JP2012095184A - Mobile station device, communication system, communication method, and integrated circuit - Google Patents

Abstract

In a communication system including a plurality of mobile station apparatuses and a base station apparatus, transmission of a reference signal for propagation path measurement is controlled, and the base station apparatus flexibly and efficiently measures channel quality for the mobile station apparatus. Makes it possible to do well.
A reception processing unit for performing an uplink grant detection process including a sounding reference signal transmission instruction and first information, and an uplink grant including a sounding reference signal transmission instruction detected by the reception processing unit. In this case, a cell-specific subframe as a subframe for transmitting a sounding reference signal, or a subframe specific to a mobile station device, which is a subframe configured in advance by a base station device among cell-specific subframes, A control unit that is set based on the information; and a transmission processing unit that transmits a sounding reference signal in a subframe set in the control unit.
[Selection] Figure 4

Description

  The present invention controls transmission of a reference signal for propagation path measurement in a communication system including a plurality of mobile station apparatuses and a base station apparatus, and the base station apparatus appropriately measures channel quality for the mobile station apparatus. The present invention relates to a mobile station device, a communication system, a communication method, and an integrated circuit.

  The evolution of cellular mobile radio access methods and networks (hereinafter referred to as “Long Term Evolution (LTE)” or “Evolved Universal Terrestrial Radio Access (EUTRA)”) is the third generation partnership project (3rd Generation Partnership Project: 3GPP). In LTE, an orthogonal frequency division multiplexing (OFDM) system, which is multicarrier transmission, is used as a communication system (downlink; referred to as DL) from a base station apparatus to a mobile station apparatus. . In LTE, a single-carrier transmission SC-FDMA (Single-Carrier Frequency Division Multiple Access) system is used as a communication system (uplink; referred to as UL) from a mobile station apparatus to a base station apparatus. Used. In LTE, a DFT-Spread OFDM (Discrete Fourier Transform-Spread OFDM) system is used as an SC-FDMA system.

  In 3GPP, a radio access method and a radio network (hereinafter referred to as “Long Term Evolution-Advanced (LTE-A)” or “Advanced Evolved Universal Terrestrial Radio Access (A-EUTRA)”) that realize more efficient communication than LTE. Is called). In LTE-A, it is required to realize backward compatibility with LTE. A base station apparatus compatible with LTE-A communicates simultaneously with both mobile station apparatuses compatible with LTE-A and mobile station apparatuses compatible with LTE, and mobile stations compatible with LTE-A It is required for LTE-A to realize that the apparatus communicates with a base station apparatus compatible with LTE-A and a base station apparatus compatible with LTE. In order to realize this requirement, LTE-A is studying to support at least the same channel structure as LTE. A channel means a medium used for signal transmission, and a channel type includes a physical downlink shared channel (PDSCH) used for transmission and reception of downlink data and control information, and a downlink channel. Physical downlink control channel (Physical Downlink Control CHannel: PDCCH) used for transmission and reception of control information, Physical uplink shared channel (Physical Uplink Shared CHannel: PUSCH) used for transmission and reception of uplink data and control information, and uplink Physical uplink control channel (Physical Uplink Control CHannel: PUCCH) used for transmission / reception of control information, Synchronization channel (Synchronization CHannel: SCH) used for establishment of downlink synchronization, Used for establishment of uplink synchronization Physical random access channel (PRACH), downlink Physical broadcast channel used for transmitting the system information click (Physical Broadcast CHannel: PBCH), and the like. A mobile station apparatus or a base station apparatus arranges a signal generated from control information, data, etc. in each channel and transmits it.

  In LTE-A, a sounding reference signal (aperiodic sounding reference signal; A-SRS: Aperiodic Sounding Reference Signal) that is transmitted only when a transmission instruction is notified from the base station apparatus via the PDCCH has been proposed. A-SRS is used for a base station apparatus to measure a propagation path with respect to a mobile station apparatus, and the measurement result is used for frequency scheduling, adaptive modulation, and the like. Information (A-SRS activation / deactivation) related to an A-SRS transmission instruction is included in downlink control information (DCI). The mobile station apparatus determines whether or not the base station apparatus has instructed transmission of A-SRS based on the information related to the transmission instruction of A-SRS included in the detected downlink control information. ) To control transmission of A-SRS. Here, dynamic control means control for each subframe.

  In LTE-A, when a mobile station apparatus detects an A-SRS transmission instruction, a method for transmitting A-SRS using a set of parameters set in advance by the base station apparatus and downlink control information are used. It has been studied to switch and use a method for transmitting A-SRS using a parameter set (Non-Patent Document 1). Information indicating which method is used is included in the downlink control information including information related to the A-SRS transmission instruction.

3GPP TSG RAN1 # 62bis, Xian, China, 11-15, October, 2010, R1-105787 “Way Forward on Aperiodic SRS”

  The base station apparatus needs to set A-SRS resources for each mobile station apparatus so that resources used for each mobile station apparatus do not collide. On the other hand, the base station apparatus transmits an A-SRS to the mobile station apparatus as soon as necessary, and performs appropriate frequency scheduling and adaptive modulation using the propagation path estimation value and channel quality measured from the received A-SRS. It is desirable to execute and start communication with low delay.

  The present invention has been made in view of the above points, and its purpose is to control transmission of a reference signal for propagation path measurement in a communication system including a plurality of mobile station apparatuses and base station apparatuses, The present invention relates to a mobile station apparatus, a communication system, a communication method, and an integrated circuit that can appropriately measure channel quality for the mobile station apparatus.

  (1) In order to achieve the above object, the present invention takes the following measures. That is, the mobile station apparatus of the present invention is a mobile station apparatus that communicates with a base station apparatus, and a reception processing unit that performs an uplink grant detection process including a sounding reference signal transmission instruction and first information, When an uplink grant including a sounding reference signal transmission instruction is detected in the reception processing unit, a cell-specific subframe or a cell-specific subframe is transmitted in advance as a subframe for transmitting the sounding reference signal from the base station apparatus. A control unit that sets a subframe unique to a mobile station device that is a configured subframe based on the first information, a transmission processing unit that transmits a sounding reference signal in the subframe set in the control unit, It is characterized by having.

  Thus, based on the first information included in the uplink together with the information indicating the A-SRS transmission instruction, Cell specific SRS subframe or UE specific SRS subframe is set as the uplink subframe for transmitting A-SRS. Thus, the base station apparatus can dynamically and flexibly control the transmission of A-SRS for each uplink subframe to the mobile station apparatus, and can efficiently measure the uplink channel quality. .

  (2) In the mobile station apparatus of the present invention, the cell-specific subframe includes a subframe not specific to the mobile station apparatus.

  As described above, the cell specific SRS subframe includes the uplink subframe that is not the UE specific SRS subframe or the UE specific SRS subframe, whereby the base station apparatus transmits the cell specific SRS subframe to the cell specific SRS subframe. Control can be performed on the mobile station apparatus, and uplink channel quality can be measured efficiently.

  (3) In the mobile station apparatus of the present invention, the control unit sets subframes after a predetermined number of subframes from the subframe in which the uplink grant is detected as a subframe for transmitting the sounding reference signal. It is characterized by that.

  In this way, uplink subframes subsequent to four uplink subframes from the timing at which an uplink grant including information indicating an A-SRS transmission instruction is detected are used as uplink subframes used for A-SRS transmission. By setting, it is possible to appropriately transmit the A-SRS to the mobile station apparatus in consideration of processing delays related to uplink grant detection processing, SRS transmission setting, and the like.

  (4) In the mobile station apparatus of the present invention, the first information is information indicating whether a parameter used for the sounding reference signal is based on information indicated by an uplink grant, and the control unit includes: When the first information indicates that a parameter used for the sounding reference signal is based on information indicated by the uplink grant, a cell-specific subframe is set as a subframe for transmitting the sounding reference signal, and the first information If one parameter does not indicate that the parameter used for the sounding reference signal is based on the information indicated by the uplink grant, a subframe specific to the mobile station apparatus is set as a subframe for transmitting the sounding reference signal. And

  In this way, an uplink subframe for transmitting A-SRS is set based on information indicating whether or not a parameter used for A-SRS is based on information indicated by an uplink grant, and is used for A-SRS. When it is indicated that the parameter is based on the information indicated by the uplink grant, Cell specific SRS subframe is set as the uplink subframe for transmitting the A-SRS, and the parameter used for the A-SRS is indicated by the uplink grant. The base station apparatus flexibly transmits the A-SRS to the mobile station apparatus by setting the UE specific SRS subframe as an uplink subframe for transmitting the A-SRS. Can be controlled by the uplink It can be efficiently measured channel quality.

  (5) Also, in the mobile station apparatus of the present invention, when the transmission processing unit indicates that the parameter used for the sounding reference signal is based on information indicated by the uplink grant, the transmission processing unit refers to sounding The sounding reference signal is transmitted based on the parameter indicated by the uplink grant including the signal transmission instruction, and the first information does not indicate that the parameter used for the sounding reference signal is based on the information indicated by the uplink grant. In this case, the sounding reference signal is transmitted based on a parameter previously configured by the base station apparatus.

  As described above, when the parameter used for the A-SRS indicates that it is based on the information indicated by the uplink grant, the A-SRS is transmitted using the resource based on the parameter indicated by the uplink grant using the Cell specific SRS subframe. If the parameter used for A-SRS does not indicate that it is based on the information indicated by the uplink grant, UE-specific SRS subframe is used to transmit A-SRS with resources based on the parameters configured in advance by the base station apparatus. The base station apparatus measures the channel quality in a wide frequency band at a high speed according to the resource usage status when there is a margin in resources used for SRS as a result of scheduling for each mobile station apparatus in the cell to be managed. But Kill.

  (6) The communication system according to the present invention is a communication system including a plurality of mobile station apparatuses and a base station apparatus that communicates with the plurality of mobile station apparatuses, and the base station apparatus includes the mobile station A transmission unit that transmits a signal to a device, a reception unit that receives a signal from the mobile station device, and an uplink channel quality measurement unit that measures channel quality from a sounding reference signal received by the reception unit, The mobile station apparatus includes: a reception processing unit that performs an uplink grant detection process including a sounding reference signal transmission instruction and first information; and an uplink including a sounding reference signal transmission instruction in the reception processing unit When grant is detected, cell specific subframe or cell specific subframe as subframe to transmit sounding reference signal A control unit that sets a subframe unique to a mobile station device, which is a subframe configured in advance from a base station device, based on the first information, and a sounding reference signal in the subframe set in the control unit. And a transmission processing unit for transmitting.

  Thus, based on the first information included in the uplink together with the information indicating the A-SRS transmission instruction, Cell specific SRS subframe or UE specific SRS subframe is set as the uplink subframe for transmitting A-SRS. Thus, the base station apparatus can dynamically and flexibly control the transmission of A-SRS for each uplink subframe to the mobile station apparatus, and can efficiently measure the uplink channel quality. .

  (7) Moreover, the communication method of this invention is a communication method used for the mobile station apparatus which communicates with a base station apparatus, Comprising: The detection process of the uplink grant containing the transmission instruction | indication of a sounding reference signal and 1st information is performed. When an uplink grant including an instruction to perform and a sounding reference signal transmission instruction is detected, a cell-specific subframe or a cell-specific subframe is transmitted in advance as a subframe for transmitting a sounding reference signal from the base station apparatus. A step of setting, based on the first information, a subframe unique to a mobile station apparatus, which is a configured subframe, and a step of transmitting a sounding reference signal in the set subframe, To do.

  Thus, based on the first information included in the uplink together with the information indicating the A-SRS transmission instruction, Cell specific SRS subframe or UE specific SRS subframe is set as the uplink subframe for transmitting A-SRS. Thus, the base station apparatus can dynamically and flexibly control the transmission of A-SRS for each uplink subframe to the mobile station apparatus, and can efficiently measure the uplink channel quality. .

  (8) An integrated circuit according to the present invention is an integrated circuit that is mounted on a mobile station device, thereby causing the mobile station device to exhibit a plurality of functions, and has a function of communicating with a base station device and a sounding reference. A function for performing an uplink grant detection process including a signal transmission instruction and first information and a cell-specific subframe for transmitting a sounding reference signal when an uplink grant including a sounding reference signal transmission instruction is detected. A subframe specific to a mobile station, which is a subframe configured in advance from a base station device among subframes specific to a cell, or a subframe specific to a cell, based on the first information, and a set subframe A function of transmitting a sounding reference signal in a frame, and causing the mobile station apparatus to exhibit a series of functions including

  Thus, based on the first information included in the uplink together with the information indicating the A-SRS transmission instruction, Cell specific SRS subframe or UE specific SRS subframe is set as the uplink subframe for transmitting A-SRS. Thus, the base station apparatus can dynamically and flexibly control the transmission of A-SRS for each uplink subframe to the mobile station apparatus, and can efficiently measure the uplink channel quality. .

  According to the present invention, transmission of a reference signal for propagation path measurement is controlled, and the base station apparatus can appropriately measure channel quality for the mobile station apparatus.

It is a schematic block diagram which shows the structure of the base station apparatus 3 which concerns on embodiment of this invention. It is a schematic block diagram which shows the structure of the transmission process part 107 of the base station apparatus 3 which concerns on embodiment of this invention. It is a schematic block diagram which shows the structure of the reception process part 101 of the base station apparatus 3 which concerns on embodiment of this invention. It is a schematic block diagram which shows the structure of the mobile station apparatus 5 which concerns on embodiment of this invention. It is a schematic block diagram which shows the structure of the reception process part 401 of the mobile station apparatus 5 which concerns on embodiment of this invention. It is a schematic block diagram which shows the structure of the transmission process part 407 of the mobile station apparatus 5 which concerns on embodiment of this invention. It is a figure which shows the transmission example of A-SRS of the mobile station apparatus 5 which concerns on embodiment of this invention. It is a flowchart which shows an example of the process regarding the setting of the uplink sub-frame which transmits A-SRS of the control part 405 of the mobile station apparatus 5 which concerns on embodiment of this invention. It is a figure explaining the outline about the whole picture of the communications system concerning the embodiment of the present invention. It is a figure which shows schematic structure of the downlink radio | wireless frame from the base station apparatus 3 which concerns on embodiment of this invention to the mobile station apparatus 5. FIG. It is a figure which shows an example of the information field of DCI format 0A in embodiment of this invention. It is a figure which shows schematic structure of the radio frame of the uplink from the mobile station apparatus 5 which concerns on embodiment of this invention to the base station apparatus 3. FIG. It is a figure which shows the structural example of the frequency bandwidth and frequency position of SRS which concern on embodiment of this invention. It is a figure which shows the structural example of Cell specific SRS subframe which concerns on embodiment of this invention, and UE specific SRS subframe. It is a figure which shows the structural example of the candidate resource of A-SRS previously comprised by UE specific SRS subframe of the mobile station apparatus 5 which concerns on embodiment of this invention. It is a figure which shows the structural example of the candidate resource of A-SRS previously comprised by UE specific SRS subframe of the mobile station apparatus 5 which concerns on embodiment of this invention. It is a figure which shows the structural example of the candidate resource of A-SRS previously comprised by UE specific SRS subframe of the mobile station apparatus 5 which concerns on embodiment of this invention.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. First, an overview of the communication system according to the present embodiment, a configuration of a radio frame, and the like will be described with reference to FIGS. Next, the configuration of the communication system according to the present embodiment will be described with reference to FIGS. Next, operation processing of the communication system according to the present embodiment will be described with reference to FIGS.

<Overview of communication system>
FIG. 9 is a diagram illustrating an outline of the overall image of the communication system according to the embodiment of the present invention. In the communication system 1 shown in this figure, a base station apparatus (also referred to as eNodeB and NodeB) 3 and a plurality of mobile station apparatuses (also referred to as UE: User Equipment) 5A, 5B, and 5C communicate. Hereinafter, in this embodiment, the mobile station devices 5A, 5B, and 5C are referred to as the mobile station device 5 and will be described. Moreover, the area which the base station apparatus 3 has jurisdiction is called a cell. Also, in this figure, the downlink (also referred to as DL: Downlink) which is the communication direction from the base station apparatus 3 to the mobile station apparatus 5 is a downlink pilot channel, a physical downlink control channel (PDCCH: Physical Downlink Control). And a physical downlink shared channel (also referred to as PDSCH: Physical Downlink Shared CHannel). In this figure, the uplink (UL: also referred to as Uplink), which is the communication direction from the mobile station apparatus 5 to the base station apparatus 3, is also referred to as a physical uplink shared channel (PUSCH: PhysicalUplink Shared CHannel). , An uplink pilot channel, and a physical uplink control channel (also referred to as PUCCH: Physical Uplink Control CHannel).

  A channel means a medium used for signal transmission. The PDSCH is a channel used for transmission / reception of downlink data and control information. The PDCCH is a channel used for transmission / reception of downlink control information. The PUSCH is a channel used for transmission / reception of uplink data and control information. The PUCCH is a channel used for transmission / reception of uplink control information (uplink control information: UCI). As the type of UCI, whether to request an acknowledgment (ACK / NACK) indicating an acknowledgment (Acknowledgement: ACK) or a negative acknowledgment (NACK) for PDSCH downlink data, and resource allocation There is a scheduling request (SR) indicating the above. Note that PUSCH is also used for UCI transmission / reception. Other channel types include synchronization channel (Synchronization CHannel: SCH) used for downlink synchronization establishment, physical random access channel (Physical Random Access CHannel: PRACH) used for uplink synchronization establishment, A physical broadcast channel (PBCH) used for transmission of downlink system information is used. The PDSCH is also used for transmission of downlink system information.

  The reference signal used for the uplink pilot channel is referred to as an uplink reference signal (UL RS). Two types of UL RS are used: a sounding reference signal (SRS) and a demodulation reference signal (DeModulation Reference Signal: DM RS). The SRS is used when the base station apparatus 3 estimates propagation path fluctuations with respect to the mobile station apparatus 5 and uses the estimated results for frequency scheduling and adaptive modulation for the PUSCH. The DM RS is used for demodulating the PUSCH and PUCCH received from the mobile station device 5 by the base station device 3. SRS is a periodic sounding reference signal (Periodic SRS: P-SRS) that periodically transmits a reference signal in subframes set in advance by the base station apparatus, and is non-subframe based on a timing when a transmission instruction is notified on PDCCH. Two types of aperiodic sounding reference signals (Aperiodic SRS: A-SRS) that transmit reference signals periodically are used. The present application relates to A-SRS, and for simplification of description, description of DM RS and P-SRS is appropriately omitted in the present embodiment.

<Configuration of downlink radio frame>
FIG. 10 is a diagram illustrating a schematic configuration of a downlink radio frame (referred to as a downlink radio frame) from the base station apparatus 3 to the mobile station apparatus 5 according to the embodiment of the present invention. In this figure, the horizontal axis represents the time domain, and the vertical axis represents the frequency domain. A downlink radio frame is a unit for resource allocation or the like, and is also referred to as a resource block (RB) (physical resource block; PRB: Physical Resource Block) composed of a frequency band and a time slot having a predetermined downlink width. ) Pairs (physical resource block pairs; referred to as PRB pairs). One downlink physical resource block pair (referred to as downlink physical resource block pair) is composed of two physical resource blocks (referred to as downlink physical resource blocks) that are continuous in the downlink time domain. Composed.

  Also, in this figure, one downlink physical resource block is composed of 12 subcarriers (referred to as downlink subcarriers) in the downlink frequency domain, and 7 OFDM (orthogonal) in the time domain. It consists of Orthogonal Frequency Division Multiplexing symbols. A downlink system band (referred to as a downlink system band) is a downlink communication band of the base station apparatus 3. In the downlink system band, a plurality of downlink physical resource blocks are arranged according to the downlink system bandwidth (referred to as downlink system bandwidth). For example, a downlink system band having a frequency bandwidth of 20 MHz is configured by 100 downlink physical resource blocks.

  In the time domain shown in this figure, a slot composed of seven OFDM symbols (referred to as a downlink slot) and a subframe composed of two downlink slots (referred to as a downlink subframe). There is a downlink radio frame composed of 10 downlink subframes. A unit composed of one downlink subcarrier and one OFDM symbol is called a resource element (RE) (downlink resource element). In each downlink subframe, at least a PDSCH used for transmitting information data (also referred to as a transport block) and a PDCCH used for transmitting control information are arranged. In this figure, the PDCCH is composed of the first to third OFDM symbols in the downlink subframe, and the PDSCH is composed of the fourth to fourteenth OFDM symbols in the downlink subframe. Note that the number of OFDM symbols constituting the PDCCH and the number of OFDM symbols constituting the PDSCH may be changed for each downlink subframe.

  Although not shown in this figure, a downlink pilot channel used for transmission of a downlink reference signal (Reference signal: RS) (referred to as downlink reference signal, also referred to as Cell specific RS, DL RS) is provided. Distributed to a plurality of downlink resource elements. Here, the downlink reference signal is a signal known in the communication system 1 that is used for estimating propagation path fluctuations of the PDSCH and PDCCH. Note that the number of downlink resource elements constituting the downlink reference signal depends on the number of transmission antennas used for communication to the mobile station apparatus 5 in the base station apparatus 3.

  PDCCH is information indicating allocation of downlink physical resource blocks to PDSCH, information indicating allocation of uplink physical resource blocks to PUSCH, mobile station identifier (Radio Network Temporary Identifier: RNTI), and information indicating a modulation scheme. , Information indicating coding rate, information indicating retransmission parameter, multi-antenna related information, transmission power control command (TPC command), information indicating A-SRS transmission instruction, parameters used for A-SRS are PDCCH (uplink) A signal generated from control information such as information (first information) indicating whether or not it is based on information indicated by (grant) and information indicating a parameter used for A-SRS is arranged. Control information included in the PDCCH is referred to as downlink control information (Downlink Control Information: DCI). DCI including information indicating assignment of the downlink physical resource block to the PDSCH is referred to as downlink assignment (also referred to as DL assignment or DL grant), and indicates the assignment of the uplink physical resource block to the PUSCH. The DCI including information is called an uplink grant (uplink grant: UL grant). Note that the downlink assignment includes a transmission power control command for PUCCH. The uplink assignment includes a transmission power control command for PUSCH. Note that the information indicating parameters used for A-SRS that may be included in the uplink grant indicates parameters such as the frequency bandwidth and frequency position of the A-SRS resource, and the time of the A-SRS resource. It is not information that clearly indicates a timing parameter (uplink subframe).

  The DCI uses a plurality of types of information formats (DCI format). Different DCI formats are composed of combinations of different information and may be composed of different numbers of bits. For example, different types of DCI format are used for DCI format including information indicating resource allocation to PUSCH for single antenna transmission and DCI format including information indicating resource allocation to PUSCH for multi-antenna transmission. The DCI format including information indicating resource allocation to the PUSCH for single antenna transmission is referred to as DCI format 0. DCI format 0 includes information indicating uplink physical resource block allocation, information indicating a modulation scheme, information indicating a coding rate, information indicating a retransmission parameter, a transmission power control command, and the like. The mobile station apparatus 5 is notified from the base station apparatus 3 whether or not information indicating an A-SRS transmission instruction is included in the DCI format. DCI format including information indicating the allocation of resources to PUSCH for single antenna transmission including information indicating an A-SRS transmission instruction is referred to as DCI format 0A.

  FIG. 11 is a diagram showing an example of an information field of DCI format 0A in the embodiment of the present invention. DCI format 0A is information indicating uplink physical resource block allocation, information indicating modulation scheme, information indicating coding rate, information indicating retransmission parameter, transmission power control command, information indicating transmission instruction of A-SRS, It includes information indicating whether a parameter used for A-SRS is based on information indicated by PDCCH, information indicating an A-SRS parameter, or the like. Information shown in each information field in FIG. 11 will be described. In the information field of A-SRS activation / deactivation, information indicating an A-SRS transmission instruction is indicated. In the information field of A-SRS dynamic parameter indicator or Resource block assignment, information indicating whether a parameter used for A-SRS is based on information indicated by PDCCH (A-SRS dynamic parameter indicator) (first information of A-SRS dynamic parameter indicator) Or information (Resource block assignment) indicating allocation of uplink physical resource blocks. In the information field of A-SRS frequency position or modulation and coding scheme and redundancy version, information (A-SRS frequency position) indicating A-SRS parameters (frequency position), or information indicating a coding scheme. Information (Modulation and coding scheme and redundancy version) indicating information and retransmission parameters (redundancy version) is shown. In the information field of A-SRS Bandwidth or TPC command for PUSCH, information (A-SRS Bandwidth) indicating a parameter (frequency bandwidth) of A-SRS or a transmission power control command (TPC command for PUSCH) is indicated. In the Other information field, other information (for example, frequency hopping flag for PUSCH, identification information of uplink grant and downlink assignment, information indicating whether data included in PUSCH is new transmission or retransmission, DM RS is used. Information relating to the codes to be transmitted, mobile station identifiers).

  The information indicating the A-SRS transmission instruction indicates whether to instruct the A-SRS transmission. Information indicating whether or not a parameter used for A-SRS is based on information indicated by PDCCH is indicated by DCI format 0A using a value (Codepoint) indicating other information by DCI format 0. For example, the codepoint of information indicating the allocation of uplink physical resource blocks (for example, the bit sequence of information indicating the allocation of uplink physical resource blocks all indicates a value of “1”) is a parameter used for A-SRS as PDCCH It is used to indicate that it is based on the information indicated by. Information indicating A-SRS parameters is indicated by DCI format 0A using an information field used to indicate other information. Here, the fact that the information field is diverted means that if the information field is the first, it is interpreted as the first control information, the second case is interpreted as the second control information, In the second case, the first control information and the second control information are different. For example, the information field of the transmission power control command is used to indicate the transmission bandwidth of A-SRS, and the information indicating the modulation scheme and the information indicating the coding rate are used to indicate the frequency position of A-SRS.

  When the information indicating the A-SRS transmission instruction does not indicate that the A-SRS transmission is instructed, the other information fields of the DCI format 0A include uplink physical resource block allocation, modulation scheme, coding rate, and retransmission parameter. , A transmission power control command, etc., and whether or not a parameter used for A-SRS is based on information indicated by PDCCH, and does not indicate an A-SRS parameter. That is, when the information indicating the A-SRS transmission instruction does not indicate that the A-SRS transmission is instructed, the information field of the A-SRS dynamic parameter indicator or Resource block assignment illustrated in FIG. 11 is an uplink physical resource block. Only the information indicating the allocation of. When the information indicating the transmission instruction of A-SRS indicates that the transmission of A-SRS is instructed, the predetermined information field of DCI format 0A is the allocation of the uplink physical resource block, or the parameter used for A-SRS is PDCCH Indicates that it is based on the information indicated by. Here, when the predetermined information field indicates uplink physical resource block allocation, the other information fields of DCI format 0A indicate modulation scheme, coding rate, retransmission parameter, transmission power control command, etc. Does not indicate a parameter. Note that the fact that the predetermined information field indicates the allocation of the uplink physical resource block implicitly indicates that the parameter used for A-SRS is not based on the information indicated by PDCCH. Here, when a predetermined information field indicates that a parameter used for A-SRS is based on information indicated by PDCCH, the other information field of DCI format 0A indicates a parameter of A-SRS, and a modulation scheme, encoding The rate, retransmission parameter, transmission power control command, etc. are not shown. Note that the fact that the predetermined information field indicates that the parameter used for A-SRS is based on the information indicated by PDCCH implies that no uplink physical resource block is allocated.

  The base station apparatus 3 uses the DCI format 0A in order to roughly indicate three things to the mobile station apparatus 5 by setting the value of each information field of the DCI format 0A as described above. The first is used only to indicate PUSCH resource allocation and not to indicate transmission of A-SRS. The second is used to indicate that transmission of A-SRS based on a parameter indicated by the uplink grant is instructed without indicating PUSCH resource allocation. The third is the allocation of PUSCH resources, and indicates the transmission of A-SRS based on the parameters set in advance by RRC (Radio Resource Control) signaling, not based on the parameters indicated by the uplink grant. Used to indicate

<Configuration of uplink radio frame>
FIG. 12 is a diagram showing a schematic configuration of an uplink radio frame (referred to as an uplink radio frame) from the mobile station apparatus 5 to the base station apparatus 3 according to the embodiment of the present invention. In this figure, the horizontal axis represents the time domain, and the vertical axis represents the frequency domain. An uplink radio frame is a unit for resource allocation or the like, and is composed of a pair of physical resource blocks (referred to as an uplink physical resource block pair) consisting of a frequency band and a time band having a predetermined width in the uplink. Is done. One uplink physical resource block pair is composed of two uplink physical resource blocks (referred to as uplink physical resource blocks) that are continuous in the uplink time domain.

  Also, in this figure, one uplink physical resource block is composed of 12 subcarriers (referred to as uplink subcarriers) in the uplink frequency domain, and 7 SC-FDMAs in the time domain. (Single-Carrier Frequency Division Multiple Access) symbols. An uplink system band (referred to as an uplink system band) is an uplink communication band of the base station apparatus 3. In the uplink system band, a plurality of uplink physical resource blocks are arranged in accordance with the uplink system bandwidth (referred to as uplink system bandwidth). For example, an uplink system band having a frequency bandwidth of 20 MHz is configured by 100 uplink physical resource blocks.

  In the time domain shown in this figure, a slot composed of seven SC-FDMA symbols (referred to as an uplink slot) and a subframe composed of two uplink slots (uplink subframe). There is an uplink radio frame composed of 10 uplink subframes. A unit composed of one uplink subcarrier and one SC-FDMA symbol is referred to as a resource element (referred to as an uplink resource element).

  In each uplink subframe, at least a PUSCH used for transmission of information data and a PUCCH used for transmission of uplink control information (UCI) are arranged. The PUCCH is a UCI (ACK / NACK) indicating an acknowledgment (ACK: Acknowledgement) or a negative acknowledgment (NACK: Negative Acknowledgement) for data received using the PDSCH, and whether or not to request allocation of uplink resources. It is used to transmit at least UCI (SR: Scheduling Request) and UCI (CQI: Channel Quality Indicator) indicating downlink reception quality (also referred to as channel quality).

  Also, PUCCH uses different types of signal configurations depending on whether a UCI consisting of ACK / NACK is transmitted, a UCI consisting of SR, and a UCI consisting of CQI are transmitted. PUCCH used for transmission of ACK / NACK is called PUCCH format 1a or PUCCH format 1b. In PUCCH format 1a, BPSK (Binary Phase Shift Keying) is used as a modulation method for modulating information about ACK / NACK. In PUCCH format 1a, 1-bit information is explicitly indicated from the modulated signal. In PUCCH format 1b, QPSK (Quadrature Phase Shift Keying) is used as a modulation method for modulating information about ACK / NACK. In PUCCH format 1b, 2-bit information is explicitly indicated from the modulated signal. The PUCCH used for SR transmission is referred to as PUCCH format 1. The PUCCH used for CQI transmission is referred to as PUCCH format 2. PUCCH used for simultaneous transmission of CQI and ACK / NACK is referred to as PUCCH format 2a or PUCCH format 2b. In PUCCH format 2b, the DM RS of the uplink pilot channel is multiplied by a modulation signal generated from ACK / NACK information. In PUCCH format 2a, 1-bit information about ACK / NACK and CQI information are transmitted. In PUCCH format 2b, 2-bit information related to ACK / NACK and CQI information are transmitted.

  Note that one PUSCH is composed of one or more uplink physical resource block pairs, and one PUCCH is symmetrical in the frequency domain and consists of two uplink physical resource blocks located in different uplink slots. Composed. For example, in FIG. 12, the uplink physical resource block having the lowest frequency in the first uplink slot in the uplink subframe and the uplink physical having the highest frequency in the second uplink slot in the uplink subframe. A resource block constitutes one of the uplink physical resource block pairs used for the PUCCH. Note that the second and third uplink physical resource blocks from the end of the uplink system band may be used for PUCCH.

  The DM RS of the uplink pilot channel is arranged in different SC-FDMA symbols depending on whether it is arranged in the same uplink physical resource block as PUSCH or in the same uplink physical resource block as PUCCH. . When the DM RS is arranged in the same uplink physical resource block as the PUSCH, the DM RS is arranged in the fourth SC-FDMA symbol in the uplink slot. When the DM RS is arranged in the same uplink physical resource block as the PUCCH including ACK / NACK, the DM RS is arranged in the third, fourth, and fifth SC-FDMA symbols in the uplink slot. When the DM RS is arranged in the same uplink physical resource block as the PUCCH including the SR, the DM RS is arranged in the third, fourth, and fifth SC-FDMA symbols in the uplink slot. When the DM RS is arranged in the same uplink physical resource block as the PUCCH including the CQI, the DM RS is arranged in the second and sixth SC-FDMA symbols in the uplink slot.

  The SRS of the uplink pilot channel is arranged in the frequency band determined by the base station apparatus 3, and the 14th SC-FDMA symbol in the uplink subframe (the seventh uplink slot of the second uplink slot of the uplink subframe). (SC-FDMA symbol). The frequency band in which the SRS is set is indicated from the frequency bandwidth and the frequency position, and the base station device 3 notifies the mobile station device 5 of information indicating the frequency bandwidth and frequency position of the SRS by RRC signaling. The SRS is arranged in an uplink subframe (Cell specific SRS subframe) having a cycle determined by the base station apparatus 3 in the cell. Information indicating which uplink subframe is set in the Cell specific SRS subframe is notified from the base station apparatus 3 to the mobile station apparatus 5 using the system information. Information indicating which uplink subframe is set in Cell specific SRS subframe is configured by information on the period, start position, and the like of the uplink subframe.

  The P-SRS is arranged in any uplink subframe of Cell specific SRS subframe with respect to the mobile station apparatus 5. The base station apparatus 3 notifies the mobile station apparatus 5 of a periodic resource or one resource as a P-SRS resource using RRC signaling. For example, the mobile station apparatus 5 to which a periodic resource is allocated as a P-SRS resource transmits the P-SRS using a periodic Cell specific SRS subframe.

  A-SRS is arrange | positioned with respect to the mobile station apparatus 5 in either uplink sub-frame of Cell specific SRS subframe. When detecting the uplink grant including the A-SRS transmission instruction, the mobile station apparatus 5 transmits the A-SRS in any uplink subframe of the Cell specific SRS subframe. In addition, when detecting the uplink grant including the A-SRS transmission instruction, the mobile station device 5 sets the Cell specific SRS subframe for transmitting the A-SRS based on the first information included in the uplink grant. To do. When the first information indicates that the parameter used for A-SRS is based on the information indicated by the uplink grant, the mobile station device 5 sets Cell specific SRS subframe as an uplink subframe for transmitting A-SRS. Set. Specifically, when the first information indicates that the parameter used for A-SRS is based on the information indicated by the uplink grant, the mobile station device 5 includes four from the subframe in which the uplink grant is detected. The first Cell specific SRS subframe after the subframe is set in the uplink subframe that transmits the A-SRS. When the mobile station apparatus 5 does not indicate that the parameter used for the A-SRS is based on the information indicated by the uplink grant, the mobile station device 5 uses the Cell specific SRS as an uplink subframe for transmitting the A-SRS. In the subframe, an uplink subframe (UE specific SRS subframe) configured in advance in the own device is set. Specifically, when the first information does not indicate that the parameter used for the A-SRS is based on the information indicated by the uplink grant, the mobile station device 5 starts from the subframe in which the uplink grant is detected. The first UE specific SRS subframe after the number of subframes is set to the uplink subframe that transmits the A-SRS. More specifically, when the first information indicates that the parameter used for the A-SRS is based on the information indicated by the uplink grant, the mobile station device 5 performs the Cell regardless of whether the UE specific SRS subframe or not. In some cases, the specific SRS subframe is set as an uplink subframe for transmitting an A-SRS, and the A-SRS is transmitted using a Cell specific SRS subframe that is not a UE specific SRS subframe.

  The UE specific SRS subframe for A-SRS is configured in the mobile station device 5 in advance. Information indicating which Cell specific SRS subframe is set in the UE specific SRS subframe is notified from the base station apparatus 3 to the mobile station apparatus 5 using RRC signaling. Information indicating which Cell specific SRS subframe is set in the UE specific SRS subframe includes information on the period of the uplink subframe in the Cell specific SRS subframe, the start position, and the like. In addition, the mobile station device 5 is configured from the base station device 3 in advance with UE specific SRS subframe when the first information does not indicate that the parameter used for A-SRS is based on the information indicated by the uplink grant. A-SRS is transmitted using parameters such as frequency bandwidth and frequency position. When the first information does not indicate that the parameter used for A-SRS is based on the information indicated by the uplink grant, parameters such as the frequency bandwidth and frequency position of A-SRS used for mobile station apparatus 5 are as follows: The base station apparatus 3 notifies the mobile station apparatus 5 in advance using RRC signaling. In other words, parameters of candidate resources that may be used for A-SRS are notified in advance from the base station apparatus 3 to the mobile station apparatus 5 using RRC signaling. Note that the same or overlapping parameters may be configured in a plurality of mobile station apparatuses 5 with respect to parameters of candidate resources that may be used for A-SRS, and the base station apparatus 3 may be any of the mobile station apparatuses 5. Only the mobile station apparatus 5 can indicate an A-SRS transmission instruction using an uplink grant, thereby preventing an A-SRS collision. In other words, the base station apparatus 3 may set a common resource for the A-SRS candidate resources for the plurality of mobile station apparatuses 5, but only a single resource is actually transmitted for the A-SRS. Is set only for the mobile station apparatus 5. From the above, the UE specific SRS subframe is a Cell specific SRS subframe that may be commonly allocated to some mobile station apparatuses 5, and further, A-SRS candidate resources are assigned to the mobile station apparatus 5. Is not an uplink subframe configured only for a certain mobile station apparatus 5.

  Also, code multiplexing is used for SRS. The plurality of mobile station apparatuses 5 that transmit SRSs at the same frequency position transmit SRSs using different code resources. For the sake of simplification of description, description of processing related to notification of SRS code resource parameters and the like is omitted.

  In PUCCH, code multiplexing in the frequency domain and code multiplexing in the time domain are used. Code multiplexing in the frequency domain is processed by multiplying each code of the code sequence by a modulated signal modulated from uplink control information in subcarrier units. Code multiplexing in the time domain is processed by multiplying each code of the code sequence by a modulated signal modulated from UCI in units of SC-FDMA symbols. A plurality of PUCCHs are arranged in the same uplink physical resource block, different code sequences are assigned to each PUCCH, and code multiplexing is realized in the frequency domain or the time domain by the assigned code sequences. In PUCCH (PUCCH format 1a, PUCCH format 1b) used for transmitting ACK / NACK, code multiplexing in the frequency domain and the time domain is used. In PUCCH (PUCCH format 1) used for transmitting SR, code multiplexing in the frequency domain and the time domain is used. In PUCCH (PUCCH format 2) used for transmitting CQI, code multiplexing in the frequency domain is used. For simplification of description, description of the contents related to PUCCH code multiplexing is omitted as appropriate.

  In the time domain, the PDSCH resource is arranged in the same downlink subframe as the downlink subframe in which the PDCCH resource including the downlink assignment used for the allocation of the PDSCH resource is arranged. The PUSCH resources are four uplink subframes from the uplink subframe corresponding to the downlink subframe in which the PDCCH resource including the downlink assignment used for allocation of the PUSCH resource is arranged in the time domain. It is arranged in a subsequent uplink subframe.

<Configuration of frequency bandwidth and frequency position of SRS>
FIG. 13 is a diagram illustrating a configuration example of the frequency bandwidth and frequency position of the SRS according to the embodiment of the present invention. A plurality of frequency bandwidths and frequency positions are configured for the SRS used in each cell, and any one of the frequency bandwidths and frequency positions is set for the mobile station apparatus 5. FIG. 13 shows a case where four types of frequency bandwidths (frequency bandwidth A, frequency bandwidth B, frequency bandwidth C, and frequency bandwidth D) are configured. The frequency bandwidth A is equal to the maximum frequency bandwidth of the SRS used in the cell. The frequency bandwidth B is equal to the frequency bandwidth obtained by dividing the maximum frequency bandwidth of the SRS used in the cell into two. The frequency bandwidth C is equal to the frequency bandwidth obtained by dividing the maximum frequency bandwidth of the SRS used in the cell into four. The frequency bandwidth D is equal to the frequency bandwidth obtained by dividing the maximum frequency bandwidth of the SRS used in the cell into eight. The frequency position of the SRS having the frequency bandwidth A is one type (frequency position A-1). There are two types of frequency positions of the SRS with the frequency bandwidth B (frequency position B-1 and frequency position B-2). There are four types of frequency positions of the SRS having the frequency bandwidth C (frequency position C-1, frequency position C-2, frequency position C-3, and frequency position C-4). There are 8 types of frequency positions of SRS of frequency bandwidth D (frequency position D-1, frequency position D-2, frequency position D-3, frequency position D-4, frequency position D-5, frequency position D-6, frequency Position D-7, frequency position D-8). As shown in FIG. 13, the relationship between each frequency bandwidth of SRS and each frequency position is a tree based structure. When frequency hopping is applied, SRSs having different frequency positions for each uplink subframe are set in the mobile station apparatus 5. In the mobile station apparatus 5, SRSs having the same configuration are used for P-SRS and A-SRS, but parameters of different frequency bandwidths and frequency positions may be set for P-SRS and A-SRS.

<Configuration of Cell specific SRS subframe and UE specific SRS subframe>
FIG. 14 is a diagram illustrating a configuration example of a Cell specific SRS subframe and a UE specific SRS subframe according to the embodiment of the present invention. In FIG. 14, Cell specific SRS subframe is configured for every two uplink subframes, and is configured from the first uplink subframe (uplink subframe # 1, uplink subframe # 3, uplink subframe # 5, uplink subframe # 7, uplink subframe # 9, uplink subframe # 11). FIG. 14 shows a case where the UE specific SRS subframe is configured for every two Cell specific SRS subframes and includes the first uplink subframe (uplink subframe # 1, uplink subframe # 5, uplink subframe # 9). Note that the configuration example illustrated in FIG. 14 is an example, and the present invention can be applied even when Cell specific SRS subframe and UE specific SRS subframe having different configurations are configured.

<A-SRS Candidate Resources Configured in UE Specific SRS Subframe>
FIG. 15 is a diagram illustrating a configuration example of A-SRS candidate resources configured in advance in the UE specific SRS subframe of the mobile station apparatus 5 according to the embodiment of the present invention. The configuration of the UE specific SRS subframe will be described using the configuration example shown in FIG. FIG. 15 shows that frequency bandwidth and frequency position parameters over the entire system band are set for the mobile station apparatus 5 as A-SRS candidate resources. Although FIG. 15 shows the case where the frequency bandwidth set as the A-SRS resource candidate is equal to the system bandwidth, it may not be equal to the system bandwidth. FIG. 15 illustrates a case where the maximum value of the frequency bandwidth that can be set as the A-SRS resource candidate is set in the mobile station apparatus 5, and the A-SRS resource candidate in a certain cell. The maximum frequency bandwidth that can be set may be smaller than the system bandwidth.

  FIG. 16 is a diagram illustrating a configuration example of A-SRS candidate resources configured in advance in the UE specific SRS subframe of the mobile station apparatus 5 according to the embodiment of the present invention. The configuration of the UE specific SRS subframe will be described using the configuration example shown in FIG. FIG. 16 shows that a part of the frequency bandwidth and frequency position parameters of the system band are set for the mobile station apparatus 5 as A-SRS candidate resources. In other words, it indicates that a part of the frequency bandwidth and frequency position parameters that can be set as A-SRS resource candidates in a certain cell are set for the mobile station apparatus 5. Although FIG. 16 shows the case where the frequency position set as the A-SRS resource candidate is set at the end of the system band, it may be set at a different frequency position.

  FIG. 17 is a diagram illustrating a configuration example of A-SRS candidate resources configured in advance in the UE specific SRS subframe of the mobile station apparatus 5 according to the embodiment of the present invention. The configuration of the UE specific SRS subframe will be described using the configuration example shown in FIG. FIG. 17 shows that a part of the frequency bandwidth parameter of the system band is set for the mobile station apparatus 5 as an A-SRS candidate resource. FIG. 17 shows a case where frequency hopping is applied to frequency positions set as A-SRS resource candidates. That is, A-SRS candidate resources at different frequency positions are set for each uplink subframe in the UE specific SRS subframe. In addition, when A-SRS candidate resources are set by applying frequency hopping, the frequency position is determined based on a predetermined frequency hopping pattern.

<Overall configuration of base station apparatus 3>
Hereinafter, the configuration of the base station apparatus 3 according to the present embodiment will be described with reference to FIGS. 1, 2, and 3. FIG. 1 is a schematic block diagram showing the configuration of the base station apparatus 3 according to the embodiment of the present invention. As shown in the figure, the base station apparatus 3 includes a reception processing unit (reception unit) 101, a radio resource control unit 103, a control unit 105, and a transmission processing unit (transmission unit) 107.

  The reception processing unit 101 demodulates and decodes received signals of PUCCH and PUSCH received from the mobile station apparatus 5 by the reception antenna 109 from the mobile station apparatus 5 using the DM RS according to an instruction from the control unit 105, and obtains control information and information data. Extract. Further, the reception processing unit 101 estimates an uplink propagation path using the SRS received from the mobile station apparatus 5 and measures channel quality. The reception processing unit 101 performs a process of extracting UCI and a process of measuring channel quality for uplink subframes and frequency resources in which the own apparatus assigns PUCCH and SRS resources to the mobile station apparatus 5. The reception processing unit 101 is instructed from the control unit 105 what processing is to be performed on which uplink subframe and which frequency resource. The reception processing unit 101 outputs the extracted UCI, the estimated propagation path estimation value, and the measured channel quality to the control unit 105, and outputs information data to the upper layer. Details of the reception processing unit 101 will be described later.

  The radio resource control unit 103 allocates SRS resources of each mobile station device 5 (Cell specific SRS subframe period, start position, UE specific SRS subframe period, start position, parameters of A-SRS candidate resources, P- SRS resource parameters), PDCCH resource allocation, PUCCH resource allocation, downlink physical resource block allocation to PDSCH, uplink physical resource block allocation to PUSCH, modulation scheme / coding rate / transmission of various channels Set the power control value. Radio resource control section 103 also sets a frequency domain code sequence, a time domain code sequence, and the like for PUCCH. Further, the radio resource control unit 103 outputs information indicating allocation of the set SRS resource to the control unit 105. A part of the information set by the radio resource control unit 103 is notified to the mobile station device 5 via the transmission processing unit 107, and for example, information indicating the allocation of SRS resources is notified to the mobile station device 5.

  Based on the uplink channel quality input through the control unit 105, the radio resource control unit 103 performs PUSCH resource allocation, transmission power value setting, and the like. For example, the radio resource control unit 103 allocates PUSCH resources to uplink physical resource blocks with good channel quality to the mobile station device 5 and transmits based on the channel quality so that the received signal can realize a predetermined error rate. Set the power value. Also, the radio resource control unit 103 sets PDSCH radio resource allocation and the like based on the UCI acquired by the reception processing unit 101 using the PUCCH and input via the control unit 105. For example, when an ACK / NACK acquired using PUCCH is input, the radio resource control unit 103 allocates PDSCH resources in which NACK is indicated by ACK / NACK to the mobile station apparatus 5.

  The radio resource control unit 103 outputs various control signals to the control unit 105. For example, the control signal includes SRS resource allocation (Cell specific SRS subframe period, start position, UE specific SRS subframe period, start position, A-SRS candidate resource parameters, P-SRS resource parameters, A -SRS resource parameters) and PUCCH resource allocation control signals.

  Based on the control signal input from radio resource control section 103, control section 105 assigns downlink physical resource blocks to PDSCH, assigns resources to PDCCH, sets a modulation scheme for PDSCH, and sets coding rates for PDSCH and PDCCH. Control such as setting is performed on the transmission processing unit 107. Also, the control unit 105 generates DCI transmitted using the PDCCH based on the control signal input from the radio resource control unit 103 and outputs the DCI to the transmission processing unit 107. The DCI transmitted using the PDCCH is a downlink assignment, an uplink grant, or the like. Also, the control unit 105 allocates SRS resources (Cell specific SRS subframe period, start position, UE specific SRS subframe period, start position, A-SRS candidate resource parameters, P-SRS resource parameters). Control is performed such that information indicating A / SRS, information indicating whether or not to perform processing using A-SRS, and the like are transmitted to the mobile station apparatus 5 via the transmission processing unit 107 using PDSCH. Information indicating whether or not processing using A-SRS is performed is the same as information indicating whether or not information indicating an A-SRS transmission instruction is included in DCI format. Further, the control unit 105 performs transmission processing of information indicating an A-SRS transmission instruction, information indicating whether or not a parameter used for A-SRS is based on information indicated by PDCCH, and information indicating an A-SRS parameter Control is performed to transmit to the mobile station apparatus 5 using the PDCCH (DCI format 0A) via the unit 107.

  Based on the control signal input from the radio resource control unit 103, the control unit 105 allocates uplink physical resource blocks to the PUSCH, allocates resources to the PUCCH, sets PUSCH and PUCCH modulation schemes, and sets the PUSCH coding rate. Control such as setting and setting of a code sequence for PUCCH is performed on the reception processing unit 101. In addition, the control unit 105 controls channel quality measurement using SRS to the reception processing unit 101 based on the control signal input from the radio resource control unit 103. In addition, the control unit 105 receives the UCI transmitted from the mobile station apparatus 5 using PUCCH from the reception processing unit 101 and outputs the input UCI to the radio resource control unit 103.

  The transmission processing unit 107 generates a signal to be transmitted using PDCCH and PDSCH based on the control signal input from the control unit 105 and transmits the signal via the transmission antenna 111. The transmission processing unit 107 receives SRS resource allocation (Cell specific SRS subframe period, start position, UE specific SRS subframe period, start position, A-SRS candidate resource parameters, which are input from the radio resource control unit 103. , P-SRS resource parameters), information indicating whether or not to perform processing using A-SRS, information data input from an upper layer, and the like are transmitted to the mobile station apparatus 5 using the PDSCH. DCI (information indicating an A-SRS transmission instruction, information indicating whether a parameter used for A-SRS is based on information indicated by PDCCH, and an A-SRS parameter input from control unit 105. Information) is transmitted to the mobile station apparatus 5 using the PDCCH. For the sake of simplification of explanation, it is assumed that the information data includes information on several types of control. Details of the transmission processing unit 107 will be described later.

<Configuration of transmission processing unit 107 of base station apparatus 3>
Hereinafter, details of the transmission processing unit 107 of the base station apparatus 3 will be described. FIG. 2 is a schematic block diagram showing the configuration of the transmission processing unit 107 of the base station apparatus 3 according to the embodiment of the present invention. As shown in this figure, the transmission processing unit 107 includes a plurality of physical downlink shared channel processing units 201-1 to 201-M (hereinafter referred to as physical downlink shared channel processing units 201-1 to 201-M). Physical downlink), a plurality of physical downlink control channel processing units 203-1 to 203-M (hereinafter, physical downlink control channel processing units 203-1 to 203-M are combined). Control channel processing unit 203), downlink pilot channel processing unit 205, multiplexing unit 207, IFFT (Inverse Fast Fourier Transform) unit 209, GI (Guard Interval) insertion unit 211, D / A (Digital / Analog converter) unit 213, transmission RF (Radio Frequency) unit 21 5 and the transmission antenna 111. Since each physical downlink shared channel processing unit 201 and each physical downlink control channel processing unit 203 have the same configuration and function, only one of them will be described as a representative. In the description of the transmission processing unit 107, a case where the number of transmission antennas is one will be described, and a case where a plurality of transmission antennas are configured and a processing unit that performs spatial multiplexing on the PDSCH will be described. For convenience of explanation, the description is omitted.

  As shown in this figure, the physical downlink shared channel processing unit 201 includes a turbo coding unit 219 and a data modulation unit 221, respectively. Also, as shown in this figure, the physical downlink control channel processing unit 203 includes a convolutional coding unit 223 and a QPSK modulation unit 225. The physical downlink shared channel processing unit 201 performs baseband signal processing for transmitting information data to the mobile station apparatus 5 by the OFDM method. The turbo encoding unit 219 performs turbo encoding for increasing the error tolerance of the data at the encoding rate input from the control unit 105 and outputs the input information data to the data modulation unit 221. The data modulation unit 221 uses the data encoded by the turbo coding unit 219 as a modulation method inputted from the control unit 105, for example, QPSK (Quadrature Phase Shift Keying), 16QAM (16-value quadrature amplitude modulation). Modulation with a modulation scheme such as 16 Quadrature Amplitude Modulation) or 64QAM (64 Quadrature Amplitude Modulation) to generate a signal sequence of modulation symbols. The data modulation unit 221 outputs the generated signal sequence to the multiplexing unit 207.

  The physical downlink control channel processing unit 203 performs baseband signal processing for transmitting the DCI input from the control unit 105 in the OFDM scheme. The convolutional coding unit 223 performs convolutional coding for increasing DCI error resistance based on the coding rate input from the control unit 105. Here, DCI is controlled in bit units. The convolutional code unit 223 also performs rate matching to adjust the number of output bits for the bits subjected to the convolutional coding process based on the coding rate input from the control unit 105. The convolutional coding unit 223 outputs the encoded DCI to the QPSK modulation unit 225. The QPSK modulation unit 225 modulates the DCI encoded by the convolutional coding unit 223 using the QPSK modulation method, and outputs the modulated modulation symbol signal sequence to the multiplexing unit 207. The downlink pilot channel processing unit 205 generates a downlink reference signal that is a known signal in the mobile station apparatus 5 and outputs the downlink reference signal to the multiplexing unit 207.

  Multiplexer 207 receives a signal input from downlink pilot channel processor 205, a signal input from each physical downlink shared channel processor 201, and a signal input from each physical downlink control channel processor 203. Are multiplexed into a downlink radio frame in accordance with an instruction from the control unit 105. A control signal related to downlink physical resource block allocation to the PDSCH and resource allocation to the PDCCH set by the radio resource control unit 103 is input to the control unit 105, and based on the control signal, the control unit 105 performs processing of the multiplexing unit 207. To control.

  Note that the multiplexing unit 207 multiplexes PDSCH and PDCCH by time multiplexing as shown in FIG. The multiplexing unit 207 performs multiplexing between the downlink pilot channel and other channels by time / frequency multiplexing. Also, the multiplexing unit 207 performs PDSCH multiplexing for each mobile station device 5 in units of downlink physical resource block pairs, and performs PDSCH using a plurality of downlink physical resource block pairs for one mobile station device 5. Sometimes it multiplexes. Further, the multiplexing unit 207 performs multiplexing of the PDCCH addressed to each mobile station apparatus 5 using a control channel element (CCE). The multiplexing unit 207 outputs the multiplexed signal to the IFFT unit 209.

  IFFT section 209 performs fast inverse Fourier transform on the signal multiplexed by multiplexing section 207, performs OFDM modulation, and outputs the result to GI insertion section 211. The GI insertion unit 211 generates a baseband digital signal including symbols in the OFDM scheme by adding a guard interval to the signal modulated by the OFDM scheme by the IFFT unit 209. As is well known, the guard interval is generated by duplicating a part of the head or tail of the OFDM symbol to be transmitted. The GI insertion unit 211 outputs the generated baseband digital signal to the D / A unit 213. The D / A unit 213 converts the baseband digital signal input from the GI insertion unit 211 into an analog signal and outputs the analog signal to the transmission RF unit 215. The transmission RF unit 215 generates an in-phase component and a quadrature component of the intermediate frequency from the analog signal input from the D / A unit 213, and removes an extra frequency component for the intermediate frequency band. Next, the transmission RF section 215 converts (up-converts) the intermediate frequency signal into a high frequency signal, removes excess frequency components, amplifies the power, and transmits to the mobile station apparatus 5 via the transmission antenna 111. Send.

<Configuration of Reception Processing Unit 101 of Base Station Device 3>
Hereinafter, details of the reception processing unit 101 of the base station apparatus 3 will be described. FIG. 3 is a schematic block diagram showing the configuration of the reception processing unit 101 of the base station apparatus 3 according to the embodiment of the present invention. As shown in this figure, the reception processing unit 101 includes a reception RF unit 301, an A / D (Analog / Digital converter) unit 303, a symbol timing detection unit 309, a GI removal unit 311, an FFT unit 313, a sub Carrier demapping section 315, propagation path estimation section 317, PUSCH propagation path equalization section 319, PUCCH propagation path equalization section 321, IDFT section 323, data demodulation section 325, turbo decoding section 327, physical uplink control A channel detection unit 329 and an uplink channel quality measurement unit 331 are provided.

  The reception RF unit 301 appropriately amplifies the signal received by the reception antenna 109, converts it to an intermediate frequency (down-conversion), removes unnecessary frequency components, and amplifies the signal level so that the signal level is appropriately maintained. The level is controlled, and quadrature demodulation is performed based on the in-phase component and the quadrature component of the received signal. The reception RF unit 301 outputs the quadrature demodulated analog signal to the A / D unit 303. The A / D unit 303 converts the analog signal quadrature demodulated by the reception RF unit 301 into a digital signal, and outputs the converted digital signal to the symbol timing detection unit 309 and the GI removal unit 311.

  The symbol timing detection unit 309 detects the symbol timing based on the signal input from the A / D unit 303, and outputs a control signal indicating the detected symbol boundary timing to the GI removal unit 311. The GI removal unit 311 removes a portion corresponding to the guard interval from the signal input from the A / D unit 303 based on the control signal from the symbol timing detection unit 309, and converts the remaining portion of the signal to the FFT unit 313. Output to. The FFT unit 313 performs fast Fourier transform on the signal input from the GI removal unit 311, performs demodulation of the DFT-Spread-OFDM scheme, and outputs the result to the subcarrier demapping unit 315. Note that the number of points in the FFT unit 313 is equal to the number of points in the IFFT unit of the mobile station apparatus 5 described later.

  The subcarrier demapping unit 315, based on the control signal input from the control unit 105, the signal demodulated by the FFT unit 313, the uplink pilot channel DM RS, the uplink pilot channel SRS, and the PUSCH signal And PUCCH signals. The subcarrier demapping unit 315 outputs the separated DM RS to the channel estimation unit 317, outputs the separated SRS to the uplink channel quality measurement unit 331, and equalizes the PUSCH signal for the PUSCH channel. And outputs the separated PUCCH signal to the PUCCH channel equalization unit 321.

  The propagation path estimation unit 317 estimates propagation path fluctuations using the DM RS separated by the subcarrier demapping unit 315 and a known signal. The propagation path estimation unit 317 outputs the estimated propagation path estimation value to the PUSCH propagation path equalization unit 319 and the PUCCH propagation path equalization unit 321. The PUSCH channel equalization unit 319 equalizes the amplitude and phase of the PUSCH signal separated by the subcarrier demapping unit 315 based on the channel estimation value input from the channel estimation unit 317. Here, equalization refers to a process for restoring the fluctuation of the propagation path received by the signal during wireless communication. The PUSCH channel equalization unit 319 outputs the adjusted signal to the IDFT unit 323.

  The IDFT unit 323 performs discrete inverse Fourier transform on the signal input from the PUSCH channel equalization unit 319 and outputs the result to the data demodulation unit 325. The data demodulating unit 325 demodulates the PUSCH signal converted by the IDFT unit 323, and outputs the demodulated PUSCH signal to the turbo decoding unit 327. This demodulation is demodulation corresponding to the modulation method used in the data modulation unit of the mobile station apparatus 5, and the modulation method is input from the control unit 105. The turbo decoding unit 327 decodes information data from the PUSCH signal input from the data demodulation unit 325 and demodulated. The coding rate is input from the control unit 105.

  The PUCCH channel equalization unit 321 equalizes the amplitude and phase of the PUCCH signal separated by the subcarrier demapping unit 315 based on the channel estimation value input from the channel estimation unit 317. The PUCCH channel equalization unit 321 outputs the equalized signal to the physical uplink control channel detection unit 329.

  The physical uplink control channel detection unit 329 demodulates and decodes the signal input from the PUCCH channel equalization unit 321 and detects UCI. The physical uplink control channel detection unit 329 performs processing for separating the frequency domain and / or the signal code-multiplexed in the frequency domain. The physical uplink control channel detection unit 329 performs processing for detecting ACK / NACK information from the PUCCH signal code-multiplexed in the frequency domain and / or the time domain using the code sequence used on the transmission side. Do. Specifically, the physical uplink control channel detection unit 329 performs a detection process using a code sequence in the frequency domain, that is, a process for separating a code-multiplexed signal in the frequency domain, for each PUCCH subcarrier signal. On the other hand, after multiplying each code of the code sequence, a signal multiplied by the code is synthesized. Specifically, the physical uplink control channel detection unit 329 performs detection processing using a code sequence in the time domain, that is, processing for separating code-multiplexed signals in the time domain, for each SC-FDMA symbol of PUCCH. Is multiplied by each code of the code sequence, and then the signal multiplied by the code is synthesized. The physical uplink control channel detection unit 329 sets detection processing for the PUCCH signal based on the control signal from the control unit 105.

  Uplink channel quality measurement section 331 measures the channel quality using the SRS input from subcarrier demapping section 315, estimates the propagation path, and transmits the channel quality measurement result and propagation path estimation value to control section 105. Output. The uplink channel quality measurement unit 331 is instructed by the control unit 105 as to which channel quality of the mobile station apparatus 5 is to be measured with respect to which frequency position and how much frequency bandwidth of which uplink subframe. The

  Based on the control information (DCI) transmitted from the base station device 3 to the mobile station device 5 using the PDCCH and the control information transmitted using the PDSCH, the control unit 105 performs the subcarrier demapping unit 315, the data demodulation, Control unit 325, turbo decoding unit 327, propagation path estimation unit 317, physical uplink control channel detection unit 329, and uplink channel quality measurement unit 331 are controlled. In addition, the control unit 105 determines which resource (uplink subframe, uplink physical resource) the PUSCH, PUCCH, and SRS transmitted from each mobile station apparatus 5 is based on the control information transmitted from the base station apparatus 3 to the mobile station apparatus 5. It is grasped whether it is composed of blocks, frequency positions, frequency bandwidths, frequency domain code sequences, time domain code sequences).

<Overall configuration of mobile station apparatus 5>
Hereinafter, the configuration of the mobile station apparatus 5 according to the present embodiment will be described with reference to FIGS. 4, 5, and 6. FIG. 4 is a schematic block diagram showing the configuration of the mobile station apparatus 5 according to the embodiment of the present invention. As shown in this figure, the mobile station apparatus 5 includes a reception processing unit 401, a radio resource control unit 403, a control unit 405, and a transmission processing unit 407.

  The reception processing unit 401 receives a signal from the base station apparatus 3, and demodulates and decodes the received signal in accordance with an instruction from the control unit 405. When the reception processing unit 401 detects a PDCCH signal addressed to itself, the reception processing unit 401 outputs the DCI obtained by decoding the PDCCH signal to the control unit 405. For example, the reception processing unit 401 includes control information indicating an A-SRS transmission instruction included in the PDCCH, and control information indicating whether a parameter used for the A-SRS is based on information indicated by the PDCCH (uplink grant). (First information), control information indicating parameters of A-SRS is output to the control unit 405. That is, the reception processing unit 401 controls the control information (first information) indicating whether information indicating an A-SRS transmission instruction and parameters used for the A-SRS are based on information indicated by PDCCH (uplink grant). ) Including uplink grants. In addition, the reception processing unit 401 receives, via the control unit 405, information data obtained by decoding the PDSCH addressed to itself based on an instruction from the control unit 405 after outputting the DCI included in the PDCCH to the control unit 405. To the upper layer. In the DCI included in the PDCCH, the downlink assignment includes information indicating the allocation of PDSCH resources. Also, the reception processing unit 401 outputs the control information generated by the radio resource control unit 103 of the base station apparatus 3 obtained by decoding the PDSCH to the control unit 405, and the radio of the own apparatus via the control unit 405. Output to the resource control unit 403. For example, the control information generated by the radio resource control unit 103 of the base station apparatus 3 includes SRS resource allocation (Cell specific SRS subframe period, start position, UE specific SRS subframe period, start position, A-SRS Information indicating candidate resource parameters, P-SRS resource parameters), information indicating whether or not processing using A-SRS is performed, and the like.

  Further, the reception processing unit 401 outputs a cyclic redundancy check (CRC) code included in the PDSCH to the control unit 405. Although omitted in the description of the base station apparatus 3, the transmission processing unit 107 of the base station apparatus 3 generates a CRC code from the information data, and transmits the information data and the CRC code by PDSCH. The CRC code is used to determine whether the data included in the PDSCH is incorrect or not. If the CRC code is the same as the information generated from the data using a predetermined generator polynomial, the data is If it is determined that there is no error and the information generated from the data using a predetermined generator polynomial is different from the CRC code, it is determined that the data is incorrect. Details of the reception processing unit 401 will be described later.

  The control unit 405 confirms the data transmitted from the base station device 3 using the PDSCH and input from the reception processing unit 401, outputs the information data to the upper layer in the data, and the base station device in the data The reception processing unit 401 and the transmission processing unit 407 are controlled based on the control information generated by the third radio resource control unit 103. Further, the control unit 405 controls the reception processing unit 401 and the transmission processing unit 407 based on an instruction from the radio resource control unit 403. For example, the control unit 405 controls the transmission processing unit 407 to transmit the A-SRS using the candidate resource instructed from the radio resource control unit 403. For example, the control unit 405 sets Cell specific SRS subframe or UE specific SRS subframe instructed from the radio resource control unit 403 as an uplink subframe for transmitting A-SRS, and sets A in the configured uplink subframe. Control the transmission processing unit 407 to transmit SRS.

  Further, the control unit 405 controls the reception processing unit 401 and the transmission processing unit 407 based on DCI transmitted from the base station apparatus 3 using the PDCCH and input from the reception processing unit 401. Specifically, the control unit 405 controls the reception processing unit 401 based on the detected downlink assignment, and controls the transmission processing unit 407 based on the detected uplink grant. For example, when detecting an uplink grant including an A-SRS transmission instruction, the control unit 405 controls the transmission processing unit 407 to transmit the A-SRS. For example, the control unit 405 controls the transmission processing unit 407 to transmit the A-SRS using resources based on the A-SRS parameter indicated by the detected uplink grant. For example, when the first information indicated by the detected uplink grant indicates that the parameter used for the A-SRS is based on the information indicated by the uplink grant, the control unit 405 transmits the A-SRS. When Cell specific SRS subframe is set as an uplink subframe, and the first information indicated by the detected uplink grant does not indicate that the parameter used for A-SRS is based on the information indicated by the uplink grant The UE specific SRS subframe is set as an uplink subframe for transmitting A-SRS, and the transmission processing unit 407 is controlled to transmit the A-SRS in the set uplink subframe. For example, when the first information indicated by the detected uplink grant indicates that the parameter used for the A-SRS is based on the information indicated by the uplink grant, the control unit 405 indicates an A-SRS transmission instruction. The transmission processing unit 407 is controlled to transmit the A-SRS based on the parameter indicated by the uplink grant including the first information indicated by the detected uplink grant is the parameter used for the A-SRS. When it is not indicated that it is based on the information indicated by the link grant, it is based on the parameter configured in advance by the base station device 3 (that is, the A-SRS candidate resource set by the base station device 3 by RRC signaling is used). The transmission processing unit 407 is controlled to transmit the A-SRS.

  The control unit 405 manages the generation of UCI in its own device. For example, when data and a CRC code are input from the reception processing unit 401, the control unit 405 generates ACK / NACK. If the CRC code is the same as the information generated from the data using a predetermined generator polynomial, ACK / NACK indicates ACK. If the generated information and the CRC code are different, ACK / NACK indicates NACK. Indicated. The control unit 405 generates ACK or NACK indicating NACK for PDSCH data whose resource allocation is indicated by DCI included in the PDCCH detected by the reception processing unit 401. For example, the control unit 405 generates an SR at a timing corresponding to an uplink subframe in which a PUCCH resource for SR is assigned in advance by the base station apparatus 3. For example, when the radio resource control unit 403 determines that the uplink resource is insufficient and the control signal for requesting the generation of SR is input from the radio resource control unit 403, the control unit 405 generates the SR. . The radio resource control unit 403 determines that the uplink resource is insufficient, and corresponds to the uplink subframe to which the PUCCH resource for SR allocated in advance by the base station apparatus 3 is allocated. , A control signal for generating SR is output to the control unit 405. In addition, when the amount of data stored in the transmission buffer exceeds a predetermined threshold, it is determined that uplink resources are insufficient. Here, the timing corresponding to the uplink subframe means a timing earlier than the uplink subframe by at least the processing delay time so that a signal can be transmitted in the uplink subframe. For example, the control unit 405 generates a CQI at a timing corresponding to an uplink subframe in which a PUCCH resource for CQI is assigned in advance by the base station apparatus 3.

  The radio resource control unit 403 stores and holds the control information generated by the radio resource control unit 103 of the base station device 3 and notified from the base station device 3, and receives the reception processing unit 401 via the control unit 405. The transmission processing unit 407 is controlled. That is, the radio resource control unit 403 has a memory function for holding various parameters. For example, the radio resource control unit 403 holds Cell specific SRS subframe and UE specific SRS subframe parameters (cycle and start position). For example, the radio resource control unit 403 holds parameters of A-SRS candidate resources. When an uplink grant indicating an A-SRS transmission instruction is detected in the reception processing unit 401, the control unit 405 may determine that parameters used for A-SRS in the uplink grant are based on information indicated by the uplink grant. When not shown, the transmission processing unit 407 controls to transmit the A-SRS using the parameters of the A-SRS candidate resources held in the radio resource control unit 403.

  The transmission processing unit 407 encodes information data and UCI in accordance with an instruction from the control unit 405, and transmits the modulated signal to the base station apparatus 3 via the transmission antenna 411 using PUSCH and PUCCH resources. Moreover, the transmission process part 407 transmits SRS (A-SRS, P-SRS) according to the instruction | indication of the control part 405. Details of the transmission processing unit 407 will be described later.

<Reception Processing Unit 401 of Mobile Station Device 5>
Hereinafter, details of the reception processing unit 401 of the mobile station apparatus 5 will be described. FIG. 5 is a schematic block diagram showing the configuration of the reception processing unit 401 of the mobile station apparatus 5 according to the embodiment of the present invention. As shown in this figure, the reception processing unit 401 includes a reception RF unit 501, an A / D unit 503, a symbol timing detection unit 505, a GI removal unit 507, an FFT unit 509, a demultiplexing unit 511, a propagation path estimation unit 513, A PDSCH channel compensation unit 515, a physical downlink shared channel decoding unit 517, a PDCCH channel compensation unit 519, and a physical downlink control channel decoding unit 521 are configured. Further, as shown in this figure, the physical downlink shared channel decoding unit 517 includes a data demodulation unit 523 and a turbo decoding unit 525. Also, as shown in this figure, the physical downlink control channel decoding unit 521 includes a QPSK demodulation unit 527 and a Viterbi decoder unit 529.

  The reception RF unit 501 appropriately amplifies the signal received by the reception antenna 409, converts it to an intermediate frequency (down-conversion), removes unnecessary frequency components, and amplifies the signal so that the signal level is properly maintained. , And quadrature demodulation based on the in-phase and quadrature components of the received signal. The reception RF unit 501 outputs the quadrature demodulated analog signal to the A / D unit 503.

  A / D section 503 converts the analog signal quadrature demodulated by reception RF section 501 into a digital signal, and outputs the converted digital signal to symbol timing detection section 505 and GI removal section 507. Symbol timing detection section 505 detects symbol timing based on the digital signal converted by A / D section 503, and outputs a control signal indicating the detected symbol boundary timing to GI removal section 507. GI removal section 507 removes a portion corresponding to the guard interval from the digital signal output from A / D section 503 based on the control signal from symbol timing detection section 505, and converts the remaining portion of the signal to FFT section 509. Output to. The FFT unit 509 performs fast Fourier transform on the signal input from the GI removing unit 507, performs OFDM demodulation, and outputs the result to the demultiplexing unit 511.

  The demultiplexing unit 511 separates the signal demodulated by the FFT unit 509 into a PDCCH signal and a PDSCH signal based on the control signal input from the control unit 405. The demultiplexing unit 511 outputs the separated PDSCH signal to the PDSCH propagation path compensation unit 515 and outputs the separated PDCCH signal to the PDCCH propagation path compensation unit 519. Also, the demultiplexing unit 511 demultiplexes the downlink resource element in which the downlink pilot channel is arranged, and outputs the downlink reference signal of the downlink pilot channel to the propagation path estimation unit 513.

  The propagation path estimation unit 513 estimates the propagation path variation using the downlink reference signal of the downlink pilot channel separated by the demultiplexing unit 511 and the known signal, and compensates for the propagation path variation. And a channel compensation value for adjusting the phase are output to the channel compensation unit 515 for PDSCH and the channel compensation unit 519 for PDCCH. PDSCH propagation path compensation section 515 adjusts the amplitude and phase of the PDSCH signal separated by demultiplexing section 511 according to the propagation path compensation value input from propagation path estimation section 513. PDSCH propagation path compensation section 515 outputs the signal whose propagation path has been adjusted to data demodulation section 523 of physical downlink shared channel decoding section 517.

  Based on an instruction from the control unit 405, the physical downlink shared channel decoding unit 517 demodulates and decodes the PDSCH and detects information data. Data demodulation section 523 demodulates the PDSCH signal input from propagation path compensation section 515, and outputs the demodulated PDSCH signal to turbo decoding section 525. This demodulation is demodulation corresponding to the modulation method used in the data modulation unit 221 of the base station device 3. The turbo decoding unit 525 decodes information data from the demodulated PDSCH signal input from the data demodulation unit 523 and outputs the decoded information data to the upper layer via the control unit 405. Note that the control information generated by the radio resource control unit 103 of the base station apparatus 3 transmitted using the PDSCH is also output to the control unit 405, and is also output to the radio resource control unit 403 via the control unit 405. The Note that the CRC code included in the PDSCH is also output to the control unit 405.

  PDCCH propagation path compensation section 519 adjusts the amplitude and phase of the PDCCH signal separated by demultiplexing section 511 according to the propagation path compensation value input from propagation path estimation section 513. PDCCH propagation path compensation section 519 outputs the adjusted signal to QPSK demodulation section 527 of physical downlink control channel decoding section 521.

  The physical downlink control channel decoding unit 521 demodulates and decodes the signal input from the PDCCH channel compensation unit 519 as described below, and detects control data. The QPSK demodulator 527 performs QPSK demodulation on the PDCCH signal and outputs the result to the Viterbi decoder 529. The Viterbi decoder unit 529 decodes the signal demodulated by the QPSK demodulator 527 and outputs the decoded DCI to the controller 405. Here, this signal is expressed in units of bits, and the Viterbi decoder unit 529 also performs rate dematching in order to adjust the number of bits for performing Viterbi decoding processing on the input bits.

  The mobile station apparatus 5 performs a different decoding process for each DCI format of different bit sizes on the PDCCH signal, and adds the DCI included in the PDCCH in which no error was detected in the CRC code added to the PDCCH together with the DCI. get. Such a process is called blind decoding. In the mobile station apparatus 5, the type of DCI format for performing blind decoding simultaneously for each downlink subframe is designated in advance from the base station apparatus 3. For example, the physical downlink control channel decoding unit 521 performs a control information detection process on a PDCCH signal in a decoding process assuming DCI format 0A.

  The control unit 405 determines whether the DCI input from the Viterbi decoder unit 529 is the DCI addressed to itself with no error, and determines that the DCI is addressed to the own device without error. 511, a data demodulator 523, a turbo decoder 525, and a transmission processor 407 are controlled. For example, when the DCI is an uplink grant indicating an A-SRS transmission instruction, the control unit 405 controls the transmission processing unit 407 to transmit the A-SRS.

<Transmission Processing Unit 407 of Mobile Station Device 5>
FIG. 6 is a schematic block diagram showing the configuration of the transmission processing unit 407 of the mobile station apparatus 5 according to the embodiment of the present invention. As shown in this figure, the transmission processing unit 407 includes a turbo coding unit 611, a data modulation unit 613, a DFT unit 615, an uplink pilot channel processing unit 617, a physical uplink control channel processing unit 619, a subcarrier mapping unit 621, An IFFT unit 623, a GI insertion unit 625, a transmission power adjustment unit 627, a D / A unit 605, a transmission RF unit 607, and a transmission antenna 411 are configured. In addition, for convenience of explanation, the present invention describes a case where the mobile station apparatus 5 includes one transmission antenna 411, but the number of transmission antennas 411 includes two or more, and related processing units. Two or more (subcarrier mapping unit 621, IFFT unit 623, GI insertion unit 625, transmission power adjustment unit 627, D / A unit 605, transmission RF unit 607) may be configured.

  The turbo coding unit 611 performs turbo coding for increasing the error tolerance of the data at the coding rate instructed by the control unit 405 and outputs the input information data to the data modulation unit 613. The data modulation unit 613 modulates the code data encoded by the turbo coding unit 611 using a modulation method instructed by the control unit 405, for example, a modulation method such as QPSK, 16QAM, or 64QAM, and converts the signal sequence of modulation symbols. Generate. Data modulation section 613 outputs the generated modulation symbol signal sequence to DFT section 615. The DFT unit 615 performs discrete Fourier transform on the signal output from the data modulation unit 613 and outputs the result to the subcarrier mapping unit 621.

  The physical uplink control channel processing unit 619 performs baseband signal processing for transmitting UCI input from the control unit 405. The UCI input to the physical uplink control channel processing unit 619 is ACK / NACK, SR, and CQI. The physical uplink control channel processing unit 619 performs signal processing related to frequency domain code multiplexing and / or time domain code multiplexing on a signal generated from UCI. The physical uplink control channel processing unit 619 multiplies the PUCCH signal used for transmission of ACK / NACK, SR, and CQI by a code sequence instructed by the control unit 405 in order to realize frequency domain code multiplexing. . The physical uplink control channel processing unit 619 multiplies the PUCCH signal used for transmission of ACK / NACK and SR by a code sequence instructed by the control unit 405 in order to realize time domain code multiplexing. The physical uplink control channel processing unit 619 performs baseband signal processing and outputs the generated signal to the subcarrier mapping unit 621.

  The uplink pilot channel processing unit 617 generates a UL RS (DM RS, P-SRS, A-SRS) that is a known signal in the base station apparatus 3 based on an instruction from the control unit 405, and a subcarrier mapping unit 621. Output to.

  The subcarrier mapping unit 621 converts the signal input from the uplink pilot channel processing unit 617, the signal input from the DFT unit 615, and the signal input from the physical uplink control channel processing unit 619 into the control unit 405. Are arranged on subcarriers according to instructions from, and output to IFFT section 623. The subcarrier mapping unit 621 shows the arrangement of A-SRS resources, the arrangement of P-SRS resources, the arrangement of DM RS resources in the PUSCH, and the arrangement of DM RS resources in the PUCCH in FIG. Arrange and output as expected.

  IFFT section 623 performs fast inverse Fourier transform on the signal output from subcarrier mapping section 621 and outputs the result to GI insertion section 625. Here, the number of points of IFFT section 623 is larger than the number of points of DFT section 615, and mobile station apparatus 5 transmits using PUSCH by using DFT section 615, subcarrier mapping section 621, and IFFT section 623. DFT-Spread-OFDM modulation is performed on the signal. GI insertion section 625 adds a guard interval to the signal input from IFFT section 623 and outputs the signal to transmission power adjustment section 627.

  The transmission power adjustment unit 627 adjusts the transmission power of the signal input from the GI insertion unit 625 based on the control signal from the control unit 405 and outputs the adjusted signal to the D / A unit 605. Note that, in the transmission power adjustment unit 627, the average transmission power of PUSCH, PUCCH, DM RS, and SRS (P-SRS, A-SRS) is controlled for each uplink subframe.

  The D / A unit 605 converts the baseband digital signal input from the transmission power adjustment unit 627 into an analog signal and outputs the analog signal to the transmission RF unit 607. The transmission RF unit 607 generates an in-phase component and a quadrature component of the intermediate frequency from the analog signal input from the D / A unit 605, and removes an extra frequency component for the intermediate frequency band. Next, the transmission RF unit 607 converts (up-converts) the intermediate frequency signal into a high frequency signal, removes excess frequency components, amplifies the power, and transmits to the base station apparatus 3 via the transmission antenna 411. Send.

<Transmission of A-SRS in Cell specific SRS subframe and UE specific SRS subframe>
FIG. 7 is a diagram illustrating an A-SRS transmission example of the mobile station apparatus 5 according to the embodiment of the present invention. Here, a case will be described in which Cell specific SRS subframe and UE specific SRS subframe are configured as shown in FIG. Here, a case will be described in which A-SRS candidate resources are configured for the mobile station apparatus 5 as shown in FIG. In FIG. 7, the upper part shows A-SRS transmitted in the uplink, and the lower part shows DCI format 0A (DCI format 0A 1, DCI format 0A 2) detected in the downlink. In FIG. 7, DCI format 0A 1 indicates that a predetermined information field (A-SRS activation / deactivation in FIG. 11) indicates transmission of A-SRS, and a different predetermined information field (A-SRS in FIG. 11). dynamic parameter indicator or resource block assignment) means DCI format 0A which does not indicate that the parameter used for A-SRS is based on information indicated by PDCCH. In FIG. 7, DCI format 0A 2 indicates that a predetermined information field (A-SRS activation / deactivation in FIG. 11) indicates transmission of A-SRS, and a different predetermined information field (A-SRS in FIG. 11). dynamic parameter indicator or resource block assignment) means DCI format 0A indicating that a parameter used for A-SRS is based on information indicated by PDCCH. In FIG. 7, the uplink subframe and the downlink subframe with the same number are assumed to have the same timing.

  The mobile station apparatus 5 that has detected the DCI format 0A 1 in the downlink subframe # 1 transmits an A-SRS in the uplink subframe # 5 that is the first UE-specific SRS subframe after the four uplink subframes. . An A-SRS transmission instruction is indicated so that the mobile station apparatus 5 can appropriately transmit the A-SRS in consideration of processing delays related to uplink grant detection processing, SRS transmission processing settings, and the like. From the timing when the uplink grant including information is detected, the uplink subframes after the four uplink subframes are set as the uplink subframe used for A-SRS transmission. The mobile station apparatus 5 uses A-SRS candidate resources configured in advance by RRC signaling in the uplink subframe # 5. Although illustration is omitted, the mobile station apparatus 5 uses the information on the allocation of PUSCH resources indicated by the DCI format 0A 1 detected in the downlink subframe # 1, and the uplink after four uplink subframes. PUSCH is transmitted in link subframe # 5. In the cell specific SRS subframe, the SRS is transmitted with the 14th SC-FDMA symbol, and the PUSCH is transmitted with the 1st to 13th SC-FDMA symbols. The mobile station apparatus 5 that has detected the DCI format 0A 2 in the downlink subframe # 2 transmits an A-SRS in the uplink subframe # 7 that is the first Cell specific SRS subframe after the four uplink subframes. . The mobile station apparatus 5 uses an A-SRS resource based on a parameter indicated by DCI format 0A 2 in the uplink subframe # 7. The mobile station apparatus 5 that has detected the DCI format 0A 1 in the downlink subframe # 4 transmits an A-SRS in the uplink subframe # 9 that is the first UE specific SRS subframe after the four uplink subframes. . The mobile station apparatus 5 uses A-SRS candidate resources configured in advance by RRC signaling in uplink subframe # 9. Although illustration is omitted, the mobile station apparatus 5 uses the DCI format 0A 1 detected in the downlink subframe # 4 to determine the uplink subframes after four uplink subframes based on the information related to PUSCH resource allocation. PUSCH is transmitted in frame # 8. The mobile station apparatus 5 that has detected the DCI format 0A 2 in the downlink subframe # 7 transmits an A-SRS in the uplink subframe # 11 that is the first Cell specific SRS subframe after the four uplink subframes. . The mobile station apparatus 5 uses an A-SRS resource based on a parameter indicated by DCI format 0A 2 in uplink subframe # 11.

  As described above, Cell specific SRS subframe or UE specific SRS subframe is used as an uplink subframe in which mobile station apparatus 5 transmits A-SRS, and parameters used for A-SRS of uplink grant (DCI format 0A). By setting based on whether or not it is based on information indicated by the PDCCH, the base station apparatus 3 can flexibly control the A-SRS transmission to the mobile station apparatus 5, and the uplink station Channel quality can be measured efficiently. As a result of scheduling for each mobile station device 5 in the cell to be managed, the base station device 3 has a cell specific SRS that is not a UE specific SRS subframe as described in FIG. Since A-SRS resources can be flexibly allocated by subframe, resources limited to UE specific SRS subframes are allocated by indicating an A-SRS transmission instruction, and compared with the case of indicating an A-SRS transmission instruction. Thus, it is possible to measure the channel quality of the frequency band according to the resource usage state at high speed. For example, the base station device 3 can measure channel quality in a wide frequency band at high speed. Channel quality in a wide frequency band can be measured at high speed. Here, a state where there is a margin in resources used for SRS means that the number of mobile station devices 5 that need to transmit SRS at a certain uplink subframe timing decreases, and mobile station devices 5 that need to transmit SRS. This means a state in which SRS resources can be allocated intensively. As shown in FIG. 17, when the base station apparatus 3 allocates resources limited to the UE specific SRS subframe and transmits the A-SRS, in order to measure the overall channel quality of the system band, at least 13 Although the time corresponding to the uplink subframe is required, as illustrated in FIG. 7, the base station device 3 can flexibly adapt to Cell specific SRS subframe according to the propagation path status of the mobile station device 5 and the usage status of SRS resources By assigning A-SRS resources to and transmitting A-SRS, it is possible to measure the overall channel quality of the system band in a time corresponding to seven uplink subframes. As described above, the present invention can shorten the time required for the base station apparatus 3 to appropriately measure the channel quality, and can shorten the time until efficient frequency scheduling and adaptive modulation are started. it can. As a result, it is possible to improve the satisfaction of a user who performs communication using the mobile station device 5. In addition, the value of the transmission power that the mobile station apparatus 5 can transmit at the maximum has a limit, and the mobile station apparatus 5 having a poor propagation path state transmits an SRS in a wide frequency band while satisfying the required quality. The base station apparatus 3 can measure the channel quality in a wide frequency band only by transmitting SRSs in a limited range of frequency bands, and transmitting SRSs multiple times in different uplink subframes. I can't.

  Note that, as described above, the Cell specific SRS subframe and the UE specific SRS subframe are not mutually exclusive. UE specific SRS subframe is a part of Cell specific SRS subframe. In other words, the mobile station apparatus 5 that has detected the DCI format 0A 1 is an uplink subframe in the Cell specific SRS subframe, and only the uplink subframe that is the UE specific SRS subframe is A-SRS. The mobile station apparatus 5 that has detected the DCI format 0A 2 is set to be an uplink subframe in a Cell specific SRS subframe, and is an uplink subframe or UE that is a UE specific SRS subframe. An uplink subframe that is not a specific SRS subframe is set as an uplink subframe that transmits an A-SRS.

  FIG. 8 is a flowchart showing an example of processing related to the setting of an uplink subframe for transmitting an A-SRS of the control unit 405 of the mobile station apparatus 5 according to the embodiment of the present invention. The control unit 405 of the mobile station apparatus 5 determines whether or not an uplink grant (DCI format 0A) indicating an A-SRS transmission instruction has been detected in the reception processing unit 401 (step S101). When the control unit 405 determines that the uplink grant indicating the A-SRS transmission instruction is detected in the reception processing unit 401 (step S101: YES), the information used for the parameter used for the A-SRS is indicated by the uplink grant. It is determined whether or not it is indicated based on (step S102). When it is determined that the parameter used for A-SRS is based on the information indicated by the uplink grant (step S102: YES), the control unit 405 determines Cell specific as the uplink subframe for transmitting the A-SRS. SRS subframe is set (step S103). When it is determined that the parameter used for A-SRS is not based on the information indicated by the uplink grant (NO in step S102), the control unit 405 determines that the UE is used as the uplink subframe that transmits the A-SRS. A specific SRS subframe is set (step S104). On the other hand, when the control unit 405 determines that the uplink grant (DCI format 0A) indicating the A-SRS transmission instruction is not detected in the reception processing unit 401 (step S101: NO), the control unit 405 transmits the A-SRS. No processing related to link frame setting is performed. After step S103 or step S104, the transmission processing unit 407 of the mobile station apparatus 5 transmits A-SRS in the uplink subframe set in the control unit 405.

  As mentioned above, in embodiment of this invention, the mobile station apparatus 5 is based on the information (1st information) which shows whether the parameter used for A-SRS is based on the information shown with an uplink grant. By setting Cell specific SRS subframe or UE specific SRS subframe as an uplink subframe for transmitting A-SRS, base station apparatus 3 flexibly controls transmission of A-SRS to mobile station apparatus 5 And uplink channel quality can be measured efficiently. More specifically, when it is indicated that the parameter used for A-SRS is based on the information indicated by the uplink grant, the mobile station apparatus 5 uses the Cell specific SRS subframe as an uplink subframe for transmitting the A-SRS. And if the parameter used for A-SRS is not indicated to be based on information indicated by the uplink grant, by setting the UE specific SRS subframe as an uplink subframe for transmitting the A-SRS, The base station apparatus 3 can flexibly control the A-SRS transmission to the mobile station apparatus 5, and can efficiently measure the uplink channel quality. When it is indicated that the parameter used for A-SRS is based on the information indicated by the uplink grant, the mobile station device 5 performs the A-SRS with the resource based on the parameter indicated by the uplink grant in the Cell specific SRS subframe. If it is not indicated that the parameter used for A-SRS is based on the information indicated by the uplink grant, the A-SRS is a resource based on the parameter configured by the base station apparatus 3 in advance in the UE specific SRS subframe. When the base station apparatus 3 has a margin for resources used for the SRS as a result of scheduling for each mobile station apparatus 5 in the cell to be managed, the channel quality of a wide frequency band according to the resource usage situation Measure at high speed It can be. Note that the mobile station apparatus 5 uses the cell specific SRS subframe as an uplink subframe for transmitting the A-SRS based on information indicating whether or not the parameter used for the A-SRS is based on information indicated by the uplink grant. Or UE specific SRS subframe is implicitly set, so that information indicating that Cell specific SRS subframe or UE specific SRS subframe is set as an uplink subframe for transmitting A-SRS is explicitly set in the uplink grant. Since it is not necessary to indicate (use a dedicated information field, use a dedicated code point), it is possible to suppress the overhead of uplink grant control information.

  In addition, the mobile station device 5 is not limited to a moving terminal, and the present invention may be realized by mounting the function of the mobile station device 5 on a fixed terminal.

  The characteristic means of the present invention described above can also be realized by mounting and controlling functions in an integrated circuit. That is, the integrated circuit of the present invention is an integrated circuit that is mounted on a mobile station device to cause the mobile station device to perform a plurality of functions, and that communicates with a base station device and transmits a sounding reference signal. A function for performing an uplink grant detection process including an instruction and first information and a cell-specific subframe as a subframe for transmitting a sounding reference signal when an uplink grant including a sounding reference signal transmission instruction is detected Or a function for setting a subframe configured by a base station device in advance in a cell-specific subframe based on the first information, and a function for transmitting a sounding reference signal in the set subframe. The mobile station apparatus is caused to exhibit a series of functions including it.

  Thus, the mobile station apparatus 5 using the integrated circuit of the present invention includes the first information included in the uplink together with the information indicating the transmission instruction of the A-SRS (the parameter used for the A-SRS is indicated by the uplink grant). The base station apparatus 3 sets the uplink subframe by setting Cell specific SRS subframe or UE specific SRS subframe as the uplink subframe for transmitting the A-SRS based on the information). A-SRS transmission can be controlled dynamically and flexibly for each frame, and the uplink channel quality can be measured efficiently.

  The operations described in the embodiments of the present invention may be realized by a program. The program that operates in the mobile station apparatus 5 and the base station apparatus 3 related to the present invention is a program (a program that causes a computer to function) that controls the CPU and the like so as to realize the functions of the above-described embodiments related to the present invention. Information handled by these devices is temporarily stored in the RAM at the time of processing, then stored in various ROMs and HDDs, read out by the CPU, and corrected and written as necessary. As a recording medium for storing the program, a semiconductor medium (for example, ROM, nonvolatile memory card, etc.), an optical recording medium (for example, DVD, MO, MD, CD, BD, etc.), a magnetic recording medium (for example, magnetic tape, Any of a flexible disk etc. may be sufficient. In addition, by executing the loaded program, not only the functions of the above-described embodiment are realized, but also based on the instructions of the program, the processing is performed in cooperation with the operating system or other application programs. The functions of the invention may be realized.

  In the case of distribution in the market, the program can be stored and distributed in a portable recording medium, or transferred to a server computer connected via a network such as the Internet. In this case, the storage device of the server computer is also included in the present invention. Moreover, you may implement | achieve part or all of the mobile station apparatus 5 and the base station apparatus 3 in embodiment mentioned above as LSI which is typically an integrated circuit. Each functional block of the mobile station device 5 and the base station device 3 may be individually chipped, or a part or all of them may be integrated into a chip. Further, the method of circuit integration is not limited to LSI, and may be realized by a dedicated circuit or a general-purpose processor. In addition, when an integrated circuit technology that replaces LSI appears due to progress in semiconductor technology, an integrated circuit based on the technology can also be used.

  The embodiment of the present invention has been described in detail with reference to the drawings. However, the specific configuration is not limited to this embodiment, and the design and the like within the scope not departing from the gist of the present invention are also claimed. Included in the range.

3 base station apparatus 5 (A to C) mobile station apparatus 101 reception processing section 103 radio resource control section 105 control section 107 transmission processing section 109 reception antenna 111 transmission antenna 201 physical downlink shared channel processing section 203 physical downlink control channel processing Unit 205 downlink pilot channel processing unit 207 multiplexing unit 209 IFFT unit 211 GI insertion unit 213 D / A unit 215 transmission RF unit 219 turbo coding unit 221 data modulation unit 223 convolution coding unit 225 QPSK modulation unit 301 reception RF unit 303 A / D unit 309 Symbol timing detection unit 311 GI removal unit 313 FFT unit 315 Subcarrier demapping unit 317 Channel estimation unit 319 PUSCH channel equalization unit 321 PUCCH channel equalization unit 323 IDFT unit 325 Data demodulation unit 32 7 turbo decoding unit 329 physical uplink control channel detection unit 331 uplink channel quality measurement unit 401 reception processing unit 403 radio resource control unit 405 control unit 407 transmission processing unit 409 reception antenna 411 transmission antenna 501 reception RF unit 503 A / D unit 505 Symbol timing detection unit 507 GI removal unit 509 FFT unit 511 Demultiplexing unit 513 Channel estimation unit 515 PDSCH channel compensation unit 517 Physical downlink shared channel decoding unit 519 PDCCH channel compensation unit 521 Physical downlink control Channel decoding unit 523 Data demodulation unit 525 Turbo decoding unit 527 QPSK demodulation unit 529 Viterbi decoder unit 605 D / A unit 607 Transmission RF unit 611 Turbo coding unit 613 Data modulation unit 615 DFT unit 617 Uplink pilot channel Processing section 619 physical uplink control channel processing unit 621 subcarrier mapping unit 623 IFFT unit 625 GI inserting section 627 transmission power adjustment unit

Claims (8)

A mobile station device that communicates with a base station device,
A reception processing unit that performs an uplink grant detection process including a sounding reference signal transmission instruction and first information;
When an uplink grant including a sounding reference signal transmission instruction is detected in the reception processing unit, a cell-specific subframe or a cell-specific subframe in advance as a subframe for transmitting a sounding reference signal A control unit configured to set a subframe specific to a mobile station device, which is a subframe configured based on the first information;
And a transmission processing unit that transmits a sounding reference signal in a subframe set in the control unit.   The mobile station apparatus according to claim 1, wherein the cell-specific subframe includes a subframe that is not specific to the mobile station apparatus.   The mobile station according to claim 1, wherein the control unit sets a subframe after a predetermined number of subframes from a subframe in which an uplink grant is detected as a subframe for transmitting a sounding reference signal. apparatus. The first information is information indicating whether a parameter used for the sounding reference signal is based on information indicated by an uplink grant,
The control unit sets a cell-specific subframe as a subframe for transmitting a sounding reference signal when the first information indicates that a parameter used for the sounding reference signal is based on information indicated by an uplink grant. If the first information does not indicate that the parameter used for the sounding reference signal is based on the information indicated by the uplink grant, a subframe specific to the mobile station apparatus is set as a subframe for transmitting the sounding reference signal. The mobile station apparatus according to claim 1, wherein:   The transmission processing unit, when the first information indicates that a parameter used for the sounding reference signal is based on information indicated by the uplink grant, a parameter indicated by the uplink grant including a transmission instruction of the sounding reference signal If the first information does not indicate that the parameter used for the sounding reference signal is based on the information indicated by the uplink grant, based on the parameter configured in advance by the base station apparatus. The mobile station apparatus according to claim 4, wherein a sounding reference signal is transmitted. A communication system comprising a plurality of mobile station devices and a base station device that communicates with the plurality of mobile station devices,
The base station device
A transmitter for transmitting a signal to the mobile station device;
A receiving unit for receiving a signal from the mobile station device;
An uplink channel quality measurement unit that measures channel quality from a sounding reference signal received by the reception unit,
The mobile station device
A reception processing unit that performs an uplink grant detection process including a sounding reference signal transmission instruction and first information;
When an uplink grant including a sounding reference signal transmission instruction is detected in the reception processing unit, a cell-specific subframe or a cell-specific subframe in advance as a subframe for transmitting a sounding reference signal A control unit configured to set a subframe specific to a mobile station device, which is a subframe configured based on the first information;
A transmission processing unit that transmits a sounding reference signal in a subframe set in the control unit. A communication method used for a mobile station apparatus communicating with a base station apparatus,
A step of performing an uplink grant detection process including a sounding reference signal transmission instruction and first information;
When an uplink grant including a sounding reference signal transmission instruction is detected, a cell-specific subframe is transmitted as a subframe for transmitting the sounding reference signal, or a subframe configured in advance by the base station apparatus in the cell-specific subframe. Setting a subframe specific to a mobile station device that is a frame based on the first information;
Transmitting at least a sounding reference signal in the set subframe. An integrated circuit that, when mounted on a mobile station device, causes the mobile station device to perform a plurality of functions,
A function of communicating with the base station device;
A function of performing an uplink grant detection process including a sounding reference signal transmission instruction and first information;
When an uplink grant including a sounding reference signal transmission instruction is detected, a cell-specific subframe is transmitted as a subframe for transmitting the sounding reference signal, or a subframe configured in advance by the base station apparatus in the cell-specific subframe. A function of setting a subframe specific to a mobile station device, which is a frame, based on the first information;
An integrated circuit characterized by causing the mobile station apparatus to exhibit a series of functions including a function of transmitting a sounding reference signal in a set subframe.