JP5530254B2 - Mobile station apparatus, base station apparatus, radio communication system, radio communication method, and integrated circuit - Google Patents

Description

  The present invention relates to a radio communication system including a mobile station apparatus and a base station apparatus, and more particularly to a transmission control method for a reference signal for channel measurement of a mobile station apparatus.

  Traditionally, cellular mobile radio access schemes and radio network evolution (hereinafter also referred to as “Long Term Evolution (LTE)” or “Evolved Universal Terrestrial Radio Access (EUTRA)”) and wider bandwidth than LTE A wireless access method and wireless network ("Long Term Evolution-Advanced (LTE-A)" or "Advanced Evolved Universal Terrestrial Radio Access (A- EUTRA) ”is also being considered in the 3rd Generation Partnership Project (3GPP).

  As communication systems in LTE, OFDMA (Orthogonal Frequency Division Multiple Access) system that performs user multiplexing using mutually orthogonal subcarriers and SC-FDMA (Single Carrier-Frequency Division Multiple Access) system are being studied. . That is, an OFDMA scheme that is a multicarrier communication scheme is proposed for the downlink, and an SC-FDMA scheme that is a single carrier communication scheme is proposed for the uplink.

  On the other hand, as a communication method in LTE-A, the OFDMA method is used in the downlink, and in the uplink, in addition to the SC-FDMA method, Clustered-SC-FDMA (Clustered-Single Carrier-Frequency Division Multiple Access, DFT-s). -OFDM with Spectrum Division Control, also called DFT-precoded OFDM) is being studied. Here, in LTE and LTE-A, the SC-FDMA system and the Clustered-SC-FDMA system proposed as uplink communication systems are based on the characteristics of the single carrier communication system (depending on the single carrier characteristics), and data (information ) Is transmitted at a low PAPR (Peak to Average Power Ratio: peak power to average power ratio, transmission power).

  In LTE-A, a frequency band used in a general wireless communication system is continuous, whereas a plurality of continuous and / or discontinuous frequency bands (hereinafter referred to as “component carrier (CC)”). Alternatively, it has been proposed to operate as one wide frequency band (also referred to as carrier aggregation) by using a combination of “carrier component (CC: Carrier Component)”. In addition, the base station device and mobile station device (UE: User Equipment) are used for downlink communication and the frequency band used for downlink communication in order to communicate more flexibly using a wide frequency band. It has also been proposed to use different frequency bandwidths (Asymmetric carrier aggregation) (Non-patent Document 1).

  FIG. 5 is a diagram for explaining a radio communication system in which frequency bands are aggregated in the prior art. It is symmetric that the frequency band used for downlink (DL: Down Link) communication and the frequency band used for uplink (UL: Up Link) communication as shown in FIG. It is also called frequency band aggregation (Symmetric carrier aggregation). As shown in FIG. 5, the base station apparatus and the mobile station apparatus use a plurality of component carriers that are continuous and / or discontinuous frequency bands in a composite manner, thereby providing a wide band configured by a plurality of component carriers. Communication can be performed in the frequency band.

  In FIG. 5, as an example, the frequency band (DL system band (width) may be used) for downlink communication having a bandwidth of 100 MHz is five downlink component carriers having a bandwidth of 20 MHz ( DCC1: Downlink Component Carrier1, DCC2, DCC3, DCC4, DCC5). In addition, as an example, five uplink component carriers (UCC1: UCC1: a frequency band used for uplink communication having a bandwidth of 100 MHz (or a UL system band (width)) may be used. Uplink Component Carrier1, UCC2, UCC3, UCC4, UCC5).

  In FIG. 5, downlink channels such as a physical downlink control channel (PDCCH) and a physical downlink shared channel (PDSCH) are arranged in each downlink component carrier.

  The base station apparatus allocates (schedules) downlink control information (DCI: Downlink Control Information) for transmitting a downlink transport block transmitted using PDSCH to the mobile station apparatus using PDCCH. . The base station apparatus transmits the downlink transport block to the mobile station apparatus using PDSCH. Here, in FIG. 5, the base station apparatus can transmit up to five downlink transport blocks (or PDSCH) to the mobile station apparatus in the same subframe.

  Further, uplink channels such as a physical uplink control channel (PUCCH) and a physical uplink shared channel (PUSCH) are arranged in each uplink component carrier.

  The mobile station apparatus uses PUCCH and / or PUSCH to indicate channel state information (CSI: Channel Statement information) indicating a downlink channel state and ACK / NACK (acknowledgment: Positive) in HARQ for the downlink transport block. Information indicating Acknowledgment / Negative Acknowledgment and uplink control information (UCI) such as scheduling request (SR) are transmitted to the base station apparatus. Here, in FIG. 5, the mobile station apparatus can transmit up to five uplink transport blocks (or PUSCH) to the base station apparatus in the same subframe.

  Similarly, FIG. 6 is a diagram for explaining a wireless communication system in which asymmetric frequency bands are aggregated in the prior art. As shown in FIG. 6, the base station apparatus and the mobile station apparatus have different frequency bands used for downlink communication and frequency bands used for uplink communication, and configure these frequency bands. Therefore, it is possible to perform communication in a wide frequency band by using component carriers that are continuous and / or discontinuous frequency bands in combination.

  In FIG. 6, as an example, five downlink component carriers (DCC1, DCC2, DCC3, DCC4, DCC5) whose frequency band used for downlink communication having a bandwidth of 100 MHz is 20 MHz. It is constituted by. In addition, as an example, it is shown that the frequency band used for uplink communication having a bandwidth of 40 MHz is configured by two uplink component carriers (UCC1, UCC2) having a bandwidth of 20 MHz. ing.

  In FIG. 6, a downlink / uplink channel is allocated to each downlink / uplink component carrier. The base station apparatus allocates (schedules) the PDSCH to the mobile station apparatus using the PDCCH, and transmits the downlink transport block to the mobile station apparatus using the PDSCH. Here, in FIG. 6, the base station apparatus can transmit up to five downlink transport blocks (PDSCH) to the mobile station apparatus in the same subframe.

  Also, the mobile station apparatus uses PUCCH and / or PUSCH to transmit channel state information, information indicating ACK / NACK in HARQ for the downlink transport block, and uplink control information such as a scheduling request to the base station apparatus. Send to. Here, in FIG. 6, the mobile station apparatus can transmit up to two uplink transport blocks (may be PUSCH) to the base station apparatus in the same subframe.

  In LTE-A, a sounding reference signal (A-SRS: Aperiodic Sounding Reference Signal) that is transmitted only when a transmission request is notified from the base station apparatus via the PDCCH has been proposed. By including the A-SRS transmission instruction information (A-SRS activation / deactivation) in the downlink control information (DCI) format (also referred to as DCI format), the mobile station device can be -It is possible to determine whether transmission of SRS is requested, and transmission control of A-SRS can be performed dynamically. In addition, the base station apparatus uses a downlink control information format for the downlink (DCI format, downlink grant: Downlink grant, downlink assignment: Downlink assignment) for the mobile station apparatus to -Instructing transmission of SRS, and transmitting A-SRS using downlink control information format (DCI format, uplink grant: UL grant, uplink assignment: also called uplink assignment) for uplink It has been proposed to direct. Furthermore, it has been proposed that an A-SRS transmission instruction is indicated by one bit (multi-bit) of an uplink grant or downlink assignment or by a predetermined code point (Non-patent Document 2).

  In LTE-A, since communication is performed using a plurality of downlink / uplink component carriers, an uplink component carrier to which PUSCH is transmitted is associated (linked) with a downlink component carrier in which the PDCCH for this PUSCH is arranged. Thus, the mobile station apparatus can determine which DCC PDCCH corresponds to which UCC. It has been proposed that the link is set by the base station apparatus, and the setting information is included in the system information and notified to the mobile station apparatus (Non-patent Document 3).

“Carrier aggregation in LTE-Advanced”, R1-082464, 3GPP TSG RAN WG1 Meeting # 53bis, Jun 30-Jul 4, 2008. “LTE-A Dynamic Aperiodic SRS-Duration, Timing, and Carrier Aggregation”, R1-103187, 3GPP TSG-RAN1 Meeting # 61, May 10-14, 2010. “CC linkage in CA”, R2-102059, 3GPP TSG-RAN2 Meeting # 69bis, Apr 12-16, 2010.

  However, in the prior art, when an SRS transmission instruction is indicated by an uplink grant, it is necessary to transmit even when PUSCH transmission is not necessary. In such a case, the uplink grant to which the PUSCH is allocated is used for the SRS. Indicating a transmission instruction is a waste of an uplink grant. In addition, when transmitting SRS without PUSCH, it is proposed to indicate an SRS transmission instruction by DL assignment, but it is necessary to include SRS transmission instruction information in a plurality of types of DCI formats. In addition, preparing a new DCI format only for an SRS transmission instruction increases the number of times of blind detection of the DCI format, making it impossible to perform efficient communication.

  The present invention has been made in view of the above points, and provides a mobile station apparatus, a base station apparatus, and a wireless communication system that can efficiently perform transmission control of SRS and PUSCH using one DCI format. The purpose is to do.

  (1) In order to achieve the above object, the present invention takes the following measures. That is, the wireless communication system of the present invention is a wireless communication system in which a base station apparatus and a mobile station apparatus perform wireless communication, and the base station apparatus transmits a sounding reference signal transmission instruction as 1-bit transmission instruction information or The first control information that is a predetermined code point is set, and an uplink grant including the transmission instruction is notified to the mobile station apparatus, and the mobile station apparatus transmits the reference signal transmission instruction according to the grant. When instructed by the instruction information, the reference signal and the physical uplink shared channel are transmitted to the base station apparatus in the same subframe, and the first control information is a predetermined code point according to the grant In this case, the reference signal is transmitted to the base station apparatus.

  (2) The radio communication system of the present invention is the radio communication system according to (1), wherein the base station device notifies the mobile station device of the grant including a channel quality indicator transmission instruction, According to the grant, the mobile station apparatus transmits the reference signal and the index to the base station apparatus in the same subframe when an instruction to transmit the index is included.

  (3) A radio communication system according to the present invention is the radio communication system according to (1) or (2), wherein the mobile station apparatus is a symbol that arranges the reference signal for a reference signal for demodulation. It is arranged in a modulation reference signal symbol.

  (4) A radio communication system according to the present invention is the radio communication system according to (1) or (2), in which the mobile station device uses the reference signal as a demodulated reference signal symbol and channel measurement in the same subframe. It is characterized by being arranged in a sounding reference signal symbol which is a symbol for arranging a reference signal for use.

  (5) A base station apparatus according to the present invention is a base station apparatus that performs radio communication with a mobile station apparatus, wherein a sounding reference signal transmission instruction is a 1-bit transmission instruction information or a first code point. It comprises at least means for setting information, and means for notifying the mobile station apparatus of an uplink grant including a transmission instruction for the reference signal.

  (6) The base station apparatus according to the present invention is the base station apparatus according to (5), characterized in that it has at least means for including a channel quality indicator transmission instruction in the grant.

  (7) A mobile station apparatus according to the present invention is a mobile station apparatus that performs radio communication with a base station apparatus, a means for detecting an uplink grant notified from the base station apparatus, and a sounding reference signal according to the grant If the first control information is a predetermined code point according to the means for transmitting the reference signal to the base station apparatus and the grant, when the transmission instruction is indicated by 1-bit transmission instruction information Comprises at least means for transmitting the reference signal to the base station apparatus.

  (8) The mobile station apparatus according to the present invention is the mobile station apparatus according to (7), wherein when the channel quality indicator transmission instruction is included according to the grant, the indicator and the reference signal are It has at least means for transmitting to the base station apparatus in the same subframe.

  (9) The mobile station apparatus according to the present invention is the mobile station apparatus according to (7) or (8), wherein the reference signal is arranged in a demodulation reference signal symbol which is a symbol in which a demodulation reference signal is arranged. It has the means to do at least.

  (10) The mobile station apparatus according to the present invention is the mobile station apparatus according to (7) or (8), wherein the reference signal includes a demodulation reference signal symbol and a channel measurement reference signal in the same subframe. It is characterized by having at least a means for arranging in a sounding reference signal symbol which is a symbol to be processed.

  (11) A radio communication method according to the present invention is a radio communication method in which a base station apparatus and a mobile station apparatus perform radio communication. In the base station apparatus, a transmission instruction for a sounding reference signal is transmitted as 1-bit transmission instruction information. Alternatively, a step of setting with first control information which is a predetermined code point, a step of notifying the mobile station apparatus of an uplink grant including a transmission instruction of the reference signal, and in the mobile station apparatus, according to the grant, When the transmission instruction of the reference signal is instructed by the transmission instruction information, transmitting the reference signal and the physical uplink shared channel to the base station apparatus in the same subframe, and according to the grant, When the control information of 1 is a predetermined code point, transmitting the reference signal to the base station device; Wherein at least include.

  (12) The radio communication method of the present invention is the radio communication method according to (11), wherein the base station apparatus notifies the mobile station apparatus of an uplink grant including a channel quality indicator transmission instruction. And, in the mobile station apparatus, when the transmission instruction of the index is included according to the grant, at least a step of transmitting the reference signal and the index to the base station apparatus in the same subframe. It is characterized by that.

  (13) The radio communication method according to the present invention is the radio communication method according to (11) or (12), and includes at least a step of arranging the reference signal in a demodulation reference signal symbol in the mobile station apparatus. It is characterized by that.

  (14) A radio communication method according to the present invention is the radio communication method according to (11) or (12), wherein, in the mobile station apparatus, the reference signal is referred to a demodulation reference signal symbol and a sounding reference in the same subframe. It includes at least a step of arranging in a signal symbol.

  (15) An integrated circuit according to the present invention is an integrated circuit that, when mounted on a base station apparatus, causes the base station apparatus to perform a plurality of functions, and transmits a sounding reference signal transmission instruction as 1-bit transmission instruction information. Alternatively, the base station apparatus is allowed to exert a function of setting with the first control information that is a predetermined code point and a function of notifying the mobile station apparatus of an uplink grant including a transmission instruction of the reference signal. Features.

  (16) An integrated circuit according to the present invention is the integrated circuit according to (15), wherein, in the base station apparatus, the base station apparatus exhibits a function of including a channel quality indicator transmission instruction in the grant. Features.

  (17) An integrated circuit according to 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 transmits a sounding reference signal notified from the base station device. A function of detecting an uplink grant including an instruction, and a function of transmitting the reference signal to the base station apparatus when a transmission instruction of the reference signal is indicated by 1-bit transmission instruction information according to the grant And, according to the grant, when the first control information is a predetermined code point, a function of transmitting the reference signal and the physical uplink shared channel to the base station apparatus in the same subframe, The apparatus is characterized by being exhibited.

  (18) An integrated circuit according to the present invention is the integrated circuit according to (17), wherein in the mobile station device, in accordance with the grant, a channel quality indicator transmission instruction is included, the indicator and The mobile station apparatus has a function of transmitting the reference signal to the base station apparatus in the same subframe.

  (19) An integrated circuit according to the present invention is the integrated circuit according to (17) or (18), wherein the mobile station apparatus has a function of arranging the reference signal in a demodulation reference signal symbol. And

  (20) An integrated circuit according to the present invention is the integrated circuit according to (17) or (18), wherein the reference signal is arranged in a demodulation reference signal symbol and a sounding reference signal symbol in the same subframe. It is characterized by being exhibited by a mobile station device.

  According to the present invention, a mobile station device, a base station device, a wireless communication system, a wireless communication method, and an integrated circuit capable of efficiently performing transmission control of SRS and PUSCH using one DCI format (uplink grant) Can be provided.

It is a block diagram which shows schematic structure of the base station apparatus 1 of this invention. It is a block diagram which shows schematic structure of the mobile station apparatus 3 of this invention. It is the flowchart which showed the process sequence of the mobile station apparatus 3 in embodiment of this invention. It is a figure which shows an example of the DCI format contained in PDCCH in this invention. It is a figure which shows the example of the frequency band aggregation in a prior art. It is a figure which shows the example of asymmetric frequency band aggregation in a prior art. It is a figure which shows schematic structure of the resource allocation and frequency hopping (FH: Frequency Hopping) of SRS.

  Before entering into a specific description of an embodiment of the present invention, an outline of the communication technology used in the present invention will be briefly described.

(Physical channel)
The physical channels used in the present invention include a physical broadcast channel (PBCH), a physical downlink shared channel (PDSCH), a physical downlink control channel (PDCCH), DL-RS (Downlink Reference Signal or Cell-specific Reference Signal), Physical Uplink Shared Channel (PUSCH), Physical Uplink Control Channel (PUCCH), Physical A random access channel (PRACH: Physical Random Access Channel), an uplink reference signal (UL-RS), and the like are included. Note that the embodiments of the present invention described later can be applied even when different physical channel types are added.

  The physical broadcast channel is transmitted for the purpose of reporting control parameters (broadcast information) that are commonly used to mobile station apparatuses in the cell. Broadcast information not notified by PBCH is notified of resources by PDCCH and is transmitted using a physical downlink shared channel. As broadcast information, a cell global ID indicating an individual ID (Identity) of the cell is notified. In the PBCH, a broadcast channel (BCH) is mapped at intervals of 40 milliseconds. The timing of 40 milliseconds is subjected to blind detection in the mobile station apparatus. That is, explicit signaling is not transmitted to the mobile station apparatus for presenting the PBCH timing. In addition, a subframe including PBCH can be decoded only by the subframe (self-decodable).

  The physical downlink control channel is a downlink channel transmitted from the base station apparatus to the mobile station apparatus, and is a hybrid automatic for PDSCH resource allocation and downlink data (DL-SCH: Downlink-Shared Channel). Downlink Assignment consisting of HARQ (Hybrid Automatic Repeat reQuest) information, Physical Uplink Shared Channel (PUSCH) resource allocation, Uplink data (UL-SCH) : Channel used for notifying the mobile station apparatus of downlink control information (DCI) such as uplink transmission permission (uplink grant) which is HARQ information for Uplink-Shared Channel (uplink shared channel) It is. Moreover, PDCCH is comprised from several control channel element (CCE: Control Channel Element), and a mobile station apparatus receives PDCCH from a base station apparatus by detecting PDCCH comprised from CCE. This CCE is composed of a plurality of resource element groups (REG: Resource Element Group, also called mini-CCE) distributed in the frequency and time domains. Here, the resource element is a unit resource composed of one OFDM symbol (time component) and one subcarrier (frequency component).

  A plurality of formats are prepared for the downlink control information transmitted on the physical downlink control channel. A format of downlink control information (DCI) is called a DCI format (DCI format). For example, the DCI format of the uplink grant is a DCI format 0 that is used when the mobile station device 3 transmits the PUSCH through one transmission antenna port, and the mobile station device 3 uses the MIMO (Multiple Input Multiple Output) for the PUSCH. A DCI format 0A and the like used for transmission by multiplexing (SM: Spatial Multiplexing) are prepared.

  Also, the DCI format for downlink assignment is more than DCI format 1 and DCI format 1 used when the base station apparatus transmits PDSCH using one transmission antenna port or a plurality of transmission antenna ports using the transmission diversity scheme. DCI format 1A having a smaller number of bits, DCI format 1C having a smaller number of bits than the DCI format 1A used for radio resource allocation such as paging information, and the case where the base station apparatus transmits PDSCH by SM using MIMO. DCI format 2 and the like are prepared. In DCI format 0 and DCI format 1A, a flag (Flag for format 0 / format 1A differentiation) is used to make the sizes of the two DCI formats the same by inserting bits into the smaller number of bits and to identify the formats. Include.

  Specifically, DCI format 0, which is an uplink grant, includes PDCCH format identification (Flag for format 0 / format 1A differentiation) information, frequency hopping flag (Frequency hopping flag), resource block allocation and hopping resource allocation (Resource block assignment and hopping resource allocation) information, modulation and coding scheme and redundancy version information, NDI (New Data Indicator) information, transmission power control command (TPC command for scheduled PUSCH) information for scheduled PUSCH, Control information such as cyclic shift for DM-RS (Cyclic shift for DM-RS) information, CQI transmission instruction (CQI request) information, padding bit (0 padding) information, cyclic redundancy check (CRC) information, etc. Field, control information field, Distribution field comprised, with bit field referred to).

  The PDCCH format identification information is information indicating the type of DCI format of the downlink control information, that is, whether it is DCI format 0 or DCI format 1A. Resource block allocation and hopping resource allocation information are information indicating resource allocation in the case of hopping and resource block allocation of PUSCH. The modulation coding scheme and redundancy version information are information indicating the PUSCH modulation scheme, coding rate, and redundancy version. The NDI information is information indicating whether the PUSCH is an initial transmission or a retransmission. The PUSCH transmission power control command information is information used for PUSCH transmission power control. DM-RS cyclic shift information is information indicating a cyclic shift of DM-RS. Padding bit (0 padding) information is a bit inserted to make the sizes of DCI format 0 and DCI format 1A the same, and the value is set to “0”. The CQI transmission instruction information can instruct the mobile station apparatus to allocate the CQI using the PUSCH resource and dynamically transmit to the base station apparatus when the base station apparatus requests the CQI. The CQI at this time is also referred to as an aperiodic CQI (A-CQI).

  Specifically, the DCI format 1A, which is a downlink assignment, includes PDCCH format identification (Flag for format 0 / format 1A differentiation) information, virtual resource block (VRB) centralized / distributed arrangement identification (Localized / Distributed VRB assignment flag) information, resource block assignment information, modulation and coding scheme (MCS) information, HARQ process number information, NDI (New Data Indicator) information, redundancy Control information (field, RV: Redundancy Version) information, PUCCH transmission power control (TPC) command information, padding bit (0 padding) information, cyclic redundancy check (CRC) information, etc. Control information field, information field, and bit field It consists referred to).

  The PDCCH format identification information is information indicating the type of DCI format of the downlink control information, that is, whether it is DCI format 0 or DCI format 1A. The virtual resource block centralized / distributed layout identification information is information indicating a method (centralized layout or distributed layout) for associating the virtual resource block indicated by the resource block layout information with the actual resource block. The resource block arrangement information is information indicating a virtual resource block assigned to the PDSCH. The modulation and coding scheme information is information relating to the PDSCH modulation scheme and coding rate, and the amount of downlink data transmitted on the PDSCH. The HARQ process number (HARQ process number) information is information indicating which number of HARQ process the downlink data transmitted on the PDSCH corresponding to the DCI format 1A corresponds to. The NDI information is information indicating whether the PDSCH is an initial transmission or a retransmission. The redundancy version information is information indicating which part of the bit sequence is transmitted among the bit sequences in which the downlink data is encoded. The PUCCH transmission power control command is information used for PUCCH transmission power control. Padding bit (0 padding) information is a bit inserted to make the sizes of DCI format 0 and DCI format 1A the same, and the value is set to “0”.

  Since the DCI format used for group scheduling for a plurality of mobile station apparatuses needs to be received by a plurality of mobile station apparatuses, all mobile station apparatuses try to search (detect) PDCCH (CSS: Common Search Space) Here, a PDCCH addressed to a certain mobile station device is arranged in a mobile station device specific search space (USS) and a common search region where a certain mobile station device tries to search (detect) the PDCCH.

  The base station apparatus assigns a sequence obtained by scrambling a CRC code generated based on DCI with RNTI (Radio Network Temporary Identity) to DCI, and transmits the DCI to the mobile station apparatus. The mobile station apparatus changes the interpretation of DCI depending on whether the CRC code is scrambled with any RNTI. For example, if the DCI is scrambled with the CRC code by C-RNTI (Cell-RNTI) or SPS (Semi Persistent Scheduling) C-RNTI assigned from the base station apparatus, the mobile station apparatus It is judged that it is DCI.

  The PDCCH is encoded (Separate Coding) separately for each mobile station apparatus and for each type. That is, the mobile station apparatus detects a plurality of PDCCHs, and acquires downlink resource allocation, uplink resource allocation, and other control information. Each PDCCH is assigned a CRC value scrambled by RNTI, and the mobile station apparatus descrambles a CRC scrambled by RNTI for each set of CCEs that may constitute PDCCH. (Descramble) is performed, and the CRC value is acquired. Then, CRC is performed using the acquired CRC value, and the PDCCH in which the CRC is successful is acquired as the PDCCH addressed to the own apparatus. In addition, when the scrambled CRC is scrambled with the RNTI assigned to the other device using the RNTI assigned to the own device, the correct CRC value cannot be obtained, so that it is recognized as the PDCCH addressed to the own device. do not do. This is also referred to as blind detection, and the range of CCE sets in which the mobile station apparatus may perform blind detection is referred to as a search space (Search Space). That is, the mobile station apparatus performs blind detection on CCEs in the search area, and detects PDCCH addressed to itself.

  The physical downlink shared channel is a channel used to transmit downlink data (DL-SCH: also called downlink shared channel) or paging information.

  The downlink reference signal is transmitted from the base station apparatus to the mobile station apparatus using the downlink. The mobile station apparatus determines downlink reception quality by measuring a downlink reference signal. The reception quality is notified to the base station apparatus using PUCCH or PUSCH as a channel quality indicator (CQI) which is a quality information indicator. The base station apparatus performs downlink communication scheduling for the mobile station apparatus based on the CQI notified from the mobile station apparatus. The reception quality includes signal-to-interference power ratio (SIR), signal-to-interference plus noise ratio (SINR), and signal-to-noise power ratio (SNR). Signal-to-noise ratio (CIR), carrier-to-interference ratio (CIR), block error rate (BLER), path loss (PL), and the like can be used.

  The physical uplink shared channel is a channel mainly used for transmitting uplink data (UL-SCH: Uplink Shared Channel, uplink shared channel). When the base station apparatus schedules the mobile station apparatus, the channel state information (downlink channel quality indicator (CQI), precoding matrix indicator (PMI), rank indicator (RI: Rank Indicator)) and HARQ positive acknowledgment (ACK: Acknowledgement) / negative acknowledgment (NACK: Negative Acknowledgement) for downlink transmission are also transmitted using PUSCH. Here, uplink data (UL-SCH) indicates transmission of user data, for example, and UL-SCH is a transport channel. In UL-SCH, HARQ and dynamic adaptive radio link control are supported, and beamforming can be used. UL-SCH supports dynamic resource allocation and semi-static resource allocation.

  The physical uplink control channel is a channel used for transmitting uplink control information (UCI). Here, UCI (also referred to as control data) is, for example, channel state information (CQI, PMI, RI) transmitted (feedback) from the mobile station apparatus to the base station apparatus, and the mobile station apparatus transmits uplink data. This includes a scheduling request (SR: Scheduling Request) for requesting allocation of resources for transmission (requesting transmission on UL-SCH), HARQ ACK / NACK for downlink transmission, and the like.

  The uplink reference signal is transmitted from the mobile station device to the base station device. UL-RS includes a sounding reference signal (SRS) and a demodulation reference signal (DM-RS). The SRS, which is a channel measurement reference signal, is measured by the base station apparatus to determine the reception quality of the uplink radio transmission signal of the mobile station apparatus, and uplink scheduling and uplink timing synchronization based on the reception quality are performed. Used for adjustment. Also, DM-RS is transmitted together with PUSCH or PUCCH, calculates a fluctuation amount of amplitude, phase or frequency of PUSCH or PUCCH signal, and a reference signal for demodulating the signal transmitted using PUSCH or PUCCH Also used as

  The transmission bandwidth of DM-RS matches the transmission bandwidth of PUSCH or PUCCH, but the transmission bandwidth of SRS is set independently of DM-RS. That is, the SRS transmission bandwidth does not necessarily match the PUSCH or PUCCH transmission bandwidth, and is preset by the base station apparatus. In addition, frequency hopping is applied to the SRS in the time axis direction. SRS can obtain a frequency diversity effect and an interference averaging effect by using frequency hopping. In the SRS, radio resources are distributed in the frequency axis direction (comb arrangement: also referred to as a transmission comb). For example, radio resources can be arranged every other subcarrier in the frequency axis direction, and a plurality of mobile station apparatuses can be arranged at the same transmission timing by changing the positions of combs (for example, comb 0 and comb 1). Thus, it is possible to perform frequency division multiple access (FDMA) for the SRS.

  A-SRS is a reference signal for channel measurement transmitted when the base station apparatus requests transmission, and a subframe for transmitting A-SRS may be set by the base station apparatus using PDCCH. It may be set using a radio resource control signal. Moreover, the sub-frame which transmits A-SRS may be set using a broadcast channel by the base station apparatus. Here, the radio resource control signal is transmitted at intervals of, for example, about 100 milliseconds to 200 milliseconds.

  Moreover, P-SRS is a reference signal for channel measurement transmitted according to a transmission cycle preset by the base station apparatus, and a subframe for transmitting P-SRS is a radio resource control signal transmitted by the base station apparatus. It may be set using a broadcast channel or may be set using a broadcast channel. In addition, setting information (SRS configuration) related to SRS parameters such as the transmission period and transmission bandwidth of each of A-SRS and P-SRS is included in the radio resource control signal after being set in advance by the base station apparatus. It may be transmitted to the device.

  In addition, SRS subframes (subframes for transmitting A-SRS and P-SRS) that are subframes for transmitting SRS may be set for each cell or for each mobile station apparatus. . The subframes for transmitting A-SRS and P-SRS may be transmitted using the same subframe or may be transmitted using different subframes. For example, the base station apparatus may set a subframe for transmitting A-SRS for each mobile station apparatus and set a subframe for transmitting P-SRS for each cell. Here, the SRS subframe set for each cell is called a cell-specific SRS subframe, and the SRS subframe set for each mobile station device is called a mobile station device-specific SRS subframe. As another example, the base station apparatus sets a subframe for transmitting P-SRS for each cell, and sets a part of the subframe for transmitting P-SRS as a subframe for transmitting A-SRS for each cell or You may set for every mobile station apparatus.

  The physical random access channel is a physical channel used for transmitting a random access preamble and has a guard time. The PRACH is mainly used for the mobile station apparatus to synchronize with the base station apparatus, and is used for initial access, handover, reconnection request, and scheduling request.

  The scheduling request is information that the mobile station apparatus requests the base station apparatus to allocate PUSCH resources. The mobile station apparatus transmits SR when information data to be transmitted accumulates in its own buffer and requests resource allocation for PUSCH. Also, the mobile station apparatus transmits the SR to the base station apparatus using the PUCCH allocated in advance from the base station apparatus. Note that the base station apparatus allocates periodic resources for the mobile station apparatus to arrange the SR when communication connection with the mobile station apparatus starts.

(SRS resource allocation and frequency hopping)
FIG. 7 is a diagram illustrating a schematic configuration of SRS resource allocation and frequency hopping (FH). In the figure, the horizontal axis is time, and the vertical axis is frequency. The left side of the figure shows an example of SRS resource allocation. In the example on the left side of the figure, 14 symbols are arranged in the time axis direction. Seven symbols correspond to one slot, and the length of one slot is 0.5 milliseconds (ms). Further, 14 symbols (corresponding to 2 slots) correspond to 1 subframe, and the length of 1 subframe is 1 millisecond. Thus, in the uplink signal in which one subframe is composed of 14 symbols, the SRS is arranged in the 14th symbol (also referred to as an SRS symbol). The SRS resource (bandwidth in the frequency axis direction) arranged in the 14th symbol is set in the base station apparatus according to the uplink system bandwidth and the transmission power of the mobile station apparatus. Further, the PRACH can be allocated with the bandwidth and the time symbol length being changed according to the type and format of the message to be transmitted. DM-RSs are arranged in the fourth and eleventh symbols (also referred to as DM-RS symbols) when one subframe is composed of 14 symbols, and the DM-RS transmission bandwidth is the PUSCH transmission band. Matches the width.

  Further, frequency hopping that changes the frequency position every time transmission is applied to the time axis direction. The right side of the figure shows an example of SRS frequency hopping. On the right side of the figure, SRS is transmitted every transmission period T. As shown in the figure, hopping is performed in the frequency direction every period T (that is, every time SRS is transmitted). The mobile station apparatus can apply frequency hopping when the hopping bandwidth, which is one of the SRS setting information, is set to a bandwidth wider than the SRS transmission bandwidth.

[Configuration of base station apparatus]
FIG. 1 is a block diagram showing a schematic functional configuration of a base station apparatus 1 according to the present invention. The base station apparatus 1 includes a transmission unit 101, a reception unit 103, a scheduling unit 105, an upper layer 107, a channel estimation unit 108, and an antenna 109. The transmission unit 101 includes a data control unit 1011, a modulation unit 1013, and a wireless transmission unit 1015. In addition, the reception unit 103 includes a wireless reception unit 1031, a demodulation unit 1033, and a data extraction unit 1035.

  The data control unit 1011 receives user data and control data, places control data on the PDCCH, and places transmission data and control data for the mobile station apparatus 3 on the PDSCH according to an instruction from the scheduling unit 105. The modulation unit 1013 performs signal processing such as data modulation, serial / parallel conversion of an input signal, IFFT, CP insertion, and filtering to generate a transmission signal. The radio transmission unit 1015 transmits the modulated data to the mobile station apparatus 3 via the antenna 109 after up-converting the modulated data to a radio frequency. Further, the transmission unit 101 includes the first to third control information in the PDCCH and transmits it to the mobile station apparatus 3 according to the instruction of the scheduling unit 105.

  The radio reception unit 1031 receives an uplink signal from the mobile station apparatus 3, down-converts the signal to a baseband signal, and outputs received data to the demodulation unit 1033. The data extraction unit 1035 confirms the correctness of the received data and notifies the scheduling unit 105 of the confirmation result. If the received data is correct, the data extraction unit 1035 separates the received data into user data and control data. The data extraction unit 1035 outputs the control data of the second layer such as downlink channel quality indication information and the success / failure of the downlink data (ACK / NACK) in the control data to the scheduling unit 105, and the other data The control data and user data of the third layer and the like are output to the upper layer 107. If the received data is incorrect, the data extraction unit 1035 stores the received data for combining with the retransmitted data, and performs a combining process when the retransmitted data is received.

  The scheduling unit 105 performs scheduling for arranging user data and control data on the PDSCH and PDCCH. Further, the scheduling unit 105 instructs the transmission unit 101 to transmit an A-SRS transmission instruction included in the PDCCH (DCI format) according to an instruction from the upper layer 107.

  The upper layer 107 includes a medium access control (MAC) layer, a radio link control (RLC) layer, a packet data convergence protocol (PDCP) layer, and a radio resource control (RRC: radio). Resource Control) layer processing. Since the upper layer 107 controls the processing units of the lower layer in an integrated manner, there is an interface between the upper layer 107, the scheduling unit 105, the channel estimation unit 108, the antenna 109, the transmission unit 101, and the reception unit 103. (However, not shown).

  The upper layer 107 includes a radio resource control unit 1071 (also referred to as a control unit). The radio resource control unit 1071 also manages various setting information, system information, paging control, communication state management of each mobile station device, mobility management such as handover, buffer status management for each mobile station device, It manages connection settings for cast and multicast bearers, manages mobile station identifiers (also referred to as UEID or RNTI (Radio Network Temporary Identifier)), and the like. In addition, the upper layer 107 exchanges information with another base station apparatus and information with an upper node. Further, the upper layer 107 sets and manages parameters such as SRS transmission bandwidth as SRS setting information, and notifies the scheduling unit 105 to notify the mobile station apparatus 3 of the SRS setting information included in the radio resource control signal. Instruct. The SRS setting information may be notified including not only the P-SRS parameters but also the A-SRS parameters. Also, the upper layer 107 instructs the scheduling unit 105 to transmit A-SRS when it is desired to perform uplink channel measurement as necessary.

  In addition, in the uplink scheduling, the scheduling unit 105 estimates the uplink channel state (wireless channel state) output from the channel estimation unit 108, requests for resource allocation from the mobile station device 3, Uplink transport format (transmission form, ie, physical resource block allocation and modulation scheme and code) for modulating each data based on usable PRB information, scheduling information input from higher layer 107, etc. Scheduling information used for uplink selection scheduling and uplink scheduling. The scheduling information used for the uplink scheduling is output to the data control unit 1011. Also, when the upper layer 107 is instructed to transmit A-SRS, the scheduling information is reset and output to the data control unit 1011.

  In addition, the scheduling unit 105 maps the downlink logical channel input from the higher layer 107 to the transport channel and outputs it to the data control unit 1011. In addition, the scheduling unit 105 processes the control data and the transport channel acquired in the uplink input from the data extraction unit 1035 as necessary, maps them to the uplink logical channel, and outputs them to the upper layer 107. To do.

  Channel estimation section 108 estimates an uplink channel state from the demodulation reference signal for demodulation of uplink data, and outputs the estimation result to demodulation section 1033. Further, in order to perform uplink scheduling, an uplink channel state is estimated from the sounding reference signal, and the estimation result is output to scheduling section 105.

[Configuration of mobile station device]
FIG. 2 is a block diagram showing a schematic functional configuration of the mobile station apparatus 3 of the present invention. The mobile station apparatus 3 includes a transmission unit 201, a reception unit 203, a scheduling unit 205, a reference signal generation unit 206, an upper layer 207, and an antenna 209. The transmission unit 201 includes a data control unit 2011, a modulation unit 2013, and a wireless transmission unit 2015. The reception unit 203 includes a wireless reception unit 2031, a demodulation unit 2033, and a data extraction unit 2035.

  User data and control data are input from the upper layer 207 to the data control unit 2011. The data control unit 2011 arranges the input data on the PUSCH or PUCCH according to an instruction from the scheduling unit 205. The modulation unit 2013 performs data modulation on PUSCH and PUCCH and outputs the data to the radio transmission unit 2015. The radio transmission unit 2015 inserts the modulated data and the uplink reference signal into discrete Fourier transform (DFT), subcarrier mapping, inverse fast Fourier transform (IFFT), and CP (Cyclic Prefix). Then, signal processing such as filtering is performed, a transmission signal is generated, up-converted to a radio frequency, and then transmitted to the base station apparatus 1 via the antenna 209.

  Radio receiving section 2031 receives the downlink signal from base station apparatus 1, down-converts it to a baseband signal, and outputs the received signal to demodulation section 2033. The demodulator 2033 demodulates the received data. The data extraction unit 2035 separates the received data into user data and control data. The data extraction unit 2035 outputs scheduling information, random access response messages, control data related to intermittent reception control, and other second layer control data to the scheduling unit 205 and outputs user data to the upper layer 207. In addition, the data extraction unit 2035 detects the code point of the control information included in the PDCCH (DCI format) and outputs it to the upper layer 207.

  The scheduling unit 205 analyzes the control data input from the data extraction unit 2035, generates uplink scheduling information, and performs data control to allocate user data and control data to PUSCH and PUCCH based on the scheduling information. Section 2011 is instructed.

  Further, the scheduling unit 205 includes a reference signal control unit 2051. The reference signal control unit 2051 extracts SRS setting information based on the scheduling information transmitted from the base station apparatus 1. Also, transmission control is performed when SRS and PUSCH or PUCCH occur at the same timing, and SRS transmission control information is generated. The reference signal control unit 2051 outputs the SRS setting information and the SRS transmission control information to the reference signal generation unit 206. Here, the SRS setting information is information for setting parameters such as SRS transmission bandwidth and transmission cycle. The SRS transmission control information is information indicating an SRS transmission control method when the SRS and other uplink channels (PUSCH, PUCCH) are allocated to the same subframe. For example, when SRS and PUCCH occur in the same subframe, this is information for instructing the mobile station apparatus 3 to perform a process of not transmitting SRS.

  In uplink scheduling, the scheduling unit 205 determines the uplink buffer status input from the higher layer 207 and uplink scheduling information (transport format and HARQ retransmission) from the base station apparatus 1 input from the data extraction unit 207. Information), and scheduling information for mapping the uplink logical channel input from the upper layer 207 to the transport channel and the uplink scheduling based on the scheduling information input from the upper layer 208, etc. Scheduling information to be generated is generated. Note that the information notified from the base station apparatus 1 is used for the uplink transport format. The scheduling information is output to the data control unit 2011.

  In addition, the scheduling unit 205 maps the uplink logical channel input from the higher layer 207 to the transport channel and outputs it to the data control unit 2011. The scheduling unit 205 also outputs the CSI, CQI, PMI, RI, and CRC check confirmation results input from the data extraction unit 207 input from the channel estimation unit 208 to the data control unit 2011. . In addition, the scheduling unit 205 processes the control data and the transport channel acquired in the downlink input from the data extraction unit 2035 as necessary, maps them to the downlink logical channel, and outputs them to the upper layer 207. To do.

  Channel estimation section 208 estimates the downlink channel state from DL-RS for downlink data demodulation, and outputs the estimation result to demodulation section 2033. Also, the channel estimation unit 208 notifies the base station apparatus 1 of the downlink channel state (radio channel state, CSI, CQI, PMI, RI) estimation result from the downlink reference signal to the downlink channel. The state is estimated, and the estimation result is output to the scheduling unit 205 as, for example, CSI, CQI, PMI, or RI.

  The reference signal generation unit 206 generates an SRS based on the SRS setting information and the SRS transmission control information input from the reference signal control unit 2051 and outputs the SRS to the wireless transmission unit 2015.

  The upper layer 207 includes a medium access control (MAC) layer, a radio link control (RLC) layer, a packet data convergence protocol (PDCP) layer, and a radio resource control (RRC: radio). Resource Control) layer processing. Since the upper layer 207 controls the processing units of the lower layer in an integrated manner, there is an interface between the upper layer 207, the scheduling unit 205, the channel estimation unit 208, the antenna 209, the transmission unit 201, and the reception unit 203. (However, not shown).

  The upper layer 207 has a radio resource control unit 2071 (also referred to as a control unit). The radio resource control unit 2071 manages various setting information, system information, paging control, communication status management of the local station, mobility management such as handover, buffer status management, unicast and multicast bearer connection setting management The mobile station identifier (UEID) is managed. In addition, the upper layer 207 extracts SRS setting information from the radio resource control signal transmitted from the base station apparatus 1 and sets SRS parameters. Further, when an A-SRS transmission instruction is included from the received DCI format, the scheduling information considering the A-SRS transmission is reset and output to the scheduling unit 205.

<Embodiment>
Embodiments of the present invention will be described below. In the embodiment of the present invention, the base station apparatus sets a sounding reference signal transmission instruction with 1-bit (multi-bit) transmission instruction information or first control information that is a predetermined code point, and transmits a sounding reference signal. An uplink grant including the instruction is notified to the mobile station apparatus. Also, according to the uplink grant, the mobile station apparatus transmits the sounding reference signal and the physical uplink shared channel to the base station apparatus in the same subframe when the sounding reference signal transmission instruction is 1 bit. If the control information is a predetermined code point, a sounding reference signal is transmitted to the base station apparatus.

  In the embodiment of the present invention, the mobile station apparatus 3 performs PUSCH transmission in the same subframe as that of A-SRS because the A-SRS transmission instruction can be set by both 1 bit (multi-bit) and a predetermined code point. It is possible to realize an uplink signal resource allocation method that does not transmit unnecessary radio resources. That is, the base station apparatus 1 can transmit an uplink grant including 1-bit (multi-bit) control information instructing transmission of A-SRS to the mobile station apparatus 3. Further, the base station apparatus 1 can transmit an uplink grant including control information that is a predetermined code point for instructing transmission of A-SRS to the mobile station apparatus 3. The mobile station device 3 determines whether the A-SRS transmission is instructed by 1-bit (multi-bit) control information or by the control information that is a predetermined code point. Whether to perform PUSCH transmission in the same subframe can be switched. That is, the mobile station apparatus 3 switches dynamically whether or not to perform PUSCH transmission in the same subframe as the A-SRS according to control information included in the uplink grant from the base station apparatus. Can do.

  Here, when the base station apparatus 1 instructs transmission of A-SRS by 1-bit (multi-bit) information, the base station apparatus 1 transmits information that instructs transmission of A-SRS included in the uplink grant ( This indicates that the mobile station apparatus 3 is instructed to transmit A-SRS by notifying the mobile station apparatus 3 of (A-SRS transmission instruction information). For example, the base station apparatus 1 sets the information instructing transmission of A-SRS included in the uplink grant to “1” and notifies the mobile station apparatus 3 to the mobile station apparatus 3 by -It can instruct the transmission of SRS. That is, the base station apparatus 1 sets the control information defined for instructing transmission of A-SRS to a predetermined value (for example, “1”) and notifies the mobile station apparatus 3 by moving The station apparatus 3 can be instructed to transmit A-SRS.

  In addition, when the base station apparatus 1 instructs transmission of A-SRS with control information (first control information) that is a predetermined code point, the base station apparatus 1 includes control information (described above) included in the uplink grant. It is indicated that the mobile station apparatus 3 is instructed to transmit A-SRS by setting predetermined information in any control information) to a predetermined value. For example, the base station apparatus 1 sets the frequency hopping flag, the resource block arrangement, and the hopping resource allocation information included in the uplink grant to predetermined values (for example, all fields are set to “1”), and then to the mobile station apparatus 3. By notifying, it is possible to instruct the mobile station apparatus 3 to transmit A-SRS. Here, when which control information in the uplink grant is set to which value, the base station apparatus 1 instructs the mobile station apparatus 3 to transmit A-SRS according to the specification. Etc., and is known between the base station apparatus 1 and the mobile station apparatus 3 in advance. That is, for example, the base station apparatus 1 uses control information defined for purposes other than instructing transmission of A-SRS (for example, frequency hopping flag, resource block arrangement, hopping resource allocation) to a predetermined value ( For example, it is possible to instruct the mobile station apparatus 3 to transmit A-SRS by setting all fields to “1”) and notifying the mobile station apparatus 3. Here, the base station apparatus 1 described above (for example, represented by 1 bit) in the predetermined information set to a predetermined value in order to instruct the mobile station apparatus 3 to transmit A-SRS. Control information defined for instructing transmission of A-SRS may be included.

  By instructing transmission of A-SRS with control information that is a predetermined code point, the base station apparatus 1 does not depend on the value set in the A-SRS transmission instruction information included in the uplink grant. The mobile station apparatus 3 can be instructed to transmit only A-SRS.

  Hereinafter, in order to simplify the explanation, the base station apparatus 1 simply instructs the mobile station apparatus 3 to transmit A-SRS using 1-bit control information. -It describes that the transmission instruction | indication of SRS is included in an uplink grant, and it transmits to the mobile station apparatus 3. FIG. In addition, the base station apparatus instructs the mobile station apparatus to transmit A-SRS using the control information that is the predetermined code point, and the first control information that is the predetermined code point is set to the uplink grant. It is also described as being transmitted to the mobile station apparatus.

  FIG. 3 is a flowchart showing a processing procedure of the mobile station apparatus 3 in the embodiment of the present invention. When the mobile station apparatus 3 receives (detects) the DCI format transmitted from the base station apparatus 1, the mobile station apparatus 3 confirms whether or not it is an uplink grant (step S101). When the received DCI format is an uplink grant (step S101: YES), the mobile station apparatus 3 checks whether or not an A-SRS transmission instruction is included in the DCI format (step S102). When the A-SRS transmission instruction is included in the uplink grant, the mobile station device 3 transmits the A-SRS and the PUSCH to the base station device 1 in the same subframe (step S103). When the A-SRS transmission instruction is not included in the uplink grant (the A-SRS transmission instruction information is set to “0”, for example) (step S102: YES), the first control information is a predetermined code. It is confirmed whether or not it is a point (step S104). When the A-SRS transmission instruction is indicated by the first control information that is a predetermined code point (step S104: YES), the mobile station device 3 transmits the A-SRS to the base station device 1 (step S104). S105). That is, the mobile station apparatus 3 transmits only A-SRS to the base station apparatus 1 without PUSCH in a certain subframe. When the first control information is not a predetermined code point (step S104: NO), the mobile station device 3 transmits PUSCH to the base station device 1 (step S106). In addition, as a means for confirming the A-SRS transmission instruction of the mobile station apparatus 3 in the embodiment of the present invention, after confirming whether or not the first control information is a predetermined code point (predetermined value). But it ’s okay. That is, when the first control information is a predetermined code point, the mobile station device 3 transmits A-SRS to the base station device 1. If the first control information is not a predetermined code point, it is confirmed whether the A-SRS transmission instruction information included in the uplink grant indicates an A-SRS transmission instruction. When the SRS transmission instruction is indicated (A-SRS transmission instruction information is set to “1”), the mobile station apparatus 3 transmits the A-SRS and the PUSCH to the base station apparatus 1 in the same subframe. Send. Further, the first control information is not a predetermined code point, and the A-SRS transmission instruction information does not indicate an A-SRS transmission instruction (A-SRS transmission instruction information is set to “0”). In this case, the mobile station device 3 transmits PUSCH to the base station device 1.

  Here, the subframe in which the mobile station device 3 transmits the A-SRS and the PUSCH may be a subframe after a specific period has elapsed after receiving the DCI format, or after a certain specific period has elapsed. The first cell-specific SRS subframe may be used, or the first mobile station apparatus-specific SRS subframe after a certain period has elapsed. In addition, the subframe in which the mobile station device 3 transmits the A-SRS and the PUSCH may be uniquely determined in advance by the system, or is notified from the base station device 1 to the mobile station device 3 as broadcast information all at once. Alternatively, it may be notified from the base station apparatus 1 to the individual mobile station apparatus 3. That is, the base station apparatus 1 may set the sub-frame which transmits A-SRS and PUSCH for every cell, and may set for every mobile station apparatus. Further, when the DCI format notified from the base station device 1 includes an A-SRS transmission stop instruction, the mobile station device 3 may be set to stop the A-SRS transmission. .

  FIG. 4 is a diagram illustrating an example of a DCI format included in the PDCCH according to the present invention. In the DCI format (uplink grant) shown in FIG. 6A, from which uplink component carrier the uplink signal is transmitted (to which uplink component carrier the PUSCH scheduled by the DCI format is arranged) ) Carrier indicator (CI) information, PDCCH format identification (Flag for format 0 / format 1A differentiation) information, frequency hopping flag (Frequency hopping flag), resource block allocation and hopping resource allocation (Resource block assignment and hopping) resource allocation) information, modulation and coding scheme and redundancy version information, NDI (New Data Indicator) information, transmission power control command (TPC command) for scheduled PUSCH for scheduled PUSCH) information, cyclic shift for DM-RS (Cyclic shift for DM-RS) information, CQI transmission instruction (also called CQI request) information, padding bit (0 padding) information, cyclic redundancy check ( CRC: Cyclic Redundancy Check) information, A-SRS transmission instruction (defined by, for example, 1 bit defined to instruct A-SRS transmission) (SRS activation, SRS request, trigger for SRS transmission) It shows that it is composed of information.

  In FIG. 5A, when an A-SRS transmission instruction is set, the mobile station device 3 transmits PUSCH and A-SRS to the base station device 1 in the same subframe. That is, when the field defined for the A-SRS transmission instruction included in the uplink grant is set to “1”, for example, the mobile station apparatus 3 uses PUSCH and A -Both SRS is transmitted to the base station apparatus 1. At this time, if the CQI transmission instruction included in the uplink grant is also set (for example, the CQI request is set to “1”), the CQI and the A-SRS are transmitted in the same subframe. Transmit to the station apparatus 1. Here, the mobile station apparatus 3 arranges CQI and UL-SCH data (transport link for Uplink Shared Channel data, UL-SCH) in the PUSCH, and sends it to the base station apparatus 1 in the same subframe together with the A-SRS. Send.

  At this time, the base station apparatus 1 can instruct the mobile station apparatus 3 to transmit CQI only (transmission of CQI without UL-SCH data, transmission of only uplink control information). For example, the base station apparatus 1 instructs the mobile station apparatus 3 to transmit only CQI by setting predetermined information of the uplink grant to a predetermined value (setting a predetermined code point). Can do. For example, the base station apparatus 1 sets the resource block arrangement, the MCS information, and the CQI request included in the uplink grant to predetermined values and notifies the mobile station apparatus 3 of the CQI to the mobile station apparatus 3. Can only instruct transmission. The mobile station apparatus 3 notified from the base station apparatus 1 of an A-SRS transmission instruction (for example, indicated by 1 bit) and predetermined information set at a predetermined code point instructing transmission of CQI only, Only CQI is arranged in PUSCH (CQI is arranged without UL-SCH data) and transmitted to base station apparatus 1 in the same subframe together with A-SRS.

  FIG. 4B shows a case where the frequency hopping flag, the resource block arrangement, and the hopping resource allocation information are set as predetermined code points as an example. That is, a case is shown where the first control information (predetermined information) is composed of a frequency hopping flag, a resource block arrangement, and hopping resource allocation information. When the first control information is a predetermined code point, the mobile station device 3 transmits A-SRS to the base station device 1. That is, when the frequency hopping flag, the resource block arrangement, and the hopping resource allocation information (first control information) defined in advance as the predetermined information are set to predetermined values, the mobile station device 3 In the frame, only A-SRS is transmitted to the base station apparatus 1 without PUSCH.

  In FIG. 4, A-SRS transmission instruction information is defined in advance as control information included in the DCI format (uplink grant). In addition, it is possible to issue an A-SRS transmission instruction using control information other than the A-SRS transmission instruction information. As a method thereof, when the first control information is a predetermined code point (predetermined value), the mobile station device 3 recognizes that transmission of A-SRS has been instructed. At this time, the base station apparatus 1 can also reuse the A-SRS transmission instruction information as a field for indicating other control information. The mobile station device 3 can replace the control information that is not used for the first control information as other control information.

  In the embodiment of the present invention, when the A-SRS transmission instruction is indicated by 1 bit (multi-bit) in the uplink grant, the mobile station apparatus 3 transmits the PUSCH and the A-SRS to the base station apparatus 1 in the same subframe. However, the mobile station apparatus 3 may transmit PUSCH and A-SRS in different subframes. For example, a mobile station apparatus that has received an uplink grant including an A-SRS transmission instruction transmits a PUSCH to the base station apparatus 1 four subframes after the subframe that has received the uplink grant, and the first after four subframes. A-SRS may be transmitted in the cell-specific SRS subframe or the mobile station apparatus-specific SRS subframe. In addition, the subframe for transmitting the A-SRS may be uniquely determined in advance by the system, may be notified simultaneously from the base station apparatus to the mobile station apparatus as broadcast information, or may be individually transmitted from the base station apparatus. May be notified to the mobile station apparatus.

  In the present invention, an A-SRS can also be arranged in a DM-RS symbol. Since 2 symbols are arranged in one subframe in the DM-RS, the mobile station apparatus 3 can transmit a plurality of A-SRSs to the base station apparatus 1 in one subframe by using the symbol. it can. Furthermore, since the OCC (Orthogonal Cover Code) used to reduce interference with other mobile station apparatuses can be applied, the base station apparatus 1 can improve the channel measurement accuracy by A-SRS. it can. In addition, when the subframe in which the A-SRS is arranged in the DM-RS symbol is the same subframe as the SRS subframe, the mobile station device 3 arranges the A-SRS in the DM-RS symbol and the SRS symbol, and You may transmit to the apparatus 1. The transmission bandwidth of the A-SRS at this time may match the transmission bandwidth of the DM-RS, may be set using the SRS setting information notified from the base station apparatus 1, or DM- The transmission bandwidth of the A-SRS arranged in the RS symbol and the transmission bandwidth of the A-SRS arranged in the SRS symbol may be set differently.

  In addition, in the present invention, when communication using multiple antennas such as MIMO is set, frequency division multiplexing (FDM) with different comb arrangements using the same symbols and distributed arrangement of SRS resources with the same symbols. : Frequency Division Multiplexing) and A-SRS for each antenna using OCC of different values in the same subframe, so that channel measurement for multiple antennas can be performed once without increasing the overhead of PDCCH. The mobile station apparatus can be instructed by the notification, MIMO communication can be performed dynamically, and efficient communication can be performed.

  Further, in the present invention, when an A-SRS transmission instruction is indicated by a predetermined code point, the remaining control information other than the first control information field that is a predetermined code point of the DCI format (uplink grant) Different control information can be assigned to the field. For example, the base station apparatus 1 can allocate the remaining fields to the mobile station apparatus 3 as A-SRS parameters. The A-SRS parameters (SRS configurations) include a transmission bandwidth (SRS transmission bandwidth) when the mobile station apparatus transmits A-SRS. The A-SRS parameter includes a cyclic shift used to maintain orthogonality between mobile station apparatuses or signals. The A-SRS parameter includes information indicating the frequency position where the A-SRS is arranged. The A-SRS parameter includes the number of transmissions or a transmission stop time for completing the transmission of A-SRS. The A-SRS parameter includes an antenna port (antenna index) for transmitting A-SRS. Further, the A-SRS parameter includes a multi-antenna simultaneous transmission flag indicating whether or not A-SRS transmission is performed using a plurality of antennas simultaneously as in MIMO. The A-SRS parameter includes a TPC command (transmission power control information) for A-SRS. The A-SRS parameter includes a carrier indicator (CI: Carrier Indicator) indicating from which component carrier the A-SRS is transmitted. The A-SRS parameter includes a cyclic shift of A-SRS. In addition, when the A-SRS is arranged in the DM-RS symbol, information indicating whether to use the OCC is included. Which of these A-SRS parameters is used may be uniquely determined in advance by the system, or may be notified simultaneously from the base station apparatus to the mobile station apparatus as broadcast information. However, the notification may be sent from the base station apparatus to the individual mobile station apparatus.

  Also, in the present invention, when the DCI format including the CQI transmission instruction includes the A-SRS transmission instruction, the mobile station apparatus 3 uses the same subframe to transmit the CQI and the A-SRS to the base station apparatus. 1 may be transmitted, or may be transmitted in different subframes.

  Further, when a DCI format including an A-SRS transmission instruction indicated by a predetermined code point is arranged in CSS, the remaining field may be used for group scheduling of A-SRS transmission.

  Further, in the present invention, when the A-SRS transmission instruction information is composed of multi-bits (a plurality of bits), the base station apparatus 1 sets a plurality of SRS setting information in advance and corresponds to a sequence (index) of information bits. And the mobile station apparatus 3 can switch SRS setting information. For example, when the A-SRS transmission instruction is composed of 2 bits, “00” is A-SRS transmission stop, “01” is A-SRS transmission using SRS setting information 1, and “10” is SRS setting. A-SRS transmission using information 2 and “11” is A-SRS transmission using SRS setting information 3, mobile station apparatus 3 performs A-SRS transmission by switching a plurality of SRS setting information. Also good.

  According to the present invention, the mobile station apparatus 3 dynamically displays the A-SRS regardless of the presence or absence of PUSCH transmission by indicating the SRS transmission instruction included in the uplink grant by 1 bit (multi-bit) or a predetermined code point. Can be transmitted to the base station apparatus 1 and efficient communication can be performed.

  Moreover, according to the present invention, when it is not necessary to perform PUSCH transmission, A-SRS can be transmitted without PUSCH transmission, thereby reducing the influence of interference on other mobile station apparatuses.

  In addition, you may make it implement | achieve a part of function of the base station apparatus 1 and the mobile station apparatus 3 in embodiment mentioned above with a computer. In that case, the program for realizing the control function may be recorded on a computer-readable recording medium, and the program recorded on the recording medium may be read by a computer system and executed. Here, the “computer system” includes an OS and hardware such as peripheral devices. The “computer-readable recording medium” refers to a storage device such as a flexible medium, a magneto-optical disk, a portable medium such as a ROM and a CD-ROM, and a hard disk incorporated in a computer system. Furthermore, the “computer-readable recording medium” is a medium that dynamically holds a program for a short time, such as a communication line when transmitting a program via a network such as the Internet or a communication line such as a telephone line, In this case, it is also possible to include one that holds a program for a certain time, such as a volatile memory inside a computer system that serves as a server or client. The program may be a program for realizing a part of the functions described above, and may be a program capable of realizing the functions described above in combination with a program already recorded in a computer system.

  Moreover, you may implement | achieve part or all of the mobile station apparatus 3 in the embodiment mentioned above and the base station apparatus 1 as LSI (Large Scale Integration) which is typically an integrated circuit. Each functional block of the mobile station device 3 and the base station device 1 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.

DESCRIPTION OF SYMBOLS 1 Base station apparatus 3 Mobile station apparatus 101 Transmitter (base station side transmitter)
103 Receiver (base station side receiver)
105 Scheduling section 107 Upper layer 108 Channel estimation section 109 Antenna 201 Transmitting section (mobile station side transmitting section)
203 Receiving unit (receiving unit on the mobile station side)
205 Scheduling unit 206 Reference signal generation unit 207 Upper layer 208 Channel estimation unit 209 Antenna 1011 Data control unit 1013 Modulation unit 1015 Radio transmission unit 1031 Radio reception unit 1033 Demodulation unit 1035 Data extraction unit 1071 Radio resource control unit 2011 Data control unit 2013 Modulation Unit 2015 wireless transmission unit 2031 wireless reception unit 2033 demodulation unit 2035 data extraction unit 2051 reference signal control unit 2071 radio resource control unit

Claims (6)

A mobile station device that communicates with a base station device,
When receiving the plurality of sounding reference signal configuration information, means for setting a plurality of sounding reference signal configuration based on the sounding reference signal configuration information,
Means for receiving an uplink grant including a 2-bit field indicating whether to request transmission of a sounding reference signal;
Means for receiving an uplink grant including a 1-bit field indicating whether to request transmission of a sounding reference signal ;
Means for transmitting a sounding reference signal generated based on a first sounding reference signal setting to the base station apparatus when an information bit corresponding to a first value is set in the 2-bit field;
Means for transmitting a sounding reference signal generated based on a second sounding reference signal setting to the base station apparatus when an information bit corresponding to a second value is set in the 2-bit field;
Means for transmitting a sounding reference signal generated based on a third sounding reference signal setting to the base station apparatus when an information bit corresponding to a third value is set in the 2-bit field;
Means for not transmitting a sounding reference signal to the base station apparatus when an information bit corresponding to a fourth value is set in the 2-bit field;
Means for transmitting a sounding reference signal to the base station apparatus when an information bit corresponding to a predetermined value is set in the 1-bit field;
A mobile station apparatus comprising: A communication method of a mobile station device that communicates with a base station device,
When receiving a plurality of sounding reference signal setting information, setting a plurality of sounding reference signal settings based on the sounding reference signal setting information;
Receiving an uplink grant including a 2-bit field indicating whether to request transmission of a sounding reference signal;
Receiving an uplink grant including a 1-bit field indicating whether to request transmission of a sounding reference signal;
When an information bit corresponding to a first value is set in the 2-bit field, transmitting a sounding reference signal generated based on a first sounding reference signal setting to the base station device;
When an information bit corresponding to a second value is set in the 2-bit field, transmitting a sounding reference signal generated based on a second sounding reference signal setting to the base station apparatus;
When an information bit corresponding to a third value is set in the 2-bit field, transmitting a sounding reference signal generated based on a third sounding reference signal setting to the base station apparatus;
When an information bit corresponding to a fourth value is set in the 2-bit field, not transmitting a sounding reference signal to the base station apparatus;
When an information bit corresponding to a predetermined value is set in the 1-bit field, transmitting a sounding reference signal to the base station apparatus;
A communication method comprising: An integrated circuit mounted on a mobile station device that communicates with a base station device,
A function of setting a plurality of sounding reference signal settings based on the sounding reference signal setting information when receiving a plurality of sounding reference signal setting information;
A function of receiving an uplink grant including a 2-bit field indicating whether or not to request transmission of a sounding reference signal;
A function of receiving an uplink grant including a 1-bit field indicating whether or not to request transmission of a sounding reference signal ;
A function of transmitting a sounding reference signal generated based on a first sounding reference signal setting to the base station apparatus when an information bit corresponding to a first value is set in the 2-bit field;
A function of transmitting a sounding reference signal generated based on a second sounding reference signal setting to the base station apparatus when an information bit corresponding to a second value is set in the 2-bit field;
A function of transmitting a sounding reference signal generated based on a third sounding reference signal setting to the base station apparatus when an information bit corresponding to a third value is set in the 2-bit field;
A function of not transmitting a sounding reference signal to the base station apparatus when an information bit corresponding to a fourth value is set in the 2-bit field;
A function of transmitting a sounding reference signal to the base station apparatus when an information bit corresponding to a predetermined value is set in the 1-bit field;
An integrated circuit characterized in that the mobile station apparatus exhibits the above. A base station device that communicates with a mobile station device,
  Means for transmitting a plurality of sounding reference signal setting information to the mobile station apparatus using a radio resource control signal;
Means for transmitting to the mobile station apparatus an uplink grant including a 2-bit field indicating whether or not to request transmission of a sounding reference signal;
Means for transmitting to the mobile station apparatus an uplink grant including a 1-bit field indicating whether or not to request transmission of a sounding reference signal;
When transmitting an uplink grant including the 2-bit field, if the mobile station apparatus is requested to transmit a sounding reference signal based on a first sounding reference signal setting, a first value is stored in the 2-bit field. Means for setting information bits corresponding to
When transmitting an uplink grant including the 2-bit field, when requesting the mobile station apparatus to transmit a sounding reference signal based on a second sounding reference signal setting, a second value is stored in the 2-bit field. Means for setting information bits corresponding to
When transmitting an uplink grant including the 2-bit field, when requesting the mobile station apparatus to transmit a sounding reference signal based on a third sounding reference signal setting, a third value is stored in the 2-bit field. Means for setting information bits corresponding to
Means for setting an information bit corresponding to a fourth value in the 2-bit field when transmitting an uplink grant including the 2-bit field and not requesting the mobile station apparatus to transmit a sounding reference signal When,
Means for setting an information bit corresponding to a predetermined value in the 1-bit field when requesting the mobile station device to transmit a sounding reference signal when transmitting an uplink grant in which the 1-bit field is set When,
A base station apparatus comprising: A communication method of a base station apparatus that communicates with a mobile station apparatus,
Transmitting a plurality of sounding reference signal setting information to the mobile station device using a radio resource control signal ;
Transmitting an uplink grant including a 2-bit field indicating whether or not to request transmission of a sounding reference signal to the mobile station device ;
Transmitting an uplink grant including a 1-bit field indicating whether or not to request transmission of a sounding reference signal to the mobile station device;
When transmitting an uplink grant including the 2-bit field, if the mobile station apparatus is requested to transmit a sounding reference signal based on a first sounding reference signal setting, a first value is stored in the 2-bit field. Setting an information bit corresponding to
When transmitting an uplink grant including the 2-bit field, when requesting the mobile station apparatus to transmit a sounding reference signal based on a second sounding reference signal setting, a second value is stored in the 2-bit field. Setting an information bit corresponding to
When transmitting an uplink grant including the 2-bit field, when requesting the mobile station apparatus to transmit a sounding reference signal based on a third sounding reference signal setting, a third value is stored in the 2-bit field. Setting an information bit corresponding to
A step of setting an information bit corresponding to a fourth value in the 2-bit field when transmitting an uplink grant including the 2-bit field and not requesting the mobile station apparatus to transmit a sounding reference signal; When,
A step of setting an information bit corresponding to a predetermined value in the 1-bit field when transmitting a sounding reference signal to the mobile station apparatus when transmitting an uplink grant including the 1-bit field; ,
A communication method comprising: An integrated circuit mounted on a base station device that communicates with a mobile station device,
A function of generating a radio resource control signal including a plurality of sounding reference signal setting information;
A function of generating an uplink grant including a 2-bit field indicating whether or not to request transmission of a sounding reference signal;
A function of generating an uplink grant including a 1-bit field indicating whether or not to request transmission of a sounding reference signal;
When generating an uplink grant including the 2-bit field, if the mobile station apparatus is requested to transmit a sounding reference signal based on a first sounding reference signal setting, a first value is stored in the 2-bit field. A function to set an information bit corresponding to
When generating an uplink grant including the 2-bit field, when requesting the mobile station apparatus to transmit a sounding reference signal based on a second sounding reference signal setting, a second value is stored in the 2-bit field. A function to set an information bit corresponding to
When generating an uplink grant including the 2-bit field, when requesting the mobile station apparatus to transmit a sounding reference signal based on a third sounding reference signal setting, a third value is stored in the 2-bit field. A function to set an information bit corresponding to
A function of setting an information bit corresponding to a fourth value in the 2-bit field when the mobile station apparatus does not request transmission of a sounding reference signal when generating an uplink grant including the 2-bit field. When,
A function of setting an information bit corresponding to a predetermined value in the 1-bit field when the mobile station apparatus requests transmission of a sounding reference signal when generating an uplink grant including the 1-bit field; ,
An integrated circuit characterized in that the base station apparatus exhibits the above.