Abstract: In a transmission system in which data addressed to multiple terminal apparatuses is multiplexed, a preferable transmission frame that efficiently uses radio resources and that enables a transmission time of the frame to be reduced is constructed. A base station apparatus uses at least one of multiple radio resources to transmit a transmission frame to a terminal apparatus. The base station apparatus includes a physical-layer frame generating unit that divides the transmission frame addressed to the terminal apparatus into multiple transmission frames and that generates physical layer frames so that the transmission frames obtained through division are transmitted in multiple radio resources, and also includes a radio transmission unit that transmits the generated physical layer frames to the terminal apparatus in the multiple radio resources.

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: OFDMA transmission by a plurality of terminal apparatuses is realized in a communication system in which CSMA/CA is premised and existing terminal apparatuses coexist. A communication method of a radio receiving apparatus of the invention includes the steps of: receiving a resource reserving signal which is transmitted from the radio transmission apparatus and which includes information indicating that the signal is addressed to the plurality of radio receiving apparatuses; and transmitting a resource reserving response signal to the radio transmission apparatus by using at least one radio resource with which the resource reserving signal is received, in which at least part of information included in the resource reserving response signal is identical to information included in the first resource reserving response signal transmitted by another of the radio receiving apparatuses.

Abstract: An object of the present invention is to protect the communication of a legacy terminal while achieving favorable communication 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: Good transmission performance is obtained even when the difference between the number of transmit antennas and the number of receive antennas is small. A modulation symbol is subjected to spreading and code multiplexing in a receive antenna direction of a terminal device, is subjected to precoding, and is transmitted. A spreading ratio of a spreading code for performing the spreading in the receive antenna direction is equal to the number of receive antennas of the terminal device. Spreading code multiplexing is performed in the receive antenna direction. Thus, it is possible to provide a base station apparatus and a terminal device providing good transmission performance by changing the number of multiplexing operations even when the difference between the number of transmit antennas and the number of receive antennas is small.

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: A terminal apparatus can be notified whether an MU-MIMO signal transmitted from a base station apparatus is linear-precoded or nonlinear-precoded by using effective signaling. According to the present invention, the base station apparatus decides whether the nonlinear precoding is used in an own cell, includes the decided nonlinear precoding setting information in system information or a layer 3 message, and notifies the terminal apparatus of the decided nonlinear precoding setting information by using a physical broadcast channel, a physical downlink share channel, or the like. The terminal apparatus performs a demodulation process for user data destined for the own terminal apparatus based on the nonlinear precoding setting information acquired from the notified system information or layer 3 message.

Abstract: The present invention provides a base station apparatus, a terminal apparatus, and a communication method, which, are capable of throughput improvement. A base station apparatus that communicates with a terminal apparatus, includes 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, in which the CSI process includes a configuration of a CSI reference signal and a configuration relating to two different code books.

Abstract: There are provided a base station apparatus, a terminal apparatus, and a communication method which are capable of realizing a LTE-A system with improved throughput by performing a CA technology including an unlicensed band while suppressing interference from an existing system. A base station apparatus according to the present invention is a base station apparatus which is included in a communication system that applies a communication scheme applied to a first frequency band capable of being used as a dedicated frequency band to a second frequency band different from the first frequency band and is capable of communicating with a terminal apparatus by using the second frequency band and the second frequency band. The base station apparatus synchronizes a frame number of a frame of a first signal transmitted using the first frequency band with a frame number of a frame of a second signal irrespective of whether or not the second signal transmitted using the second frequency band is transmitted.

Abstract: Communication opportunities of existing terminal devices are ensured, in a communication system in which terminal devices capable of using a new CCA level and the existing terminal devices using an existing CCA level coexist, on the premise of CSMA/CA. A communication method of a radio transmission device of the present invention includes a step of signaling information indicating a first CCA section and a second CCA section to the radio reception device. A communication method of a radio reception device of the present invention includes a step of performing the carrier sense based on a first CCA level and a second CCA level, and a step of performing the carrier sense based on the first CCA level, in the first CCA section, based on information indicating the first CCA section.

Abstract: Provided are a base station apparatus, a terminal device, and a communication method that can realize a small cell network while reducing load on the terminal device, the small cell network including a small cell performing massive MIMO transfer. The base station apparatus of the present invention is a second base station apparatus included in a communication system in which a plurality of the second base station apparatuses capable of acquiring assistance information from a first base station apparatus communicates with a terminal device, the base station apparatus including a codebook that describes a plurality of linear filters, in which the same cell identification number as at least one of the other second base station apparatuses is configured, and a synchronization signal correlated with the cell identification number is transmitted on the basis of the plurality of linear filters after first precoding of the synchronization signal.

Abstract: Provided are a base station apparatus, a terminal device, and a communication method that can realize a small cell network while reducing load on the terminal device, the small cell network including a small cell performing massive MIMO transfer. The base station apparatus of the present invention is a second base station apparatus included in a communication system in which a plurality of the second base station apparatuses capable of acquiring assistance information from a first base station apparatus communicates with a terminal device, the base station apparatus including a codebook that describes a plurality of linear filters, in which the same cell identification number as at least one of the other second base station apparatuses is configured, and a synchronization signal correlated with the cell identification number is transmitted on the basis of the plurality of linear filters after first precoding of the synchronization signal.

Abstract: There has been a problem that a time period between transmission of a synchronization signal and the next transmission thereof may become 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 that is able to be used exclusively includes: a DL signal generation unit that generates a signal to be transmitted to the terminal apparatus; a radio transmission unit that transmits the signal; and a connected terminal management unit that receives information about a plurality of subframes in which a signal is able to be transmitted to the terminal apparatus from another base station apparatus that communicates with the terminal apparatus in the first frequency band.

Abstract: Communication opportunities of existing terminal devices are ensured, in a communication system in which with CSMA/CA as a premise, terminal devices capable of using a new CCA level and the existing terminal devices using an existing CCA level coexist. A communication method of a radio reception device of the present invention includes receiving a signal of information on a CCA level used for carrier sense from a radio transmission device, determining the CCA level used for the carrier sense based on the signal, and performing the carrier sense, based on the CCA level.

Abstract: An object is to mitigate interference by using effective knowledge or information as to an interference signal while reducing an increase in the amount of calculation. A terminal device includes a reception unit that receives downlink control information from a base station apparatus. In a case of a prescribed transmission mode, a downlink shared channel destined for the terminal apparatus is demodulated on the basis of a power offset between transmit power of the terminal apparatus and transmit power of another terminal apparatus in the downlink shared channel included in the downlink control information. Whether or not to perform interference cancellation is determined according to a value of the power offset.

Abstract: Provided are a radio transmission apparatus, a radio reception apparatus, and a communication method capable of realizing a radio LAN system in which user throughput is improved by using OFDMA while suppressing overhead. A radio transmission apparatus of the invention selects any one group from a plurality of groups each indicating a combination of a plurality of radio reception apparatuses, notifies at least a plurality of radio reception apparatuses belonging to the selected group of an identification number assigned in advance to the selected group, and allocates transmission data addressed to the radio reception apparatuses belonging to the selected group to each of a plurality of frequency resources on the basis of order of the radio reception apparatuses, which is determined in advance in the selected group.

Abstract: Optimal transmit power control is performed in a band other than licensed bands. When the way of specifying transmit power differs between the licensed band and a frequency band other than the licensed band, the expression of the transmit power control is changed to perform transmit power control. A terminal apparatus includes a carrier aggregation radio transmission unit configured to simultaneously transmit a plurality of component carriers, and a transmit power control unit configured to control transmit power of each of the plurality of component carriers, wherein the transmit power control unit calculates a transmit power of a dedicatedly usable first component carrier among the plurality of component carriers in consideration of the transmit power of the first component carrier, and calculates a transmit power of a second component carrier other than the dedicatedly usable first component carrier in consideration of the transmit power of the first component carrier.

Abstract: A channel estimation unit estimates channel state information to or from a base station device. A feedback information generation unit performs a decomposition process for the channel state information and thereby acquires first decomposition information that includes plural singular values and second decomposition information that includes plural right singular vectors respectively associated with the plural singular values. The feedback information generation unit mutually replaces portions of the plural singular values, thereby acquires first replacement information, and further acquires second replacement information based on the first replacement information and the plural right singular vectors. The feedback information generation unit performs a conversion process for the second replacement information and thereby acquires second conversion information. A radio transmission unit notifies the base station device of the second conversion information.

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: In a wireless communication system that performs non-linear pre-coding, degradation in transmission performance due to a feedback error is improved. The terminal device according to the present invention is a terminal device which receives radio signals that are space-multiplexed and on which non-linear pre-coding is performed, from a base station device including multiple antennas, the terminal device including: a channel state estimator 53 that estimates channel state information on a channel between the terminal device and the base station device; a terminal antenna module 51 that acquires a linear filter that is calculated in the base station device; and a channel equalization module 57 that performs channel equalization processing on the radio signals that are received at a first point in time, based on the channel state information at a second point in time that precedes the first point in time and on the linear filter.