Abstract: Provided are a communication system in which a base station apparatus and a terminal apparatus highly efficiently exchange channel state information based on different channel information norms, such a base station apparatus, and such a terminal apparatus. The base station apparatus chooses a channel information norm that the base station apparatus requests the terminal apparatus to conform to, generates control information containing information that designates the channel information norm, and transmits the control information to the terminal apparatus. The terminal apparatus receives the control information, estimates a channel between the terminal apparatus and the base station apparatus, generates channel state information between the terminal apparatus and the base station apparatus on the basis of the control information and the channel, and reports the channel state information to the base station apparatus.

Abstract: A terminal device according to an aspect of the present invention includes a reception module that receives a control channel and a spatially multiplexed data signal channel, a control signal detection module that extracts, from an output from the reception module, a demodulation control information which is a transmission parameter of a signal that is transmitted to the terminal device, in a data signal channel that is output from the reception module, and assistance control information which is a transmission parameter of a signal that is transmitted to a different terminal device, in the data signal channel that is output from the reception module, a channel estimator that obtains a channel estimate by using a reference signal, a signal detection module that demultiplexes the data signal channel by using the demodulation control information, the assistance control information, and the channel estimate, and a decoding module that decodes a signal that is output by the signal detection module, in which infor

Abstract: Provided are a base station apparatus, a terminal apparatus, and an integrated circuit, by which the terminal apparatus performing interference suppression and cancellation is able to efficiently suppress an interference signal. The base station apparatus of the invention is a base station apparatus that notifies a first terminal apparatus of terminal information which is information of a second terminal apparatus and which causes interference. The base station apparatus always transmits, to the terminal apparatus performing interference suppression, a coded bit sequence, which includes the large number of systematic bits, regardless of a state of retransmission request, and notifies the terminal information of an interference signal. The terminal apparatus suppresses the interference signal based on the terminal information, and detects a desired signal from the coded bit sequence.

Abstract: A feedback information notification method of the present invention notifies of channel quality information indicating a channel quality during multi-user MIMO transmission at a first feedback timing, and differential channel quality information based on a difference value between a channel quality during the multi-user MIMO transmission and a channel quality indicated by the channel quality information of which notification is most recently sent, at a second feedback timing.

Abstract: Provided are a base station apparatus, a terminal apparatus, a wireless communication system, and an integrated circuit in which the terminal apparatus is able to appropriately combine signals received by a plurality of receive antennas in the wireless communication system for performing nonlinear MU-MIMO transmission. The base station apparatus of the invention has a plurality of antennas, is able to apply nonlinear precoding to data signals addressed to a plurality of terminal apparatuses, and spatially multiplexes and transmit the data signals, and based on the data signals and channel information between the base station apparatus and the terminal apparatuses, searches for a perturbation vector to be added to the data signals, and further calculates a covariance matrix of the signals obtained by adding the perturbation vector to the data signals.

Abstract: Provided are a base station apparatus, a terminal device, and a transmission method which allow detection of a desired signal at high accuracy irrespective of whether an interference signal is an initially transmitted signal or a retransmitted signal. The base station apparatus notifies the terminal device of terminal information which is information about an interfering terminal device, and includes a terminal information generation unit that generates terminal information, and the terminal information generation unit therein generates the terminal information that varies depending on redundancy versions of an interference signal, and, even in a case where the interference signal has been transmitted by using a redundancy version with the large number of parity bits, the terminal device is able to perform appropriate suppression and cancellation of the interference, thus making it possible to improve throughput.

Abstract: A transmitter apparatus to transmit to a plurality of receiver apparatuses a data signal at the same timing and on the same frequency, includes a transmitter unit that transmits a demodulation reference signal addressed to a first receiver apparatus and a demodulation reference signal addressed to a second receiver apparatus different from the first receiver apparatus at the same timing and on the same frequency.

Abstract: A transmitting device in a wireless communication includes a control module configured to indicate a method out of a plurality of interpolation methods, each of which interpolates channel values in missing subcarriers based on positions of representative subcarriers, which are selected out of the subcarriers defining a frequency band used in the wireless communication, and values in the representative subcarriers, and a transmitting module configured to transmit information about a selected interpolation method.

Abstract: A wireless reception device is notified of whether a multi-user MIMO signal transmitted from a wireless transmission device has undergone linear precoding or non-linear precoding without increasing the amount of control information. A wireless transmission device having a plurality of transmit antennas 303, for transmitting spatially multiplexed signals to a plurality of wireless reception devices includes a group construction unit 307 configured to classify the wireless reception devices into a plurality of groups and to determine a precoding scheme for each of the groups, a selection unit 315 configured to select one group from among the groups, and a precoding unit 323 configured to precode transmit data addressed to each of wireless reception devices belonging to the selected group, using a precoding scheme determined for the selected group.

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: A terminal device according to an aspect of the present invention includes a reception module that receives a control channel and a spatially multiplexed data signal channel, a control signal detection module that extracts, from an output from the reception module, a demodulation control information which is a transmission parameter of a signal that is transmitted to the terminal device, in a data signal channel that is output from the reception module, and assistance control information which is a transmission parameter of a signal that is transmitted to a different terminal device, in the data signal channel that is output from the reception module, a channel estimator that obtains a channel estimate by using a reference signal, a signal detection module that demultiplexes the data signal channel by using the demodulation control information, the assistance control information, and the channel estimate, and a decoding module that decodes a signal that is output by the signal detection module, in which infor

Abstract: A radio communication system includes a multiple number of transmitting apparatus and a receiving apparatus including a multiple number of receive antennas, in which the transmitting apparatus generates a reference signal that is obtained by adding a different time shift to a known signal between the transmitting apparatus and the receiving apparatus, multiplexes a data signal with the reference signal and transmits the resultant signal. The receiving apparatus separates reference signals multiplexed on the signals received from the multiple transmitting apparatus, and estimates channel information from the reference signals, which have been transmitted through common frequencies in part or whole of the signal spectra. Then, the data signal is decoded based on the estimated channel information.

Abstract: The present invention switches an interference suppression system between a linear precoding and a nonlinear precoding in accordance with a communication environment. A wireless transmission apparatus is provided with a plurality of transmission antenna units (303), and multiplexes spatially and transmits a plurality of series of data with respect to at least one wireless reception apparatus, and includes a selection unit (307) configured to select any one precoding system from a plurality of types of precoding systems and a precoding unit (315) configured to carry out precoding with respect to the plurality of series of data using the selected precoding system. In addition, the selection unit selects either of a first precoding system carrying out linear processing with respect to the plurality of series of data or a second precoding system carrying out nonlinear processing with respect to the plurality of series of data.

Abstract: It is intended to provide a transmission device, a reception device and a communication system capable of improving transmission characteristics by performing packet combining by HARQ in MU-MIMO transmission using non-linear precoding. In a case of receiving NAK from any of terminal devices (400), a base station device (100) retransmits a packet, in which an error occurs, addressed to this terminal device. The base station device (100) transmits the data to be retransmitted together with other transmission data addressed to a different terminal device or addressed to the own terminal device by spatial multiplexing transmission with MU-MIMO. At this time, for the retransmission data, precoding is performed such that a perturbation term same as a perturbation term which has been added to this data by non-linear precoding at the time of initial transmission is added.

Abstract: A base station device according to the present invention receives wireless frames transmitted by terminal devices in nearby cells, estimates the state of the propagation channels between the terminal devices in the nearby cells and itself, based on the received signals thereof, and performs precoding on transmission data addressed to terminal devices in its own cell, based on the estimation results of the propagation channel state, and transmits.

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: In a codebook-based closed loop type MIMO, improvement for complexity in a mobile station apparatus, and reduction of amount of overhead needed for notification from the mobile station apparatus should be provided. A wireless transmission apparatus that includes a plurality of transmission antennas, performs precoding on a data signal for each of a plurality of reception apparatuses and spatially multiplexes and transmits the signal after the precoding. The wireless transmission apparatus performs sharing a codebook describing a plurality of linear filters associated with each other is shared with the each reception apparatus, and precoding on the data signal for each reception apparatus, based on a first linear filter that is extracted from the codebook in each reception apparatus based on the association and that is notified from each reception apparatus.

Abstract: A base station apparatus according to the present invention is capable of adjusting antenna gains in a horizontal direction and a vertical direction of the plurality of antennas included in the base station apparatus, by adjusting a phase and an amplitude of a signal addressed and transmitted to a terminal apparatus, stores a codebook which is shared with the terminal apparatus and describes a plurality of linear filters associated with antenna gains in the horizontal direction and antenna gains in the vertical direction, acquires control information indicating at least one out of a plurality of linear filters described in the codebook, of which notification is sent from the terminal apparatus, performs precoding on the signal addressed to the terminal apparatus, based on the control information and the first codebook, and transmits the signal subjected to the precoding.

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.