KR20150042689A - Methods for Transmitting and Receiving Random Access Response and Apparatuses Thereof - Google Patents

Abstract

The present invention provides a PDSCH resource allocation method for RAR message transmission for a MTC terminal, and a quasi-static PDSCH resource allocation method and apparatus for RAR transmission rather than dynamic scheduling via PDCCH.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a method and a device for random access response,

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and apparatus for transmitting and receiving a random access response in a wireless communication system, and more particularly, To a method and apparatus for determining a resource to which a response is assigned and transmitting and receiving a random access response.

Machine type communication (hereinafter referred to as "MTC" communication) is a type of data communication in which one or more objects represent machine to machine communication that does not necessarily require human interaction . MTC communication that does not require human interaction refers to all communication methods in which communication is performed without human intervention in the communication process.

The MTC terminal can be installed in a place where the radio wave environment is worse than that of a general terminal. It may be necessary to repeatedly transmit control information and / or data of each physical channel transmitted only in one subframe in a plurality of subframes in order for the MTC terminal to operate in a place where the radio wave environment is worse than that of a general terminal.

On the other hand, since a random access response (RAR) for a general terminal is not repeatedly transmitted in a plurality of subframes, a resource to which a random access response is allocated is repeatedly transmitted with a random access response Can be determined without considering.

The present invention provides a method and an apparatus for transmitting / receiving a random access response by determining a resource to which a random access response is allocated when a random access response for a MTC terminal is repeatedly transmitted in a plurality of subframes in order to overcome the above- The purpose.

A method for receiving a random access response in a terminal, the method comprising the steps of: receiving a random access response from a mobile station in a subframe in which a random access preamble is transmitted and a subframe in which the random access response Receiving subframe information indicating a relationship; Transmitting a random access preamble; And receiving a random access response associated with the random access preamble through a subframe determined based on the subframe information.

Another embodiment of the present invention provides a method for a terminal to receive a random access response, comprising: determining a resource block to which a random access response is assigned; Transmitting a random access preamble; And receiving a random access response associated with the random access preamble through the determined resource block.

Another embodiment of the present invention is a method for a base station to transmit a random access response, the method comprising: determining a relationship between a subframe in which a terminal transmits a random access preamble and a subframe in which the terminal receives a random access response related to the random access preamble Transmitting subframe information indicating the subframe information; Receiving a random access preamble; And transmitting a random access response related to the random access preamble through a subframe determined based on the subframe information.

Another embodiment of the present invention is a method for a base station transmitting a random access response, comprising: transmitting information on a resource block to which a random access response is allocated to a terminal; Receiving a random access preamble; And transmitting a random access response associated with the random access preamble through the resource block.

According to another embodiment of the present invention, there is provided a terminal for receiving a random access response, comprising: a transmitter for transmitting a random access preamble; And a receiving unit that receives a random access response associated with the random access preamble through a subframe determined based on the subframe information, wherein the receiving unit receives the random access preamble before transmitting the random access preamble, Frame information indicating a relation between a subframe for transmitting the random access response and a subframe for receiving the random access response associated with the random access preamble.

Another embodiment of the present invention is a terminal for receiving a random access response, comprising: a control unit for determining a resource block to which a random access response is allocated; A transmitting unit for transmitting a random access preamble; And a receiver for receiving a random access response associated with the random access preamble through the determined resource block.

Another embodiment of the present invention is a base station for transmitting a random access response, comprising: a receiver for receiving a random access preamble; And a transmitter for transmitting a random access response related to the random access preamble, wherein the transmitter transmits, before receiving the random access preamble, a subframe in which the terminal transmits the random access preamble and a subframe in which the terminal transmits the random access preamble, Frame information indicating a relation between sub-frames for receiving a random access response associated with a preamble.

Another embodiment of the present invention is a base station for transmitting a random access response, comprising: a receiver for receiving a random access preamble; And a transmitter for transmitting a random access response related to the random access preamble, wherein the transmitter transmits information on a resource block to which the random access response is allocated to the terminal before receiving the random access preamble As shown in Fig.

According to the present invention described above, it is possible to provide a method of determining a resource to which a random access response is allocated when a random access response for a MTC terminal is repeatedly transmitted in a plurality of subframes.

1 is a diagram illustrating an initial cell access procedure of a UE.
FIG. 2 is a diagram illustrating a random access procedure in FIG. 1. FIG.
3 is a diagram illustrating a process of transmitting a random access preamble and a random access response in the case of a general terminal.
4 is a diagram illustrating a process in which a random access preamble and a random access response are repeatedly transmitted in the case of an MTC terminal.
5 is a flowchart illustrating a method of setting a RAR transmission subframe according to an embodiment.
6 is a diagram showing an example in which the start sub-frame of the RAR transmission sub-frame is set in the FDD system.
7 is a diagram showing an example in which the start sub-frame of the RAR transmission sub-frame is set in the TDD system.
8 is a diagram showing another example in which the start sub-frame of the RAR transmission sub-frame is set in the TDD system.
9 is a diagram showing an example in which the starting sub-frame of the RAR transmission sub-frame is selected from a plurality of candidates.
10 is a flow diagram illustrating a method for setting up RAR transmission resources according to one embodiment.
11 is a diagram showing an example of a resource block allocated for RAR transmission.
12 is a diagram showing another example of a resource block allocated for RAR transmission.
13 is a flowchart illustrating a method of setting RAR transmission resources according to another embodiment.
14 is a block diagram showing the configuration of a terminal according to an embodiment of the present invention.
15 is a block diagram showing a configuration of a base station according to an embodiment of the present invention.

Hereinafter, some embodiments of the present invention will be described in detail with reference to exemplary drawings. It should be noted that, in adding reference numerals to the constituent elements of the drawings, the same constituent elements are denoted by the same reference numerals even though they are shown in different drawings. In the following description of the present invention, a detailed description of known functions and configurations incorporated herein will be omitted when it may make the subject matter of the present invention rather unclear.

The wireless communication system in the present invention is widely deployed to provide various communication services such as voice, packet data and the like. A wireless communication system includes a user equipment (UE) and a base station (BS, or eNB). The user terminal in this specification is a comprehensive concept of a terminal in wireless communication. It is a comprehensive concept which means a mobile station (MS), a user terminal (UT), an SS (User Equipment) (Subscriber Station), a wireless device, and the like.

A base station or a cell generally refers to a station that communicates with a user terminal and includes a Node-B, an evolved Node-B (eNB), a sector, a Site, a BTS A base transceiver system, an access point, a relay node, a remote radio head (RRH), a radio unit (RU), and a small cell.

That is, in the present specification, a base station or a cell has a comprehensive meaning indicating a part or function covered by BSC (Base Station Controller) in CDMA, Node-B in WCDMA, eNB in LTE or sector (site) And covers various coverage areas such as megacell, macrocell, microcell, picocell, femtocell and relay node, RRH, RU, and small cell communication range.

Since the various cells listed above exist in the base station controlling each cell, the base station can be interpreted into two meanings. i) the device itself providing a megacell, macrocell, microcell, picocell, femtocell, small cell in relation to the wireless region, or ii) indicating the wireless region itself. i indicate to the base station all devices that are controlled by the same entity or that interact to configure the wireless region as a collaboration. An eNB, an RRH, an antenna, an RU, an LPN, a point, a transmission / reception point, a transmission point, a reception point, and the like are exemplary embodiments of a base station according to a configuration method of a radio area. ii) may indicate to the base station the wireless region itself that is to receive or transmit signals from the perspective of the user terminal or from a neighboring base station.

Therefore, a base station is collectively referred to as a base station, collectively referred to as a megacell, macrocell, microcell, picocell, femtocell, small cell, RRH, antenna, RU, low power node do.

Herein, the user terminal and the base station are used in a broad sense as the two transmitting and receiving subjects used to implement the technical or technical idea described in this specification, and are not limited by a specific term or word. The user terminal and the base station are used in a broad sense as two (uplink or downlink) transmitting and receiving subjects used to implement the technology or technical idea described in the present invention, and are not limited by a specific term or word. Here, an uplink (UL, or uplink) means a method of transmitting / receiving data to / from a base station by a user terminal, and a downlink (DL or downlink) .

There are no restrictions on multiple access schemes applied to wireless communication systems. Various multiple access schemes such as Code Division Multiple Access (CDMA), Time Division Multiple Access (TDMA), Frequency Division Multiple Access (FDMA), Orthogonal Frequency Division Multiple Access (OFDMA), OFDM-FDMA, OFDM- Can be used. An embodiment of the present invention can be applied to asynchronous wireless communication that evolves into LTE and LTE-Advanced via GSM, WCDMA, and HSPA, and synchronous wireless communication that evolves into CDMA, CDMA-2000, and UMB. The present invention should not be construed as limited to or limited to a specific wireless communication field and should be construed as including all technical fields to which the idea of the present invention can be applied.

A TDD (Time Division Duplex) scheme in which uplink and downlink transmissions are transmitted using different time periods, or an FDD (Frequency Division Duplex) scheme in which they are transmitted using different frequencies can be used.

In systems such as LTE and LTE-Advanced, the uplink and downlink are configured on the basis of one carrier or carrier pair to form a standard. The uplink and the downlink are divided into a Physical Downlink Control Channel (PDCCH), a Physical Control Format Indicator CHannel (PCFICH), a Physical Hybrid ARQ Indicator CHannel, a Physical Uplink Control CHannel (PUCCH), an Enhanced Physical Downlink Control Channel (EPDCCH) Transmits control information through the same control channel, and is configured with data channels such as PDSCH (Physical Downlink Shared CHannel) and PUSCH (Physical Uplink Shared CHannel), and transmits data.

On the other hand, control information can also be transmitted using EPDCCH (enhanced PDCCH or extended PDCCH).

In this specification, a cell refers to a component carrier having a coverage of a signal transmitted from a transmission point or a transmission point or transmission / reception point of a signal transmitted from a transmission / reception point, and a transmission / reception point itself .

The wireless communication system to which the embodiments are applied may be a coordinated multi-point transmission / reception system (CoMP system) or a coordinated multi-point transmission / reception system in which two or more transmission / reception points cooperatively transmit signals. antenna transmission system, or a cooperative multi-cell communication system. A CoMP system may include at least two multipoint transmit and receive points and terminals.

The multi-point transmission / reception point includes a base station or a macro cell (hereinafter referred to as 'eNB'), and at least one mobile station having a high transmission power or a low transmission power in a macro cell area, Lt; / RTI >

Hereinafter, a downlink refers to a communication or communication path from a multiplex transmission / reception point to a terminal, and an uplink refers to a communication or communication path from a terminal to a multiplex transmission / reception point. In the downlink, a transmitter may be a part of a multipoint transmission / reception point, and a receiver may be a part of a terminal. In the uplink, the transmitter may be a part of the terminal, and the receiver may be a part of multiple transmission / reception points.

Hereinafter, a situation in which a signal is transmitted / received through a channel such as PUCCH, PUSCH, PDCCH, EPDCCH, and PDSCH is expressed as 'PUCCH, PUSCH, PDCCH, EPDCCH and PDSCH are transmitted and received'.

In the following description, an indication that a PDCCH is transmitted or received or a signal is transmitted or received via a PDCCH may be used to mean transmitting or receiving an EPDCCH or transmitting or receiving a signal through an EPDCCH.

That is, the physical downlink control channel described below may mean a PDCCH, an EPDCCH, or a PDCCH and an EPDCCH.

Also, for convenience of description, EPDCCH, which is an embodiment of the present invention, may be applied to the portion described with PDCCH, and EPDCCH may be applied to the portion described with EPDCCH according to an embodiment of the present invention.

Meanwhile, the High Layer Signaling described below includes RRC signaling for transmitting RRC information including RRC parameters.

The eNB performs downlink transmission to the UEs. The eNB includes a physical downlink shared channel (PDSCH) as a main physical channel for unicast transmission, downlink control information such as scheduling required for reception of a PDSCH, A physical downlink control channel (PDCCH) for transmitting scheduling grant information for transmission in a Physical Uplink Shared Channel (PUSCH). Hereinafter, the transmission / reception of a signal through each channel will be described in a form in which the corresponding channel is transmitted / received.

1 is a diagram illustrating an initial cell access procedure of a UE.

Referring to FIG. 1, in the initial cell access procedure of the UE, the UE 10 receives a Primary Synchronization Signal (PSS) and a Secondary Synchronization Signal (SSS), which are synchronization signals transmitted from the Node B 20 (S 102). In the LTE Frequency Division Duplex (FDD), the PSS can be transmitted in the last symbol (#n) of the first slot of the subframe # 0 and the subframe # 5 in one radio frame (for example, 10 ms) The SSS may be transmitted in the previous symbol (# n-1) of the last symbol (# n) of the first slot of # 0 and the subframe # 5. In LTE TDD, the PSS / SSS can be transmitted at a different location than the FDD. When the terminal 10 detects the PSS and the SSS, it can acquire the cell ID and the downlink synchronization information, and can obtain a cell-specific reference signal (CRS) based on the information obtained based on the PSS / ) To perform additional synchronization and conventional control channel decoding.

The terminal 10 receives the signal from the base station 20 through the PBCH based on the CRS (S104), and extracts the MIB (master information block) transmitted through the PBCH (S106). The MIB may include information indicating the bandwidth of the cell, information indicating the PHICH configuration, and information indicating the system frame number. The terminal 10 can know the resource to which the PDCCH is allocated based on the information included in the MIB.

The terminal 10 receives a signal from the base station 20 via the PDCCH based on the CRS (S108), and extracts downlink control information (DCI) transmitted through the PDCCH (S110). The DCI may be control information for a PDSCH to which a system information block (SIB) is transmitted, and may be transmitted through a common search space.

Based on the DCI, the UE 10 receives a signal through a PDSCH based on a demodulation reference (DM-RS) from the base station (S112), and extracts the SIB transmitted through the PDSCH (S114).

Thereafter, the terminal 10 and the base station 20 perform a random access procedure (S116), and the terminal 10 can be placed in the RRC connected state in the RRC idle state .

2 is a diagram illustrating in more detail step S116 of performing the random access procedure of FIG.

Referring to FIG. 2, the BS 20 transmits PRACH configuration information to the UE 10 (S202). PRACH setting information may be included in SIB2. The PRACH setting information may include parameters preambleInitialReceivedTargetPower and powerRampingStep used when determining the transmission power of the PRACH. Details of the parameters preambleInitialReceivedTargetPower and powerRampingStep will be described later.

The terminal 10 determines the transmission power of the PRACH and transmits a random access preamble to the base station 20 through the PRACH (S204).

The base station 20 receiving the random access preamble transmits scheduling information on a random access response (RAR) to the UE 10 through the PDCCH or EPDCCH (S206). The downlink control information (DCI) including the scheduling information for the RAR may be scrambled with the RA-RNTI and transmitted through the PDCCH or the EPDCCH common search space (CSS).

The base station 20 transmits the RAR through the PDSCH to the UE 10, and the UE 10 receiving the scheduling information for the RAR receives the RAR using the RAR (S208).

3 is a diagram illustrating a process of transmitting a random access preamble and a random access response in the case of a general terminal.

Referring to FIG. 3, the UE 10 transmits a random access preamble through the PRACH in the uplink subframe #n. The base station 20 receiving the random access preamble transmits the RAR through the PDSCH in the downlink subframe # (n + k). At this time, the UE 10 transmits a random access preamble in one uplink subframe (subframe #n), and the base station 20 transmits a random access preamble in one downlink subframe (subframe # (n + k) Lt; / RTI > When the terminal 10 fails to transmit the random access preamble (or when the terminal 10 fails to receive the RAR), the terminal 10 transmits a random access preamble through the PRACH to the next PRACH transmission subframe.

[Low-cost MTC based on LTE]

As the LTE network spreads, mobile operators want to minimize the number of Radio Access Terminals (RATs) to reduce network maintenance costs. However, conventional MTC products based on a GSM / GPRS network are increasing, and MTC using a low data rate can be provided at low cost. Therefore, there is a problem in that two RATs must be operated respectively, since LTE network is used for general data transmission and GSM / GPRS network is used for MTC. Therefore, Of the total revenue.

In order to solve this problem, it is necessary to replace a cheap MTC terminal using a GSM / EGPRS network with an MTC terminal using an LTE network, and various requirements for lowering the price of the LTE MTC terminal are required for the 3GPP RAN WG1 standard conference . In addition, in the standard meeting, a document describing various functions that can be provided to satisfy the requirements is being created.

The main items related to the physical layer specification change, which are currently being discussed in the 3GPP, include technologies such as narrow band support, single RF chain, Half duplex FDD and long DRX (Discontinued Reception) to support the low-cost LTE MTC terminal. However, the above methods, which are considered for lowering the price, can reduce the performance of the MTC terminal as compared with the conventional LTE terminal.

In addition, about 20% of MTC terminals supporting MTC services such as smart metering are installed in a 'Deep indoor' environment such as a basement, so that for successful MTC data transmission, Compared with the coverage of the first embodiment. In addition, considering the performance reduction due to the above-mentioned specification change, the coverage of the LTE MTC terminal should be improved by 20 dB or more.

In order to improve the coverage while lowering the price of the LTE MTC terminal, a power spectral density (PSD) boosting, a low coding rate, a time domain repetition, Various methods for one transmission are considered for each physical channel.

The requirements of low-cost MTC terminal based on LTE are as follows.

● The data transmission rate should satisfy the minimum data transmission rate provided by MTC terminal based on EGPRS (enhanced GPRS), that is, downlink 118.4kbps and uplink 59.2kbps.

√ Frequency efficiency should be improved dramatically compared to GSM / EGPRS MTC terminal.

√ The service area provided should not be less than that provided by the GSM / EGPRS MTC terminal.

√ The power consumption should not be larger than the GSM / EGPRS MTC terminal.

√ General LTE terminal and LTE MTC terminal should be available at the same frequency.

√ Reuse existing LTE / SAE networks.

√ Perform optimization not only in FDD mode but also in TDD mode.

√ Low-cost LTE MTC terminals should support limited mobility and low power consumption modules.

In the present invention, a low-priced MTC terminal that requires less coverage and improvement in radio channel transmission / reception performance than a general LTE / LTE-Advanced terminal will be referred to as a coverage limited MTC terminal.

Limited Coverage In order to support extended coverage for MTC terminals, the base station repeatedly transmits PDCCH or EPDCCH and PDSCH transmissions, which were performed on a downlink subframe basis, through a plurality of downlink subframes, and the corresponding MTC terminal It is necessary to perform decoding by combining the PDCCH or the EPDCCH and the PDSCH received through the plurality of downlink subframes.

Accordingly, not only the RAR for any MTC terminal performing the random access procedure but also the PDCCH including the scheduling information for the RAR is repeatedly transmitted through a plurality of downlink subframes, This may lead to excessive overhead for the PDCCH common search space (CSS).

The present invention proposes a PDSCH resource allocation scheme for RAR message transmission for the MTC terminal. In particular, we propose semi-static PDSCH resource allocation scheme for RAR transmission rather than dynamic scheduling via PDCCH.

The present invention proposes a PDSCH resource allocation scheme for RAR transmission for a MTC terminal. Specifically, a RAR transmission downlink subframe allocation method, a RAR repetition number determination method, and a PRB (Physical Resource Block) allocation method for RAR transmission in each downlink subframe are proposed.

In order to improve the reception performance of the random access preamble of the MTC terminal in any LTE / LTE-A base station, a random access preamble format for the MTC terminal is newly defined or an existing random access preamble format is repetitively transmitted Can be considered.

For example, in the case of a coverage-limited MTC terminal, a preamble generated based on a random access preamble format for an existing general LTE / LTE-A terminal is repeated M times and M number of uplink subframes UL Subframe # (n-M + 1) to UL subframe #n) may be considered. At this time, the base station can repeatedly transmit the RAR to the coverage limited MTC terminal L times in L downlink subframes (DL subframe # (n + k) to DL subframe # (n + k + L-1) .

In other words, in the case of the coverage limited MTC terminal, the length of the preamble format defined in M uplink subframes, i.e., the sum of the CP length and the sequence length of the preamble format, i.e., the value of T _CP + T _SEQ , A sequence length, and a length of T _SEQ ) is increased, a method of transmitting a preamble generated based on a new random access preamble format can be considered.

Also, application of a semi-static scheduling method instead of a conventional dynamic scheduling method is considered for allocating a RAR message transmission resource for a coverage-limited MTC terminal in a base station.

In order to apply the quasi-static scheduling to the corresponding RAR, it is necessary to define a method of allocating one or more downlink subframes to which the RAR is transmitted and a PRB for RAR transmission in the corresponding downlink subframe.

In the present invention, a method for allocating a DL sub-frame for a RAR, a method for determining a RAR repetition frequency associated therewith and a resource block (s) allocation scheme in the corresponding DL sub-frame are proposed.

[Starting downlink subframe for RAR and the number of iterations]

5 is a flowchart illustrating a method of setting a RAR transmission subframe according to an embodiment.

Referring to FIG. 5, the BS 20 transmits subframe information indicating a relation between a subframe in which a random access preamble is transmitted to a UE 10 and a subframe in which a random access response is transmitted (S510). The UE 10 transmits a random access preamble to the Node B 20 in step S520 and receives a random access response for the random access preamble on the downlink subframe determined based on the subframe information from the Node B 20 S530).

In one example, the subframe information may be information indicating a subframe difference of a downlink subframe in which the transmission of the random access response starts from the uplink subframe in which the transmission of the random access preamble is terminated. That is, when the transmission of the random access preamble in the uplink subframe #n is terminated, the transmission of the random access response in the downlink subframe # (n + k) may be set to start, and the subframe information may be set to k Value. ≪ / RTI > The corresponding k value may be limited to any positive integer.

For example, in the case of an FDD system, the value of k may be four. 6 is a diagram showing an example in which the start sub-frame of the RAR transmission sub-frame is set in the FDD system. Referring to FIG. 6, in the downlink subframe (subframe # (n + 4)) four subframes from the uplink subframe (subframe #n) where the transmission of the repeated random access preamble is terminated, The transmission can be started.

As another example, in the TDD system, the value of k may be a value set based on the UL-DL configuration (UL-DL configuration) and the subframe number of the UL subframe in which the transmission of the repeated random access preamble is terminated. 7 is a diagram showing an example in which the start sub-frame of the RAR transmission sub-frame is set in the TDD system. In the example of FIG. 7, the UL-DL setting is 1 and the subframe number of the uplink subframe in which transmission of the repeated random access preamble is ended is 3. In Fig. 7, in this case, the value of k may be determined to be 6, and the transmission of the repeated random access response may start from subframe 9. [

In step S510, the subframe information including the information indicating the value of k may be transmitted from the base station 20 to the terminal 10 through higher layer signaling (e.g., RRC). Alternatively, the value of k may be a value previously set between the base station 20 and the terminal 10.

The subframe information may be information indicating an index of the starting subframe of the RAR transmission subframe. In the case of the TDD system, based on the UL-DL setting and the subframe number (#n) of the uplink subframe in which transmission of the repeated random access preamble is terminated, the index #p of the starting subframe of the RAR transmission subframe is Can be determined. 8 is a diagram showing another example in which the start sub-frame of the RAR transmission sub-frame is set in the TDD system. In the example of FIG. 8, when the transmission of the repeated random access preamble is ended in the uplink subframe (subframe #n), the index of the downlink subframe in which transmission of the random access response starts is determined as #p . At this time, when the radio frame in which the transmission of the repeated random access preamble is terminated is #M, the radio frame in which the transmission of the repeated random access response starts is the next radio frame # (M + 1). That is, when the transmission of the repeated random access preamble ends in the radio frame #M and the subframe #n, transmission of the repeated random access response can start in the radio frame # (M + 1) and the subframe #p. At this time, the value of #p may be set to the same value regardless of the UL-DL setting, or may be set to a different value according to the UL-DL setting. On the other hand, the transmission of the repeated random access response may start at the radio frame # (M + N) (N is a positive integer). Although the present embodiment has been described above with reference to the TDD system, it is also applicable to the FDD system.

In step S510, the subframe information including information indicating the value of p and / or N may be transmitted from the base station 20 to the terminal 10 via higher layer signaling (e.g., RRC). Alternatively, the value of p and / or the value of N may be a value previously set between the base station 20 and the terminal 10. [

On the other hand, the value of k or the value of p described above may not have a single value but may have a plurality of values within a certain range.

For example, the value of k may have a value of all positive integers satisfying k1? K? K2. When the terminal 10 ends the transmission of the random access preamble repeated in the uplink subframe #n, the terminal 10 transmits the random access preamble in the downlink subframe # (n + k1) to the subframe # (n + k2) It can be expected that the RAR transmission starts from one of the included subframes. That is, in case of FDD, the UE 10 can expect to start RAR transmission from one of the k2-k1 + 1 subframes, and in the case of TDD, from the one of k2-k1 + You can expect the RAR transmission to begin. The terminal 10 can perform RAR detection for each candidate of the RAR transmission start subframe.

9 is a diagram showing an example in which the starting sub-frame of the RAR transmission sub-frame is selected from a plurality of candidates. In the example of Fig. 9, k has a range of 4? K? 6. The terminal 10 tries to detect RARs in L subframes starting from the subframe # (n + 4), attempts RAR detection in L subframes starting from the subframe # (n + 5) + 6), RAR detection can be attempted in L subframes.

In the above-described embodiments, the UE 10 receives subframe information including information indicating k, p, and / or N from the base station 20 through upper layer signaling, It is described that it is statically scheduled. However, in other embodiments, k, p, and / or N may have a predetermined value in terminal 10 and base station 20.

On the other hand, the L value, which is the number of times the random access response is repeated, may be defined as a function of the M value or the random access preamble format, which is the number of repetitions of the random access preamble format. For example, the L value, which is the number of times the random access response is repeated, may be set to be proportional to the M value, which is the number of repetitions of the random access preamble format. As another example, the L value, which is the number of times the random access response is repeated, may be set to be proportional to the length of the random access preamble format (i.e., the value of T _CP + T _{SEQ in} the preamble format).

Alternatively, the base station 20 may set an L value, which is the number of times the random access response is repeated, and transmit the set L value to the MTC terminals in the cell through cell-specific RRC signaling. That is, the base station 20 may include the L value in the system information for the MTC terminal and broadcast it to the MTC terminals in the cell.

[Resource block allocation for RAR]

10 is a flow diagram illustrating a method for setting up RAR transmission resources according to one embodiment.

Referring to FIG. 10, the UE 10 determines a physical resource block (PRB) to which a random access response is allocated (S1010). The terminal 10 transmits a random access preamble to the base station 20 (S1020), and receives a random access response for the random access preamble through the PRB determined in operation S1010 (S1030).

In one example, PRBs for RAR transmission may be allocated in a localized manner.

11 is a diagram showing an example of a resource block allocated for RAR transmission. Referring to FIG. 11, the number ( _PRB ) of PRBs allocated for RAR transmission in one downlink subframe and the position (frequency position, or PRB index) of the corresponding PRB may be a fixed value. In one example, the value of R _PRB may be a natural number less than or equal to 6, and the location of the PRB may be the center frequency of the system band.

12 is a diagram showing another example of a resource block allocated for RAR transmission. Referring to FIG. 12, the number of PRBs allocated for RAR transmission (R _PRB ) is fixed, but the position of the PRB allocated for the corresponding RAR transmission per downlink subframe may be frequency hopping. When frequency hopping is applied to the RAR transmission, the position of the PRB allocated for the RAR transmission in each downlink subframe depends on the bandwidth (number of PRBs, N _PRB ) of the corresponding system and the subframe index or slot number As shown in FIG.

In the embodiment of FIG. 10, the PRB allocated for the RAR transmission is a preset value or determined according to a predetermined rule. However, in another embodiment, the PRB allocated for the RAR transmission may be set at the base station 20 and broadcast to MTC terminals in the cell via cell-specific RRC signaling.

13 is a flowchart illustrating a method of setting RAR transmission resources according to another embodiment.

Referring to FIG. 13, the UE 10 receives information on a physical resource block (PRB) to which a random access response is allocated from the BS 20 (S1310). The terminal 10 transmits a random access preamble to the base station 20 (S1320), and receives a random access response for the random access preamble through the PRB determined in operation S1010 (S1330).

In this case, the PRB allocation information for the corresponding RAR can be set in a bitmap format for the PRBs constituting the entire system bandwidth by reusing the PRB allocation signaling format for the existing EPDCCH set configuration. In this case, the PRB allocation may be allocated in a localized or distributed manner.

Alternatively, when the PRB information is allocated through the cell-specific RRC signaling, the value of the number of PRBs allocated for the RAR transmission (R _PRB ) and the value of the R _PRB allocation information in the downlink sub-frame in which the first RAR transmission occurs , The value of the hopping size (H _PRB ) of the corresponding RAR can be signaled.

14 is a block diagram showing the configuration of a terminal according to an embodiment of the present invention.

14, the terminal 1400 includes a controller 1410, a transmitter 1420, and a receiver 1430.

The controller 1410 is a PDSCH resource allocation method for RAR message transmission for the MTC terminal, which is necessary for performing the above-described embodiments. It is not a dynamic scheduling through a PDCCH, but a semi-static semi-static PDSCH resource allocation.

The transmitter 1420 transmits uplink control information, data, and a message to the base station through the corresponding channel.

The receiver 1430 receives the downlink control information, data, and a message from the base station through the corresponding channel.

In one embodiment, the subframe in which the random access response is transmitted may be set.

Before transmitting the random access preamble, the receiving unit 1430 transmits the subframe information indicating the relation between the subframe in which the terminal transmits the random access preamble and the subframe in which the terminal receives the random access response related to the random access preamble .

The transmitting unit 1420 transmits a random access preamble, and the receiving unit 1430 can receive a random access response related to the random access preamble through a subframe determined based on the subframe information.

The subframe information may include information indicating a difference between a subframe in which the UE transmits the random access preamble and a subframe in which the UE receives the random access response.

Alternatively, the subframe information may include information indicating an index of a subframe in which the UE receives the random access response.

Alternatively, the subframe information may include information of the radio frame and information of the subframe in which the UE receives the random access response.

At this time, the subframe information may include a plurality of candidate values, and the receiving unit 1430 may attempt to receive the random access response using each candidate value.

The random access preamble can be repeatedly received through a plurality of subframes. The number of the plurality of subframes can be determined based on at least one of the number of times of repeated transmission of the random access preamble and the format of the random access preamble. Alternatively, the receiving unit 1430 can receive information indicating the number of the plurality of subframes.

In another embodiment, a resource block to which a random access response is sent may be set.

The control unit 1410 can determine a resource block to which a random access response is assigned.

The transmitting unit 1420 transmits a random access preamble, and the receiving unit 1430 can receive a random access response related to the random access preamble through the determined resource block.

In one example, the number of resource blocks is pre-installed and the location of the resource block may be determined based on at least one of the downlink bandwidth, the index of the subframe, and the index of the slot.

Alternatively, the receiving unit 1430 may receive information on a resource block to which a random access response is allocated.

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

15, the base station 1500 includes a control unit 1510, a transmission unit 1520, and a reception unit 1530.

The controller 1510 is a PDSCH resource allocation method for RAR message transmission for the MTC terminal, which is required for performing the above-described present invention. The PDSCH resource allocation method is not a dynamic scheduling based on a PDCCH, but a semi-static semi-static PDSCH resource allocation.

The transmitting unit 1520 and the receiving unit 1530 are used to transmit and receive signals, messages, and data necessary for carrying out the present invention to and from the terminal.

In one embodiment, the subframe in which the random access response is transmitted may be set.

Before transmitting the random access preamble, the transmitter 1520 transmits the subframe information indicating the relationship between the subframe in which the terminal transmits the random access preamble and the subframe in which the terminal receives the random access response related to the random access preamble Lt; / RTI >

The receiving unit 1530 can receive the random access preamble.

After the random access preamble is received, the transmitting unit 1520 may transmit a random access response related to the random access preamble to the subframe determined based on the subframe information.

The subframe information may include information indicating a difference between a subframe in which the UE transmits the random access preamble and a subframe in which the UE receives the random access response.

Alternatively, the subframe information may include information indicating an index of a subframe in which the UE receives the random access response.

Alternatively, the subframe information may include information of the radio frame and information of the subframe in which the UE receives the random access response.

At this time, the subframe information may include a plurality of candidate values.

The random access preamble can be repeatedly transmitted through a plurality of subframes. The transmitting unit 1520 can transmit information indicating the number of the plurality of subframes.

The foregoing description is merely illustrative of the technical idea of the present invention, and various changes and modifications may be made by those skilled in the art without departing from the essential characteristics of the present invention. Therefore, the embodiments disclosed in the present invention are intended to illustrate rather than limit the scope of the present invention, and the scope of the technical idea of the present invention is not limited by these embodiments. The scope of protection of the present invention should be construed according to the following claims, and all technical ideas within the scope of equivalents should be construed as falling within the scope of the present invention.

Claims (36)

A method for a terminal to receive a random access response,
Receiving subframe information indicating a relation between a subframe in which the UE transmits a random access preamble and a subframe in which the UE receives a random access response related to the random access preamble;
Transmitting the random access preamble;
And receiving a random access response associated with the random access preamble through a subframe determined based on the subframe information. The method according to claim 1,
Wherein the subframe information includes information indicating a difference between a subframe in which the UE transmits the random access preamble and a subframe in which the UE receives the random access response. The method according to claim 1,
Wherein the subframe information includes information indicating an index of a subframe in which the UE receives the random access response. The method according to claim 1,
Wherein the subframe information includes information of a radio frame and information of a subframe in which the terminal receives the random access response. The method according to claim 1,
Wherein the subframe information includes a plurality of candidate values,
And in the step of receiving the random access response, the terminal attempts to receive the random access response using each candidate value. The method according to claim 1,
Wherein the random access preamble is repeatedly received via a plurality of subframes,
Wherein the number of the plurality of subframes is determined based on at least one of the number of times of repeated transmission of the random access preamble and the format of the random access preamble. The method according to claim 1,
Wherein the random access preamble is repeatedly received via a plurality of subframes,
Further comprising receiving information indicating a number of the plurality of subframes. A method for a terminal to receive a random access response,
Determining a resource block to which a random access response is assigned;
Transmitting a random access preamble; And
And receiving a random access response associated with the random access preamble through the determined resource block. 9. The method of claim 8,
Wherein the number of the resource blocks and the position of the resource blocks are set in advance in the step of determining a resource block to which the random access response is allocated. 9. The method of claim 8,
In determining the resource block to which the random access response is allocated, the number of resource blocks is preset and the location of the resource block is determined based on at least one of the downlink bandwidth, the index of the subframe, and the index of the slot ≪ / RTI > 9. The method of claim 8,
Wherein in the step of determining a resource block to which the random access response is allocated, information on a resource block to which the random access response is allocated is received from a base station.
A method for a base station to transmit a random access response,
Transmitting subframe information indicating a relation between a subframe in which a terminal transmits a random access preamble and a subframe in which the terminal receives a random access response associated with the random access preamble;
Receiving a random access preamble;
And transmitting a random access response associated with the random access preamble through a subframe determined based on the subframe information. 13. The method of claim 12,
Wherein the subframe information includes information indicating a difference between a subframe in which the UE transmits the random access preamble and a subframe in which the UE receives the random access response. 13. The method of claim 12,
Wherein the subframe information includes information indicating an index of a subframe in which the UE receives the random access response. 13. The method of claim 12,
Wherein the subframe information includes information of a radio frame and information of a subframe in which the terminal receives the random access response. 13. The method of claim 12,
Wherein the subframe information comprises a plurality of candidate values. 13. The method of claim 12,
Wherein the random access preamble is repeatedly transmitted through a plurality of subframes,
Further comprising transmitting information indicating a number of the plurality of subframes. A method for a base station to transmit a random access response,
Transmitting information on a resource block to which a random access response is allocated to a terminal;
Receiving a random access preamble;
And transmitting a random access response associated with the random access preamble through the resource block. A terminal for receiving a random access response,
A transmitter for transmitting a random access preamble; And
And a receiving unit that receives a random access response associated with the random access preamble through a subframe determined based on the subframe information,
Wherein the receiver indicates a relation between a subframe in which the terminal transmits the random access preamble and a subframe in which the terminal receives the random access response associated with the random access preamble before transmitting the random access preamble And receiving the subframe information. 20. The method of claim 19,
Wherein the subframe information includes information indicating a difference between a subframe in which the terminal transmits the random access preamble and a subframe in which the terminal receives the random access response. 20. The method of claim 19,
Wherein the subframe information includes information indicating an index of a subframe in which the UE receives the random access response. 20. The method of claim 19,
Wherein the subframe information includes information of a radio frame and information of a subframe in which the terminal receives the random access response. 20. The method of claim 19,
Wherein the subframe information includes a plurality of candidate values,
Wherein the receiving unit attempts to receive the random access response using each candidate value. 20. The method of claim 19,
Wherein the random access preamble is repeatedly received via a plurality of subframes,
Wherein the number of the plurality of subframes is determined based on at least one of the number of times of repeated transmission of the random access preamble and the format of the random access preamble. 20. The method of claim 19,
Wherein the random access preamble is repeatedly received via a plurality of subframes,
Wherein the receiving unit receives information indicating a number of the plurality of subframes. A terminal for receiving a random access response,
A control unit for determining a resource block to which a random access response is allocated;
A transmitting unit for transmitting a random access preamble; And
And receiving a random access response associated with the random access preamble through the determined resource block. 27. The method of claim 26,
Wherein the number of the resource blocks and the location of the resource blocks are set in advance. 27. The method of claim 26,
Wherein the number of resource blocks is preset and the location of the resource block is determined based on at least one of a downlink bandwidth, an index of a subframe, and an index of a slot. 27. The method of claim 26,
And information on a resource block to which the random access response is allocated is received from the base station through the receiving unit. A base station for transmitting a random access response,
A receiver for receiving a random access preamble; And
And a transmitter for transmitting a random access response related to the random access preamble,
Wherein the transmitter transmits a random access preamble to a terminal for indicating a relationship between a subframe in which the terminal transmits the random access preamble and a subframe in which the terminal receives the random access response related to the random access preamble, And transmits the frame information. 31. The method of claim 30,
Wherein the subframe information includes information indicating a difference between a subframe in which the UE transmits the random access preamble and a subframe in which the UE receives the random access response. 31. The method of claim 30,
Wherein the subframe information includes information indicating an index of a subframe in which the UE receives the random access response. 31. The method of claim 30,
Wherein the subframe information includes information of a radio frame and information of a subframe in which the UE receives the random access response. 31. The method of claim 30,
Wherein the subframe information comprises a plurality of candidate values. 31. The method of claim 30,
Wherein the random access preamble is repeatedly transmitted through a plurality of subframes,
Wherein the transmission unit further transmits information indicating the number of the plurality of subframes. A base station for transmitting a random access response,
A receiver for receiving a random access preamble; And
And a transmitter for transmitting a random access response related to the random access preamble,
Wherein the transmitter transmits information on a resource block to which the random access response is allocated to the terminal before receiving the random access preamble.

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