Abstract: To provide a base station apparatus, a terminal apparatus, and a communication method capable of improving a frequency efficiency or throughput by suppressing an overhead associated with feedback from the terminal apparatus in a case that the base station apparatus acquires highly accurate CSI. A terminal apparatus according to an aspect of the present invention includes a receiver configured to receive at least one NZP CSI-RS, and a transmitter configured to transmit a signal including at least one piece of CSI. The at least one piece of CSI includes at least an RI and a PMI, the receiver acquires a first value for configuring the number of vectors indicated by the PMI, and in a case that a value of the RI exceeds a prescribed value, the number of vectors is configured by a second value being a value equal to or less than the first value.

Abstract: A method that carries out uplink multiple access while reducing complexity in processing accompanying exchange of control information. A terminal device that performs uplink multiple access communication includes a reception unit that receives a frame including first uplink multiple access information, and a transmission unit that transmits a frame including second uplink multiple access information based on the frame including the first uplink multiple access information, and further, after standby of a predetermined period, initiates the uplink multiple access communication.

Abstract: A BSS to which a destination wireless communication apparatus of a physical layer frame belongs is identified, and accuracy of preamble detection is improved by changing a reception operation. A wireless communication apparatus includes a reception unit that detects a frame including information for identifying a BSS, and a control unit that switches between a first operation in a case where the frame is a frame which is associated with a BSS to which the wireless communication apparatus belongs and a second operation in a case where the frame is a frame which is not associated with the BSS to which the wireless communication apparatus belongs. Carrier sensing is not performed in the first operation, and the carrier sensing is performed in the second operation.

Abstract: Communication efficiency can be enhanced during multiplex communication. A radio control station apparatus includes a multi-beam antenna unit capable of controlling each of a plurality of beam performances and an RF system for transmission. The RF system further includes a multiplexing unit configured to perform multiplexing by using a plurality of frequency channels or a plurality of sub-carriers, allocates at least one of the plurality of different frequency channels or at least one of the plurality of different sub-carriers to each of transmit signals to be transmitted to the plurality of radio terminal apparatuses, multiplexes the above allocated frequency channels or sub-carriers in the multiplexing unit, and transmits the multiplexed signal through the multi-beam antenna unit using a plurality of beams.

Abstract: A terminal apparatus for communicating with a base station apparatus, the terminal apparatus including: a receiver configured to receive downlink control information and a downlink shared channel; and a signal detection unit configured to demodulate the downlink shared channel (PDSCH) by using the downlink control information, wherein the downlink control information includes information for indicating an antenna port number and the number of code division multiplexing (CDM) groups for a demodulation reference signal (DMRS), each of the CDM groups indicates a DMRS port to be multiplexed by CDM, the PDSCH is demodulated in consideration of a power ratio of the DMRS and the PDSCH, and whether or not to consider powers of the DMRS and the PDSCH, based on the number of the CDM groups, is determined based on the downlink control information.

Abstract: To provide a terminal apparatus and a communication method capable of improving reliability and frequency efficiency in a case of transmission by beamforming. Provided are a higher layer processing unit configured with demodulation reference signal (DMRS) antenna port groups for indicating two groups of antenna ports of a DMRS, a receiver configured to receive the DMRS, downlink control information (DCI), and a downlink shared channel (PDSCH), and a decoding unit configured to decode the PDSCH, wherein the PDSCH includes a transport block, and in a case that the number of the transport blocks configured in the DCI is one, the PDSCH demodulated using a DMRS of a first group and/or the PDSCH demodulated using a DMRS of a second group is used to decode one transport block.

Abstract: Provided are a terminal apparatus and a communication method capable of improving reliability and frequency efficiency in a case that transmission is performed by beamforming. A receiver configured to receive a DMRS, DCI, and a PDSCH, and a decoding unit configured to decode the PDSCH are included, wherein the DCI includes a transmission configuration indicator (TCI) and the number of DMRS antenna ports, the TCI is information indicating a spatial reception filter for receiving the DMRS, the PDSCH includes a transport block, and in a case that two of the TCIs are indicated and the number of DMRS antenna ports is less than or equal to a prescribed number, and that the DCI includes a configuration of one transport block, the PDSCH transmitted from a part of the DMRS antenna ports is received based on a first TCI, and the PDSCH transmitted from a rest of the DMRS antenna ports is received based on a second TCI to decode the one transport block.

Abstract: An object of the present invention is to protect the communication of a legacy terminal while achieving favorable communication by rendering the CCA level of a CCA-variable terminal apparatus variable in an environment, premised on CSMA/CA, where the CCA-variable terminal apparatus and a legacy terminal apparatus coexist. A terminal apparatus for performing wireless communication with a base station apparatus includes: a receiving unit that receives a radio signal transmitted from the base station apparatus; a CCA-variable channel information processing unit that acquires first CCA-variable channel instruction information contained in the radio signal and containing information regarding a range of a CCA level that is available on a certain channel and that is used for clear channel assessment; and a higher layer unit that selects, according to the first CCA-variable channel instruction information, a channel to be used.

Abstract: Methods and apparatus for accessing channels in a wireless system by performing a channel access procedure on a first plurality of transmission beams to determine a second plurality of transmission beams for a serving cell, the second transmission beams including one or more of the first transmission beams that are idle; and transmitting a signal on one of the second transmission beams.

Abstract: According to the present invention, transmission is efficiently and repeatedly performed within a slot. The number of repetitions in the slot is calculated using OFDM symbol allocation in a slot notified using a predetermined field during RRC signaling or DCI formatting and the number of divisions in the slot notified by the RRC signaling (or the number of OFDM symbols serving as repetition unit). When the calculated number of repetitions does not satisfy a predetermined condition, repeated transmission is not performed.

Abstract: A radio communication apparatus that is a transmission opportunity holder efficiently transmits an instruction of frame transmission, to multiple terminal apparatuses. A radio communication apparatus of the present invention includes a transmission unit configured to transmit a first frame to obtain a TXOP, transmit a Trigger frame providing an instruction of transmission of a second frame addressed to the radio communication apparatus itself, to at least one of the multiple terminal apparatuses in the TXOP, and transmit a third frame addressed to at least one of the multiple terminal apparatuses in the TXOP. A value indicating a TXOP that is written in the second frame and that the third frame is to obtain is different from a value obtained by dividing a value indicating the TXOP written in the first frame by a value indicating a duration elapsed from start of transmission of the first frame to communication completion of the second frame.

Abstract: To provide a base station apparatus, a terminal apparatus, and a communication method for achieving a high frequency efficiency while coexisting with other radio access systems in an environment where multiple frame formats are multiplexed for use. A base station apparatus according to the present invention includes a transmitter configured to configure at least one frame structure of multiple frame structures in the second frequency band, notify the terminal apparatus of control information relating to the frame structure, and configure a non-transmit period with prescribed length between multiple signal transmit periods of the frame structure.

Abstract: Provided are a communications device and a communication method for implementing coexistence with another wireless access system, that is, fair access to a wireless medium while reducing interfering power and interfered power. The communications device is provided with: a reception unit for executing the carrier-sense for reserving a wireless medium; a control unit for setting a plurality of wireless medium acquisition classes; and a transmission unit for transmitting a radio signal, wherein each of the plurality of wireless medium acquisition classes includes a value indicating at least a data transmission period and an idle period, each of the plurality of wireless medium acquisition classes is classified based on a length of a fixed frame period including at least the data transmission period and the idle period; the radio signal includes information indicating a selected wireless medium acquisition class; and the radio signal is one of a SIB and a PDCCH.

Abstract: A terminal apparatus, a location server, and methods for performing positioning measurement are provided.

Abstract: A decrease in access rate to a wireless medium caused by an exposed terminal apparatus is improved. A wireless communication apparatus of the present invention includes a reception unit that receives a frame indicating start of a medium protection operation, and acquires, from the frame indicating the start of the medium protection operation, BSS identification information for identifying a BSS to which a transmission-source wireless communication apparatus of the frame indicating the start of the medium protection operation belongs, and a transmission unit that determines whether or not to start a transmission operation of a frame addressed to another wireless communication apparatus belonging to a BSS to which the wireless communication apparatus belongs based on the BSS identification information.

Abstract: A method that carries out uplink multiple access while reducing complexity in processing accompanying exchange of control information. A terminal device that performs uplink multiple access communication includes a reception unit that receives a frame including uplink multiple access connection information, a first autonomous decentralized control unit that instructs securing time of a wireless resource, and a second autonomous decentralized control unit that instructs securing time of a wireless resource after reception of a frame including the uplink multiple access connection information. The terminal device is instructed securing time of the wireless resource by the first autonomous decentralized control unit in a case that a frame including the uplink multiple access connection information is not received. Securing time of the wireless resource is instructed by the second autonomous decentralized control unit in a case that a frame including the uplink multiple access connection information is received.

Abstract: A CCA level is made to be variable efficiently while maintaining the fairness relating to acquisition of a transmission opportunity by wireless terminal apparatuses, and thus efficiency of a radio resource is improved. Provided is a terminal apparatus that performs wireless communication with a base station apparatus, and includes; a MAC frame categorization unit categorizing MAC frames, in each of which media access control header is attached to transmission data, based on a type of MAC frame; and a QoS control unit performing a carrier sense using a first CCA level, in a case where the MAC frame is included in a first category that results from the categorization by the MAC frame categorization unit, and performing the carrier sense using a second CCA level different from the first CCA level, in a case where the MAC frame is included in a second category different from the first category.

Abstract: Provided is a base station apparatus, a terminal apparatus, and a communication method, capable of improving communication performance such as throughput and communication efficiency in a system using a plurality of frame formats. A terminal apparatus according to the present invention, includes a reception unit to receive information indicating at least one frame structure out of a plurality of frame structures from the base station apparatus, a control unit to perform a transmit power control associated with the frame structure, and a transmission unit to generate a transmit signal based on the frame structure and the transmit power control and transmit the transmit signal to the base station apparatus.

Abstract: Provided are a base station apparatus, a terminal apparatus, and a communication method that allows throughput to be improved in a case of using a large number of antennas. The base station of the present invention includes a transmitter configured to transmit a channel state information reference signal (CSI-RS) and configuration information of the CSI-RS to a terminal apparatus, and a receiving unit configured to receive the channel state information (CSI) related to the CSI-RS from the terminal apparatus, wherein the CSI-RS is a periodic CSI-RS transmitted periodically or an aperiodic CSI-RS transmitted aperiodically, and the configuration information of the CSI-RS includes information indicating a feedback information format for reporting the CSI.

Abstract: A terminal device acquires a parameter indispensable in canceling or suppressing an interference signal, cancels or suppresses interference with high precision, and reduces a degradation in reception performance due to the interference.