Abstract: An objective of the present invention is to provide, in a heterogeneous communication network constituted of multiple heterogeneous communication systems, a communication apparatus and a communication method for enabling optimization of radio resources, as a whole network.

Abstract: MU-MIMO is implemented with little changes in the mechanism of the DCF. There is provided a wireless terminal station apparatus that is used in a wireless communication system formed of one wireless base station apparatus and a plurality of wireless terminal station apparatus, in which grouping is performed on the wireless terminal station apparatus in such a way that the wireless terminal station apparatus belongs to any one of a plurality of groups, and the wireless terminal station apparatus includes a backoff controlling portion that performs control such that a backoff value at the time of random backoff, the backoff value of the wireless terminal station apparatus belonging to at least one group, is selected from a set of candidates for a backoff value which is a set of values formed of predetermined limited numbers.

Abstract: Provided are a control station apparatus, a communication method, and a communication system that enable a radio access network that is capable of flexibly adapting to various required conditions. A control station apparatus according to an embodiment of the present invention includes a function for communicating with a base station apparatus and a communication apparatus, a function for transferring data received from the communication apparatus to the base station apparatus, and a function for transferring data received from the base station apparatus to the communication apparatus, and the control station apparatus efficiently selects a communication method used in a case of communicating with the base station apparatus, and a communication method used in a case of communicating with the communication apparatus.

Abstract: A reduction in interference improves throughput and increase opportunity for communication by each terminal apparatus. A base station apparatus that communicates with a terminal apparatus transmits information relating to a transmit power for a UE-specific reference signal in a state of being included in downlink control information, in a case of a predetermined transmission mode. A terminal apparatus that communicates with a base station apparatus includes a reception unit that receives downlink control information which includes information relating to a transmit power for a UE-specific reference signal, from the base station apparatus, in a case of a predetermined transmission mode, and a reception signal is demodulated based on the downlink control information.

Abstract: A time period between transmission of a synchronization signal and the next transmission thereof may become undesirably longer depending on a usage state of an unlicensed band and a terminal apparatus requires a long time to measure receive power of signals from a plurality of base station apparatuses that perform communication in the unlicensed band. A base station apparatus that communicates with a terminal apparatus in a second frequency band different from a first frequency band includes: a DL signal generator that generates a signal to be transmitted to the terminal apparatus; a radio transmitter that transmits the signal; and a connected terminal manager that receives subframe information to be transmitted to the terminal apparatus from another base station apparatus that communicates with the terminal apparatus in the first frequency band. The radio transmitter transmits the signal with at least one subframe included in the subframe information.

Abstract: Provided are a base station apparatus, a terminal apparatus, and a communication method that achieve a radio access network capable of being flexibly compatible with various requirements. The base station apparatus according to an aspect of the present invention includes a transmission unit configured to generate a transmit signal based on a frame format in which a radio parameter is configurable, and configured to notify the terminal apparatus of information indicating the radio parameter configured in the frame format. The terminal apparatus according to an aspect of the present invention includes a reception unit configured to acquire information indicating a radio parameter configured in a frame format, and configured to demodulate a signal generated based on the frame format, based on the radio parameter.

Abstract: Provided are a base station apparatus, a terminal apparatus, and a communication method that achieve a radio access network capable of being flexibly compatible with various requirements. The base station apparatus according to an aspect of the present invention is a base station apparatus for communicating with the terminal apparatus, the base station apparatus includes a transmission unit configured to generate a transmit signal based on a frame format in which a radio parameter is configurable, and the radio parameter configured in the frame format is configured based on a radio medium through which the transmission unit transmits the transmit signal.

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, capable of increasing the number of terminal apparatuses that can be spatially multiplexed by the base station apparatus in uplink. A base station apparatus according to an aspect of the present invention is a base station apparatus for communicating with multiple terminal apparatuses, the base station apparatus including a transmission unit configured to notify the terminal apparatuses of DMRS configuration information of DMRSs transmitted over multiple subframes. In addition, a terminal apparatus according to the aspect of the present invention includes: a reception unit that acquires the DMRS configuration information of the DMRSs transmitted across the multiple subframes, notified by the base station apparatus; an uplink reference signal generation unit that generates the DMRSs transmitted across the multiple subframes, based on the DMRS configuration information; and a transmission unit that transmits the DMRSs.

Abstract: A terminal device decreases degradation of communication performance that is caused by interference and increases in the case that a CCA level is increased. The terminal device communicating with a base station apparatus includes a transmitting unit that transmits a frame, a transmission burst length setting unit that modifies a transmission burst length of the frame, and a carrier sense unit that performs carrier sensing before the frame is transmitted. The transmission burst length is different depending on whether a threshold value for the carrier sensing is configured to a first value or a second value.

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. There is provided a first terminal device that communicates with a base station apparatus, including: a higher layer processing unit that determines NAICS information indicating whether or not NAICS has to be used; a reception unit that receives downlink control information which is transmitted from the base station apparatus; and a control unit that changes interpretation of the downlink control information based on a configuration that is determined by the higher layer processing unit.

Abstract: A radio communication system realizing flexible QoS control is provided. A radio communication system according to an aspect of the present invention includes multiple base station devices, each of the multiple base station devices including a reception unit configured to exert a carrier sense function. The multiple base station devices include first base station devices and second base station devices. Each of the first base station devices includes a control unit configured to acquire a first radio parameter common to the first base station devices. Each of the second base station devices includes a control unit configured to acquire a second radio parameter common to the second base station devices. First communication quality provided by the first radio parameter is different from second communication quality provided by the second radio parameter.

Abstract: To provide a communication apparatus and a communication method capable of simultaneously directing main beams to reception stations and transmission stations the numbers of which exceed the number N of RF systems provided to the communication apparatus itself. The communication apparatus according to the present invention includes a transmission unit configured to generate non-orthogonal multiplexed signals including downlink signals addressed to multiple terminal apparatuses, an antenna capable of forming an antenna directivity pattern including multiple main beams, and a transmission beam control unit configured to generate a signal controlling the antenna directivity pattern, wherein the non-orthogonal multiplexed signals are simultaneously transmitted by use of the multiple main beams, and the number of main beams included in the antenna directivity pattern is more than the number of RF systems of the antenna.

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.

Abstract: A signal that is transmitted to a terminal apparatus itself is demodulated with high precision, and throughput is improved. A terminal apparatus that communicates with a base station apparatus includes a signal detection unit that demodulates a signal that is transmitted to the terminal apparatus itself, based on first modulation mapping in a case where a predetermined transmission mode is configured, and that demodulates a signal based on second modulation mapping in a case where a transmission mode other than the predetermined transmission mode is configured.

Abstract: In an LTE-A system, there is a problem that it is difficult to perform stable communication in a case where there is a time when another system occupies an unlicensed band being used. There is provided a base station apparatus that communicates with a terminal device in a second frequency band different from a first frequency band capable of being used as a dedicated frequency band. The base station apparatus includes: a wireless transmission unit that transmits data or control information to the terminal device; and a wireless reception unit that receives data or control information transmitted from the terminal device.

Abstract: There are provided a base station apparatus, a terminal apparatus, and a commutation method, which are capable of improving throughput. A higher layer processing unit that configures a CSI process that is a configuration relating to reporting of a channel state information (CSI), for the terminal apparatus for which a prescribed transmission mode is configured, and a reception unit that receives the CSI based on the CSI process are included. The plurality of CSI reference signal configurations are configured for the CSI process, and information that is based on at least one CSI reference signal configuration, among the plurality of CSI reference signal configurations, is received as the CSI.

Abstract: A bi-directional communication method needs to be switched on the basis of cost of bi-directional communication. Provided is a communication system including a first terminal apparatus and a second terminal apparatus, in which the first terminal apparatus includes a radio unit that transmits a first signal by using a first communication path that is a direct communication path to the second terminal apparatus, the second terminal apparatus includes a radio unit that transmits a second signal by using a second communication path that is a communication path different from the first communication path, and the first terminal apparatus transmits the first signal on the basis of a feature amount of the second signal transmitted by the second terminal apparatus.

Abstract: A communication service that needs a plurality of different required conditions is efficiently provided. According to an aspect of the present invention, there is provided a communication system that includes a base station apparatus and a terminal apparatus and provides a communication service based on a plurality of communication modes that satisfy different communication qualities, in which the plurality of communication modes includes a first communication mode and a second communication mode, in which a communication route included in the first communication mode and a communication route included in the second communication mode are different from each other, and in which a trigger for the base station apparatus to start communication based on the second communication mode is included in information transmitted by the terminal apparatus in accordance with the first communication mode.

Abstract: There is provided a method in which a terminal apparatus that changes a threshold of carrier sense from a predetermined value and a terminal apparatus that does not change the threshold of the carrier sense from the predetermined value are suitably present together. The terminal apparatus that performs communication with a base station apparatus includes a carrier sense unit that controls the threshold of the carrier sense that is performed in order to control the transmission opportunity, a transmit power control unit that performs transmit power control when the threshold of the carrier sense is controlled for changing, and a reception unit that receives a frame that is transmitted from the base station apparatus.