JP6128692B2 - Mobile station apparatus, base station apparatus and communication method - 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 wireless 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. 7 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. 7, the base station apparatus and the mobile station apparatus can use a wide band composed of a plurality of component carriers by using a plurality of component carriers that are continuous and / or discontinuous frequency bands. Communication can be performed in the frequency band.

  In FIG. 7, 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 (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. 7, 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. 7, the base station apparatus can transmit up to five downlink transport blocks (or PDSCH) to the mobile station apparatus in the same subframe.

  Also, 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. 7, 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. 8 is a diagram for explaining a wireless communication system in which asymmetric frequency bands are aggregated in the prior art. As shown in FIG. 8, 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. 8, as an example, five downlink component carriers (DCC1, DCC2, DCC3, DCC4, DCC5) having a frequency band of 20 MHz are used for downlink communication having a bandwidth of 100 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. 8, downlink / uplink channels are allocated to downlink / uplink component carriers, respectively. 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. 8, the base station apparatus can transmit up to five downlink transport blocks (or 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. 8, the mobile station apparatus can transmit up to two uplink transport blocks (or 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 a predetermined code point (Non-patent Document 2).

“Carrier aggregation in LTE-Advanced”, R1-082464, 3GPP TSGRAN 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.

  However, in the prior art, a mobile station apparatus instructed to transmit A-SRS by the base station apparatus transmits A-SRS to the base station apparatus without switching parameters used for A-SRS transmission. That is, the mobile station apparatus arrange | positions A-SRS in the PUSCH resource (a part of PUSCH resource) scheduled by the base station apparatus, and was transmitting to the base station apparatus (in-band A-SRS transmission). For example, the mobile station apparatus transmits A-SRS to the base station apparatus with a transmission bandwidth having the same bandwidth as the PUSCH resource scheduled by the base station apparatus.

  In addition, the mobile station apparatus transmits the A-SRS to the base station apparatus by setting the A-SRS in the resource set by the base station apparatus with the setting information different from the setting information for the PUSCH resource (outbound A-SRS transmission). . For example, the mobile station apparatus transmits A-SRS to the base station apparatus with a wide transmission bandwidth set by the base station apparatus.

  Here, when a mobile station apparatus communicates with a base station apparatus in an environment with good communication quality, even if the A-SRS is transmitted in-band, the base station apparatus is within the range of PUSCH resources scheduled for the mobile station apparatus. However, since channel measurement can only be performed and communication quality cannot be improved by frequency selective scheduling, efficient communication cannot be performed. In addition, when the mobile station device communicates with the base station device in an environment with poor communication quality, even if the A-SRS is transmitted out-of-band, the channel measurement accuracy by the base station device deteriorates, and efficient communication is performed. I can't do it. That is, in the prior art, the mobile station apparatus instructed to transmit A-SRS by the base station apparatus transmits A-SRS to the base station apparatus without switching the parameter used for A-SRS transmission. There is a problem that efficient communication cannot be performed between the base station apparatus and the mobile station apparatus.

  The present invention has been made in view of the above points, and can perform efficient communication between a base station apparatus and a mobile station apparatus based on A-SRS transmitted from the mobile station apparatus. An object is to provide a mobile station device, a base station device, a wireless communication system, a wireless communication method, and an integrated circuit.

  (1) In order to achieve the above object, the present invention takes the following measures. That is, the radio communication system of the present invention is a radio communication system in which a base station apparatus and a mobile station apparatus perform radio communication, and the base station apparatus is arranged in a physical uplink shared channel resource. Radio resource control including transmission control information for setting whether to transmit a sounding reference signal or to transmit a second sounding reference signal arranged in a resource different from the physical uplink shared channel resource A signal is transmitted to the mobile station apparatus, and the mobile station apparatus is notified of the uplink grant including a sounding reference signal transmission instruction, and the mobile station apparatus transmits the sounding reference signal included in the uplink grant. When the instruction is received, transmission of the first sounding reference signal is set by the transmission control information. The first sounding reference signal is transmitted to the base station apparatus, and when the transmission of the second sounding reference signal is set by the transmission control information, the second sounding reference signal is transmitted. A sounding reference signal is transmitted to the base station apparatus.

  (2) The radio communication system of the present invention is a radio communication system in which a base station apparatus and a mobile station apparatus perform radio communication, and the base station apparatus is arranged in a physical uplink shared channel resource. An uplink grant including control information indicating whether a second sounding reference signal to be transmitted or a second sounding reference signal arranged in a resource different from the physical uplink shared channel resource is transmitted to the mobile station apparatus And the mobile station apparatus transmits the first sounding reference signal or the second sounding reference signal to the base station apparatus based on control information included in the uplink grant. .

  (3) The radio communication system of the present invention is a radio communication system in which a base station apparatus and a mobile station apparatus perform radio communication, and the base station apparatus is arranged in a physical uplink shared channel resource. When the mobile station apparatus is instructed to transmit the sounding reference signal, the transmission instruction information included in the uplink grant is set as the first value and is arranged in a resource different from the physical uplink shared channel resource. When instructing the mobile station apparatus to transmit the second sounding reference signal, the transmission instruction information is set as a second value, and the transmission instruction information set to the first value or the second value is set. Including the uplink grant to the mobile station apparatus, and the mobile station apparatus uses the first value for the transmission instruction information included in the uplink grant. The first sounding reference signal is transmitted to the base station apparatus, and when the transmission instruction information included in the uplink grant is the second value, the second sounding reference signal is transmitted. A signal is transmitted to the base station apparatus.

  (4) The radio communication system of the present invention is a radio communication system in which a base station apparatus and a mobile station apparatus perform radio communication, and the base station apparatus is arranged in a physical uplink shared channel resource. When the mobile station apparatus is instructed to transmit the sounding reference signal, 1-bit transmission instruction information included in the uplink grant is set to a predetermined value and arranged in a resource different from the physical uplink shared channel resource. When the mobile station apparatus is instructed to transmit the second sounding reference signal, the first control information included in the uplink grant is set at a predetermined code point, and the transmission instruction of the sounding reference signal is transmitted. Transmission instruction information or the predetermined code set with the instruction information or the first control information and set to the predetermined value The mobile station apparatus notifies the mobile station apparatus of an uplink grant including the first control information set in the mobile station, and notifies the mobile station apparatus of an uplink grant including an instruction to transmit the sounding reference signal. When the transmission instruction information included in the uplink grant indicates a transmission instruction of the sounding reference signal, the first sounding reference signal is transmitted to the base station apparatus, and is included in the uplink grant. When the first control information to be transmitted is a predetermined code point, the second sounding reference signal is transmitted to the base station apparatus.

  (5) A radio communication system according to the present invention is the radio communication system according to (1), wherein the base station apparatus transmits a transmission instruction for the sounding reference signal using 1-bit transmission instruction information or a predetermined code point. It is characterized by being set with certain first control information.

  (6) The wireless communication system of the present invention is the wireless communication system according to (1), wherein the base station apparatus sets the transmission control information for each uplink component carrier.

(7) A radio communication system according to the present invention is the radio communication system according to (4), in which the base station apparatus
An uplink grant including the parameter of the second sounding reference signal and the first control information is notified to the mobile station apparatus, and the mobile station apparatus determines that the first control information is predetermined according to the uplink grant. The second sounding reference signal in which the parameter included in the uplink grant is set is transmitted to the base station apparatus.

  (8) A base station apparatus according to the present invention is a base station apparatus that performs radio communication with a mobile station apparatus, and transmits a first sounding reference signal arranged in a physical uplink shared channel resource, Means for notifying the mobile station apparatus of a radio resource control signal including transmission control information for setting in the mobile station apparatus whether to transmit a second sounding reference signal arranged in a resource different from an uplink shared channel resource And at least means for notifying the mobile station apparatus including a sounding reference signal transmission instruction in the uplink grant.

  (9) A base station apparatus according to the present invention is a base station apparatus that performs radio communication with a mobile station apparatus, and transmits a first sounding reference signal arranged in a physical uplink shared channel resource, It has at least means for notifying the mobile station apparatus of an uplink grant including control information indicating whether to transmit a second sounding reference signal arranged in a resource different from the uplink shared channel resource .

  (10) A base station apparatus of the present invention is a base station apparatus that performs radio communication with a mobile station apparatus, and transmits the first sounding reference signal arranged in a physical uplink shared channel resource. Means for setting transmission instruction information included in the uplink grant as a first value, and transmission of a second sounding reference signal arranged in a resource different from the physical uplink shared channel resource. When instructing the mobile station device, the means for setting the transmission instruction information as a second value and the uplink grant including the transmission instruction information set to the first value or the second value as the mobile And at least means for notifying the station device.

  (11) A base station apparatus according to the present invention is a base station apparatus that performs radio communication with a mobile station apparatus, and transmits the first sounding reference signal arranged in a physical uplink shared channel resource. In the case where the second sounding reference signal is arranged in a resource different from the physical uplink shared channel resource, and means for setting the 1-bit transmission instruction information included in the uplink grant to a predetermined value. When instructing transmission to the mobile station apparatus, means for setting the first control information included in the uplink grant to a predetermined code point, and transmitting a sounding reference signal to the transmission instruction information or the first Means for setting with control information, transmission instruction information set to the predetermined value or set to the predetermined code point And at least means for notifying the mobile station apparatus of an uplink grant including the first control information, and means for notifying the mobile station apparatus of an uplink grant including an instruction to transmit the sounding reference signal. Features.

  (12) A mobile station apparatus according to the present invention is a mobile station apparatus that performs radio communication with a base station apparatus, the means for receiving transmission control information notified from the base station apparatus, and the base station apparatus When the transmission of the first sounding reference signal is set by the transmission control information when the means for receiving the uplink grant and the transmission instruction of the sounding reference signal included in the uplink grant are received , When the transmission of the second sounding reference signal is set by the transmission control information and the means for transmitting the first sounding reference signal to the base station apparatus, the second sounding reference signal is Means for transmitting to the base station apparatus.

  (13) A mobile station apparatus according to the present invention is a mobile station apparatus that performs radio communication with a base station apparatus, and includes means for receiving an uplink grant notified from the base station apparatus, and is included in the uplink grant And at least means for transmitting the first sounding reference signal or the second sounding reference signal to the base station apparatus based on the control information.

  (14) A mobile station apparatus of the present invention is a mobile station apparatus that performs radio communication with a base station apparatus, and is included in the uplink grant, means for receiving an uplink grant notified from the base station apparatus, and When the transmission instruction information is the first value, the means for transmitting the first sounding reference signal to the base station apparatus, and the transmission instruction information included in the uplink grant is the second value Comprises at least means for transmitting a second sounding reference signal to the base station apparatus.

  (15) A mobile station apparatus according to the present invention is a mobile station apparatus that performs radio communication with a base station apparatus, and includes a means for receiving an uplink grant notified from the base station apparatus, and is included in the uplink grant When the transmission instruction information indicates an instruction to transmit a sounding reference signal, means for transmitting the first sounding reference signal to the base station apparatus and first control information included in the uplink grant are predetermined. In the case of a code point, it has at least means for transmitting a second sounding reference signal to the base station apparatus.

  (16) A radio communication method of the present invention is a radio communication method in which a base station apparatus and a mobile station apparatus perform radio communication, and the base station apparatus is arranged in a physical uplink shared channel resource. Transmission control information for setting to the mobile station apparatus whether to transmit a second sounding reference signal to be transmitted or a second sounding reference signal arranged in a resource different from the physical uplink shared channel resource. A step of notifying a device, a step of notifying the mobile station device including a sounding reference signal transmission instruction in an uplink grant, and the mobile station device transmitting a sounding reference signal included in the uplink grant When the transmission of the first sounding reference signal is set by the transmission control information. Includes transmitting the first sounding reference signal to the base station apparatus, and, if transmission of the second sounding reference signal is set by the transmission control information, the second sounding reference signal. Transmitting at least one signal to the base station apparatus.

  (17) 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, wherein the base station apparatus is arranged in a physical uplink shared channel resource. An uplink grant including control information indicating whether a second sounding reference signal to be transmitted or a second sounding reference signal arranged in a resource different from the physical uplink shared channel resource is transmitted to the mobile station apparatus Notifying, and the mobile station apparatus, based on control information included in the uplink grant, transmitting the first sounding reference signal or the second sounding reference signal to the base station apparatus; It is characterized by including at least.

  (18) 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, and the base station apparatus is arranged in a physical uplink shared channel resource. When the mobile station apparatus is instructed to transmit the sounding reference signal, the transmission instruction information included in the uplink grant is set as a first value, and the physical uplink shared channel resource is arranged in a different resource. When instructing the mobile station apparatus to transmit the second sounding reference signal to be transmitted, the step of setting the transmission instruction information as a second value, and the setting of the first value or the second value A step of notifying the mobile station apparatus of an uplink grant including transmission instruction information; and before the mobile station apparatus is included in the uplink grant When the transmission instruction information is the first value, the step of transmitting the first sounding reference signal to the base station apparatus, and the transmission instruction information included in the uplink grant is the second value. In this case, the method includes at least a step of transmitting the second sounding reference signal to the base station apparatus.

  (19) A radio communication method of the present invention is a radio communication method in which a base station apparatus and a mobile station apparatus perform radio communication, and the base station apparatus is arranged in a physical uplink shared channel resource. When instructing the mobile station apparatus to transmit the sounding reference signal of 1 bit, the step of setting 1-bit transmission instruction information included in the uplink grant to a predetermined value and a resource different from the physical uplink shared channel resource When instructing the mobile station apparatus to transmit the second sounding reference signal arranged in the base station, a step of setting the first control information included in the uplink grant to a predetermined code point, and transmission of the sounding reference signal A step of setting an instruction with the transmission instruction information or the first control information, and transmission set to the predetermined value Informing the mobile station apparatus of an uplink grant including indication information or first control information set at the predetermined code point, and transmitting the uplink grant including an instruction to transmit the sounding reference signal to the mobile station apparatus And when the transmission instruction information included in the uplink grant indicates a transmission instruction for the sounding reference signal, the mobile station apparatus transmits the first sounding reference signal to the base station. Transmitting to the base station apparatus, and transmitting the second sounding reference signal to the base station apparatus when the first control information included in the uplink grant is a predetermined code point. It is characterized by including at least.

  (20) An integrated circuit according to the present invention is an integrated circuit that causes a base station apparatus to perform a plurality of functions by being mounted in a base station apparatus, and is arranged in a physical uplink shared channel resource. The mobile station apparatus transmits transmission control information for setting whether to transmit the sounding reference signal of the mobile station apparatus or to transmit the second sounding reference signal arranged in a resource different from the physical uplink shared channel resource. And a function of notifying the mobile station apparatus of the uplink grant including a sounding reference signal transmission instruction in the uplink grant.

  (21) An integrated circuit according to the present invention is an integrated circuit that causes a base station apparatus to perform a plurality of functions by being mounted on a base station apparatus, and is arranged in a physical uplink shared channel resource. An uplink grant including control information indicating whether a second sounding reference signal to be transmitted or a second sounding reference signal arranged in a resource different from the physical uplink shared channel resource is transmitted to the mobile station apparatus The base station apparatus is allowed to exhibit the function to perform.

  (22) An integrated circuit according to the present invention is an integrated circuit that causes a base station device to perform a plurality of functions by being mounted on a base station device, and is arranged in a physical uplink shared channel resource. When the mobile station apparatus is instructed to transmit the sounding reference signal of the mobile station apparatus, the transmission instruction information included in the uplink grant is set as a first value, and the physical uplink shared channel resource is arranged in a different resource. A function to set the transmission instruction information as a second value when instructing the mobile station apparatus to transmit the second sounding reference signal to be transmitted, and the transmission set to the first value or the second value A function of notifying the mobile station apparatus of an uplink grant including instruction information is provided to the base station apparatus.

  (23) An integrated circuit according to the present invention is an integrated circuit that causes a plurality of functions to be exhibited by the base station device by being mounted on the base station device, and is arranged in a physical uplink shared channel resource. In the case where the mobile station apparatus is instructed to transmit the sounding reference signal, a function for setting transmission instruction information of 1 bit included in the uplink grant to a predetermined value and a resource different from the physical uplink shared channel resource are included. When instructing the mobile station apparatus to transmit the second sounding reference signal to be arranged, a function of setting the first control information included in the uplink grant to a predetermined code point, and a sounding reference signal transmission instruction Function for setting the transmission instruction information or the first control information, and the transmission instruction information set to the predetermined value. Notifies the mobile station apparatus of an uplink grant including the first control information set at the predetermined code point, and an uplink grant including an instruction to transmit the sounding reference signal. The base station apparatus is allowed to exhibit the function of

  (24) An integrated circuit according to the present invention is an integrated circuit that allows a mobile station apparatus to perform a plurality of functions by being mounted on a mobile station apparatus, and receives transmission control information notified from a base station apparatus. A function, a function of receiving the uplink grant notified from the base station apparatus, and a first sounding reference signal according to the transmission control information when receiving a transmission instruction of the sounding reference signal included in the uplink grant. When the transmission of the second sounding reference signal is set by the function of transmitting the first sounding reference signal to the base station apparatus and the transmission control information. The mobile station apparatus has a function of transmitting the second sounding reference signal to the base station apparatus.

  (25) An integrated circuit according to the present invention is an integrated circuit that allows a mobile station apparatus to perform a plurality of functions by being mounted on a mobile station apparatus, and receives an uplink grant notified from a base station apparatus. A function of transmitting a first sounding reference signal or a second sounding reference signal to the base station apparatus on the basis of control information included in the uplink grant. Features.

  (26) An integrated circuit according to the present invention is an integrated circuit that, when mounted on a mobile station apparatus, causes the mobile station apparatus to perform a plurality of functions, and receives an uplink grant notified from the base station apparatus. A function, a function of transmitting a first sounding reference signal to the base station apparatus when the transmission instruction information included in the uplink grant is a first value, and the transmission included in the uplink grant. When the instruction information is a second value, the mobile station apparatus is caused to exhibit a function of transmitting a second sounding reference signal to the base station apparatus.

  (27) An integrated circuit according to the present invention is an integrated circuit that allows a mobile station apparatus to perform a plurality of functions by being mounted on a mobile station apparatus, and receives an uplink grant notified from a base station apparatus. A function, a function of transmitting a first sounding reference signal to the base station apparatus when the transmission instruction information included in the uplink grant indicates a transmission instruction of a sounding reference signal, and the uplink grant When the included first control information is a predetermined code point, the mobile station apparatus is caused to exhibit a function of transmitting a second sounding reference signal to the base station apparatus.

  ADVANTAGE OF THE INVENTION According to this invention, based on A-SRS transmitted from a mobile station apparatus, the mobile station apparatus, base station apparatus, radio | wireless communication which can perform efficient communication between a base station apparatus and a mobile station apparatus A system, a wireless communication method, and an integrated circuit 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 a figure which shows schematic structure of in-band A-SRS (1st A-SRS) and out-band A-SRS (2nd A-SRS). It is a figure which shows an example of the DCI format containing the transmission instruction | indication of A-SRS in 1st Embodiment. It is a figure which shows an example of the DCI format containing the transmission instruction | indication of A-SRS in 2nd Embodiment. It is a figure which shows an example of the DCI format containing the transmission instruction | indication of A-SRS in 3rd Embodiment. 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 channel used in the present invention includes 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 to notify 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, 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 quasi-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.

  Also, in the A-SRS, parameters such as a transmission bandwidth are set independently of the in-band A-SRS (Inband A-SRS) and PUSCH arranged using the PUSCH resource (that is, the SRS described above). There is Outband A-SRS (set by setting information). The in-band A-SRS is also referred to as a first A-SRS. When the uplink grant includes a transmission instruction for the first A-SRS, the in-band A-SRS is always transmitted to the base station apparatus together with the PUSCH. The That is, the first A-SRS is always transmitted in the same subframe as PUSCH. The first A-SRS can improve communication characteristics at a cell edge where the communication environment is poor.

  That is, the base station apparatus transmits an uplink grant including resource allocation information for the PUSCH and a first A-SRS transmission instruction to the mobile station apparatus, and the mobile station apparatus includes the PUSCH resource allocated by the base station apparatus. 1st A-SRS is arrange | positioned and it transmits to a base station apparatus.

  The out-band A-SRS is also referred to as a second A-SRS, and parameters such as a transmission bandwidth are set independently of the PUSCH like the P-SRS, and are always transmitted to the base station apparatus together with the PUSCH. There is no need. Since the second A-SRS can be transmitted independently of the PUSCH, the second A-SRS can be arranged in a frequency band different from the frequency band in which the PUSCH is arranged, and dynamic frequency selection scheduling. Can be used.

  That is, the base station apparatus sets parameters (for example, transmission bandwidth, resources, etc.) for the mobile station apparatus to transmit the second A-SRS to the mobile station apparatus. The base station apparatus transmits an uplink grant including a second A-SRS transmission instruction to the mobile station apparatus, and the mobile station apparatus arranges the second A-SRS in the resource set by the base station apparatus. And transmit to the base station apparatus. That is, a mobile station apparatus arrange | positions 2nd A-SRS in the resource different from the PUSCH resource allocated by the uplink grant from a base station apparatus, and transmits to a base station apparatus. In the base station apparatus, the mobile station apparatus sets a resource for arranging the second A-SRS independently of the PUSCH resource.

  FIG. 3 is a diagram illustrating a schematic configuration of an in-band A-SRS (first A-SRS) and an out-band A-SRS (second A-SRS). FIG. 2A shows a schematic configuration of the first A-SRS. The first A-SRS is set, for example, with the same transmission bandwidth as the PUSCH and is included in the PUSCH resource. Moreover, 1st A-SRS is always transmitted to a base station apparatus with PUSCH. When the first A-SRS and the P-SRS are transmitted at the same timing, the first A-SRS and the P-SRS may be set in advance so as to be transmitted at the same timing by being arranged in different combs. May be transmitted at different timings. That is, the symbol in which the first A-SRS is arranged does not necessarily have to be an SRS symbol, and the symbol in which the first A-SRS is arranged may be any of the symbols in which PUSCH is arranged. . Here, the symbols for arranging the first 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 the base station The notification may be sent from the apparatus to the individual mobile station apparatus.

  FIG. 2B shows a schematic configuration of the second A-SRS. Unlike the first A-SRS, the second A-SRS has parameters set independently of the PUSCH. Therefore, a wide transmission bandwidth necessary for performing frequency selective scheduling can be set. Moreover, since 2nd A-SRS can be arrange | positioned independently (in a different resource) from PUSCH, it is not necessarily required to transmit in the same subframe as PUSCH. That is, since the mobile station apparatus 3 may transmit the second A-SRS to the base station apparatus without PUSCH (UL-SCH data), the base station apparatus assigns the PUSCH resource to the second by scheduling. It can be assigned to other mobile station apparatuses that do not transmit A-SRS, and the frequency utilization efficiency can be improved throughout the system. When the P-SRS and the second A-SRS are transmitted at the same timing, the second A-SRS may be set to be transmitted, or the P-SRS may be set to be transmitted. good. Moreover, you may set so that a different comb may be set and P-SRS and 2nd A-SRS may be transmitted at the same timing. Here, the same timing indicates that the transmission timing is the same for each symbol.

  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. 9 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) among 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 by including not only the P-SRS parameters but also the A-SRS parameters (first A-SRS and second A-SRS). 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. Also, the upper layer 107 determines the communication environment of the mobile station apparatus 3 based on the channel estimation value of the uplink signal obtained from the channel estimation unit 108, and performs optimal resource allocation for PUSCH. Further, the upper layer 107 can instruct the mobile station apparatus 3 to perform optimal A-SRS transmission in consideration of the communication environment of the mobile station apparatus 3. In order to instruct the mobile station device 3 to switch transmission of the second A-SRS in which parameters and the like are set independently of the first A-SRS and the PUSCH using the PUSCH resource, -Output including the information instructing transmission switching between the SRS and the second A-SRS in the scheduling information.

  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. Further, when the upper layer 107 is instructed to transmit the first or second A-SRS, the scheduling information is reset and output to the data control unit 1011.

  Also, 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 wireless transmission unit 2015 inserts discrete Fourier transform (DFT), subcarrier mapping, inverse fast Fourier transform (IFFT), and CP (Cyclic Prefix) into the modulated data and the uplink reference signal. 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 assigns 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 SRS (A-SRS, P-SRS) based on the SRS setting information and the SRS transmission control information input from the reference signal control unit 2051, and outputs them to the radio 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. Further, the upper layer 207 sets the first A-SRS or the second A-SRS according to the A-SRS transmission instruction from the base station apparatus 1 and outputs the first A-SRS to the scheduling unit 205 as scheduling information.

<First Embodiment>
A first embodiment of the present invention will be described below. In the first embodiment, the base station apparatus transmits the first sounding reference signal arranged in the physical uplink shared channel resource or is arranged in a resource different from the physical uplink shared channel resource. The mobile station apparatus is notified of transmission control information for setting the mobile station apparatus to transmit the 2 sounding reference signals, and the mobile station apparatus is notified of the uplink grant including a sounding reference signal transmission instruction. When the mobile station apparatus receives the transmission instruction for the sounding reference signal included in the uplink grant and the transmission of the first sounding reference signal is set by the transmission control information, the mobile station apparatus uses the first sounding reference signal. Is transmitted to the base station apparatus, and when the transmission of the second sounding reference signal is set by the transmission control information, the second sounding reference signal is transmitted to the base station apparatus.

  In the first embodiment, the base station apparatus 1 determines (controls) a radio resource where the A-SRS is arranged by a radio resource control signal (RRC signaling). That is, the base station apparatus 1 uses the RRC signaling to instruct the mobile station apparatus 3 to arrange and transmit the first A-SRS in the PUSCH resource allocated by the uplink grant. be able to. In addition, the base station apparatus 1 arranges the second A-SRS in the set resource (independent of the PUSCH resource) for the mobile station apparatus 3 and transmits it to the base station apparatus. Signaling can be used to indicate. That is, the base station apparatus 1 transmits the A-SRS to the mobile station apparatus 3 by arranging it in the PUSCH resource or by arranging it in the set resource (independent of the PUSCH resource). Can be indicated using RRC signaling.

  For example, the base station apparatus 1 determines (controls) a radio resource in which the A-SRS is arranged by a radio resource control signal (RRC signaling) according to a change in the communication environment of the mobile station apparatus 3. For example, when the base station apparatus 1 determines that the communication environment of the mobile station apparatus 3 has deteriorated, the base station apparatus 1 instructs the mobile station apparatus 3 to transmit the first A-SRS to be arranged using the PUSCH resource. When it is determined that the communication environment of the mobile station apparatus 3 has improved, the mobile station apparatus 3 is configured to transmit the second A-SRS having a wide transmission bandwidth in which parameters are set independently of the PUSCH. Can be directed to. For example, if the base station apparatus 1 determines that the mobile station apparatus 3 is at the cell edge, the base station apparatus 1 instructs the mobile station apparatus 3 to transmit the first A-SRS arranged in the PUSCH resource. When it is determined that the mobile station apparatus 3 is in the cell center, a parameter is set independently of PUSCH (arranged in a resource different from PUSCH). The mobile station apparatus 3 can be instructed to transmit SRS. Here, the base station apparatus 1 determines which A-SRS is used for transmission for each uplink component carrier in advance for the mobile station apparatus 3 that performs communication using a plurality of uplink component carriers. The same A-SRS (either one of the first A-SRS or the second A-SRS) may be set for each mobile station apparatus.

  FIG. 4 is a diagram illustrating an example of a DCI format including an A-SRS transmission instruction according to the first embodiment. 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 the A-SRS transmission instruction is included in the uplink grant, the mobile station device 3 performs the first A according to the radio resource control signal notified from the base station device 1. -SRS or 2nd A-SRS is transmitted to the base station apparatus 1. That is, when the field defined for A-SRS transmission instruction included in the uplink grant is set to a predetermined value (for example, “1”), the mobile station device 3 The A-SRS is transmitted to the base station apparatus 1.

  FIG. 6B shows an A-SRS transmission instruction method in the case where the A-SRS transmission instruction information is not included in the DCI format. In FIG. 5B, when the frequency hopping flag and the padding bit information are a predetermined code point (predetermined value), the mobile station apparatus 3 recognizes that an A-SRS transmission instruction has been notified, and A-SRS is transmitted to the station apparatus 1.

  In the same figure, when 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 set in the same subframe. It transmits to the base 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.

  Here, at this time, the cyclic shift applied to the A-SRS (the first A-SRS and the second A-SRS respectively) may be the same as the P-SRS, and the cyclic shift of the DM-RS The information may be defined in association with each other, may be uniquely determined in advance by the system, may be notified as broadcast information from the base station device 1 to the mobile station device 3 all at once, or may be individually transmitted from the base station device 1 The mobile station apparatus 3 may be notified. In addition, the number of transmissions of A-SRS (first A-SRS and second A-SRS, respectively) and a transmission timer are set in advance from the base station apparatus 1, and are transmitted to the mobile station apparatus 3 using a radio resource control signal or the like. When notified, the mobile station apparatus 3 transmits A-SRS to the base station apparatus 1 until the number of transmissions or the transmission timer reaches expiration.

  Moreover, the parameter of 2nd A-SRS may be the same as P-SRS, may be uniquely determined beforehand by the system, and is transmitted from the base station apparatus 1 to the mobile station apparatus 3 as broadcast information. It may be notified all at once, or may be notified from the base station device 1 to the individual mobile station devices 3. Different cyclic shifts may be applied to the first A-SRS and the second A-SRS. For example, the cyclic shift of the first A-SRS is set to the same cyclic shift as the cyclic shift of the DM-RS transmitted in the same subframe, and the cyclic shift of the second A-SRS is changed from the base station apparatus 1. You may notify with the radio | wireless resource control signal for every mobile station apparatus 3. FIG. The cyclic shift between the first A-SRS and the second A-SRS is a parameter applied to the cyclic shift of the DM-RS (for example, the cyclic shift index of the DM-RS, the cyclic shift index of the DM-RS, etc.). Different values may be applied individually in association with the click shift information), or the same value may be applied. That is, the base station apparatus 1 can set the cyclic shift of the first A-SRS and the cyclic shift of the second A-SRS in association with the parameters applied to the cyclic shift of the DM-RS. The mobile station apparatus 3 can uniformly (mechanically) set the cyclic shift applied to the first A-SRS and the second A-SRS from the parameters applied to the DM-RS. .

<Second Embodiment>
Next, a second embodiment of the present invention will be described below. In the second embodiment, when instructing the mobile station apparatus to transmit the first sounding reference signal arranged in the physical uplink shared channel resource, the base station apparatus transmits the transmission instruction information included in the uplink grant. When the mobile station apparatus is instructed to transmit the second sounding reference signal that is set in the resource different from the physical uplink shared channel resource, the transmission instruction information is set as the second value. Then, the mobile station apparatus is notified of the uplink grant including the transmission instruction information set to the first value or the second value. When the transmission instruction information included in the uplink grant is the first value, the mobile station apparatus transmits the first sounding reference signal to the base station apparatus, and the transmission instruction information included in the uplink grant is the first value. If the value is 2, the second sounding reference signal is transmitted to the base station apparatus.

  In the second embodiment, by adding A-SRS transmission instruction information composed of a plurality of bits (bit sequence) of 2 bits or more to the DCI format (uplink grant), it is indicated in the A-SRS transmission instruction information. Depending on the bit sequence (predetermined value), transmission of the first A-SRS and the second A-SRS can be switched dynamically. That is, since the base station apparatus 1 can dynamically control the A-SRS transmission method of the mobile station apparatus 3 as necessary, and can perform optimal channel measurement, the base station apparatus and the mobile station Efficient communication can be performed with the apparatus.

  That is, the base station apparatus 1 uses the A-SRS transmission instruction information to transmit the first A-SRS to the mobile station apparatus 3 by arranging the first A-SRS in the PUSCH resource allocated by the uplink grant. Can be instructed. Also, the base station apparatus 1 arranges the second A-SRS for the mobile station apparatus 3 in the set resource (independent of the PUSCH resource) and transmits it to the base station apparatus. It can be instructed using SRS transmission instruction information. That is, the base station apparatus 1 transmits the A-SRS to the mobile station apparatus 3 by arranging it in the PUSCH resource or by arranging it in the set resource (independent of the PUSCH resource). Can be instructed using the A-SRS transmission instruction information.

  FIG. 5 is an example of a DCI format including an A-SRS transmission instruction in the second embodiment. The DCI format shown in FIG. 4A has the same configuration as the DCI format shown in FIG. 4A, but the A-SRS transmission instruction information is composed of two or more bits. By configuring the A-SRS transmission instruction information with a plurality of bits, it is possible to dynamically switch the transmission instruction between the first A-SRS and the second A-SRS.

  FIG. 4A shows the configuration of control information when A-SRS transmission instruction (SRS activation) information is added to the DCI format. For example, when the A-SRS transmission instruction information is composed of 2 bits, “00” is the A-SRS transmission stop, “01” is the first A-SRS transmission, and “10” is the second A-SRS. Indicates transmission. Also, as shown in FIG. 5B, when the A-SRS transmission instruction information is “11”, the control information included in the DCI format is recognized as another control information, and for example, A-SRS transmission Recognizing that the control information other than the instruction information is the setting information (SRS configurations for 2nd A-SRS) indicating the second A-SRS parameters such as the transmission bandwidth and cyclic shift of the second A-SRS, It can set so that 2nd A-SRS which set the parameter based on the setting information may be transmitted. The mobile station apparatus 3 can perform A-SRS transmission by dynamically switching between the first A-SRS and the second A-SRS. Here, the second A-SRS parameter (SRS configurations for 2nd A-SRS) included in the setting information includes a transmission bandwidth (SRS transmission) when the mobile station device 3 transmits the second A-SRS. Bandwidth). The second A-SRS parameter includes a cyclic shift used for maintaining orthogonality between mobile station apparatuses or signals. The parameter of the second A-SRS includes information indicating the frequency position where the second A-SRS is arranged. Further, the second A-SRS parameter includes the number of transmissions or the transmission stop time for completing the transmission of the second A-SRS. Moreover, the antenna port (antenna index) which transmits 2nd A-SRS is contained in the parameter of 2nd A-SRS. Further, the second 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 parameter of the second A-SRS includes a TPC command (transmission power control information) for the second A-SRS. Also, which of these second A-SRS parameters is used may be uniquely determined in advance by the system, or from the base station apparatus 1 to the mobile station apparatus 3 as broadcast information. May be notified all at once, or may be notified from the base station apparatus 1 to the individual mobile station apparatuses 3.

<Third Embodiment>
Next, a third embodiment of the present invention will be described below. In the third embodiment, when the base station apparatus instructs the mobile station apparatus to transmit the first sounding reference signal arranged in the physical uplink shared channel resource, the base station apparatus transmits 1 bit included in the uplink grant. When the instruction information is set to a predetermined value and the mobile station apparatus is instructed to transmit a second sounding reference signal arranged in a resource different from the physical uplink shared channel resource, the instruction information included in the uplink grant is included. 1 control information is set at a predetermined code point, a sounding reference signal transmission instruction is set with the transmission instruction information or the first control information, and transmission instruction information or a predetermined code point is set to a predetermined value. The mobile station apparatus is notified of the uplink grant including the first control information set in, and the sounding reference signal And it notifies the uplink grant including a transmission instruction to the mobile station apparatus. When the transmission instruction information included in the uplink grant indicates a transmission instruction of the sounding reference signal, the mobile station apparatus transmits the first sounding reference signal to the base station apparatus, and the mobile station apparatus includes the first sounding reference signal included in the uplink grant. When the control information of 1 is a predetermined code point, a second sounding reference signal is transmitted to the base station apparatus.

  In the third embodiment, the base station apparatus 1 notifies the mobile station apparatus 3 of the transmission instruction of the first A-SRS with 1-bit transmission instruction information (SRS activation for 1st A-SRS), and the second A-SRS transmission instruction is notified by the first control information which is a predetermined code point. That is, the base station apparatus 1 uses the 1-bit transmission instruction information to transmit the first A-SRS to the mobile station apparatus 3 in the PUSCH resource allocated by the uplink grant. Can be instructed. In addition, the base station apparatus 1 is configured to arrange for the mobile station apparatus 3 to transmit the second A-SRS within the set resource (independent of the PUSCH resource) to the base station apparatus. The first control information (predetermined control information set to a predetermined value), which is a code point, can be instructed. Here, which control information included in the DCI format (uplink grant) is set as predetermined control information (first control information), and when the predetermined control information is set to any value, the base station apparatus Whether the transmission of the second A-SRS is instructed by 1 is defined in advance by specifications or the like.

  Here, when the transmission of the second A-SRS is notified by the first control information, a control information field other than the first control information may be used to indicate other control information. For example, the base station device 1 can assign the mobile station device 3 as a second A-SRS parameter to a control information field other than the first control information. The second A-SRS parameter (SRS configurations for 2nd A-SRS) includes a transmission bandwidth (SRS transmission bandwidth) when the mobile station device 3 transmits the second A-SRS. The second A-SRS parameter includes a cyclic shift used for maintaining orthogonality between mobile station apparatuses or signals. The parameter of the second A-SRS includes information indicating the frequency position where the second A-SRS is arranged. Further, the second A-SRS parameter includes the number of transmissions or the transmission stop time for completing the transmission of the second A-SRS. Moreover, the antenna port (antenna index) which transmits 2nd A-SRS is contained in the parameter of 2nd A-SRS. Further, the second 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 parameter of the second A-SRS includes a TPC command (transmission power control information) for the second A-SRS. Also, which of these second A-SRS parameters is used may be uniquely determined in advance by the system, or from the base station apparatus 1 to the mobile station apparatus 3 as broadcast information. May be notified all at once, or may be notified from the base station apparatus 1 to the individual mobile station apparatuses 3.

  In the third embodiment, the base station apparatus 1 dynamically changes parameters such as the transmission bandwidth, transmission timing, and cyclic shift of the second A-SRS according to the communication environment of the mobile station apparatus 3, Interference with other mobile station apparatuses can be reduced, flexible SRS arrangement can be performed, and communication quality can be improved.

  In addition, unnecessary transmission of the second A-SRS can be reduced by controlling the transmission instruction of the second A-SRS using the first control information that is a predetermined code point with few false detections. Other mobile station apparatuses due to erroneous transmission of A-SRS 2 can reduce the influence of interference on SRS.

  FIG. 6 is a diagram illustrating an example of a DCI format including an A-SRS transmission instruction according to the third embodiment. 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 uses the CQI and UL-SCH data (Uplink
Shared Channel data, transport block for UL-SCH) is arranged and transmitted to base station apparatus 1 in the same subframe together with A-SRS.

  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. 5B 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. 6, 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 the transmission of the second A-SRS is 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 apparatus 3 can read the control information that is not used for the first control information as other control information (for example, A-SRS setting information).

  Here, when the base station apparatus 1 instructs the transmission of A-SRS by 1-bit transmission instruction information, the base station apparatus 1 transmits information (A-) that instructs the transmission of the 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 (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. Here, when the base station apparatus 1 does not transmit A-SRS to the mobile station apparatus 3, the information instructing transmission of the A-SRS included in the uplink grant is set to “0”, for example. Then, the mobile station apparatus 3 is notified.

  In addition, when the base station apparatus 1 instructs transmission of A-SRS by control information (first control information) that is a predetermined code point (predetermined value), the base station apparatus 1 is included in the uplink grant. Indicates that the mobile station apparatus 3 is instructed to transmit A-SRS by setting predetermined information in the control information (any of the control information described above) to a predetermined value. Yes. 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.

  In the third embodiment, when the A-SRS transmission instruction is indicated by the 1-bit transmission instruction information in the uplink grant, the mobile station apparatus 3 bases the PUSCH and the first A-SRS in the same subframe. Transmit to the station apparatus 1. In addition, when the first control information is a predetermined code point and the PUSCH transmission instruction is received with different uplink grants at the same timing, the mobile station device 3 receives, for example, the uplink grant. After 4 subframes from the subframe, the PUSCH is transmitted to the base station apparatus 1 and the second A-SRS is transmitted in the first cell-specific SRS subframe or mobile station apparatus-specific SRS subframe after the 4th subframe. Also good. In addition, the subframe for transmitting the second A-SRS may be uniquely determined in advance by the system, or may be notified simultaneously from the base station apparatus 1 to the mobile station apparatus 3 as broadcast information, Notification may be made from the base station apparatus 1 to the individual mobile station apparatus 3.

  In the third embodiment, when a DCI format including an A-SRS transmission instruction indicated by a predetermined code point is arranged in the CSS, other control information fields that are not used for the A-SRS transmission instruction are A -You may use for the group scheduling of SRS transmission.

  According to the third embodiment, the mobile station device 3 indicates PU-SCH by indicating the A-SRS transmission instruction included in the uplink grant with 1-bit transmission instruction information or first control information that is a predetermined code point. Regardless of the presence or absence of transmission, the first A-SRS and the second A-SRS can be dynamically switched and transmitted to the base station apparatus 1, and channel measurement in accordance with the communication environment can be performed.

  Further, according to the third embodiment, when PUSCH transmission is not necessary, A-SRS can be transmitted without PUSCH, thereby reducing the influence of interference on other mobile station apparatuses.

  Also, in the first to third embodiments of the present invention, when the A-SRS transmission instruction is included in the DCI format including the CQI transmission instruction, the mobile station apparatus 3 uses the CQI and the A-SRS. May be transmitted to the base station apparatus 1 in the same subframe, or may be transmitted in different subframes.

  In the first to third embodiments of the present invention, when communication is performed using a plurality of uplink component carriers, the second A-SRS parameter may be set for each uplink component carrier. It may be set for each mobile station apparatus.

  According to the present invention, the base station apparatus 1 can communicate with the communication environment (including communication quality, channel quality, communication state, channel state, and radio propagation path state) and the position of the mobile station apparatus 3 (for example, cell center (cell center)). Or cell edge (cell edge)) and the mobile station apparatus 3 can be instructed to switch between the first A-SRS and the second A-SRS for transmission according to the number of mobile station apparatuses in the cell. . For example, if the first A-SRS (in-band A-SRS) arranged in the PUSCH resource is transmitted in an environment with poor communication quality such as a cell edge, the channel measurement accuracy is improved. Further, if a second A-SRS (out-band A-SRS) having a wide transmission bandwidth arranged in a resource different from PUSCH in an environment with good communication quality such as a cell center is transmitted, frequency selection scheduling is performed. Communication quality can be improved. That is, efficient communication between the base station apparatus 1 and the mobile station apparatus 3 can be realized by dynamically switching the first A-SRS and the second A-SRS according to the communication environment or the like. .

  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, “computer-readable recording medium” means that a program is held dynamically for a short time, like a communication line when a program is transmitted via a network such as the Internet or a communication line such as a telephone line. 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 becomes a server or client in that case. 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 (8)

Via a higher layer signal, receiving a plurality of parameter sets each including a parameter relating to the antenna port and a parameter relating to cyclic shift relating to the sounding reference signal;
A receiving unit for receiving a downlink control information format including a sounding reference signal request field via a physical downlink control channel;
A transmitting unit for transmitting a sounding reference signal based on a value of the sounding reference signal request field;
With
The transmitter is
Based on the value of the sounding reference signal request field, one of the plurality of parameter sets is selected, and the sounding reference signal is generated and transmitted using one of the selected parameter sets. Yes Mobile station device. The transmitter is
When the value of the sounding reference signal request field is set to the first value, the parameter related to the antenna port and the parameter related to the cyclic shift included in the first parameter set among the plurality of parameter sets. To set the sounding reference signal,
When the value of the sounding reference signal request field is set to the second value, the parameter related to the antenna port and the parameter related to the cyclic shift included in the second parameter set among the plurality of parameter sets. To set the sounding reference signal,
The mobile station apparatus according to claim 1, wherein when the value of the sounding reference signal request field is set to a third value, the sounding reference signal is not transmitted. The mobile station apparatus according to claim 2, wherein the downlink control information format including the sounding reference signal request field is used for scheduling of a physical uplink shared channel with a plurality of antenna ports. Via a higher layer signal, send multiple parameter sets, each containing parameters for antenna ports and parameters for cyclic shift, for the sounding reference signal,
A transmitter for transmitting a downlink control information format including a sounding reference signal request field via a physical downlink control channel;
A receiving unit for receiving a sounding reference signal based on a value of the sounding reference signal request field;
With
The transmitter is
Wherein one of said plurality of parameter sets to the mobile station apparatus is selected, so as to generate and transmit the sounding reference signal using one of said plurality of parameter set selected, the sounding reference A base station device that determines the value of the signal request field. The transmitter is
When requesting transmission of a sounding reference signal using the first parameter set, the value of the sounding reference signal request field is set to a first value,
When requesting transmission of a sounding reference signal using the second parameter set, the value of the sounding reference signal request field is set to a second value;
The base station apparatus according to claim 4, wherein when not requesting transmission of a sounding reference signal, the value of the sounding reference signal request field is set to a third value. The transmitter is
The base station apparatus according to claim 5, wherein the sounding reference signal request field is set to a downlink control information format used for scheduling of a physical uplink shared channel with a plurality of antenna ports. A communication method in a mobile station apparatus that communicates with a base station apparatus,
Receiving a plurality of parameter sets each including a parameter related to an antenna port and a parameter related to cyclic shift via a higher layer signal,
Receiving a downlink control information format including a sounding reference signal request field via a physical downlink control channel;
A third step of determining which one of the plurality of parameter sets to use based on a value of the sounding reference signal request field;
A fourth step of transmitting a sounding reference signal set using a parameter related to the antenna port and a parameter related to the cyclic shift included in the parameter set;
Have
The fourth step includes
Based on the value of the sounding reference signal request field, one of the plurality of parameter sets is selected, and the sounding reference signal is generated and transmitted using one of the selected parameter sets. Communication method. A communication method in a base station device that communicates with a mobile station device,
A first step of transmitting a plurality of parameter sets each including a parameter related to an antenna port and a parameter related to cyclic shift with respect to a sounding reference signal via an upper layer signal;
A second step of transmitting a downlink control information format including a sounding reference signal request field via a physical downlink control channel;
Receiving a sounding reference signal based on a value of the sounding reference signal request field;
Have
The second step includes
Selecting one of said plurality of parameter sets, so as to generate and transmit the sounding reference signal using one of said plurality of parameter set selected, the sounding reference signal request field value Determine the communication method.