JP2014138318A - Base station device, terminal device, communication system and communication method - Google Patents

Abstract

A base station apparatus and the like capable of effectively using a frequency spectrum are provided.
Base station apparatuses 1-1 to 1-2 include a wireless communication unit that performs wireless communication using an existing carrier and an additional carrier, and a lower frequency side or a higher frequency side than the existing carrier. Information that identifies a region of a frequency resource in which the additional carrier may exist in one or both of the terminal devices (mobile station devices 21-1 to 21-n, 31-1 to 31-1) 31-m), and a carrier information transmission control unit that wirelessly transmits to 31-m).
[Selection] Figure 1

Description

  The present invention relates to a base station device, a terminal device, a communication system, and a communication method.

Conventionally, LTE (Long Term Evolution) is known as one of the standards studied by 3GPP (Third Generation Partnership Project). LTE is being revised sequentially.
In LTE, an access scheme based on OFDMA (Orthogonal Frequency Division Multiple Access) is employed. Also, in LTE, a control signal (SS: Synchronization Signals) for time synchronization and a control signal (RS: Reference Signals) for estimating a propagation path are inserted in a downlink OFDM signal.

In LTE, multiple types of RS are defined according to the purpose. As RS, for example, common reference signal (CRS: Common RS) for the purpose of demodulation, channel measurement, and reception power measurement, CSI-RS (Channel State Information RS) for the purpose of channel measurement, and demodulation are used. There are DM-RS (DeModulation RS) as a main purpose.
Regarding RS, generally, since RS is inserted in a different area for each antenna, there is a problem that RS overhead increases as the number of antennas increases. For the purpose of reducing such RS overhead, it has been proposed to introduce a new carrier type (NCT: New Carrier Type), which is a carrier that is not backward compatible and has a low CRS insertion density.

  On the other hand, NCT is being studied for use in various applications in addition to reducing overhead by utilizing the lack of backward compatibility. One such application is the effective use of spectrum.

FIG. 13 is a diagram illustrating an example of spectrum additional allocation with respect to an existing spectrum. The horizontal axis of the graph in FIG. 13 represents the frequency.
A spectrum 2001 is an existing spectrum (existing spectrum X).
A spectrum 2002 is a spectrum (additional spectrum Y) additionally allocated continuously to the existing spectrum X on the low frequency side.
In this example, the additional spectrum Y is assigned to the lower continuous frequency for the existing spectrum X which has been performing the LTE service on the existing spectrum X.

In this case, it is desirable to implement the LTE service using a spectrum (composite spectrum) obtained by combining the existing spectrum X and the additional spectrum Y.
FIG. 14 is a diagram illustrating an example of operation of a composite spectrum. The horizontal axis of the graph in FIG. 14 represents the frequency.
A spectrum 2011 is a composite spectrum of the existing spectrum X and the additional spectrum Y.
In this example, the existing spectrum X and the additional spectrum Y are used in combination.

  However, in such a composite spectrum operation, for example, the terminal device Z that can use the bandwidth of the existing spectrum X may support the bandwidth of the composite spectrum (X + Y) different from the bandwidth. It may not be possible. In this case, there has been a problem that such a terminal device Z cannot enjoy the LTE service at all.

As a technique for solving such a problem, it has been proposed to use carrier aggregation (CA) (see, for example, Non-Patent Document 1).
FIG. 15 is a diagram for explaining an example of carrier aggregation. The horizontal axis of the graph in FIG. 15 represents the frequency.
The spectrum 2021 is an existing spectrum, and a compatible carrier (compatible carrier) is provided.
A spectrum 2022 is an additional spectrum, and an additional carrier (additional carrier) is provided.
A guard band is provided between the existing spectrum and the additional spectrum.
The difference between the center frequency of the existing spectrum and the center frequency of the additional spectrum is, for example, 100 kHz × N (N is an integer of 1 or more).

In such carrier aggregation, since the existing spectrum is maintained as it is, the terminal device Z that can use the bandwidth of the existing spectrum can enjoy the LTE service with the existing spectrum.
However, such carrier aggregation may require a guard band between the carrier of the existing spectrum and the additional carrier (in the example of FIG. 15, a guard band is provided), and insertion of the guard band There is a concern that the spectrum utilization efficiency will be reduced.
Further, in the LTE mechanism, it is necessary to arrange the carrier of the existing spectrum and the additional carrier by a multiple of the raster whose center frequency is 100 kHz. For this reason, there is a possibility that the space between the carriers cannot be completely filled, and there is a concern that the spectrum utilization efficiency will be lowered.

In addition, as a technique for solving the above problems, it has been proposed to use a technique called a carrier segment. In the carrier segment, the center frequency of the compatible carrier is fixed, the compatible carrier is arranged at the center, and additional carriers that are not backward compatible are extended in the upper and lower bands.
FIG. 16 is a diagram for explaining an example of a carrier segment. The horizontal axis of the graph in FIG. 16 represents the frequency.
The spectrum 2031 includes a center frequency and is provided with a compatible carrier (compatible carrier).
The spectrum 2032 is an additional spectrum that is continuous on the low frequency side with respect to the center spectrum 2031, and a carrier of an additional segment (additional segment) is provided.
The spectrum 2033 is an additional spectrum that is continuous on the high frequency side with respect to the center spectrum 2031, and a carrier of an additional segment (additional segment) is provided.
In this example, the additional segment on the low frequency side and the additional segment on the high frequency side are symmetric with respect to the center frequency with respect to the center spectrum 2031.

Even with such a carrier segment technique, the terminal device Z that can use the bandwidth of the existing spectrum due to the presence of the compatible carrier (the same bandwidth as the bandwidth of the existing spectrum) enjoys the LTE service. be able to.
However, in such a carrier segment, the position of the compatible carrier is changed (relative to the position of the carrier in the existing spectrum), so it is necessary to renew the communication system (base station device, etc.), and it is practically applied. Is often difficult.

R1-112081, Ericsson and ST-Ericsson, “Considations on use cases for induc- tion of additional carrier types”, 3GPP RAN WG1 # 66, August, 2011

  As described above, the conventional carrier aggregation method and the conventional carrier segment method have insufficient points, and a new method has been desired.

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide a base station device, a terminal device, a communication system, and a communication method capable of effectively using a frequency spectrum.

  (1) In order to solve the above-described problem, a base station apparatus according to the present invention includes a radio communication unit that performs radio communication using an existing carrier and an additional carrier, and a lower frequency side than the existing carrier. A carrier information transmission control unit configured to wirelessly transmit information identifying a region of a frequency resource in which one or both of the high frequency sides may have the additional carrier to the terminal device by the wireless communication unit; It is characterized by providing.

  (2) In the base station apparatus according to (1) described above, the carrier information transmission control unit is further invalid in a frequency resource region in which the additional carrier may exist. The information specifying the region portion is wirelessly transmitted to the terminal device by the wireless communication unit.

  (3) In order to solve the above-described problem, a terminal device according to the present invention includes a radio communication unit that performs radio communication using an existing carrier and an additional carrier, and a lower frequency side or higher frequency than the existing carrier. A carrier information reception control unit configured to receive, by the wireless communication unit, information identifying a region of a frequency resource in which the additional carrier may be present on one or both of the frequency sides, from a base station device; It is characterized by providing.

  (4) In the terminal device according to (3) described above, the carrier information reception control unit may further include an invalid area among frequency resource areas in which the additional carrier may exist. Information for specifying a part is received by the wireless communication unit from the base station apparatus by radio.

  (5) In order to solve the above-described problem, a communication system according to the present invention includes a base station device and a terminal device, and the base station device has a lower frequency side or higher frequency side than an existing carrier. Wirelessly transmits information identifying a region of a frequency resource in which one or both may have additional carriers to the terminal device, and the terminal device wirelessly receives the information from the base station device, The base station apparatus and the terminal apparatus communicate with each other wirelessly using the existing carrier and the additional carrier.

  (6) In order to solve the above-described problem, in the communication method according to the present invention, the base station apparatus may have an additional carrier on one or both of the lower frequency side and the higher frequency side than the existing carrier. Wirelessly transmits information identifying a region of a frequency resource having a characteristic to the terminal device, the terminal device wirelessly receives the information from the base station device, and the base station device and the terminal device are It communicates by radio | wireless using a carrier and the said additional carrier.

  According to the present invention, the frequency spectrum can be used effectively.

1 is a block diagram showing a schematic configuration of a communication system according to an embodiment of the present invention. It is a block diagram which shows the schematic structure of the mobile station apparatus which concerns on one Embodiment of this invention. It is a block diagram which shows the schematic structure of the base station apparatus which concerns on one Embodiment of this invention. It is a block diagram which shows the schematic structure of the spectrum which concerns on one Embodiment of this invention. It is a figure which shows an example of the existing carrier and additional segment which concern on 1st Embodiment of this invention. It is a sequence diagram which shows an example of the procedure of the process performed in the base station apparatus and mobile station apparatus in the carrier segment base approach which concerns on 1st Embodiment of this invention. It is a figure for demonstrating an example of the process which notifies the structure of a frequency resource from the base station apparatus which concerns on 1st Embodiment of this invention to a mobile station apparatus. It is a figure which shows an example of a structure of the resource block (RB) which concerns on 1st Embodiment of this invention. It is a figure which shows an example of the compatible carrier and additional carrier which concern on 2nd Embodiment of this invention. It is a sequence diagram which shows an example of the procedure of the process performed in the base station apparatus and mobile station apparatus which concern on 2nd Embodiment of this invention. It is a figure for demonstrating an example of the process which notifies the structure of a frequency resource from the base station apparatus which concerns on 2nd Embodiment of this invention to a mobile station apparatus. It is a figure which shows an example of arrangement | positioning of PSS, SSS, and DS in the frequency resource of the additional carrier which concerns on 2nd Embodiment of this invention. It is a figure which shows an example of the additional allocation of the spectrum with respect to the existing spectrum. It is a figure which shows an example of operation | use of a composite spectrum. It is a figure for demonstrating an example of a carrier aggregation. It is a figure for demonstrating an example of a carrier segment.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
<Schematic configuration of communication system according to this embodiment>
FIG. 1 is a block diagram showing a schematic configuration of a communication system according to an embodiment of the present invention.
The communication system according to the present embodiment is connected so that the plurality of base station apparatuses 1-1 to 1-2 can directly or indirectly communicate with each other between the plurality of base station apparatuses 1-1 to 1-2. A plurality of lines 3-1 to 3-3 and a plurality of mobile station devices (an example of a terminal device) 21-1 to 21-n, 31-1 to 31-m (n and m are each an integer of 1 or more) Is provided. FIG. 1 also shows cells (communication areas) 11-1 to 11-2 of the base station apparatuses 1-1 to 1-2.

Here, in the communication system, various numbers may be used as the number of base station devices, the number of lines connecting the base station devices, and the number of mobile station devices. In the example of FIG. 1, n mobile station devices 21-1 to 21-n exist in the cell 11-1 of the base station device 1-1, and the cell 11-2 of the base station device 1-2. There are m mobile station apparatuses 31-1 to 31-m.
Further, as each of the lines 3-1 to 3-3, for example, a wired communication line may be used, or a wireless communication line may be used.

<Schematic configuration of mobile station apparatus according to this embodiment>
FIG. 2 is a block diagram showing a schematic configuration of a mobile station apparatus according to an embodiment of the present invention. In the present embodiment, each of the mobile station devices 21-1 to 21-n and 31-1 to 31-m has the same configuration and performs the same operation, and thus will be collectively described as the mobile station device 21.
The mobile station apparatus 21 according to the present embodiment includes an antenna 101, a radio communication unit 102, an input unit 103, an output unit 104, a storage unit 105, and a control unit 106.
The control unit 106 includes a carrier information reception control unit 201.

The antenna 101 communicates (transmits and receives) wireless signals.
The wireless communication unit 102 processes a signal to be transmitted, transmits the signal wirelessly from the antenna 101, and processes the wireless signal received by the antenna 101. For example, the wireless communication unit 102 communicates with a base station device (in the present embodiment, the base station devices 1-1 to 1-2) by radio. For example, in an old type mobile station apparatus, the radio communication unit 102 communicates by radio using an existing carrier (only), and in a new type mobile station apparatus, an existing carrier and an additional carrier To communicate wirelessly.
The input unit 103 performs input from the outside. The input unit 103 includes an operation unit that receives an operation performed by a user (person), for example. The operation unit includes, for example, a touch panel or a key. The input unit 103 includes a voice input unit that inputs sound (for example, voice) from the outside, for example. The input unit 103 includes a data input unit that inputs data from, for example, an external memory or device.
The output unit 104 performs output to the outside. The output unit 104 includes, for example, a display unit that displays information on a screen. The display unit is composed of, for example, a liquid crystal screen. The output unit 104 includes, for example, a sound output unit that outputs sound (for example, sound) to the outside. The output unit 104 includes a data output unit that outputs data to, for example, an external memory or device.
The storage unit 105 stores various types of information. The storage unit 105 is composed of a memory, for example. The storage unit 105 stores a program processed by a processor such as the control unit 106, for example.
The control unit 106 performs various processes and controls.

The carrier information reception control unit 201 uses the radio communication unit 102 to specify information specifying a region of a frequency resource in which an additional carrier on one or both of the low frequency side and the high frequency side may exist. By this, it receives from the base station apparatus 1-1 to 1-2 by radio.
Further, the carrier information reception control unit 201 further transmits, by the radio communication unit 102, information that specifies an invalid area portion among frequency resource areas in which additional carriers may exist, to the base station apparatus 1- 1 to 1-2 is received by radio.

<Schematic configuration of base station apparatus according to this embodiment>
FIG. 3 is a block diagram showing a schematic configuration of a base station apparatus according to an embodiment of the present invention. In this embodiment, since each base station apparatus 1-1 to 1-2 has the same configuration and performs the same operation, these will be collectively described as the base station apparatus 1.
The base station apparatus 1 according to the present embodiment includes an antenna 121, a wireless communication unit 122, a communication unit 123, a storage unit 124, and a control unit 125.
The control unit 125 includes a carrier information transmission control unit 301.

The antenna 121 communicates (transmits and receives) wireless signals.
The wireless communication unit 122 processes a signal to be transmitted, transmits the signal wirelessly from the antenna 121, and processes the wireless signal received by the antenna 121. The wireless communication unit 122 communicates wirelessly with, for example, mobile station devices (in this embodiment, mobile station devices 21-1 to 21-n, 31-1 to 31-m). In this embodiment, the wireless communication unit 122 communicates wirelessly using an existing carrier and an additional carrier.
The communication unit 123 communicates (transmits and receives) information with other base station apparatuses via lines (in the present embodiment, lines 3-1 to 3-3). This communication may be performed, for example, via a wired line, or may be performed via a wireless line.
The storage unit 124 stores various types of information. The storage unit 124 is composed of a memory, for example. The storage unit 124 stores a program processed by a processor such as the control unit 125, for example. In addition, the storage unit 124 stores, for example, information (for example, information for management) related to mobile station apparatuses that are connected so that wireless communication is possible.
The control unit 125 performs various processes and controls.

The carrier information transmission control unit 301 uses the radio communication unit 122 to specify information for specifying a region of frequency resources in which an additional carrier on one or both of the lower frequency side and the higher frequency side than the existing carrier may exist. To transmit to the mobile station devices 21-1 to 21-n and 31-1 to 31-m by radio.
Further, the carrier information transmission control unit 301 further transmits, by the wireless communication unit 122, information identifying an invalid area portion of the frequency resource area in which an additional carrier may exist, to the mobile station apparatus 21- 1 to 21-n and 31-1 to 31-m are transmitted by radio.

<Schematic configuration of spectrum according to this embodiment>
FIG. 4 is a block diagram showing a schematic configuration of a spectrum according to an embodiment of the present invention. The horizontal axis of the graph in FIG. 4 represents the frequency.
The spectrum 401 is an existing spectrum (existing band (frequency band)), and a compatible carrier (compatible carrier) is provided.
The spectrum 402 is an additional spectrum (new band) continuous on the low frequency side with respect to the existing spectrum.
The spectrum 403 is an additional spectrum (new band) continuous on the high frequency side with respect to the existing spectrum.

In this embodiment, as shown in FIG. 4, an additional spectrum (new band) having an arbitrary bandwidth is assigned to the upper and lower (high and low) frequency bands of the existing band. Further, in this embodiment, it is not necessary to insert a guard band, and a spectrum (new band) continuous with the existing band can be provided.
In this way, a new spectrum is operated in addition to the existing operating spectrum. In this case, the center frequency of the existing operation spectrum is not moved.
Note that the additional spectrum (new band) may be assigned to only one of the upper and lower (high and low) frequency bands of the existing band, for example.
For example, an invalid part (for example, an invalid resource block (RB)) may be provided between the additional spectrum (new band) and the existing band.

[First Embodiment]
A first embodiment will be described.
In this embodiment, signals transmitted by radio from base station apparatuses 1-1 to 1-2 (for example, eNB: E-UTRAN NodeB) are transmitted to mobile station apparatuses 21-1 to 21-n, 31-1 to 31-31. Assume downlink communication received by m (UE: User Equipment). It is also possible to apply the reverse of the downlink and the uplink.
Furthermore, in this embodiment, OFDMA or SC-FDMA (Single Carrier-Frequency Division Multiple Access) that performs allocation in the frequency domain is assumed as an access scheme. Here, for the sake of simplicity, a description will be given assuming that one mobile station apparatus B receives a signal transmitted from one base station apparatus A. However, as another example, 2 The present invention can be applied even when more than one mobile station apparatus exists, and its generality is not lost.

  The downlink (DL: Down Link) represents communication in the direction from the base station apparatuses 1-1 to 1-2 to the mobile station apparatuses 21-1 to 21-n and 31-1 to 31-m. The link (UL: Up Link) represents communication in the direction from the mobile terminal devices 21-1 to 21-n and 31-1 to 31-m to the base station devices 1-1 to 1-2.

In this embodiment, a use case as shown in FIG. 5 is assumed.
FIG. 5 is a diagram illustrating an example of the existing carrier and the additional segment according to the present embodiment. The horizontal axis of the graph in FIG. 5 represents the frequency.
In this example, an additional spectrum 511-1 on the low frequency side is given as a first additional segment (additional segment 1) to an existing carrier (compatible carrier) 501, and an additional spectrum 511- on the high frequency side is added. 2 is assigned as a second additional segment (additional segment 2), and an additional spectrum 511-3 on the higher frequency side is assigned as a third additional segment (additional segment 3).

  The base station apparatus A notifies the mobile station apparatus B of the presence of the additional segments 1, 2, and 3 for the existing downlink compatible carrier (compatible carrier) 501 and adds the additional segments 1, 2, and 3. Is used to transmit a downlink signal from the base station apparatus A to the mobile station apparatus B.

FIG. 6 is a sequence diagram illustrating an example of a processing procedure performed in the base station apparatus A and the mobile station apparatus B in the carrier segment-based approach according to the present embodiment.
The base station apparatus A wirelessly transmits to the mobile station apparatus B a signal for synchronizing the existing carrier (synchronization signal of the existing carrier) (process T1).
Here, “notifying” means transmitting a common signal to a plurality of mobile station apparatuses. In addition, in the present embodiment, the signal to be notified is PSS (Primary Synchronization Signal) / SSS (Secondary Synchronization Signal) which is a synchronization signal defined in LTE, and includes, for example, CRS.

The mobile station apparatus B that has received the synchronization signal of the existing carrier wirelessly transmitted from the base station apparatus A performs time and frequency synchronization (time / frequency synchronization with the existing carrier) with respect to the signal transmitted by the base station apparatus A. (Processing T2). PSS, SSS, CRS, etc. are used for this process.
In this process, the mobile station apparatus B determines (determines) the frequency bandwidth of the existing carrier (compatible carrier) 501, that is, the number of frequency resource blocks (RB: Resource Block) in the present embodiment (discussed later). (Corresponding to (1) in 7).

When such synchronization processing is completed, processing for adding the spectra 511-1 to 511-3 (additional segments 1, 2, 3) is performed.
The base station apparatus A notifies the mobile station apparatus B by wirelessly transmitting a signal including information on the number of blocks of the extension frequency (process T3) (corresponding to (2) in FIG. 7 described later). .
Further, the base station apparatus A wirelessly transmits to the mobile station apparatus B a signal including information on the position of the effective frequency block (process T4) (corresponding to (3) in FIG. 7 described later). .) As a result, the invalid RB position (that is, the RB position other than the valid RB position) is notified from the base station apparatus A to the mobile station apparatus B. In the invalid RB, no downlink signal is transmitted from the base station apparatus A, and the mobile station apparatus B performs a reception process assuming that no downlink signal is transmitted.

  The mobile station apparatus B that has received the above signals performs predetermined processing on these signals and prepares to receive the signals of the additional segments 1, 2, and 3 (processing T5). As a result, the mobile station apparatus B can receive downlink signals in the additional segments 1, 2, and 3.

Subsequently, a process of receiving a downlink signal by the mobile station apparatus B using the existing carrier (compatible carrier) 501 and the spectrums 511-1 to 511-3 (additional segments 1 to 3) will be described below.
The base station apparatus A wirelessly transmits a signal of control information (DCI: Downlink Control Information) including downlink allocation information to the mobile station apparatus B (process T6), and the mobile station apparatus B transmits the signal of this DCI. Is received and processed (process T7).
Subsequently, the base station apparatus A wirelessly transmits a downlink data signal to the mobile station apparatus B (process T8), and the mobile station apparatus B transmits the data signal according to the already received DCI information. Is received and processed (process T9).

  Here, the DCI transmitted from the base station apparatus A to the mobile station apparatus B includes information for demodulating downlink data continuously transmitted from the base station apparatus A to the mobile station apparatus B. Yes. Information for demodulating the downlink data includes, for example, information such as the RB position, the number of MIMO (Multiple Input Multiple Output) spatial multiplexing layers, the modulation scheme, and the coding rate.

FIG. 7 is a diagram for explaining an example of processing for notifying the configuration of the frequency resource from the base station apparatus A to the mobile station apparatus B according to the present embodiment. The horizontal axis of the graph in FIG. 7 represents the frequency.
In the example of FIG. 7, a plurality of blocks 601-1 to 601-15 having different frequencies (frequency bands) are shown in correspondence with the configuration of the frequency resource shown in FIG. 5.

In the example of FIG. 7, the three blocks 601-1 to 601-3 from the lowest frequency are invalid blocks.
Subsequently, in the example of FIG. 7, one block 601-4 from the lowest frequency is an effective block, and corresponds to the block of the additional spectrum 511-1 (additional segment 1) shown in FIG. .
Subsequently, in the example of FIG. 7, the six blocks 601-5 to 601-10 from the lowest frequency are effective blocks and correspond to the blocks of the existing carrier (compatible carrier) 501 shown in FIG. .
Subsequently, in the example of FIG. 7, one block 601-11 from the lower frequency is an invalid block.
Subsequently, in the example of FIG. 7, one block 601-12 from the lowest frequency is an effective block, and corresponds to the block of the additional spectrum 511-2 (additional segment 2) shown in FIG. .
Subsequently, in the example of FIG. 7, one block 601-13 from the lower frequency is an invalid block.
Subsequently, in the example of FIG. 7, the two blocks 601-14 to 601-15 from the lowest frequency are effective blocks, and the additional spectrum 511-3 (additional segment 3) shown in FIG. Corresponds to a block.

As shown in processes (1) to (3) in FIG. 7, in this embodiment, the base station apparatus A notifies the mobile station apparatus B of the configuration of the frequency resource.
As processing (1) in FIG. 7, the number of frequency resource blocks (RBs) is notified (for example, notified) from the base station apparatus A to the mobile station apparatus B regarding the existing carrier (compatible carrier) 501.
As process (2) in FIG. 7, the number of blocks (RB) of all frequency resources (extended frequency resources) including additional segments 1 to 3 is notified from the base station apparatus A to the mobile station apparatus B.
As a process (3) in FIG. 7, the base station apparatus A notifies the mobile station apparatus B of an invalid frequency resource block (RB).

Next, a method of allocating a physical downlink shared data channel (PDSCH) including the existing carrier (compatible carrier) 501 and the additional segments 1 to 3 will be described.
In the present embodiment, the PDSCH regions that can be assigned differ depending on the type of physical downlink control channel (PDCCH) that is a channel for transmitting DCI.

FIG. 8 is a diagram illustrating an example of a configuration of a resource block (RB) according to the present embodiment.
In FIG. 8, the horizontal axis represents time, and the vertical axis represents frequency.
FIG. 8 shows a configuration example of the frequency resource in the existing carrier (compatible carrier) 501 and the extended segments in the upper and lower (high and low) frequency bands, and the index (RB) before the additional segment is set as an RB index ( As an example of the configuration, it may also be used after setting an additional segment.) And an example of an index after setting an additional segment.

PDSCH and PDCCH are classified as follows. PDCCH does not exist in the areas of additional segments 1 to 3.
PDSCH region 1 is a PDSCH in an existing carrier (compatible carrier) 501.
PDSCH region 2 is an extended segment region existing in a frequency region lower than existing carrier (compatible carrier) 501.
PDSCH region 3 is an extended segment region that exists in a higher frequency region than the existing carrier (compatible carrier) 501.
-PDCCH is PDCCH which exists in the existing carrier (compatible carrier) 501. FIG.
EPDCCH (Enhanced Physical Downlink Control Channel) 1 is an EPDCCH defined in the PDSCH region 1 in the existing carrier (compatible carrier) 501.
EPDCCH2 is an EPDCCH defined in PDSCH region 2 or PDSCH region 3 in the additional segment.

Here, in the present embodiment, it is assumed that there are 20 RBs as the existing carrier (compatible carrier) 501, and numbers 0 to 19 are assigned in order from the low frequency region to the high frequency region (this book). In this embodiment, this method is referred to as index method A). This number is the one before setting the additional segments 1 to 3, and is not applied to the additional segments 1 to 3.
In addition, after setting the additional segments 1 to 3, it is assumed that there are a total of 50 RBs including invalid RBs, and numbers 0 to 49 are assigned in order from the low frequency region to the high frequency region. (This method is referred to as index method B in this embodiment). However, it is assumed that the four RBs of numbers 46 to 49 are invalid, and in the present embodiment, these RB areas are referred to as “blank areas”.

It is assumed that only the PDSCH region 1 can be scheduled for the PDCCH regardless of whether or not the additional segments 1 to 3 are set.
Here, only the index of index method A can be used as an index when DCI carried by PDCCH notifies RB. That is, in the present embodiment, only the numbers 0 to 19 in the index method A are supported. When such a configuration is used, for example, as another configuration example, when the allocation of the PDSCH region 2 and the PDSCH region 3 by the PDCCH is associated, the number of bits of the field for specifying the RB becomes variable, and the mobile station apparatus B It is possible to avoid that the processing in is complicated.

  Instead, all the PDSCH regions (PDSCH regions 1 to 3 in the present embodiment) can be allocated in EPDCCH1 and EPDCCH2. That is, after the additional segments 1 to 3 are set, only the index of the index method B can be used for the EPDCCH.

As described above, in the communication system according to the present embodiment, the existing carrier common to all the mobile station devices 21-1 to 21-n and 31-1 to 31-m and a specific mobile station device (additional segment) Base station apparatuses 1-1 to 1-2 that wirelessly transmit downlink signals using additional segments (additional carriers) that can be used and are added to existing carriers; Mobile station apparatuses 21-1 to 21-n and 31-1 to 31-m that wirelessly receive downlink signals.
In the communication system according to the present embodiment, information (additional segment information) indicating the position of a frequency resource (extended frequency resource) in which an additional segment may exist is transmitted to the base station apparatuses 1-1 to 1-2. To the mobile station devices 21-1 to 21-n and 31-1 to 31-m. Also, for example, in the area indicated by the additional segment information, the area is subdivided into two or more blocks, and downlink transmission is valid or downlink transmission is invalid in each block. Information identifying whether or not there is (valid / invalid identification information) is transmitted from the base station apparatuses 1-1 to 1-2 to the mobile station apparatuses 21-1 to 21-n and 31-1 to 31-m.

  Therefore, according to the communication system according to the present embodiment, the allocated frequency spectrum can be used effectively, and a new spectrum (additional spectrum) can be used in a flexible manner. Thus, according to the communication system according to the present embodiment, the frequency spectrum can be used effectively.

  As a specific example, in the communication system according to the present embodiment, there is a limit to the frequency bandwidth supported by the old type mobile station device, and the frequency bandwidth supported by the new type mobile station device is wider. However, it is possible to flexibly add a new spectrum (new frequency band) and realize communication while ensuring communication connectivity of an old type mobile station apparatus. In the communication system according to the present embodiment, for example, an expanded frequency resource of any size can be added above and below (high or low) an existing carrier (compatible carrier), and it is invalid using information such as a bitmap. It is also possible to deal with a discontinuous spectrum by notifying the region portion. Further, in the communication system according to the present embodiment, for example, for the existing carrier (compatible carrier) only, consecutive numbers are assigned in order from the low frequency region to the high frequency region (or in reverse order), or It is possible to assign consecutive numbers in order from the low frequency region to the high frequency region (or vice versa) for the existing carrier (compatible carrier) and the entire additional carrier (including the invalid region part). is there.

[Second Embodiment]
A second embodiment will be described.
In the present embodiment, mobile station devices 21-1 to 21-n and 31-1 to 31-m (UE) transmit signals transmitted by radio from base station devices 1-1 to 1-2 (for example, eNB). Assume downlink communication to be received. It is also possible to apply the reverse of the downlink and the uplink.
Furthermore, in this embodiment, OFDMA or SC-FDMA that implements allocation in the frequency domain is assumed as an access scheme. Here, for the sake of simplicity, a description will be given assuming that one mobile station apparatus B receives a signal transmitted from one base station apparatus A. However, as another example, 2 The present invention can be applied even when more than one mobile station apparatus exists, and its generality is not lost.

  The downlink (DL) represents communication in the direction from the base station apparatuses 1-1 to 1-2 to the mobile station apparatuses 21-1 to 21-n and 31-1 to 31-m. ) Represents communication in the direction from the mobile terminal devices 21-1 to 21-n and 31-1 to 31-m to the base station devices 1-1 to 1-2.

In this embodiment, a use case as shown in FIG. 9 is assumed.
FIG. 9 is a diagram illustrating an example of a compatible carrier and an additional carrier according to the present embodiment. The horizontal axis of the graph in FIG. 9 represents the frequency.
In this example, a carrier (compatible carrier) that is compatible with the existing spectrum 801 is provided, and an additional carrier (additional carrier) in an additional segment (additional segment) is added to the spectrum 802 on the lower frequency side. Is provided.
The interval between the center frequency of the compatible carrier and the center frequency of the additional carrier may be arbitrary.

Then, the base station apparatus A notifies the mobile station apparatus B of the presence of an additional carrier with respect to the downlink compatible carrier (compatible carrier) having such backward compatibility, and the downlink signal is transferred to the mobile base station using the additional segment. The data is transmitted from the device A to the mobile station device B.
Here, as a procedure for adding an additional carrier, for example, a procedure similar to the procedure for adding a secondary cell based on carrier aggregation can be used, but the difference from the conventional carrier aggregation procedure is that And the center frequency interval of the additional carrier is not limited to 100 kHz raster (that is, a multiple of 100 kHz).

FIG. 10 is a sequence diagram illustrating an example of a processing procedure performed in the base station apparatus A and the mobile station apparatus B according to the present embodiment. Note that the compatible carrier synchronization processing (for example, processing similar to processing T1 to processing T2 shown in FIG. 6) is completed between the base station apparatus A and the mobile station apparatus B before the processing process starts. Suppose that
The base station apparatus A wirelessly transmits a signal including information on the relative position of the carrier to be added (additional carrier) (relative position information) to the mobile station apparatus B (processing T21). In the present embodiment, as the relative position information of the additional carrier, information specifying the position of the expanded frequency resource where the additional carrier can exist is used.
The mobile station apparatus B that receives this signal and is notified of the relative position information detects and identifies (specifies) the absolute position of the additional carrier (process T22). For example, the mobile station apparatus B identifies the center frequency as the absolute position of the additional carrier.

Here, as a method of notifying the relative position information of the additional carrier, various methods may be used. For example, the following (notification method example 1) to (notification method example 3) are used. Can do.
(Notification method example 1) As a base station apparatus A, the mobile station apparatus B directly notifies the mobile station apparatus B of the value of the offset of the center frequency (the difference between the center frequency of the compatible carrier and the center frequency of the additional carrier). Is used. In this method, for example, a configuration for notifying the numerical value of the frequency offset may be used as the configuration for reporting the offset value of the center frequency, or the frequency offset value may be set in units of RBs or subcarriers. A configuration for notification may be used.

  As (Notification Method Example 2), a method is used in which the base station device A notifies the mobile station device B of the number of RBs from one reference point to another reference point on the frequency. As these reference points, arbitrary points may be used, or only one of the reference points may be used. As an example, the minimum number of RB configurations of LTE is defined as 6 (6RB), and the distance (frequency difference value) between the lower end of 6RB at the center of the compatible carrier and the upper end of 6RB at the center of the additional carrier The base station apparatus A notifies the mobile station apparatus B.

  (Example 3 of the notification method) is as follows. The base station device A sends the mobile station device B the number of RBs of the additional carrier and the upper and lower (high and low) positions of the additional carrier with respect to the compatible carrier (on the lower frequency side than the compatible carrier). A method of notifying information specifying whether it is located or located on a higher frequency side than the compatible carrier is used. When the compatible carrier and the additional carrier are arranged completely continuously, the mobile station device B can specify the center frequency of the additional carrier only by notifying the base station device A of these pieces of information.

  Further, in the above (Notification method example 1) to (Notification method example 3), as in the process of “(3) Invalid RB notification” in FIG. When the base station apparatus A introduces signaling that designates the RB that becomes invalid in the resource to the mobile station apparatus B, it is not necessary that the compatible carrier and the additional carrier are continuous, and a blank RB is introduced between the compatible carrier and the additional carrier. Is possible.

FIG. 11 is a diagram for explaining an example of processing for notifying the configuration of the frequency resource from the base station apparatus A to the mobile station apparatus B according to the present embodiment. The horizontal axis of the graph in FIG. 11 represents the frequency.
In the example of FIG. 11, a plurality of blocks 901 to 903 and 911 to 913 having different frequencies (frequency bands) are shown in correspondence with the configuration of the frequency resource shown in FIG. 9.

In the example of FIG. 11, the frequency band of the compatible carrier is higher than the frequency band of the additional carrier.
In the example of FIG. 11, three block portions 901 to 903 from the lowest frequency are shown in the frequency band of the compatible carrier. As an example, the block portion 901 is composed of 9 RBs, the block portion 902 is composed of 6 RBs, and the block portion 903 is composed of 9 RBs.
In the example of FIG. 11, three block portions 911 to 913 are shown in the frequency band of the additional carrier from the lowest frequency. As an example, the block portion 911 is composed of 9 RBs, the block portion 912 is composed of 6 RBs, and the block portion 913 is composed of 9 RBs.

As shown in the processes (1) to (2) in FIG. 11, in the present embodiment, the base station apparatus A notifies the mobile station apparatus B of the frequency resource configuration.
As processing (1) in FIG. 11, the base station apparatus A notifies the mobile station apparatus B of the number of frequency resource blocks (RBs) regarding compatible carriers (for example, notification).
As process (2) in FIG. 11, the base station apparatus A notifies the mobile station apparatus B of a signal for specifying the position of the additional carrier. Thereby, the mobile station apparatus B can detect (discover) the synchronization signal.
Further, in the process (2) in FIG. 11, for example, the above (Notification Method Example 1) to (Notification Method Example 3) can be used.

Here, the example of FIG. 11 shows the case where the frequency band width (number of RBs) of the compatible carrier and the frequency band width (number of RBs) of the additional carrier are the same. A configuration in which the widths of these frequency bands (number of RBs) are different may be used.
Furthermore, an invalid RB may be provided and notified from the base station apparatus A to the mobile station apparatus B.

Next, the process shown in FIG. 10 will be described.
After the completion of the above-described (Process T22), the mobile station apparatus B can perform a measurement process such as an additional carrier received power measurement.
The base station apparatus A wirelessly transmits a measurement instruction signal for an additional carrier to the mobile station apparatus B (process T23). Receiving this signal, the mobile station apparatus B performs the measurement process of the additional carrier (process T24).

When the mobile station apparatus B satisfies a predetermined condition (condition for reporting the result of the measurement) as the measurement process of the additional carrier, the mobile station apparatus B transmits a signal (measurement report signal) including the measurement result to the base station apparatus A. Wirelessly transmitted (process T25).
Based on the content of such a measurement report, the base station apparatus A wirelessly transmits a signal instructing to attach (attach) an additional carrier to the mobile station apparatus B by carrier aggregation (see FIG. 2). Process T26).
Thereby, an additional carrier is provided (attached) to the mobile station apparatus B, and the mobile station apparatus B can use the additional carrier (process T27).
Note that the process (process T23 to process T25) related to the measurement for instructing the addition (attachment) of the additional carrier is not necessarily required, and these processes (process T23 to process T25) may be omitted.

  Note that, for the center frequency of the additional carrier specified here, the mobile station apparatus A measures the power (reception power / interference power) of the adjacent cell. Specifically, as a signal to be used, for example, a synchronization signal (PSS / SSS) defined in LTE Release 8 or a signal (DS: (Discovery Signal) may be added.

The purpose of introducing the DS is to use it as a complementary application when the power measurement accuracy of neighboring cells in CRS is insufficient. Specifically, when the frequency of CRS transmission in NCT is reduced for the purpose of reducing overhead, the accuracy of power measurement may not be sufficient. If CRS included in all bandwidths (that is, areas 911, 912, and 913 in FIG. 11) is used when mobile station apparatus B detects an additional carrier, the minimum bandwidth of LTE including PSS and SSS is used. It is considered that the power measurement accuracy can be improved as compared with the case where only 6RB (that is, 912 in FIG. 11) is used. However, the power consumption due to the processing for detecting the bandwidth and the complexity of the processing circuit are problems. Become. For this reason, transmitting a signal (DS) of a predetermined pattern by concentrating on a certain limited RB and time (subframe) not only improves power measurement accuracy but also improves consumption and simplifies the processing circuit. It is effective for conversion. Here, the determined pattern means that the RB, subcarrier, subframe, OFDM symbol, and modulation pattern (amplitude / phase) in which DS is transmitted are uniquely determined by broadcast information such as a physical cell ID. Point to.
Specifically, the DS is in a subframe in which PSS / SSS is arranged, and may exist only in an RB in which PSS / SSS is arranged. The DS may exist in all subframes in which the PSS / SSS is arranged, or, for example, the DS is transmitted in one subframe every M (M is an integer of 2 or more). It is also possible to reduce DS overhead. This M may be a fixed value, or may be notified from the mobile station apparatus B to the base station apparatus A as a parameter. Thereby, it is possible to set an optimal DS transmission cycle according to the station placement scenario, and it is possible to optimize overhead.

FIG. 12 is a diagram illustrating an example of the arrangement of PSS, SSS, and DS in the frequency resources of additional carriers according to the present embodiment.
FIG. 12 shows RB 1011 (only one is labeled in FIG. 12) constituting subframe 0/5 for the 6 RBs at the center of the additional carrier, and the arrangement of PSS, SSS, and DS An example is shown.

As described above, in the communication system according to the present embodiment, the existing carrier common to all the mobile station devices 21-1 to 21-n and 31-1 to 31-m and a specific mobile station device (additional segment) Base station apparatuses 1-1 to 1-2 that wirelessly transmit downlink signals using additional segments (additional carriers) that can be used and are added to existing carriers; Mobile station apparatuses 21-1 to 21-n and 31-1 to 31-m that wirelessly receive downlink signals.
In the communication system according to the present embodiment, information (additional segment information) indicating the position of a frequency resource (extended frequency resource) in which an additional segment may exist is transmitted to the base station apparatuses 1-1 to 1-2. To the mobile station devices 21-1 to 21-n and 31-1 to 31-m. Also, for example, in the area indicated by the additional segment information, the area is subdivided into two or more blocks, and downlink transmission is valid or downlink transmission is invalid in each block. Information identifying whether or not there is (valid / invalid identification information) is transmitted from the base station apparatuses 1-1 to 1-2 to the mobile station apparatuses 21-1 to 21-n and 31-1 to 31-m.

  Therefore, according to the communication system according to the present embodiment, the allocated frequency spectrum can be used effectively, and a new spectrum (additional spectrum) can be used in a flexible manner. Thus, according to the communication system according to the present embodiment, the frequency spectrum can be used effectively.

  As a specific example, in the communication system according to the present embodiment, there is a limit to the frequency bandwidth supported by the old type mobile station device, and the frequency bandwidth supported by the new type mobile station device is wider. However, it is possible to flexibly add a new spectrum (new frequency band) and realize communication while ensuring communication connectivity of an old type mobile station apparatus. In the communication system according to the present embodiment, for example, an expanded frequency resource of any size can be added above and below (high or low) an existing carrier (compatible carrier), and it is invalid using information such as a bitmap. It is also possible to deal with a discontinuous spectrum by notifying the region portion. Further, in the communication system according to the present embodiment, for example, for the existing carrier (compatible carrier) only, consecutive numbers are assigned in order from the low frequency region to the high frequency region (or in reverse order), or It is possible to assign consecutive numbers in order from the low frequency region to the high frequency region (or vice versa) for the existing carrier (compatible carrier) and the entire additional carrier (including the invalid region part). is there.

[Configuration example of the above embodiment]
As one configuration example, a wireless communication unit (in the above embodiment, the wireless communication unit 122) that communicates wirelessly using an existing carrier and an additional carrier, and a lower frequency side or a higher frequency side than the existing carrier Information identifying a frequency resource area in which one or both of the additional carriers may be present is transmitted to the terminal device (in the above embodiments, the mobile station devices 21-1 to 21) by the wireless communication unit. -N, 31-1 to 31-m), a carrier information transmission control unit (in the above embodiment, carrier information transmission control unit 301) that transmits wirelessly, In the embodiment, the base station apparatuses 1-1 to 1-2).
In addition, as a terminal device, apparatuses other than a mobile station apparatus may be used, for example.

  As an example of the configuration, in such a base station apparatus, the carrier information transmission control unit further includes information for specifying an invalid area portion among frequency resource areas in which the additional carrier may exist. The wireless communication unit wirelessly transmits to the terminal device.

As one configuration example, a wireless communication unit (in the above embodiment, the wireless communication unit 102) that communicates wirelessly using an existing carrier and an additional carrier, and a lower frequency side or a higher frequency side than the existing carrier Information specifying a region of a frequency resource in which one or both of the additional carriers may be present is transmitted to the base station device (in the above embodiments, the base station devices 1-1 to 1-1) by the wireless communication unit. 1-2) wirelessly receiving a carrier information reception control unit (in the above embodiment, the carrier information reception control unit 201), and a terminal device (in the above embodiment, the mobile station device 21) -1 to 21-n, 31-1 to 31-m).
In addition, as a terminal device, apparatuses other than a mobile station apparatus may be used, for example.

  As an example of the configuration, in such a terminal device, the carrier information reception control unit further includes information for specifying an invalid area portion among the frequency resource areas in which the additional carrier may exist. The wireless communication unit receives wirelessly from the base station apparatus.

  As one configuration example, a base station apparatus and a terminal apparatus are included, and the base station apparatus has a frequency at which an additional carrier may exist on one or both of a lower frequency side and a higher frequency side than an existing carrier. Information identifying a resource region is wirelessly transmitted to the terminal device, the terminal device wirelessly receives the information from the base station device, and the base station device and the terminal device transmit the existing carrier and the 1 is a communication system (communication system as shown in FIG. 1 in the above embodiments), characterized in that communication is performed wirelessly using an additional carrier.

  As an example of the configuration, the base station apparatus transmits, to the terminal apparatus, information identifying a frequency resource area in which an additional carrier on one or both of the low frequency side and the high frequency side may exist. Transmitting by radio, the terminal device receives the information from the base station device by radio, and the base station device and the terminal device communicate by radio using the existing carrier and the additional carrier, This is a communication method (in the above embodiment, a communication method performed in the communication system as shown in FIG. 1).

[Summary of the above embodiments]
As mentioned above, although embodiment of this invention was explained in full detail with reference to drawings, the concrete structure is not restricted to this embodiment, The design change etc. of the range which does not deviate from the summary of this invention are included.

  Further, a program for realizing the function of each device (for example, a base station device or a mobile station device) according to each embodiment described above is recorded on a computer-readable recording medium and recorded on this recording medium. The processing may be performed by causing the computer system to read and execute the program.

The “computer system” mentioned here may include an operating system (OS) and hardware such as peripheral devices.
The “computer-readable recording medium” means a flexible disk, a magneto-optical disk, a ROM (Read Only Memory), a writable nonvolatile memory such as a flash memory, a portable medium such as a DVD (Digital Versatile Disk), A storage device such as a hard disk built in a computer system.

Further, the “computer-readable recording medium” refers to a volatile memory (for example, DRAM (DRAM)) in a computer system that becomes a server or a client when a program is transmitted via a network such as the Internet or a communication line such as a telephone line. Dynamic Random Access Memory)) that holds a program for a certain period of time is also included.
The program may be transmitted from a computer system storing the program in a storage device or the like to another computer system via a transmission medium or by a transmission wave in the transmission medium. Here, the “transmission medium” for transmitting a program refers to a medium having a function of transmitting information, such as a network (communication network) such as the Internet or a communication line (communication line) such as a telephone line.
Further, the above program may be for realizing a part of the functions described above. Furthermore, what can implement | achieve the function mentioned above in combination with the program already recorded on the computer system, and what is called a difference file (difference program) may be sufficient.

DESCRIPTION OF SYMBOLS 1, 1-1 to 1-2 ... Base station apparatus, 3-1 to 3-3 ... Line | wire, 11-1 to 11-2 ... Cell (communication area), 21, 211-1 to 21-n, 31- 1, 31-m ... mobile station apparatus, 101, 121 ... antenna, 102, 122 ... wireless communication unit, 103 ... input unit, 104 ... output unit, 105, 124 ... storage unit, 106, 125 ... control unit, 123 ... Communication unit 201 ... carrier information reception control unit 301 ... carrier information transmission control unit 401-403, 511-1 to 511-3, 801-802, 2001-2002, 2011, 2021-2022, 2031-2033 ... spectrum 501 ... existing carrier (compatible carrier), 601-1 to 601-15 ... block, 901-903, 911-913 ... block part, 1011 ... resource block (RB)

Claims (6)

A wireless communication unit that communicates wirelessly using an existing carrier and an additional carrier; and
Information specifying a region of a frequency resource in which the additional carrier may exist on one or both of the lower frequency side and the higher frequency side than the existing carrier is wirelessly transmitted to the terminal device by the radio communication unit. A carrier information transmission control unit for transmitting by:
A base station apparatus comprising: The carrier information transmission control unit is further configured to wirelessly transmit information identifying an invalid region portion of the frequency resource region in which the additional carrier may exist to the terminal device by the wireless communication unit. Send,
The base station apparatus according to claim 1. A wireless communication unit that communicates wirelessly using an existing carrier and an additional carrier; and
Information identifying a region of frequency resources in which one or both of the additional carrier on the lower frequency side or the higher frequency side than the existing carrier may exist is transmitted from the base station device by the radio communication unit. A carrier information reception control unit for receiving wirelessly;
A terminal device comprising: The carrier information reception control unit further transmits, from the base station apparatus, information specifying an invalid area portion of the frequency resource area in which the additional carrier may exist from the base station apparatus. Receive by,
The terminal device according to claim 3. A base station device and a terminal device,
The base station apparatus wirelessly transmits to the terminal apparatus information specifying a frequency resource area in which an additional carrier on one or both of the lower frequency side and the higher frequency side than the existing carrier may exist. And
The terminal device receives the information from the base station device by radio,
The base station device and the terminal device communicate by radio using the existing carrier and the additional carrier,
A communication system characterized by the above. The base station device wirelessly transmits to the terminal device information identifying the region of the frequency resource in which an additional carrier on one or both of the low frequency side and the high frequency side may exist.
The terminal device receives the information from the base station device by radio,
The base station device and the terminal device communicate by radio using the existing carrier and the additional carrier,
A communication method characterized by the above.

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