슈퍼 TTI 서브프레임의 구성 서브프레임 중 첫 번째 서브프레임의 TBS를 나타내고, 수학식1에 의해 계산될 수 있다.

denotes the TBS of the first subframe among the constituent subframes of the super TTI subframe, and may be calculated by Equation (1).

는 슈퍼 TTI 서브프레임의 구성 서브프레임 중 두번째 서브프레임의 TBS를 나타내고, 수학식1에 의해 계산될 수 있다.

denotes the TBS of the second subframe among the constituent subframes of the super TTI subframe, and may be calculated by Equation (1).

On the other hand, in the case of a floating subframe (eg, the floating subframe (FLS1, FLS2, FLS3) of FIG. 13C ) reconstructed in 1 ms units after the CCA end time, the method M40 is l _DataStart = 0,1,2,3, l _Using Equation 1 to which DataEnd = 13 is applied, the TBS of the floating subframe can be calculated.

1.7.1.2. TBS Determination Method (Method M41)

Method M41 is a method similar to a method of defining _{N PRBs} in the TBS table defined in 3GPP LTE according to a special subframe configuration, and obtains TBS by using _{N PRBs defined by Equation 3 below.}

는 데이터 전송 시 할당된 자원의 PRB(Physical RB) 개수이다. 여기서,

는 서비스되고 있는 시스템 대역폭에 따른 하향링크 시스템의 RB 개수를 의미한다(예, 20MHz 시스템의 경우에 100개).In Equation 3,

is the number of PRBs (Physical RBs) of resources allocated during data transmission. here,

denotes the number of RBs in the downlink system according to the system bandwidth being serviced (eg, 100 in the case of a 20 MHz system).

α indicates _{a compensation value for reflecting the case where the number of OFDM symbols actually using N PRB} is different from that of a normal subframe, and is determined by the following method M41-1 or M41-2.

Method M41-1 is a method of determining α corresponding to DwPTS according to the number of OFDM symbols of partial subframes, such as a special subframe configuration for DwPTS transmission, defined in 3GPP LTE.

)으로, α를 결정하는 방법이다.Method M41-2 is based on the number of OFDM symbols actually used in a partial subframe compared to all OFDM symbols in one general subframe (eg,

), which is a method of determining α.

Alternatively, the method M41-2 may determine α by using Equation 4 below reflecting the number of OFDM symbols used for data transmission except for OFDM symbols corresponding to the PDCCH region.

는 부분 서브프레임의 PDCCH 영역에 대응하는 OFDM 심볼의 개수를 나타낸다.In Equation 4,

denotes the number of OFDM symbols corresponding to the PDCCH region of the partial subframe.

는 일반 서브프레임의 PDCCH 영역에 대응하는 OFDM 심볼의 개수, 또는 TBS를 정의하기 위해 기 사용된 값(예, 3)을 나타낸다.In Equation 4,

denotes the number of OFDM symbols corresponding to the PDCCH region of a general subframe, or a value (eg, 3) previously used to define TBS.

On the other hand, in the case of a super TTI subframe (eg, super TTI subframes (SS1, SS2) of FIG. 13B ) consisting of two subframes (eg, partial subframe + normal subframe), method M41 is a super TTI subframe _{After obtaining N PRBs} for each of the constituent subframes of the frame, the entire TBS may be obtained.

1.7.2. unlicensed Subframe composition according to channel occupation of band

Due to the maximum channel occupancy time limitation according to the frequency operation regulation in the unlicensed band and the diversity of CCA time points, it is difficult for the partial subframe to operate according to the subframe boundary. Accordingly, it is possible to start/stop transmission of a partial subframe in any OFDM symbol unit within the subframe. As described above, the partial subframe may be included in the first part and the last part in the COT, and subframes other than that follow the subframe definition according to the LTE standard.

-1번, 예,

=7인 경우에, OFDM 심볼 13번) 중 임의의 OFDM 심볼부터, 마지막 OFDM 심볼(OFDM 심볼 2×

-1번, 예,

=7인 경우에, OFDM 심볼 13번)까지의 OFDM 심볼 구간을 포함한다. 즉, COT에 속한 첫번째 부분 서브프레임은, 0~13번까지의 OFDM 심볼, 1~13번까지의 OFDM 심볼, ..., 또는 13~13번까지의 OFDM 심볼을 포함할 수 있다.The first partial subframe belonging to the COT includes the first OFDM symbol (OFDM symbol 0) to the last OFDM symbol (OFDM symbol 2 ×

-1, yes,

=7, from any OFDM symbol of OFDM symbol number 13) to the last OFDM symbol (OFDM symbol 2×

-1, yes,

=7, the OFDM symbol interval up to OFDM symbol No. 13) is included. That is, the first partial subframe belonging to the COT may include OFDM symbols 0 to 13, OFDM symbols 1 to 13, ..., or OFDM symbols 13 to 13.

-1번, 예,

=7인 경우에, OFDM 심볼 13번) 중 임의의 OFDM 심볼까지의 OFDM 심볼 구간을 포함한다. 즉, COT에 속한 마지막 부분 서브프레임은, 0~0번까지의 OFDM 심볼, 0~1번까지의 OFDM 심볼, ..., 또는 0~13번까지의 OFDM 심볼을 포함할 수 있다.The last partial subframe belonging to the COT is from the first OFDM symbol (OFDM symbol No. 0) to the first OFDM symbol (OFDM symbol No. 0) to the last OFDM symbol (OFDM symbol 2×

-1, yes,

=7, the OFDM symbol interval up to any OFDM symbol among OFDM symbols No. 13) is included. That is, the last partial subframe belonging to the COT may include OFDM symbols 0 to 0, OFDM symbols 0 to 1, ..., or OFDM symbols 0 to 13.

이다. As shown in Table 4, the number of OFDM symbols is,

am.

On the other hand, when data (PDSCH) is transmitted, a reference signal (RS) included in the data (PDSCH) is DM-RS (Demodulated RS), CRS, CSI-RS (Channel State Information-RS), etc., and such RS is used for data transmission/reception and channel state measurement/reporting.

In addition, according to the frequency regulation of the unlicensed band, the device operating in the unlicensed band can access and use the channel. Since one TTI is included in all or some OFDM symbols of a subframe, it is necessary to adjust a region including RS (hereinafter, 'RS region'). On the other hand, when some or all frames of the system are configured for a time less than 1 ms (eg, 1 TTI is a subframe having a shorter length (eg, 0.5 ms, or 1 slot size) than the length defined by 3GPP). Alternatively, even in the case where a partial section is configured), the RS region adjustment method according to an embodiment of the present invention described below may be applied.

As illustrated in FIGS. 18A and 18B , when only a portion of one subframe is used for data transmission due to CCA, the following configuration methods (Method M50, Method M51, Method M52, Method M53, Method M54) Through one or a combination of two or more, the RS region may be configured. 18A and 18B, for convenience of explanation, OFDM symbol numbers in one subframe are described as 0 to 13, OFDM symbols 0 to 6 are for the 1st slot, and OFDM symbols 7 to Number 13 is for the second slot. In particular, OFDM symbols 7 to 13 refer to OFDM symbols 0 to 6 in the second slot.

(a), (b), (c) of FIG. 18a and (d), (e) of FIG. 18b show a general subframe including an RS region, (a-1), (b-1) of FIG. 18a ), (c-1) and (d-1), (e-1) of FIG. 18B show partial subframes including the adjusted RS region.

Method M50 is a method in which the PDCCH region of the normal subframe is shifted by the number of the first OFDM symbol of the partial subframe to be disposed in the partial subframe, and the PDSCH region of the normal subframe is disposed at the same position in the partial subframe. That is, the PDCCH region of the normal subframe is arranged in a partial subframe starting from the first OFDM symbol of the partial subframe, and the PDSCH region of the normal subframe is arranged at the same position in the partial subframe. For example, in (a) of FIG. 18A, OFDM symbols 0 to 2 are set as the PDCCH region, and in (a-1) of FIG. 18A, when the first OFDM symbol of a partial subframe is OFDM symbol No. 4 was exemplified. In this case, the PDCCH regions corresponding to OFDM symbols 0 to 2 of the normal subframe are disposed in the regions corresponding to OFDM symbols 4 to 6 of the partial subframe. In addition, the PDSCH region corresponding to OFDM symbols 7 to 13 of the general subframe is disposed in the region corresponding to OFDM symbols 7 to 13 of the partial subframe. As another example, it is assumed that OFDM symbols 0 to 1 of a normal subframe are set as a PDCCH region, and the first OFDM symbol of a partial subframe is OFDM symbol No. 4. In this case, the PDCCH regions corresponding to OFDM symbols 0 to 1 of the general subframe are disposed in the regions corresponding to OFDM symbols 4 to 5 of the partial subframe, and OFDM symbols 6 to 6 of the general subframe The PDSCH region corresponding to No. 13 is arranged in a region corresponding to OFDM symbols Nos. 6 to 13 of the partial subframe.

Method M51 is a method of shifting the PDCCH region and the PDSCH region of the normal subframe by the number of the first OFDM symbol of the partial subframe. That is, the PDCCH region and the PDSCH region of the normal subframe are arranged to start from the first OFDM symbol of the partial subframe. For example, in FIG. 18A (b), OFDM symbols 0 to 2 are set as the PDCCH region, and in FIG. 18A (b-1), the first OFDM symbol of a partial subframe is OFDM symbol 4 was exemplified. In this case, the region corresponding to OFDM symbols 0 to 9 of the normal subframe is disposed in the region corresponding to OFDM symbols 4 to 13 of the partial subframe.

Method M52 is a method of configuring partial subframes in units of slots. Specifically, in the method M52, the first slot of the normal subframe is shifted by the number of the first OFDM symbol of the partial subframe to be placed in the partial subframe, and the second slot of the normal subframe is placed at the same position in the partial subframe way to do it For example, in (c) of FIG. 18A, OFDM symbols 0 to 2 are set as the PDCCH region, and in (c-1) of FIG. 18A, the first OFDM symbol of a partial subframe is OFDM symbol 3 was exemplified. In this case, the region corresponding to OFDM symbols 0 to 3 of the first slot in the general subframe is disposed in the region corresponding to OFDM symbols 3 to 6 of the first slot in the partial subframe, and the general subframe The PDSCH region corresponding to OFDM symbols 0 to 6 (OFDM symbols 7 to 13) of the second slot in the frame is OFDM symbols 0 to 6 (OFDM symbols 7 to 13) in the second slot in the partial subframe. 13) is placed in the area corresponding to the

Method M53 is a method in which the PDCCH region of the normal subframe is arranged to start from the first OFDM symbol of the second slot in the partial subframe, and the PDSCH region of the normal subframe is arranged at the same position in the partial subframe. That is, in the PDSCH region of the partial subframe, the OFDM symbol number is mapped 1:1 with the OFDM symbol number for the PDSCH region of the normal subframe. For example, in (d) of FIG. 18B, OFDM symbols 0 to 2 are set as the PDCCH region, and in (d-1) of FIG. 18B, the first OFDM symbol of the partial subframe is OFDM symbol 3 was exemplified. In this case, the PDCCH regions corresponding to OFDM symbols 0 to 2 of the normal subframe are regions corresponding to OFDM symbols 0 to 2 (OFDM symbols 7 to 9) of the second slot in the partial subframe. is placed on In addition, the PDSCH region corresponding to OFDM symbols 3 to 6 of the general subframe is disposed in the region corresponding to OFDM symbols 3 to 6 of the partial subframe, and OFDM symbols 10 to 13 of the general subframe The PDSCH region corresponding to is arranged in the region corresponding to OFDM symbols 10 to 13 of the partial subframe. Meanwhile, according to method M53, the positions of the resources (R0 to R3) for the CRS in the partial subframe are the same as the positions of the resources (R0 to R3) for the CRS in the normal subframe.

Method M54 is a method of arranging a second slot of a normal subframe to be positioned in a first slot of a partial subframe, and a method of arranging a first slot of a normal subframe to be positioned in a second slot of a partial subframe. In particular, the second slot of the normal subframe is omitted by the number of the first OFDM symbol of the partial subframe, and the remainder is placed in the first slot of the partial subframe. For example, in (e) of FIG. 18B, OFDM symbols 0 to 2 are set as the PDCCH region, and in (e-1) of FIG. 18B, the first OFDM symbol of a partial subframe is OFDM symbol 3 was exemplified. In this case, the region corresponding to OFDM symbols 0 to 6 of the first slot in the general subframe is in OFDM symbols 0 to 6 (OFDM symbols 7 to 13) of the second slot in the partial subframe. placed in the corresponding area. In addition, the region corresponding to OFDM symbols 3 to 6 (OFDM symbols 10 to 13) of the second slot in the general subframe corresponds to OFDM symbols 3 to 6 in the first slot in the partial subframe. placed in the area.

19 is a diagram illustrating a partial subframe including an RS region when data is transmitted in a part of the last subframe within a range in which the maximum COT is not exceeded. Specifically, (a) of FIG. 19 shows a general subframe including an RS region, and (a-1) of FIG. 19 shows a partial subframe including an adjusted RS region. As illustrated in FIG. 19 , the last subframe of the UCC occupied channel may be configured to include as many OFDM symbols as the length of the last subframe (starting from OFDM symbol 0). The method illustrated in FIG. 19 is similar to method M51. For example, in FIG. 19(a), OFDM symbols 0 to 2 are set as the PDCCH region, and in FIG. 19(a-1), the last subframe belonging to the COT is a partial subframe and a partial subframe. The case where the last OFDM symbol of the frame is OFDM symbol 8 has been exemplified. In this case, the PDCCH region corresponding to OFDM symbols 0 to 2 of the general subframe is disposed in the region corresponding to OFDM symbols 0 to 2 of the partial subframe, and OFDM symbols 3 to 2 of the general subframe The PDSCH region corresponding to No. 8 is arranged in a region corresponding to OFDM symbols No. 3 to No. 8 of the partial subframe.

1.7.3. unlicensed Frame composition according to channel occupation of band

As described above, when the channel of the unlicensed band is occupied, the frame is a first subframe, a last subframe, and an intermediate subframe, and an initial signal transmitted as needed (illustrated in FIGS. 13A, 13B, and 13C) initial signal). Specifically, the frame is configured within a range that does not exceed the maximum COT, as shown in Equation 5 below.

는 i번째 서브프레임의 전송 시간을 나타낸다.In Equation 5,

denotes the transmission time of the i-th subframe.

는 COT에 속하는 n개의 서브프레임들 중 1번째 서브프레임의 전송 시간을 나타내고,

는 COT에 속하는 n개의 서브프레임들 중 마지막 서브프레임의 전송 시간을 나타낸다.

represents the transmission time of the first subframe among n subframes belonging to the COT,

denotes the transmission time of the last subframe among n subframes belonging to the COT.

는 COT에 속하는 n개의 서브프레임들 중 중간 서브프레임(2^nd, 3^rd, ..., n-1^th)번째 서브프레임의 전송 시간을 나타낸다.

denotes the transmission time ^{of the middle subframe (2 nd} , 3 ^rd , ..., n-1 ^th ) th subframe among n subframes belonging to the COT.

는 프레임에 초기 신호가 포함된 경우에, 초기 신호의 전송 시간을 나타낸다.

indicates the transmission time of the initial signal when the frame includes the initial signal.

의 특성을 갖는다. 이 경우에, 점유 채널에 속한 첫번째 서브프레임은, 초기 신호 전송 직후의 첫번째 OFDM 심볼부터 해당 서브프레임의

번째 OFDM 심볼(마지막 OFDM 심볼)까지 포함하도록 구성될 수 있다. 구체적으로, 점유 채널에 속한 첫번째 서브프레임은 다음의 방법들(방법 M60, 방법 M61, 방법 M62, 방법 M63) 중 하나 또는 둘 이상의 조합을 통해, 구성될 수 있다.Meanwhile, LTE has a characteristic that data transmission (TTI) is performed in units of 1 ms in a subframe composed of OFDM. Due to the characteristics of LTE, the first subframe from which the initial signal is excluded among the subframes belonging to the occupied channel is, as shown in Table 4,

has the characteristics of In this case, the first subframe belonging to the occupied channel is from the first OFDM symbol immediately after the initial signal transmission to the

It may be configured to include up to the second OFDM symbol (the last OFDM symbol). Specifically, the first subframe belonging to the occupied channel may be configured through one or a combination of two or more of the following methods (method M60, method M61, method M62, method M63).

를 k로 설정하는 방법이다. 여기서, k는 OFDM 심볼 번호 in the 1ms TTI를 나타낸다. 구체적으로, k는 초기 신호 전송 이후 데이터 전송이 가능한 OFDM 심볼 번호로써, #0~2×

-1의 임의의 정수이다. Methods M60 to M63 include:

How to set k to Here, k represents an OFDM symbol number in the 1ms TTI. Specifically, k is an OFDM symbol number capable of data transmission after initial signal transmission, #0~2×

Any integer of -1.

Method M60 is a case where partial subframes are not allowed (ie, the same as the method of setting k to 0). That is, when only subframes in units of 1ms are allowed, method M60 configures the first subframe as shown in Table 5 below.

으로 설정하는 방법이다. 즉,

이고,

이다. 방법 M61은 첫번째 서브프레임을 아래의 표 6과 같이 구성한다. Method M61, when a partial subframe is configured in units of slots, k is 0 or

how to set it to in other words,

ego,

am. Method M61 configures the first subframe as shown in Table 6 below.

로 설정하는 방법이다. 즉,

과

이고,

이다. 방법 M62는 첫번째 서브프레임을 아래의 표 7과 같이 구성한다. Method M62, when a subframe is configured in units of slots or in units of 1ms subframes (normal subframes), k is 0 or

how to set it to in other words,

class

ego,

am. Method M62 configures the first subframe as shown in Table 7 below.

가 설정되는 경우에,

를 3GPP에서 정의되는 3, 9, 10, 11, 12, 6 중 하나로 설정하는 방법이다. 방법 M63은 첫번째 서브프레임을 아래의 표 8과 같이 구성한다. Method M63 is one of the configurable lengths of DwPTS in a special subframe defined in LTE frame structure type 2 (TDD).

If is set,

is one of 3, 9, 10, 11, 12, 6 defined in 3GPP. Method M63 configures the first subframe as shown in Table 8 below.

의 특성을 갖는다. 수학식5의 조건을 만족하는 마지막 서브프레임의 가장 큰 OFDM 심볼 개수를 포함하도록, 서브프레임은 구성될 수 있다. 구체적으로, 점유 채널에 속한 마지막 서브프레임은 다음의 방법들(방법 M70, 방법 M71, 방법 M72, 방법 M73) 중 하나 또는 둘 이상의 조합을 통해, 구성될 수 있다.On the other hand, the last subframe within the limited COT of the channel occupied after performing CCA, as shown in Table 4,

has the characteristics of A subframe may be configured to include the largest number of OFDM symbols of the last subframe that satisfies the condition of Equation (5). Specifically, the last subframe belonging to the occupied channel may be configured through one or a combination of two or more of the following methods (method M70, method M71, method M72, method M73).

를 m으로 설정하는 방법이다. 여기서, m은 1ms TTI 내에서의 OFDM 심볼 번호를 나타낸다. 구체적으로, m은 수학식5의 조건을 만족하는 OFDM 심볼 번호로써, 0에서 2×

-1 사이의 임의의 정수이다. Method M70, Method M71, Method M72, and Method M73 are

How to set m to . Here, m represents an OFDM symbol number within 1ms TTI. Specifically, m is an OFDM symbol number that satisfies the condition of Equation 5, from 0 to 2×

Any integer between -1.

로 설정하는 방법과 동일하게 운용(설정)될 수 있다. 즉, 1ms 단위의 서브프레임(노멀 서브프레임)만 허용되는 경우에, 방법 M70은 마지막 서브프레임을 아래의 표 9와 같이 구성한다.Method M70 uses m when partial subframes are not allowed.

It can be operated (set) in the same way as the setting method. That is, when only a subframe (normal subframe) in units of 1 ms is allowed, the method M70 configures the last subframe as shown in Table 9 below.

또는

로 설정하는 방법이다. 즉,

이고,

이다. 방법 M71은 마지막 서브프레임을 아래의 표 10과 같이 구성한다. Method M71, when a partial subframe is configured in units of slots, m

or

how to set it to in other words,

ego,

am. Method M71 configures the last subframe as shown in Table 10 below.

또는

로 설정하는 방법이다. 즉,

이고,

이고,

이다. 방법 M72는 마지막 서브프레임을 아래의 표 11과 같이 구성한다. Method M72, when subframes are configured in units of slots or 1ms subframes (normal subframes), m

or

how to set it to in other words,

ego,

ego,

am. Method M72 configures the last subframe as shown in Table 11 below.

가 설정되는 경우에,

를 3GPP에서 정의되는 3, 9, 10, 11, 12, 6 중 하나로 설정하는 방법이다. 방법 M73은 마지막 서브프레임을 아래의 표 12와 같이 구성한다. Method M73 is one of the configurable lengths of DwPTS in a special subframe defined in LTE frame structure type 2 (TDD).

If is set,

is one of 3, 9, 10, 11, 12, 6 defined in 3GPP. Method M73 configures the last subframe as shown in Table 12 below.

~

이고, 초기 신호가 전송되는 구간은

을 의미한다. On the other hand, from the time when CCA is performed/finished to before the initial signal is transmitted (ie, the period excluding the period in which data is transmitted and the period in which the initial signal is transmitted), the base station transmits an arbitrary signal (blocking signal; eg, initial By transmitting a signal including the same information as the signal information, or an arbitrary dummy signal, etc.), channel occupation by other license-exempt band operating devices can be prevented. In particular, the section in which data is transmitted is

~

and the period in which the initial signal is transmitted is

means

Now, a method of constructing a frame in the COT according to Equation 5 described above will be described in detail with reference to FIGS. 20 to 26 . Below, the maximum COT is C (a predetermined time such as 4, 10, 13) ms, and the initial signal is 1 OFDM symbol long (eg, 0, 2, 3 OFDM symbol units, or a predetermined time) ) is assumed to have In addition, in the following, the blocking signal is used for the purpose of allowing the base station to terminate CCA and operate in units of OFDM symbols or to block channel access by other unlicensed band operating devices, in units smaller than OFDM symbols, in units of OFDM symbols, or in OFDM symbols Assume that you can have time in larger units, etc.

A subframe in which the first subframe, the last subframe, and the middle subframe are not all subframes composed of only some OFDM symbols within 1 TTI, or only the first subframe or the last subframe consists of only some OFDM symbols within 1 TTI can be Hereinafter, it is assumed that one of the first subframe and the last subframe or both the first subframe and the last subframe are subframes composed of only some OFDM symbols within 1 TTI.

A case in which an intermediate subframe excluding the first subframe and the last subframe among subframes belonging to the COT has a length of 1 TTI (as a unit of one subframe, defined as 1 ms in LTE) will be described. As described above, if the first subframe and the last subframe are partial subframes composed of only some OFDM symbols in the subframe, the first subframe and the last subframe may satisfy Equation 6 below.

In Equation 6, n(= 0, 1, ..., C) ≤ C.

The length of the last subframe is inferred from the first subframe, the initial signal, and the blocking signal through Equations 5 and 6, or an initial signal or a predefined method (the last subframe mapping according to the first subframe, etc.) can be directed through

On the other hand, a case in which the subframe of the occupied channel is configured to include the subframe in slot units (eg, 0.5 ms) will be described.

20 is a diagram illustrating a first subframe, an intermediate subframe, and a last subframe of an occupied channel. In FIG. 20, the start and end of the first subframe are performed in units of slots.

As illustrated in (f1), (f2), and (f5) of FIG. 20, if the CCA ends before the start of the slot, the base station transmits an initial signal or a blocking signal until the start of the slot. Data transmission can be performed while preventing channel occupation by the band operating device.

As illustrated in (f3) and (f6) of FIG. 20 , the first subframe includes an initial signal and may be configured in units of slots.

As illustrated in (f4) of FIG. 20, the first subframe may be limited to a subframe length of 1 ms TTI.

In addition, as illustrated in (f7) of FIG. 20, the base station may perform CCA, initial signal transmission, blocking signal transmission, etc. instead of transmitting the PDCCH in the PDCCH region in the first subframe.

To this end, it may be defined (or set) so that the base station performs (starts, ends) CCA as follows by reflecting the LTE characteristics composed of subframes and OFDM symbol units. Specifically, the base station may be configured (operated) to perform (start, end) CCA before the subframe boundary, before the end of the PDCCH (PDSCH start or EPDCCH start), or before the slot boundary. The base station may notify (set) the data transmission time to the terminal so that the terminal performs an operation for data reception at the data transmission time. In particular, the data transmission time may include the size (or start/end position) of the first/last subframe, and the terminal may efficiently perform an operation for data reception by recognizing the notified (set) data transmission time. can

In particular, the CCA section definition complies with the unlicensed band frequency operation regulations, and when the base station wants to occupy (or use) an additional channel after the COT expires, it operates according to the subframe time synchronization (eg, HARQ ACK / NACK of data transmission, In the case of uplink data transmission and data transmission having a constant period in response to the UL Grant (eg, dedicated RS (DRS), etc.), it may be applied for channel occupation (or use). can be done together.

The base station may perform CCA in the PDCCH transmission period (eg, OFDM symbols 0 to 3).

Alternatively, when the base station performs additional data transmission after the previous data transmission, the PDCCH transmission period (eg, OFDM symbol 0) before the start of the first subframe after the previous data transmission or within the first subframe after the previous data transmission It can also be performed (start, end) before No. 3). Specifically, when the last subframe of the previous data transmission ends in some OFDM symbols of the PDCCH transmission period in the subframe, the base station may perform (start, end) CCA in the PDCCH transmission period. The base station, when the last subframe of the previous data transmission ends after the PDCCH transmission period in the subframe, the period corresponding to the DwPTS defined in the TDD frame (eg, OFDM symbol Nos. 2, 8, 9, 11) ) before performing CCA (start, end).

In the case where the intermediate subframe newly transmitted after the second slot guarantees the COT as much as the complete TTI, the intermediate subframe consists of a subframe equal to the general TTI, as illustrated in (m1) of FIG. 20, or in FIG. As illustrated in (m2) of 20, it may be configured in units of slots.

Alternatively, as illustrated in (m3) and (m4) of FIG. 20, the base station transmits a blocking signal (or an initial signal, or a blocking signal + an initial signal) instead of transmitting the PDCCH in the PDCCH region in the intermediate subframe. or CCA may be performed.

As illustrated in (11), (12), and (13) of FIG. 20, the last subframe may be transmitted according to the slot end time or TTI end time. Alternatively, as illustrated in (14) of FIG. 20, the last subframe is a subframe in slot units according to Equations 5 and 6, or a sub corresponding to the longest applicable length among the lengths defined in DwPTS. It may consist of a frame. For example, in ( 14 ) of FIG. 20 , the case where the last subframe corresponds to special subframe configuration No. 9 is exemplified.

21 and 22 show a case in which the first subframe and the last subframe of an occupied channel are configured as a slot (1/2 full subframe or slot-based subframe) or a normal subframe according to an embodiment of the present invention; indicates 21 and 22 , it is assumed that max COT ≤ k(ms).

Specifically, in FIG. 21, the PDCCH+PDSCH region of the first subframe (subframe n) after CCA has a slot length (1/2 TTI length), and the PDCCH+PDSCH region of the last subframe (subframe n+k) is It has a normal subframe length (1 TTI length). In FIG. 22, the PDCCH+PDSCH region of the first subframe (subframe n+1) after CCA has a normal subframe length (1 TTI length), and PDCCH+PDSCH of the last subframe (subframe n+k+1) The region has a time slot length (1/2 TTI length).

23 and 24 show a case in which only the first subframe of the occupied channel consists of a slot (1/2 full subframe or slot-based subframe) or a normal subframe. In FIGS. 23 and 24 , it is assumed that max COT ≤ k(ms).

Specifically, in FIG. 23, the PDCCH+PDSCH region of the first subframe (subframe n, or subframe n+k+1) among subframes belonging to the occupied channel has a time slot length (1/2 TTI length), The PDCCH+PDSCH region of the remaining subframes (subframes n+1, n+2, ..., n+k) has a normal subframe length (1 TTI length). In FIG. 24 , the PDCCH+PDSCH region of the first subframe (subframe n+1, or subframe n+k+1) among subframes belonging to the occupied channel has a normal subframe length (1 TTI length) or a time slot It has a length (1/2 TTI length), and the PDCCH+PDSCH region of the remaining subframes (eg, subframes n+2, n+3, ..., n+k) has a normal subframe length (1 TTI length) have

The base station aligns the start time of the slot through the initial signal and the blocking signal, and configures (or transmits) the subframe according to the start of the slot or the normal subframe.

When the last subframe is configured to have a length of 1 ms or 1 slot, the base station, as illustrated in FIG. 22, matches the end time of the first slot (within 1 TTI) within the maximum COT to the last subframe (subframe n+ k+1) and release the occupied channel, and as illustrated in FIGS. 21, 23, and 24, the last subframe (subframe n+) according to the second slot end time, which is a subframe boundary k) and release the occupied channel.

The base station performs CCA (hereinafter 'first CCA') to access (or occupy, use) the channel for the first time, and performs CCA (hereinafter 'second CCA') to reuse the channel after max COT. there is. Since the last subframe of the COT by the first CCA consists of a slot or a normal subframe, the subframe after the second CCA may be determined according to the last subframe in the previous COT. For example, when the last subframe (subframe n+k) of the COT by the first CCA is configured as a normal subframe, as illustrated in FIGS. 21 , 23 , and 24 , the second CCA The PDCCH+PDSCH region in the first subframe (subframe n+k+1) of the COT has a slot unit length (1/2 TTI length). For another example, as illustrated in FIG. 22 , the PDCCH+PDSCH region in the last subframe (subframe n+k+1) of the COT by the first CCA has a time slot length (1/2 TTI length) In this case, the PDCCH+PDSCH region in the first subframe (subframe n+k+2) of the COT by the second CCA has a normal subframe length (1 TTI length).

(a), (b), (c), (d), (e), (f), and (g) of FIG. 21, and (h), (i), (j), (k) of FIG. 22 ), (l), (m), and (n) have different execution times of the first CCA.

In addition, (a), (b), (c), (d), (e), (f), and (g) of FIG. 23, and (h), (i), (j) of FIG. 24, The embodiments exemplified in (k), (l), (m), and (n) have different timing of performing the first CCA.

Meanwhile, a case in which the first subframe consists of a normal subframe (1 ms TTI length) or partial subframes as long as the length defined in DwPTS will be described.

25 and 26 , the longest DwPTS among DwPTS that can be used within the length (or time) from the CCA end time to the start of the next subframe may be applied to the first subframe. Specifically, as shown in Table 13 below, the configuration of the first subframe may be determined according to the CCA end time and the initial signal transmission time.

25 and 26 show a case in which the PDCCH+PDSCH region of a subframe belonging to an occupied channel has a DwPTS length or a normal subframe length (1 TTI length). In FIGS. 25 and 26 , it is assumed that max COT ≤ k (ms).

As illustrated in (a) and (b) of FIG. 25 , the PDCCH+PDSCH region of the first subframe (subframe n or subframe n+k+1) among subframes belonging to the occupied channel has a special subframe configuration It may have a length of DwPTS for 4 or a length of DwPTS for special subframe configuration 2/7, and the PDCCH+PDSCH region of the last subframe (subframe n+k) has a normal subframe length (1 TTI length). ) can have

As illustrated in (c) of FIG. 25 , the PDCCH+PDSCH region of the first subframe (subframe n or subframe n+k+1) among subframes belonging to the occupied channel has a special subframe configuration 2/7. may have a length of DwPTS, and the PDCCH+PDSCH region of the last subframe (subframe n+k) may have a normal subframe length (1 TTI length).

As illustrated in (d) of FIG. 25 , the PDCCH+PDSCH region of the first subframe (subframe n or subframe n+k+1) among subframes belonging to the occupied channel has a special subframe configuration 2/7. It may have a length of DwPTS for DwPTS or a length of DwPTS for special subframe configuration 9, and the PDCCH+PDSCH region of the last subframe (subframe n+k+1) is DwPTS for special subframe configuration 0/5. can have a length of

As illustrated in (e) of FIG. 25 , the PDCCH+PDSCH region of the first subframe (subframe n or subframe n+k+1) among subframes belonging to the occupied channel has a special subframe configuration 1/6. It may have a length of DwPTS for DwPTS or a length of DwPTS for special subframe configuration 9, and the PDCCH+PDSCH region of the last subframe (subframe n+k+1) is DwPTS for special subframe configuration 0/5. can have a length of

As illustrated in (f) and (g) of FIG. 25 , the PDCCH+PDSCH region of the first subframe (subframe n or subframe n+k+1) among subframes belonging to the occupied channel has a special subframe configuration. It may have a length of DwPTS for 9, and the PDCCH+PDSCH region of the last subframe (subframe n+k+1) may have a length of DwPTS for special subframe configuration 0/5.

As illustrated in (h) and (i) of FIG. 26, the PDCCH+PDSCH region of the first subframe (subframe n or subframe n+k+2) among subframes belonging to the occupied channel has a special subframe configuration. It may have a length of DwPTS for 0/5 or a normal subframe length (1 TTI length), and the PDCCH+PDSCH region of the last subframe (subframe n+k+1) is for special subframe configuration 9 It may have a length of DwPTS.

As illustrated in (j) of FIG. 26, the PDCCH+PDSCH region of the first subframe (subframe n or subframe n+k+2) among subframes belonging to the occupied channel has a special subframe configuration 0/5. It may have a length of DwPTS for DwPTS or a general subframe length (1 TTI length), and the PDCCH+PDSCH region of the last subframe (subframe n+k+1) is the DwPTS for special subframe configuration 1/6. can have a length.

As illustrated in (k) of FIG. 26 , the PDCCH+PDSCH region of the first subframe (subframe n or subframe n+k+2) among subframes belonging to the occupied channel has a special subframe configuration 0/5. It may have a length of DwPTS for DwPTS or a general subframe length (1 TTI length), and the PDCCH+PDSCH region of the last subframe (subframe n+k+1) is the DwPTS for special subframe configuration 2/7. can have a length.

As illustrated in (l) of FIG. 26, the PDCCH+PDSCH region of the first subframe (subframe n+1, or subframe n+k+2) among the subframes belonging to the occupied channel is a general subframe length ( 1 TTI length) or may have a length of DwPTS for special subframe configuration 4, and the PDCCH+PDSCH region of the last subframe (subframe n+k+1) is DwPTS for special subframe configuration 3/8 can have a length of

As illustrated in (m) and (n) of FIG. 26, the PDCCH+PDSCH region of the first subframe (subframe n+1, or subframe n+k+2) among subframes belonging to the occupied channel is general It may have a subframe length (1 TTI length) or a length of DwPTS for special subframe configuration 4, and the PDCCH+PDSCH region of the last subframe (subframe n+k+1) has special subframe configuration 4 It may have a length of DwPTS for

(a), (b), (c), (d), (e), (f), and (g) of FIG. 25, and (h), (i), (j), (k) of FIG. 26 ), (l), (m), and (n) have different CCA end times and different initial signal transmission times.

27 is a diagram showing the configuration of the base station 100 according to an embodiment of the present invention.

Specifically, the base station 100 includes a processor 110 , a memory 120 , and a radio frequency (RF) converter 130 .

The processor 110 is the above-described '1. and implement procedures, functions, and methods described in connection with the base station in 'Method for Managing Radio Resource Allocation and Usage'.

The memory 120 is connected to the processor 110 and stores various information related to the operation of the processor 110 .

The RF converter 130 is connected to the processor 110 and transmits or receives a wireless signal. And the base station 100 may have a single antenna or multiple antennas.

28 is a diagram showing the configuration of the terminal 200 according to an embodiment of the present invention.

Specifically, the terminal 200 includes a processor 210 , a memory 220 , and an RF converter 230 .

The processor 210 is the above-described '1. It may be configured to implement procedures, functions, and methods described in relation to the terminal in 'Method for managing radio resource allocation and use'.

The memory 220 is connected to the processor 210 and stores various information related to the operation of the processor 210 .

The RF converter 230 is connected to the processor 210 and transmits or receives a wireless signal. And the terminal 200 may have a single antenna or multiple antennas.

2. How to manage access to radio resources

29 is a diagram illustrating a format and a transmission period of a discovery signal (DRS) periodically transmitted by a base station.

The base station may simultaneously service periodic data transmission and aperiodic data transmission. The base station periodically transmits a discovery signal, DRS, to inform the terminal that it does not currently provide a service, but can provide a service, or to allow the terminal to search for a base station. Specifically, FIG. 29 shows a DRS measurement timing configuration (DMTC).

As illustrated in FIG. 29 , the DRS may be transmitted through a period of 40, 80, and 160 msec (DMTC period). The time at which the DRS is transmitted is determined by a specific offset (DMTC offset) within the DMTC period. The base station transmits a DRS that can be discovered by the UE during a DMTC occasion duration or a DRS occasion duration. Here, the DMTC occasion period may have a length of at least 1 msec (1 subframe) to a maximum of 5 msec (5 subframes) in the case of frequency division duplex (FDD), and at least 2 msec (2 subframes) in the case of time division duplex (TDD) ) can have a maximum length of 5 msec (5 subframes).

The DRS is periodically transmitted in a predetermined format at a predetermined time point through the setting of a DMTC period, a DMTC offset, and a DMTC occasion period. The UE may perform base station discovery using DRS. One or more base stations may transmit DRS based on the DMTC period, DMTC offset, and DMTC occasion period set for each base station, or may transmit through multiple channels (carriers) of frequencies.

In FIG. 29, when the base station transmits a cell-specific reference signal (CRS), a primary synchronization signal (PSS), and a secondary synchronization signal (SSS) within a subframe (eg, 5 subframes) belonging to the DMTC occasion period was exemplified. The CRS is transmitted through antenna port 0 in all downlink subframes (including a downlink pilot time slot (DwPTS) of a special subframe). In the case of FDD, the PSS is transmitted within the first subframe of subframes belonging to the DMTC occasion period, and in the case of TDD, it is transmitted within the second subframe of subframes belonging to the DMTC occasion period. The SSS is transmitted in the first subframe among subframes belonging to the DMTC occasion period.

On the other hand, when the devices share a frequency (in the case of using a shared band or an unlicensed band), a resource access method that can transmit data while complying with the existing frequency regulation is required. This will be described with reference to FIG. 30 .

30 is a diagram illustrating a method of transmitting a DRS while complying with the unlicensed band frequency regulation. Specifically, FIG. 30 shows a method in which a plurality of base stations (LL1, LL2, LL3) access and occupy (occupation or occupancy) resources according to frequency regulation, and transmit their own DRS through the occupied resources.

Each of the base stations LL1, LL2, and LL3 performs clear channel assessment (CCA) in order to transmit the DRS. 2 exemplifies a case in which each base station LL1 to LL3 performs both normal CCA and extended CCA (Ext-CCA). T _CCA represents a time at which normal CCA is performed, and T _{Ext - CCA} represents a time at which extended CCA is performed. CCA may be performed not only by the base station but also by the terminal. And T _MAX represents the maximum channel occupancy time according to the frequency operation regulation in the unlicensed band, and the channel occupancy time of the base stations LL1 to LL3 cannot exceed _{T MAX .}

Each of the base stations LL1 to LL3 may access and occupy the resources of the unlicensed band according to the result of the CCA. That is, the base stations LL1 to LL3 transmit DRS when resource access and data transmission are possible due to CCA.

However, the base station LL3 cannot access the channel in which the characteristics of the DRS (eg, having periodicity, transmitted at a predetermined time) are reflected due to channel occupation and use of the base station LL1. That is, the base station LL3 cannot transmit the DRS at its own DRS transmission time determined by the DMTC offset within the DMTC period due to the channel occupation of the base station LL1. In this case, there is a need for a method for efficiently sharing (accessing and occupying resources) a frequency.

31 is a diagram illustrating a method of accessing a resource through clear channel assessment (CCA) to which the unlicensed band frequency regulation is applied. Specifically, Figure 31 shows the CCA performed by the device to access and occupy the unlicensed band frequency resource according to the unlicensed band frequency regulation stipulated by the European telecommunications standards institute (ETSI). T _COT represents the channel occupancy time, and T _Frame represents a fixed frame period, which is T _COT + T _idle . Here, T _idle represents the idle time, and T _CCA or T _{Ext -} Includes _CCA.

31A shows frame based equipment (FBE) in which the device performs CCA based on a fixed period and occupies a channel according to the CCA result. The device may perform short control signaling transmission within the _{T COT.} T _control represents a time during which control signaling transmission is performed.

31B shows that the device performs additional CCA (extended CCA) when the channel size (transmission strength of a signal transmitted by another device) measured in the initial CCA process is equal to or greater than a threshold level (TL). It represents load based equipment (LBE). The device may perform short control signaling transmission within the _{T COT.} T _control indicates a time during which control signaling transmission is performed, and may be less than or equal to 0.05x50ms.

On the other hand, as illustrated in FIG. 31 , the resource access method through CCA that applies the frequency regulation of the unlicensed band mutatis mutandis does not consider cellular operation (long term evolution (LTE) operation). Therefore, there is a need for a method of efficiently and appropriately accessing and using radio resources in an unlicensed band or a shared band while complying with the frequency regulations of the unlicensed band while considering LTE operation. In this specification, for convenience of description, the 'unlicensed band or shared band' is referred to as an unlicensed band.

2.1. wireless accessing resources for channel discovery, channel status evaluation ( assessment ), and channel operation

In the present specification, when the transmitting apparatus (transmitter) is a base station, the receiving apparatus (receiver) is a terminal, and when the transmitting apparatus is a terminal, the receiving apparatus may be a base station.

An embodiment of the present invention provides downlink communication (or downlink service, downlink) from a base station to a terminal, uplink communication from a terminal to a base station (or uplink service, uplink), and direct communication between terminals (or , D2D (device to device) communication, direct link service). In the present specification, unless otherwise specified, the term "service" includes a downlink service, an uplink service, and a direct link service.

In order to describe channel discovery, channel state evaluation, and channel operation according to an embodiment of the present invention, terms (idle channel, occupied channel, operable channel, and operating channel) used in this specification are defined as follows. The idle channel refers to a channel in which it is determined that no service is provided through the corresponding channel or that the service is provided but data transmission is not performed by any device. The occupied channel refers to a channel on which a specific device is determined to perform or perform data transmission through a corresponding channel for a service. The operable channel refers to a channel in which a service is not provided or a channel determined to be capable of performing a service among channels. The operating channel refers to a channel in which a data service is attempted or a service is performed among available channels.

2.1.1. Channel navigation

32 is a diagram illustrating a channel search procedure according to an embodiment of the present invention.

Channel search is a necessary function in the following cases and may be performed by a transmitting device or a receiving device. The device may perform a channel search to find an operable channel (a serviceable channel). Alternatively, the device may perform channel discovery in order to perform a data service through an operable channel. Alternatively, the device may perform a channel search when a channel search is required according to a request or the like (eg, FIG. 33 ). Alternatively, the device may perform a channel search before data service in order to service data by occupying a channel based on the channel search result of the receiving device. Alternatively, the device may perform a channel search in order to check whether the operation channel is continuously operable. Alternatively, when the device wants to change the operating channel to another operating available channel, the device may perform a channel search.

Specifically, the number of channels to be searched is set (S10).

The device measures the state of the i-th channel among the search target channels (S110).

The device determines whether the i-th channel is a service-operable channel through channel discovery (S12).

If the i-th channel is a service operable channel, the device includes the ith channel in the operable channel group (S13). That is, the device stores the i-th channel as the k-th operable channel and increases the k value (S14).

If the i-th channel is not a service-operable channel, the device determines the i-th channel as a non-operable channel (S15).

The device repeats the above-described processes (S11 to S15) as many as the number of channels to be searched.

Meanwhile, when the device provides data service using any one of the operable channels belonging to the operable channel group, the device changes the corresponding operable channel to the operating channel.

Meanwhile, the operable channel determination procedures S11 to S15 performed by the device when searching for a channel are procedures for determining whether a searched channel is an operable channel or a non-operable channel. Specifically, when the device searches for a channel, conditions such as whether another device is operating a service through the corresponding channel, whether another device is operating a service through the corresponding channel, but whether the service can be operated normally due to channel conditions such as interference Through this, it can be determined whether the corresponding channel is an operable channel. A channel discovery procedure including a procedure for determining whether an operable channel is available may be performed by a transmitting device or a receiving device.

33A, 33B, 33C, 33D, 33E, and 33F are diagrams illustrating a channel search method according to an embodiment of the present invention.

In the channel search method illustrated in FIGS. 33A to 33F , the transmitting apparatus (transmitter) and the receiving apparatus (receiver) may vary according to a service provided through a channel. Specifically, when a service provided through a channel is a downlink service, the transmitting apparatus is a base station, and the receiving apparatus is a terminal. Alternatively, when the service provided through the channel is an uplink service, the transmitting apparatus is a terminal and the receiving apparatus is a base station. Alternatively, when the service provided through the channel is a direct link service, the transmitting device is a terminal to transmit data, and the receiving device is a terminal receiving data.

In the channel discovery method illustrated in FIG. 33A (hereinafter, 'first channel discovery method'), a new operation channel is added, or the operation channel is changed to a new channel, in a state in which the transmitting device and the receiving device are already capable of transmitting and receiving data, It may be applied to a case where the operation channel is reselected by re-judging whether the operation channel is suitable for the operation channel in which data transmission/reception is currently performed.

Specifically, the transmitting device requests the receiving device to search for a channel suitable for the receiving device to receive data ( S20 ). The channel search request signal transmitted by the transmitting device may include information about a channel to be searched (eg, a channel identifier), and a channel search time.

As a response to the channel search request, the receiving device searches for a channel (S21), and reports an operable channel suitable for data reception among the searched channels to the transmitting device (S22). Specifically, when reporting an operable channel, the receiving device may report the channel status (interference strength, whether another device uses the corresponding channel, etc.) together with channel identification information (eg, a channel identifier). Alternatively, the receiving device may report only the channel most suitable for the operating channel selection criterion among the operable channels, or arrange and report the operable channels in an order suitable for the operation channel selection criterion.

The transmitting device selects (reselects) an operating channel from among the operable channels based on the information reported from the receiving device (S23), and provides a service (data transmission) through the selected channel (S24). Specifically, the transmitting device may transmit the operation channel selection result to the receiving device and provide a data service. Alternatively, the transmitting apparatus may transmit data (operation channel identification information + data) together with identification information of a selected channel when providing a data service. Alternatively, when the operation channel selection result is the same as the previous operation channel, the transmitting device may transmit the corresponding fact (the corresponding fact transfer procedure may be omitted) and provide a data service.

The channel search method illustrated in FIG. 33B (hereinafter, 'second channel search method') is a method in which the channel search request process ( S20 ) of the transmitting apparatus is omitted in the first channel search method. The second channel discovery method may be applied when a receiving device wants to add a new operating channel or change a new operating channel to a new channel in a situation where the receiving device receives a data service from the transmitting device.

The receiving device searches for a channel (S30), and reports the channel search result to the transmitting device (S31).

The transmitting device selects (reselects) an operating channel based on the channel search result (S32), and provides a data service through the selected channel (S33).

The second channel discovery method differs only in that the receiving device reports the channel discovery result to the transmitting device without a request from the transmitting device, and the remaining operations are the same as or similar to those of the first channel discovery method.

On the other hand, without the process (S31) of the receiving device reporting the channel search result to the transmitting device, the transmitting device may change the operating channel.

In the channel discovery method illustrated in FIG. 33C (hereinafter, 'third channel discovery method'), when the receiving device intends to perform channel discovery (the same as or similar to the second channel discovery method), the corresponding fact ( Channel search) is requested (S40), and then the channel search (S42) is performed according to a response (S41).

The channel search response transmitted from the transmitting device to the receiving device may include accept, reject, perform after a specific time, perform at a specific time, and the like. In addition, the channel search response may include information about a channel to be searched (eg, a channel identifier) along with a channel search time, etc., in the same or similar manner to the channel search request ( S20 ) of the first channel search method.

Subsequent procedures ( S43 , S44 , and S45 ) may be performed the same as or similar to the first channel search method.

In the channel search method illustrated in FIG. 33D (hereinafter, 'fourth channel search method'), as in the first channel search method, the transmitting device requests the receiving device to search for a channel (S50), and the receiving device asks the transmitting device This is a method of performing a channel search according to the response (S51) and then performing a channel search according to the response (S52). Meanwhile, the process ( S51 ) of the receiving device responding to the channel search request of the transmitting device may be omitted.

The response to the channel search request may include, like the third channel search method, accept, reject, perform after a specific time, perform at a specific time, and the like. In addition, the response to the channel search request may include, in the same or similar manner to the channel search request (S20) of the first channel search method, a channel search time along with information (eg, a channel identifier) on a channel to be searched. there is. In this case, additional information needs to be received from the transmitting device.

Subsequent procedures ( S53 , S54 , and S55 ) may be performed the same as or similar to the first channel search method.

The channel search method illustrated in FIG. 33E (hereinafter, 'fifth channel search method') is a method in which the transmitting apparatus searches for a channel, different from the first to fourth channel search methods.

Specifically, the transmitting device selects (reselects) any one of the channels discovered through the channel search (S60) as the operating channel (S61), and transmits data to the receiving device through the selected channel (S62).

In the fifth channel discovery method, the transmitting device re-scans the operating channel to reselect the operating channel, includes another channel in the operable channel group, or searches for the operable channel among other channels and operates it as the corresponding operable channel It can be applied when changing a channel or adding a new operating channel.

Meanwhile, when the transmitting apparatus provides a service through the newly changed operating channel, the fifth channel discovery method may be performed the same as or similar to the data transmission method of the first channel discovery method.

In the channel search method illustrated in FIG. 33f (hereinafter, 'sixth channel search method'), in the fifth channel search method, the receiving device requests a channel search (S70) and the transmitting device sends a response to the channel search request. It is a method further comprising the step of transmitting to the receiving device (S71). Meanwhile, the process ( S71 ) in which the transmitting device responds to the channel search request may be omitted.

Unlike the fourth channel search method, the sixth channel search method may be applied when it is impossible or difficult to maintain an operable channel due to a decrease in quality of a channel through which data is received, a search for a device having a high priority, or the like. Specifically, the sixth channel search method may be applied when the device intends to change the operating channel to another channel due to the need for channel change, and the receiving device requests the transmitting device to search for a channel, thereby causing the transmitting device to operate. You can change the channel.

Like the third channel search method, the response to the channel search request may include acceptance, rejection, performing after a specific time, performing at a specific time, and the like. In addition, the response to the channel search request may include information about a channel to be searched (eg, a channel identifier) and a channel search time, etc., in the same or similar manner to the channel search request (S20) of the first channel search method. can

Subsequent procedures ( S72 , S73 , and S74 ) may be performed the same as or similar to the fifth channel search method.

2.1.2. Channel status evaluation ( assessment )

Channel state evaluation may be performed when the device intends to transmit data through a channel to be used.

34 is a diagram illustrating a data transmission procedure by channel state evaluation according to an embodiment of the present invention.

For example, the case where it is necessary to evaluate the channel state includes a case where it is necessary to determine whether another device or system uses the channel, whether the channel is in a state suitable for data transmission, and the like. Specifically, the transmitting device may directly measure the channel state and determine whether the channel is accessible based on the measurement result, or the transmitting device may determine whether the channel is accessible with the help of the receiving device.

When the transmitting device measures the channel state, after evaluating the channel state before data transmission, data may be continuously transmitted at a given time without additional channel state evaluation, or data may be transmitted after evaluating the channel state at every data transmission. there is.

If the transmitting device determines whether the channel is accessible with the help of the receiving device, the receiving device may evaluate the channel state at the request of the transmitting device and then report the channel state evaluation result to the transmitting device. The transmitting device may transmit data based on the reported channel state evaluation result. Alternatively, the receiving device evaluates the channel state in advance without the help (request) of the sending device, and reports (indicates) the fact to the sending device, and the sending device omits the channel state evaluation when transmitting data and transmits the data. may be In particular, by the base station evaluating the channel state for uplink data reception, it is possible to provide the data transmission opportunity to the terminal. In addition, since the receiving device measures the channel state without the transmitting device measuring the channel state, reception of the receiving device can be guaranteed, and a hidden node or the like can be detected.

Specifically, the transmitting device (transmitter) may determine whether the channel state evaluation is necessary (S80), and when the channel state evaluation is required, directly evaluate the channel state or request the receiving device (receiver) to evaluate the channel state (S81) ). Alternatively, the receiving device may evaluate the channel state in advance and report the result to the transmitting device without a request for channel state evaluation from the transmitting device.

The transmitting device determines whether the channel is accessible based on the channel state evaluation result (S82), and if the channel is accessible, transmits data through the corresponding channel (S83).

The transmitting device determines whether a channel state evaluation for additional data transmission is necessary (S84). The transmitting device continues to transmit data at a given time, if no channel state evaluation is required for further data transmission. The transmitting device repeats the above-described processes (S80 to S83) when it is necessary to evaluate the channel state for additional data transmission.

2.1.3. Channel operation

When the device selects an operation channel through the above-described channel search and performs a data service through the selected channel, the following channel operation is required. Specifically, the device needs to check whether the selected operation channel can be continuously operated. In addition, the device needs to change the operating channel to a new operable channel and provide a service through the changed channel. Also, the device needs to delete the channel when no more operational channels exist or are unnecessary.

2.1.3.1. Check whether continuous operation is possible

The continuous operation availability check process is a process of determining whether the corresponding channel can be continuously operated as an operation channel when data transmission between the transmitting device and the receiving device is performed through a channel. Such a continuous operation possibility confirmation process may be performed through a process of confirming (searching) an operation channel during the above-described channel discovery process. The continuous operation availability check process may be performed by the transmitting device or the receiving device. In this case, the device may stop data transmission while checking (searching) the operating channel for more accurate discovery.

2.1.3.2. Change and deletion of operating channels

The device changes the operating channel to another channel when a device (or system) that has priority over the operating channel being used for data service wants to use the corresponding channel or when there is a lot of interference in the corresponding operating channel. do. In addition, the device deletes (cancels) the corresponding channel when the management channel is no longer needed or when the service through the corresponding management channel is to be terminated. Specifically, in order to change or delete an operating channel, the device may perform the following process.

The device may discover a third channel while servicing through the operating channel, determine whether the discovered channel is an operable channel, and if the discovered channel is an operable channel, store the discovered channel as an operable channel. there is. Through this, the device can prepare for the operation channel change.

Alternatively, when a device (or system) that can preferentially use the operating channel is found (searched), the device selects the operating channel as a suitable channel (eg, the least interference channel or idle channel, etc.) among the stored operable channels. can be changed Specifically, when the device changes the channel, the device transmitting or receiving data transmits the fact (channel change) to the other device, and then performs the channel change process (or reuse the carrier change process of carrier aggregation operation, etc.) and, when the channel change is completed, the service is performed through the changed channel. Alternatively, the device releases (deletes) the channel by the channel deletion and creation (addition) process (or reuses the carrier deletion and creation (addition) process of carrier aggregation, carrier deactivation and activation process of carrier aggregation, etc.) Data service can be provided through operation channels excluding the channels that have been used.

Alternatively, the device may delete the current operating channel when the service is unavailable or unnecessary. Specifically, the device may delete the current operating channel through the channel deletion process (or reuse the carrier deletion process or deactivation process of carrier aggregation).

Meanwhile, as illustrated in FIG. 35 , there is a need for a channel management method for a case where the transmission area of the transmitting apparatus and the receiving area of the receiving apparatus are different from each other. Specifically, in FIG. 35 , the transmission device 100T has the transmission region CV1 , the reception device 101S has the reception region CV2 , and the transmission device 102T has the transmission region CV3 . did.

The transmitter 100T and the transmitter 102T transmit data through the same channel (eg, #CH1), the transmitter 100T transmits data to the receiver 101S, and the transmitter 102T It is assumed that data is transmitted to the receiving device 103S. The reception device 101S may receive signals from the transmission device 100T and the transmission device 102T.

The transmitter 100T transmits data to the receiver 101S through the channel #CH1 found by the above-described channel search, and the transmitter 102T also transmits the channel #CH1 found by the channel search. data is transmitted to the receiving device 103S through

When the receiving device 101S simultaneously receives signals from the transmitting device 100T and the transmitting device 102T, interference may occur due to the received signal.

In this situation, the receiving device 101S checks the fact that the transmitting device 102T is using the same channel (#CH1) as the transmitting device 100T through the channel search, and transmits the fact to the transmitting device 100T. can be notified to Through this, the receiving device 101S may change the channel for the service with the transmitting device 100T to a new channel (eg, #CH2) to perform the service with the transmitting device 100T. Thereafter, each of the transmitting device 100T and the transmitting device 102T may provide a data service to each of the receiving device 101S and the receiving device 103S using the channel #CH2 and the channel #CH1. there is. Through this, interference can be reduced.

Alternatively, even when a service is started or a channel is changed between the transmitting device 100T and the receiving device 101S (when selecting or reselecting an operating channel), the receiving device 101S sends the channel #CH1 to the transmitting device 100T. It may also convey the fact that it is being used by another device (or other service). Through this, the transmitting device 100T and the receiving device 101S may not determine the channel #CH1 as an operable channel. Alternatively, the transmitting device 100T and the receiving device 101S may set a low priority of an operable channel for the channel #CH1 to help in selecting (reselecting) an operating channel.

2.2. Channel access/data transmission operation for data transmission with periodicity

The embodiment of the present invention can be applied to transmission of all data transmitted by timing or period, such as a feedback signal, uplink data, a retransmission signal, a periodic allocation-based signal, etc. as well as DRS having periodicity. Hereinafter, for convenience of description, an embodiment of the present invention will be described using DRS transmission as an example. On the other hand, in the transmission of downlink data (eg, DRS), the transmitting device is the base station and the receiving device is the terminal. In the transmission of uplink data, a transmitting device is a terminal, and a receiving device is a base station. In direct link data transmission, a transmitting device and a receiving device are terminals.

2.2.1. Access and occupation of radio resources for data transmission with periodicity

2.2.1.1. How to adjust the transmission timing of data having periodicity

36 is a diagram illustrating a method of periodically transmitting data by changing a data transmission time point according to an embodiment of the present invention. Specifically, as illustrated in FIG. 36 , the base stations LL4, LL5, and LL6 may change the transmission timing of periodically transmitted data (hereinafter, 'periodic data') to ensure data transmission. When the transmission time of periodic data is changed, the time of CCA performed immediately before the transmission time of periodic data is also changed.

As illustrated in FIG. 36 , the base stations LL4 to LL6 change the settings for the DMTC period, the DMTC offset, and the DMTC occasion period of the DRS, which are periodicity data, so that the time point at which the CCA is performed does not overlap with other base stations. can Specifically, the DMTC offsets off1, off2, off3 of the base stations LL4 to LL6 may be adjusted so that the DRS transmission times of the base stations LL1 to LL3 do not overlap each other. As illustrated in FIG. 36 , since the DRS transmission time points of the base stations LL4 to LL6 are adjusted so as not to overlap each other, the CCA time points of the base stations LL4 to LL6 performed immediately before the DRS transmission time also do not overlap with each other.

The base station LL4 performs CCA for the channel of the unlicensed band during _{T CCA} before the DRS transmission time determined by the DMTC offset (off1). Since the base station LL4 determines that the state of the corresponding channel is the idle state through the CCA, the base station LL4 transmits the DRS at the scheduled DRS transmission time within the DMTC period.

The base station LL5 performs CCA on the channel of the unlicensed band during _{T CCA} before the DRS transmission time determined by the DMTC offset (off2). Since the base station LL5 determines that the state of the corresponding channel is the idle state through the CCA, it transmits the DRS at the scheduled DRS transmission time within the DMTC period.

The base station LL6 performs CCA for the channel of the unlicensed band during _{T CCA} before the DRS transmission time determined by the DMTC offset (off3). Since the base station LL6 determines that the state of the corresponding channel is the idle state through the CCA, it transmits the DRS at the scheduled DRS transmission time in the DMTC period. That is, all of the base stations LL4 to LL6 can guarantee their own periodic DRS transmission.

On the other hand, the process of adjusting the transmission time of the DRS is performed when the DMTC period, the DMTC offset, and the DMTC occasion period of the DRS are initially set, or it is found that the DRS transmission times of the base stations LL4 to LL6 overlap each other. It may be carried out if

On the other hand, unlike the method illustrated in FIG. 36 , the base station does not change (maintains) the DMTC period, the DMTC offset, and the DMTC occasion period of the DRS, and may transmit the DRS by continuously performing CCA until the time when the channel is available. there is. For example, assuming the situation illustrated in FIG. 2 , a corresponding method will be described. The base station LL3 performs CCA on the channel of the unlicensed band before the DRS transmission time determined by the DMTC offset within the first DMTC period. Since the corresponding channel is used by the base station LL1, the base station LL3 determines the status of the corresponding channel as a busy (or busy, occupied) state. In this case, the base station LL3 ignores the DMTC offset and continues to perform CCA until it can use (occupy) the corresponding channel. When the DRS transmission of the base station LL1 is completed within the first DMTC period, the base station LL3 determines that the corresponding channel is in an idle state, and transmits the DRS when it is determined as the valid state. As a result, since the base station LL3 transmits the DRS having periodicity at a time other than the time determined by the DMTC offset, the UE cannot determine that the DRS is transmitted at a time other than the scheduled transmission time. In this case, the UE may continue to expect DRS reception until DRS reception and may perform an operation (eg, blind decoding) for DRS reception. Alternatively, in order to reduce unnecessary reception or power consumption of the terminal, the base station LL3 may indicate to the terminal that the DRS has been transmitted after the CCA. Alternatively, in order to prevent continuous reception of the terminal, the base station LL3 sets a reception time to the terminal, and allows the terminal to expect DRS reception during the reception time from a scheduled DRS transmission time to perform an operation for DRS reception. you can make it do

2.2.1.2. CCA How to change the point of view

37 is a diagram illustrating a method of transmitting periodic data by changing a CCA time point according to another embodiment of the present invention. Specifically, as illustrated in FIG. 37 , if the device performed CCA on a channel of an unlicensed band in order to transmit periodicity data (eg, DRS) within the previous transmission period, the channel is being used by another device. If it is determined that the periodicity data cannot be transmitted, CCA is performed earlier than before within the subsequent transmission period to transmit the periodicity data. The method illustrated in FIG. 37 is performed by the following Step 1, Step 2, and Step 3.

First, the device (eg, the base station) performs CCA for the unlicensed band, and when it is determined that the corresponding channel is being used or occupied (occupation or busy), the CCA time point for the next transmission period of periodicity data (eg, DRS) Advance more than before (Step 1). _{Specifically, the device obtains a first time point advanced by T k} (= T _{k -1} +T _m ) from a periodic data transmission time point, and a second time point that is advanced by a CCA duration (or CCA time) from the first time point. CCA starts at this point. Here, T _m is a constant unit and is the minimum unit in which the special signal of step 2 is transmitted. The sum of the transmission time (transmission period) and T _k of periodic data does not exceed the maximum channel occupancy time suggested by the frequency regulation, T _k is set If the sum of the periodic data transmission time and T _k exceeds the maximum channel occupancy time, the device sets T _k =T _{k -1} .

If the device does not occupy the channel even within the next transmission period of periodic data, it performs step 1 again.

Meanwhile, when the device determines that the corresponding channel is in an available state (idle state) as a result of performing CCA, step 2 is performed.

The device occupies an idle channel and transmits periodicity data (eg, DRS) over the channel (step 2). _{Specifically, in order to occupy the corresponding channel during the period (T k} ) from the CCA completion time to the periodicity data transmission time as well as the periodicity data transmission period (duration), the device is special until the periodic data transmission time point. signal can be transmitted. By sending a special signal, the device can prevent other devices from occupying the corresponding channel during the _{T k period.}

If the device has successfully transmitted the periodicity data, _{it resets to T k} =0 (step 3). That is, the device resets the CCA time point for the next transmission period of the periodic data to a time advanced by the CCA duration from the transmission time of the periodic data.

Step 1, Step 2, and Step 3 described above will be described in detail with reference to FIG. 37 . Among the base stations LL4, LL5, and LL6 illustrated in FIG. 37, the base station LL6 transmits the DRS within the first DMTC period, before the DRS transmission time determined by the DMTC offset CCA for the channel (general CCA + extended CCA) carry out Since the corresponding channel is used by the base station LL4, the base station LL6 determines that the corresponding channel is busy and cannot transmit the DRS at the scheduled DRS transmission time. In this case, the base station LL6 sets the CCA time point for the second DMTC transmission period to T _{m than the CCA time point for the first DMTC transmission period.} advance as much as _{That is, the base station LL6 performs CCA} for the second DMTC transmission period at a time advanced _{by T k} (=0+T _m ) + T _CCA + T _{Ext -} CCA from the DRS transmission time determined by the DMTC offset. However, since the corresponding channel is used by the base station LL4, the base station LL6 determines that the corresponding channel is busy and cannot transmit the DRS within the second DMTC period.

The base station LL6 sets the CCA time for the third DMTC transmission period to T _{m than the CCA time for the second DMTC transmission period.} advance as much as _{That is, the base station LL6 performs CCA} for the third DMTC transmission period at a time advanced _{by T k} (=T _m +T _m ) + T _CCA + T _{Ext -} CCA from the DRS transmission time determined by the DMTC offset. As a result of the CCA, the base station LL6 determines that the corresponding channel is in an idle state, and in order to prevent channel occupation by other devices, T _k During the transmission, a special signal is transmitted, and the DRS is transmitted at the scheduled DRS transmission time.

Since the base station LL6 has successfully transmitted the DRS, it _{sets T k} for the fourth DMTC transmission period to 0. That is, the base station LL6 performs CCA for the fourth DMTC transmission period at a time advanced _{by T k} (=0) + T _CCA + T _{Ext - CCA} from the DRS transmission time determined by the DMTC offset.

On the other hand, since the base station LL4 could not transmit the DRS due to the base station LL6 within the third DMTC transmission period, the CCA time for the fourth DMTC transmission period is T _{m than the CCA time for the third DMTC transmission period.} advance as much as That is, the base station LL4 performs CCA for the fourth DMTC transmission period at a time advanced _{by T k} (=T _m ) + T _CCA + T _{Ext - CCA} from the DRS transmission time determined by the DMTC offset. Meanwhile, T _m may have a different value depending on the base stations LL4 to LL6.

2.2.2. CCA Data transmission according to change settings at the time

38A, 38B, 38C, 38D, and 38E show a method of transmitting periodic data and aperiodic data (general data without periodicity) by changing the CCA time point according to another embodiment of the present invention; It is a drawing.

When the device determines that the channel is idle as a result of CCA and occupies the channel to transmit data, _{the sum of the transmission period of the special signal (T k} ) and the transmission period of the data is the time limited by the frequency regulation (maximum channel occupancy time, T _MAX ) must not be exceeded. As a result, the transmission time (transmission period) of periodic data is limited to the change of the CCA time point.

On the other hand, when the device transmits aperiodic data and periodic data at the same time, as illustrated in FIG. 38a , additional CCA for periodic data (eg, DRS) is required, but the CCA time is not sufficient, so DRS can be transmitted does not exist. That is, when the base station intends to transmit aperiodic data, it performs CCA on the channel of the unlicensed band, and transmits the aperiodic data using the corresponding channel occupied through the CCA. However, in order for the base station to transmit DRS at the scheduled DRS transmission time, CCA must be additionally performed, but due to the transmission of aperiodic data, there is not enough time to perform CCA for DRS transmission, so that DRS transmission is not possible. A method for solving this problem will be described in detail with reference to FIGS. 38B to 38E . 38B (A), 38C (A), 38D (A), and 38E (A) show FIG. 38A.

The method illustrated in FIG. 38B is a method in which the device prematurely terminates the channel occupation for the previous aperiodic data transmission, taking into account the CCA period for the transmission of periodic data (eg, DRS). As illustrated in (B) of FIG. 38B, when the base station occupies a channel and transmits aperiodic data, in order to transmit the DRS at the scheduled DRS transmission time, the CCA period for DRS transmission is considered, The transmission of periodicity data is terminated earlier than the scheduled time (end at time PT1). Then, the base station performs CCA for DRS transmission, and transmits the DRS at the time of DRS transmission using the channel occupied through the CCA.

The method illustrated in FIGS. 38c and 38d is a method in which the device simultaneously occupies channels for periodic data and aperiodic data, and transmits aperiodic data and periodic data during a channel occupation time (period) through one CCA. . In the method illustrated in FIGS. 38C and 38D , the channel occupancy time (T _COT ) includes the DRS occasion period.

Specifically, in the method illustrated in FIG. 38C , the device performs CCA for transmission of aperiodic data (CCA for transmission of periodic data is omitted). For example, as illustrated in (B) of FIG. 38C , the base station performs CCA for transmission of aperiodic data, and uses a channel occupied through CCA, aperiodic data during the _{channel occupation time (T COT )} and DRS can be transmitted. Through this, the base station can successfully transmit the DRS at the scheduled DRS transmission time.

In the method illustrated in FIG. 38D , the device performs CCA for transmission of periodic data (omitting CCA for transmission of aperiodic data). For example, as illustrated in (B) of FIG. 38d , the base station performs CCA for transmission of periodic data, and uses a channel occupied through CCA, first transmits DRS during the _{channel occupation time (T COT )} After that, the aperiodic data can be transmitted. Through this, the base station can successfully transmit the DRS at the scheduled DRS transmission time.

In the method illustrated in FIG. 38E, when the device needs to transmit periodic data shortly after the time point at which the aperiodic data is to be transmitted, the CCA for transmitting the aperiodic data is delayed to a time point after transmitting the periodic data. way to do it For example, as illustrated in (B) of FIG. 38E , when the time interval between the time point PT2 at which the base station intends to transmit aperiodic data and the scheduled DRS transmission time point PT3 is less than or equal to a predetermined value, the aperiodic The CCA time point for data transmission is delayed after the DRS transmission time point (PT4). And, the base station performs CCA before the scheduled DRS transmission time (PT3), and transmits the DRS using the channel occupied through the CCA. In addition, the base station performs CCA for transmission of aperiodic data after the DRS transmission is completed (PT4), and transmits the aperiodic data using the channel occupied through the CCA. Through this, the device may increase the chance of transmitting periodic data, and may guarantee more reliable data transmission.

2.2.3. Data transfer through improved channel access

For transmission of periodicity data (eg, DRS), a transmitting device (eg, a base station) performs CCA. As a result of the CCA, if the transmitting device determines that the channel is in an available state (idle state), it transmits the periodicity data at a time point when the periodicity data should be transmitted. If, as a result of the CCA, the transmitting device determines that the channel is in an occupied state (busy or occupied state), the periodicity data may not be transmitted or the periodicity data may be transmitted by performing CCA until the channel becomes available. When the transmitting device performs CCA until a channel is available, it transmits periodicity data at a time other than the scheduled transmission time of periodicity data due to CCA added more than scheduled. When the transmitting device transmits periodicity data at a time other than the scheduled transmission time, the receiving device (eg, the terminal) cannot determine that the periodicity data is transmitted at a time other than the scheduled transmission time, so data is received You can expect to receive data and receive (eg, blind decoding) until the time. Alternatively, the transmitting device may indicate to the receiving device that the periodic data has been transmitted after the CCA, so that the receiving device may reduce unnecessary reception or power consumption.

On the other hand, when the transmitting device fails to transmit periodic data because the channel is occupied by another device as a result of the CCA, it omits transmitting the periodicity data at the predetermined transmission time within the corresponding transmission period, and the scheduled transmission time within the next transmission period , and may attempt to transmit periodic data by performing CCA before the scheduled transmission time within the next transmission period. Even in this case, as described above, the transmitting apparatus determines whether to transmit periodicity data according to the CCA result. If it is continuously determined that the channel is in the occupied state, the transmitting device cannot transmit the periodicity data at the scheduled transmission time. To solve this, when the transmitting device performs CCA, the channel accessibility for transmission of periodic data is higher than that of other data (eg, aperiodic data), so that the channel is more easily opened during transmission of periodic data can be accessed and possessed. In order to increase the channel accessability for transmission of periodic data, the method of adjusting the transmission time of periodic data (2.1.1.) or the method of changing the CCA time (2.1.2.) may be used.

Alternatively, in order to increase the channel accessability for transmission of periodic data, a method of reducing a unit time (CCA slot) for CCA or a method of reducing the number of unit times for CCA (hereinafter 'CCA unit time') may be used. may be Here, the CCA unit time (CCA slot) is a unit time during which CCA is performed, and may be several tens of us or a predetermined time. The device selects an arbitrary number q within the range of values that the number of CCA unit times can have (hereinafter 'CCA unit time number range', eg, 0 to N-1) when performing CCA, and q * ( CCA is performed as much as CCA slot time). Here, q is the number of CCA unit times (CCA slots). That is, the device may set the length of a CCA unit time (CCA slot) for transmission of periodic data to have a smaller value than other data (eg, aperiodic data). Alternatively, the device may set the CCA unit time number range to a different value for each data, and set the CCA unit time number range for periodic data to a smaller value than other data (eg, aperiodic data). For example, the device sets the CCA unit time count range for periodic data 0 to N ₁ -1, and the CCA unit time count range for aperiodic data 0 to N ₂ -1 (provided that N ₁ ≤ N ₂ ) can be set.

If the device fails to transmit periodic data within the previous transmission period (eg, it is determined that the channel is occupied during q * (CCA slot time)), the number of CCA unit times for periodic data within the next transmission period Reduce or keep the range (e.g. (0~N ₃ -1)->(0~N ₄ -1), except that N ₄ ≤ N ₃ ), and CCA units for other data (e.g. aperiodic data) The time count range may be widened (eg, (0~N ₅ -1)->(0~N ₆ -1), provided that N ₅ ≤ N ₆ ). Through this, the device may increase the transmission possibility (probability) of periodic data.

Alternatively, the device may adjust the periodicity of the periodicity data in order to increase the channel accessability for transmission of the periodicity data. Specifically, the device adjusts the transmission period of periodic data so that the periodic data can be transmitted more frequently than the existing period (eg, transmission period value PE1) (eg, transmission period value PE1 -> transmission period value PE2, where PE2≤ PE1) can be done. Alternatively, if the device has failed to transmit periodicity data before, at the next transmission, the transmission period of periodicity data is reduced than before (eg, PE1->PE2, but, PE2≤PE1), and then successfully transmits periodicity data In the case of transmission, the periodic data transmission period may be reset (eg, PE2->PE1), and the periodicity data may be transmitted in the reset transmission period PE1.

2.3. unlicensed Depending on the band frequency operation unlicensed How to operate a cellular system in band

A method of operating a cellular system in an unlicensed band according to the unlicensed band frequency operation regulations will be described in detail with reference to FIGS. 39A and 39B .

39A and 39B are diagrams illustrating a frame structure for cellular operation in an unlicensed band frequency according to an embodiment of the present invention. Specifically, FIGS. 39A and 39B show frames for applying the above-described method of occupying and using a channel in the unlicensed band to a cellular system operating in the unlicensed band.

Fig. 39a shows FBE, and Fig. 39b shows LBE. T _RSV represents the transmission time of the reservation signal (or the same or similar signal to the above-mentioned special signal, or the same or similar signal to the above-described initial signal), T _{RSV _ TOTAL} is the channel reservation time for channel occupation, T _idle + T _RSV or T _CCA + T _{Ext - CCA} + T _RSV . T _CCA1 is T _CCA + T _{Ext - CCA} .

_{Basically, a channel occupation time (TCOT} ) for data transmission is set based on a subframe in which the cellular system allocates and uses resources to transmit data (eg, 1 ms in the case of LTE). . Specifically, the channel occupancy time (T _COT ) is set to at least one or more subframe lengths (or TTI) or more, and must be set within _{the maximum channel occupancy time (T MAX ) according to the license-exempt frequency operation regulations.} T _COT is data transmission time (T _TX ) + special signal transmission time (T _RSV ).

In particular, the channel reservation time (T _{RSV_TOTAL} ) for channel occupancy is set by at least one subframe length (1 ms or TTI length), and if necessary, the subframe length (or TTI length) may be extended in units of there is.

On the other hand, due to the variation of the CCA length set for channel sharing with the device operating in the unlicensed band, when the time at which the CCA ends is not precisely aligned with the subframe time point (boundary time point), another device occupies the corresponding channel To prevent this, the device may transmit a reservation signal (eg, the same or similar signal as the special signal described above, or the same or similar signal as the initial signal described above). Therefore, the device must transmit data by defining the channel occupancy time (T _COT ) as T _COT = T _TX + T _{RSV .} T _COT does not exceed the maximum channel occupancy time (T _{MAX ), and T TX} indicates a time for data transmission (in unit of subframe or in unit of TTI). In addition, T _RSV transmits a reservation signal (or special signal) to prevent channel occupation by other devices when a device occupies a channel for data transmission, and indicates a time at which this reservation signal is transmitted.

2.4. Special design for signals

A special signal for accessing and occupying the channel of the unlicensed band is used to prevent channel occupation by other devices.

40 is a diagram illustrating a special signal for periodic data transmission according to an embodiment of the present invention.

Specifically, as illustrated in FIG. 40 , the device transmits a special signal immediately after CCA when not transmitting periodicity data (eg, DRS transmitted when a small cell is in an off state). For example, the base station transmits a special signal from the CCA completion time to the DRS transmission time determined by the DMTC offset. In FIG. 40, as in FIG. 1, a case in which the DRS occasion period includes 5 subframes is exemplified.

In FIG. 40, it is assumed that the section in which the special signal is transmitted has one subframe length, but this is only an example. The period in which the special signal is transmitted does not exist at all, or may exist in units of CCA, in units of one symbol period of LTE, or in units of several symbols.

If DRS transmission starts in the i-th subframe, the subframe immediately before DRS transmission corresponds to a subframe in which a special signal is transmitted and is set (recognized) as the i-1th subframe. The base station may transmit a signal (reference signal (RS), PSS, or SSS) corresponding to the i-1 th subframe through the corresponding symbol and subcarrier. For example, the base station may transmit, as a special signal, a CRS and a channel state information-reference signal (CSI-RS) in the i-1 th subframe.

On the other hand, the special signal is a signal necessary for the device to transmit data according to the subframe boundary after CCA, but as illustrated in FIG. symbol), it is also necessary to prevent access to the channel by other devices. For example, the base station is a channel by another device in the period (Er1) in which RS (eg, CRS, CSI-RS), PSS, SSS, etc. are not transmitted within the i-1 th subframe to the i + 4 th subframe. You need to block access.

To this end, even in a state in which the device does not perform data transmission, data such as a physical downlink control channel (PDCCH), an enhanced physical downlink control channel (EPDCCH), or a physical downlink shared channel (PDSCH) in an interval Er1 is a special signal It is possible to block access to the channel by other devices. Specifically, even if the state of the small cell is off (that is, the state of the small cell does not perform data transmission), the small cell transmits data such as PDCCH, EPDCCH, or PDSCH in the interval Er1, Access to the channel by other devices can be prevented.

Or, in order to prevent channel access by other devices in the period Er1, the device uses RS (CRS, CSI-RS, DM-RS (demodulated RS), PRS (positioning RS), etc.) defined in the existing LTE. It can be used as a special signal. For example, the base station may transmit RS (CRS, CSI-RS, DM-RS, PRS, etc.) as a special signal in the period Er1 to prevent channel access by other devices. A method of using this RS as a special signal will be described in detail with reference to FIGS. 42, 43, 44A, 44B, and 44C.

42 is a diagram illustrating a method of using RS as a special signal according to an embodiment of the present invention. Specifically, FIG. 42 shows a case in which a device configures a special signal using CRS, DM-RS, and CSI-RS within one subframe. In the present specification, one subframe includes a first time slot and a second time slot, and the first time slot and the second time slot have 7 orthogonal frequency division multiplexing (OFDM) symbols on the time axis and 12 on the frequency axis. A case including subcarriers (numbers 0 to 11) is exemplified. In this specification, OFDM symbol numbers in one subframe are described as 0 to 13, OFDM symbols 0 to 6 are for the first time slot, and OFDM symbols 7 to 13 are for the second time slot will be. In particular, OFDM symbols 7 to 13 refer to OFDM symbols 0 to 6 in the second time slot.

42 (A) shows CRS, DM-RS, and CSI-RS configured within one PRB (physical resource block) pair belonging to a general subframe. As illustrated in (A) of FIG. 42, a special signal is still needed in some OFDM symbol intervals (eg, OFDM symbols 2-3 and 9-10).

As illustrated in (B) and (C) of FIG. 42 , the OFDM symbol for transmission of the DM-RS may be changed, or the configuration of the CSI-RS may be changed to be included in an OFDM symbol period requiring a special signal. For example, as illustrated in (B) of FIG. 42, the base station transmits the DM-RS transmitted in OFDM symbols 5-6 in the OFDM symbol period (eg, OFDM symbol 2-3) that requires a special signal. As much as possible, OFDM symbols for DM-RS may be changed or added. In addition, as illustrated in (B) of FIG. 42, the base station changes the OFDM symbol for the CSI-RS so that the CSI-RS is transmitted in the OFDM symbol interval (eg, OFDM symbol 9-10) that requires a special signal. can be added Similarly, as illustrated in (C) of FIG. 42, the base station transmits the CSI-RS in an OFDM symbol interval (eg, OFDM symbol 2-3, 9-10) that requires a special signal. OFDM symbols can be changed or added for

On the other hand, when the device transmits PSS or SSS, a special signal may be configured as illustrated in FIG. 43 so that RS according to an embodiment of the present invention is not transmitted in a region in which PSS or SSS is transmitted. 43 is a diagram illustrating a special signal for a subframe in which synchronization signals (PSS, SSS) are transmitted, according to another embodiment of the present invention. 43(A) and (B) show FDD, and FIGS. 43(C) and (D) show TDD. As illustrated in (A) to (D) of FIG. 43, the base station transmits CSI-RS or DM-RS in an OFDM symbol interval (eg, OFDM symbol 2-3, 9-10) that requires a special signal As much as possible, OFDM symbols for CSI-RS or DM-RS may be changed or added.

On the other hand, a method of configuring a special signal when a special signal is transmitted only in a partial region within one subframe due to CCA (eg, before the DRS transmission time) is described in detail with reference to FIGS. 44A, 44B, and 44C. Explain.

44A, 44B, and 44C are diagrams illustrating a method of transmitting a special signal in a partial region of a subframe according to another embodiment of the present invention. (B) and (C) of FIGS. 44A, 44B, and 44C respectively show (B) and (C) of FIG. 42 . 44A to 44C illustrate the case where OFDM symbols of channels occupied by the device after CCA (that is, a partial region in which a special signal is transmitted in one subframe, or a partial subframe) are OFDM symbols 4 to 13.

As illustrated in (B-1) and (C-1) of FIG. 44A, in OFDM symbols (eg, OFDM symbols 4 to 13) of the channel occupied by the device after CCA, (B) or ( The transmission format illustrated in C) is mapped from the last OFDM symbol (OFDM symbol No. 13). For example, regions corresponding to OFDM symbols Nos. 4 to 13 illustrated in (B) of FIG. 44A are disposed in areas corresponding to OFDM symbols Nos. 4 to 13 illustrated in (B-1) of FIG. 44A do. Similarly, regions corresponding to OFDM symbols Nos. 4 to 13 illustrated in (C) of FIG. 44A are disposed in areas corresponding to OFDM symbols Nos. 4 to 13 illustrated in (C-1) of FIG. 44A.

As illustrated in (B-2) and (C-2) of FIG. 44B , the OFDM symbol (eg, OFDM symbol No. 4-13) of the channel occupied by the device after CCA is shown in (B) or (C) of FIG. 44B ) is mapped from OFDM symbol 0 to the exemplified transmission format. For example, the regions corresponding to OFDM symbols Nos. 0 to 9 illustrated in (B) of FIG. 44B are disposed in areas corresponding to OFDM symbols Nos. 4 to 13 illustrated in (B-2) of FIG. 44B do. Similarly, the regions corresponding to OFDM symbols Nos. 0 to 9 illustrated in (C) of FIG. 44B are disposed in areas corresponding to OFDM symbols Nos. 4 to 13 illustrated in (C-2) of FIG. 44B.

As illustrated in (B-3) and (C-3) of FIG. 44C, the OFDM symbol (eg, OFDM symbol No. 4-13) of the channel occupied after CCA, that is, the partial subframe is to be configured in units of time slots. may be Specifically, in the first time slot of the partial subframe, the transmission format illustrated in (B) or (C) of FIG. 44C is mapped from OFDM symbol 0, and in the second time slot of the partial subframe, (B of FIG. 44C) ) or the transmission format illustrated in (C) may be configured from OFDM symbol 7 onwards. For example, the regions corresponding to OFDM symbols 0 to 2 (the first time slot) illustrated in (B) of FIG. 44C are OFDM symbols Nos. 4 to 6 illustrated in (B-3) of FIG. 44C The area corresponding to OFDM symbols 7 to 13 (the second time slot) exemplified in (B) of FIG. 44C and disposed in the region corresponding to It is placed in the area corresponding to No. to No. 13. Similarly, regions corresponding to OFDM symbols 0 to 2 (first time slot) illustrated in (C) of FIG. 44C correspond to OFDM symbols Nos. 4 to 6 illustrated in (C-3) of FIG. 44C The area corresponding to OFDM symbols 7 to 13 (the second time slot) illustrated in (C) of FIG. 44C and located in the region where It is placed in the area corresponding to number 13.

On the other hand, when the device transmits general data other than DRS, the above-described method of configuring the special signal may use the RS included in the PDSCH as the special signal.

45 is a diagram illustrating a configuration of a transmission apparatus 300 according to an embodiment of the present invention.

The transmitter 300 includes a processor 310 , a memory 320 , and a radio frequency (RF) converter 330 .

The processor 310 is described above in '2. It may be configured to implement the procedures, functions, and methods described in relation to the transmitting apparatus in 'Method for managing access to radio resources'.

The memory 320 is connected to the processor 310 and stores various information related to the operation of the processor 310 .

The RF converter 330 is connected to the processor 310 and transmits or receives a radio signal. In addition, the transmitter 300 may have a single antenna or multiple antennas.

46 is a diagram illustrating a configuration of a receiving apparatus 400 according to an embodiment of the present invention.

Specifically, the receiving device 400 includes a processor 410 , a memory 420 , and an RF converter 430 .

The processor 410 is described above in '2. It may be configured to implement procedures, functions, and methods described in relation to a receiving device in 'Method for managing access to radio resources'.

The memory 420 is connected to the processor 410 and stores various information related to the operation of the processor 410 .

The RF converter 430 is connected to the processor 410 and transmits or receives a wireless signal. In addition, the receiving device 400 may have a single antenna or multiple antennas.

Although the embodiments of the present invention have been described in detail above, the scope of the present invention is not limited thereto, and various modifications and improved forms of the present invention are also provided by those skilled in the art using the basic concept of the present invention as defined in the following claims. is within the scope of the right.

Claims (40)

delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete As a method in which a base station transmits a discovery signal (DRS) and downlink data through an unlicensed band channel,
during a first period, performing a first clear channel assessment (CCA) for transmission of the DRS;
When it is determined through the first CCA that the state of the unlicensed band channel is idle for the first period, transmitting the DRS through the unlicensed band channel; and
performing a second CCA for transmission of the downlink data during a second period including a number of second CCA slots greater than the number of first CCA slots included in the first period
A transmission method of a base station comprising a. 22. The method of claim 21,
The number of first CCA slots included in the first period is one
The transmission method of the base station. 22. The method of claim 21,
The step of transmitting the DRS comprises:
When the transmission of the DRS fails, including the step of reducing the transmission period of the DRS
The transmission method of the base station. 22. The method of claim 21,
The length of the first CCA slot is smaller than the length of the second CCA slot
The transmission method of the base station. 22. The method of claim 21,
The step of performing the first CCA,
Selecting the number of the first CCA slots included in the first period within a first range,
The step of performing the second CCA,
Selecting the number of the second CCA slots included in the second period within a second range greater than the first range
The transmission method of the base station. A method in which a terminal receives a discovery signal (DRS) and downlink data from a base station through an unlicensed band channel,
When it is determined through a first clear channel assessment (CCA) of the base station that the state of the unlicensed band channel is idle for a first period, the DRS is received from the base station through the unlicensed band channel. step; and
When it is determined through the second CCA of the base station that the state of the unlicensed band channel is idle for a second period, receiving the downlink data from the base station through the unlicensed band channel,
The second period includes a number of second CCA slots greater than the number of first CCA slots included in the first period
A reception method of the terminal. As a method for the transmitter to transmit first data having periodicity through a channel of an unlicensed band,
adjusting at least one of a transmission time of the first data and a clear channel assessment (CCA) time of the channel to occupy the channel;
determining whether the channel can be occupied by performing CCA on the channel at the CCA time point; and
When the channel can be occupied, transmitting the first data through the channel at the time of transmission of the first data
A transmission method of a transmitter comprising a. 28. The method of claim 27,
The adjusting step is
Adjusting a transmission offset for the transmission time of the first data so that the transmission time of the first data does not overlap with the time when another device transmits periodic data through the channel
Transmitter transmission method. 28. The method of claim 27,
The determining step is
Irrespective of a transmission offset for a transmission time of the first data, continuously performing CCA on the channel until the channel can be occupied
Transmitter transmission method. 30. The method of claim 29,
The transmitting step is
transmitting the first data at a time point at which the channel can be occupied, not at a time point at which the first data is scheduled to be transmitted; and
Informing a receiver to receive the first data that the first data has been transmitted at a time other than the predetermined time
Transmitter transmission method. 28. The method of claim 27,
The adjusting step is
When the first data cannot be transmitted within the previous transmission period for the first data, the CCA time point is set as a time point that is advanced by a predetermined value from the time point at which CCA is started within the previous transmission period comprising the steps of
Transmitter transmission method. 32. The method of claim 31,
The step of setting the CCA time point is,
The sum of the first duration between the transmission time of the first data and the time at which the CCA is terminated determined by the transmission offset for the first data and the second period for the transmission of the first data for the channel In the case of exceeding the limited occupancy time, setting the CCA time point as a time point at which CCA started within the previous transmission period comprises the step of
Transmitter transmission method. 32. The method of claim 31,
The transmitting step is
When the channel can be occupied, from the time when CCA is terminated to the transmission time of the first data, a special signal for preventing occupation of the channel by another device is transmitted through the channel including steps
Transmitter transmission method. 34. The method of claim 33,
When the first data is successfully transmitted through the channel, CCA ends before the transmission time of the first data determined by the transmission offset of the first data within the next transmission period for the first data Setting a CCA time point for the next transmission period to be possible
Transmission method of the transmitter further comprising a. 28. The method of claim 27,
When the transmitter is a base station, the first data is a discovery signal (DRS),
When the transmitter is a terminal, the first data is an uplink signal transmitted to the base station.
Transmitter transmission method. A method in which a transmitter transmits first data having periodicity and second data having aperiodicity through a channel of an unlicensed band,
Considering the limited occupancy time for the channel, at least one of a first clear channel assessment (CCA) for transmission of the first data, a second CCA for transmission of the second data, and transmission of the second data adjusting; and
When the channel is occupied through at least one of the first CCA and the second CCA, transmitting the first data through the channel at a first time point determined by a transmission offset of the first data;
A transmission method of a transmitter comprising a. 37. The method of claim 36,
Prior to the adjusting step,
If the channel is occupied through the second CCA, further comprising the step of transmitting the second data through the channel,
The adjusting step is
In order to secure a duration during which the first CCA is performed, the step of terminating the transmission of the second data early
Transmitter transmission method. 37. The method of claim 36,
The adjusting step is
When the channel is occupied through the second CCA, including the step of omitting the first CCA,
The transmitting step is
Transmitting the first data and the second data using the channel occupied through the second CCA
Transmitter transmission method. 37. The method of claim 36,
The adjusting step is
When the channel is occupied through the first CCA, omitting the second CCA,
The transmitting step is
Transmitting the second data after transmitting the first data using the channel occupied through the first CCA
Transmitter transmission method. 37. The method of claim 36,
The adjusting step is
When the time interval between the time point at which the second data is to be transmitted and the first time point is less than or equal to a predetermined value, delaying the time point of the second CCA after the time point at which the first data is transmitted
Transmitter transmission method.

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