Abstract: To realize transmission performances equivalent to those of an MU-MIMO BLAST ZF-THP system without increasing a signal processing amount in a base station apparatus in a downlink MU-MIMO transmission system. A transmission apparatus is provided with a plurality of transmission antennas, generates a transmission signal addressed to each reception apparatus based on information indicating spatial correlation of channels to and from a plurality of reception apparatuses, space-multiplexes the generated each transmission signal in the same wireless resource, and transmits it to each reception apparatus.

Abstract: The disclosed is a transmission device including a plurality of transmission antennas for transmitting signals in the same channel at the same time point to a plurality of reception devices, characterized by including: a dedicated reference signal generator configured to generate dedicated reference signals for the respective reception devices; a data signal generator configured to generate data signals for the respective reception devices; a spatial multiplexer configured to spatially multiplex at least some of the dedicated reference signals and at least some of the data signals; and a transmitter configured to transmit the spatially multiplexed signals.

Abstract: A wireless communication system in which a base station apparatus having a plurality of transmission antennas and one or more terminal apparatuses communicate with each other is provided with at least two methods of a first feedback method and a second feedback method regarding propagation path information at the time of reception. In accordance with a communication condition between the base station apparatus and the terminal apparatus, or the function of the terminal apparatus, the terminal apparatus performs feedback by one of the two methods of the first feedback method and the second feedback method. The base station apparatus performs spatial multiplexing transmission on the basis of the propagation path information that has been fed back. Thus, in a system in which CSI is fed back for MIMO transmission, desired transmission characteristics can be efficiently obtained.

Abstract: When spatial multiplexing is performed to any of a plurality of receiving antennas included in each terminal, it becomes possible to obtain excellent receiving characteristics by combining signals received by all antennas appropriately. A receiving antenna unit 28 receives channel state information from each terminal, a channel matrix H is obtained. A transmit weight/interference coefficient calculation unit 24 calculates a transmit weight and an interference coefficient based on channel matrix. The transmit weight is input to transmit weight multiplication units 17 and 23. The interference generation unit 15 generates an interference signal based on the interference coefficient. An interference subtraction unit 13 subtracts the interference signal from a desired signal. A modulo unit 14 adds a signal so that amplitude of an information signal output from the interference subtraction unit 13 falls within a constant range.

Abstract: When signals received by receiving antennas included in each terminal are subjected to MMSE combining, it is configured that each terminal is able to grasp position of desired signal in signal vector obtained after combining. A base station 100 receives by a receiving antenna 23 from the terminal apparatus channel state information between a transmitting antenna 16 and spatial multiplexing object antennas included in each terminal apparatus. A transmit weight calculation unit 19 calculates a transmit weight for performing spatial multiplexing transmission to the terminal apparatus based on the channel state information. Transmit weight multiplication unit s 12 and 18 multiplies an information signal addressed to each terminal apparatus to be performed spatial multiplexing by the transmit weight. A signal multiplexing unit 13 multiplexes the information signal multiplied by the transmit weight and an information to specify the information signal that needs to be demodulated by each terminal apparatus.

Abstract: A multiplexed signal generator is configured to multiplex a signal addressed to a first reception device which has been subjected to a power suppression process of suppressing the power of the signal, and a signal addressed to a second reception device which is not subjected to the power suppression process.

Abstract: A wireless communication apparatus includes: a channel information acquiring unit that, acquires a transmitted signal channel matrix that is channel information as a transmitted signal of a pre-interference-removal transmitted signal group and an interference signal channel matrix that is channel information as an interference signal of the non-interference-removed transmitted signal group; an interference signal calculating unit that generates an interference signal group at the time of reception by the non-interference-removed transmitted signal group with respect to the pre-interference-removal transmitted signal group, based on the pre-interference-removal transmitted signal group, the non-interference-removed transmitted signal group, the transmitted signal channel matrix, and the interference signal channel matrix; a subtracting unit that subtracts the interference signal group from the pre-interference-removal transmitted signal group to generate a post-interference-removal transmitted signal group; an

Abstract: Disclosed is a transmission device including a plurality of antennas for transmitting signals in the same channel at the same time point to a plurality of reception devices, characterized by including: a DRS generator configured to generate DRSs (dedicated reference signals) for the respective reception devices; a nonlinear spatial multiplexer configured to generate a nonorthogonal DRS by use of a first group of DRSs including at least one of the DRSs; and a transmitter configured to transmit a signal containing at least the nonorthogonal DRS.

Abstract: A control station device performs communications controlled by a central control station device. The control station device acquires information related to a control station device that becomes an interference source to a coverage area controlled by the control station device. The control station device notifies the central control station device of the information related to the control station device that becomes the interference source. The control station device acquires, from the central control station device, information related to a possibility of communications thereof. In this way, the control station device is provided that forms the communication system excellent in frequency usage efficiency based on interference source information and the like indicating an inter-cell interference status measured at each cell.

Abstract: There is provided a first base station device in a communication system in which, within a wide coverage area of a first cell, at least one second cell having a coverage area narrower than the coverage area of the first cell is present, the first base station device controlling the first cell. The first base station device supplies information concerning a transmission weight to a second base station device which controls the second cell, the transmission weight being used by a terminal device which transmits a data signal to the second base station device. With this configuration, in a system in which a plurality of cells with a small zone radius are present in a cell with a large zone radius, it is possible to determine, with a small amount of calculations, transmission and reception weights that can eliminate interference received by the cell with a large zone radius from the plurality of cells with a small zone radius.

Abstract: In a communication system, a first cell that covers a wide region includes, in a cover region thereof, a second cell that covers a smaller region than the first cell, one first terminal device or more positioned in the first cell receive a signal on which precoding has been performed and that is transmitted by a first base station apparatus that controls the first cell, and one second terminal device or more positioned in the second cell receive a signal on which precoding has been performed and that is transmitted using the same frequency as in the first cell by a second base station apparatus that controls the second cell. The communication system determines the number of streams to be transmitted by the second base station apparatus on the basis of information regarding the number of streams to be transmitted by the first base station apparatus. As a result, in a system in which interference between cells exists, interference may be reduced with a simple structure using transmit and receive filters.

Abstract: A wireless communication system includes a plurality of transmission devices, each of which transmits signals resulting from precoding performed for a plurality of resources, and a reception device that receives at least one desired signal and a plurality of undesired signals, the number of which is greater than or equal to the degree of freedom that the plurality of resources have. The at least one desired signal and the plurality of undesired signals have been transmitted from the transmission devices. The plurality of resources is the unit of precoding. At least one of the plurality of transmission devices transmits signals on each of which precoding has been performed such that equivalent channel vectors of the plurality of undesired signals in the reception device are made to be orthogonal to a reception weight vector used in the reception device.

Abstract: A wireless communication system in which a base station apparatus having a plurality of transmission antennas and one or more terminal apparatuses communicate with each other is provided with at least two methods of a first feedback method and a second feedback method regarding propagation path information at the time of reception. In accordance with a communication condition between the base station apparatus and the terminal apparatus, or the function of the terminal apparatus, the terminal apparatus performs feedback by one of the two methods of the first feedback method and the second feedback method. The base station apparatus performs spatial multiplexing transmission on the basis of the propagation path information that has been fed back. Thus, in a system in which CSI is fed back for MIMO transmission, desired transmission characteristics can be efficiently obtained.

Abstract: Provided is a radio communication system in which a base station apparatus with a plurality of transmission antennas spatially multiplexes and transmits a transmission signal addressed to a plurality of mobile station apparatuses, and in which the mobile station apparatuses receive the signal transmitted from the base station apparatus. The mobile station apparatuses select a desired precoding vector from predetermined candidates, and give the base station apparatus information identifying the selected precoding vector.

Abstract: To realize transmission performances equivalent to those of an MU-MIMO BLAST ZF-THP system without increasing a signal processing amount in a base station apparatus in a downlink MU-MIMO transmission system. A transmission apparatus is provided with a plurality of transmission antennas, generates a transmission signal addressed to each reception apparatus based on information indicating spatial correlation of channels to and from a plurality of reception apparatuses, space-multiplexes the generated each transmission signal in the same wireless resource, and transmits it to each reception apparatus.

Abstract: When signals received by receiving antennas included in each terminal are subjected to MMSE combining, it is configured that each terminal is able to grasp position of desired signal in signal vector obtained after combining. A base station 100 receives by a receiving antenna 23 from the terminal apparatus channel state information between a transmitting antenna 16 and spatial multiplexing object antennas included in each terminal apparatus. A transmit weight calculation unit 19 calculates a transmit weight for performing spatial multiplexing transmission to the terminal apparatus based on the channel state information. Transmit weight multiplication unit s 12 and 18 multiplies an information signal addressed to each terminal apparatus to be performed spatial multiplexing by the transmit weight. A signal multiplexing unit 13 multiplexes the information signal multiplied by the transmit weight and an information to specify the information signal that needs to be demodulated by each terminal apparatus.

Abstract: When spatial multiplexing is performed to any of a plurality of receiving antennas included in each terminal, it becomes possible to obtain excellent receiving characteristics by combining signals received by all antennas appropriately. A receiving antenna unit 28 receives channel state information from each terminal, a channel matrix H is obtained. A transmit weight/interference coefficient calculation unit 24 calculates a transmit weight and an interference coefficient based on channel matrix. The transmit weight is input to transmit weight multiplication units 17 and 23. The interference generation unit 15 generates an interference signal based on the interference coefficient. An interference subtraction unit 13 subtracts the interference signal from a desired signal. A modulo unit 14 adds a signal so that amplitude of an information signal output from the interference subtraction unit 13 falls within a constant range.

Abstract: A precoding deciding unit selects precoding for the spatial multiplexing of signals addressed to a plurality of receivers form a plurality of precodings. A filter multiplication unit multiplies the signals by filter coefficients to be used in the precoding selected by the precoding deciding unit.

Abstract: Disclosed is a transmission device including a plurality of antennas for transmitting signals in the same channel at the same time point to a plurality of reception devices, characterized by including: a DRS generator configured to generate DRSs (dedicated reference signals) for the respective reception devices; a nonlinear spatial multiplexer configured to generate a nonorthogonal DRS by use of a first group of DRSs including at least one of the DRSs; and a transmitter configured to transmit a signal containing at least the nonorthogonal DRS.

Abstract: The disclosed is a transmission device including a plurality of transmission antennas for transmitting signals in the same channel at the same time point to a plurality of reception devices, characterized by including: a dedicated reference signal generator configured to generate dedicated reference signals for the respective reception devices; a data signal generator configured to generate data signals for the respective reception devices; a spatial multiplexer configured to spatially multiplex at least some of the dedicated reference signals and at least some of the data signals; and a transmitter configured to transmit the spatially multiplexed signals.