Sharp Kabushiki Kaisha Corporation

Kozue Hirata

Takashi Onodera

Hiroshi Nakano

Hiromichi Tomeba

Shimpei To

Minoru Kubota

Alvaro Ruiz Delgado

Naoki Okamoto

Nakano Hiroshi

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. The transmission apparatus includes: an ordering determination partwhich determines an order in which a transmission signal addressed to each reception apparatus is generated based on information indicating spatial correlation of channels; a linear filter generation partwhich generates a linear filter based on the determined order; a THP partwhich performs a THP process by using the determined order and the linear filter; and a linear filter multiplication partwhich multiplies an output of the THP partby the linear filter.

Transmission apparatus, reception apparatus, wireless communication system, control program and integrated circuit

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.

Communication system, transmitter, receiver and communication method

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.

Base station device, terminal device, and wireless communication system using the base station device and the terminal device

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 unitreceives channel state information from each terminal, a channel matrix H is obtained. A transmit weight/interference coefficient calculation unitcalculates a transmit weight and an interference coefficient based on channel matrix. The transmit weight is input to transmit weight multiplication unitsand. The interference generation unitgenerates an interference signal based on the interference coefficient. An interference subtraction unitsubtracts the interference signal from a desired signal. A modulo unitadds a signal so that amplitude of an information signal output from the interference subtraction unitfalls within a constant range. A signal multiplexing unitperforms spatial multiplexing to the signal performed nonlinear arithmetic.

Receiving apparatus, transmitting apparatus and wireless communication system using them

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 stationreceives by a receiving antennafrom the terminal apparatus channel state information between a transmitting antennaand spatial multiplexing object antennas included in each terminal apparatus. A transmit weight calculation unitcalculates a transmit weight for performing spatial multiplexing transmission to the terminal apparatus based on the channel state information. Transmit weight multiplication unit sandmultiplies an information signal addressed to each terminal apparatus to be performed spatial multiplexing by the transmit weight. A signal multiplexing unitmultiplexes 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.

Base station apparatus, terminal apparatus and wireless communication system using them

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.

Transmission device, reception device, wireless communication system, transmission control method, reception control method, and processor

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; and a transmission antenna group that transmits the post-interference-removal transmitted signal group and the non-interference-removed transmitted signal group from mutually different transmission antennas.

Wireless communication apparatus, wireless communication system, and communication method

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.

Growing community of inventors

Osaka, Japan

Kozue Hirata