The present disclosure provides a terminal device that allows constraints on user allocation to be prevented and spread codes to be allocated in a scheduler when non-adaptive HARQ is employed using a PHICH. A codeword generator generates code words by encoding data, a layer mapping unit places each CW in one or a plurality of layers, a DMRS generator generates a reference signal for each layer in which a CW is placed by using any resource among a plurality of resources defined by a mutually orthogonal plurality of OCCs, and an ACK/NACK demodulator receives a response signal indicating a retransmission request. When a response signal requesting retransmission of only a CW placed in a plurality of layers is received, the DMRS generator uses each resource having the same OCC among the plurality of resources for the reference signals generated in the corresponding layers.

The present invention provides a terminal device that allows constraints on user allocation to be prevented and spread codes to be allocated in a scheduler when non-adaptive HARQ is employed using a PHICH. A codeword generator (103) generates code words (CW) by encoding data, a layer mapping unit (108) places each CW in one or a plurality of layers, a DMRS generator (110) generates a reference signal for each layer in which a CW is placed by using any resource among a plurality of resources defined by a mutually orthogonal plurality of OCCs, and an ACK/NACK demodulator (102) receives a response signal indicating a retransmission request. When a response signal requesting retransmission of only a CW placed in a plurality of layers is received, the DMRS generator (110) uses each resource having the same OCC among the plurality of resources for the reference signals generated in the corresponding layers.

An apparatus for mapping data in a wireless communication system. The apparatus includes circuitry for generating a precoding matrix for multi-antenna transmission based on a precoding matrix indicator (PMI) feedback from at least one remote receiver where the PMI indicates a choice of precoding matrix derived from a matrix multiplication of two matrices from a first code book and a second codebook. The apparatus further includes circuitry for precoding one or more layers of a data stream with the precoding matrix and transmitting the precoded layers of data stream to the remote receiver.

A method for constructing a codebook in a multiple-antenna wireless communication system and an apparatus therefor are disclosed. Specifically, constructing a codebook in a multiple-antenna wireless communication system comprises the steps of: receiving parameters for constructing a codebook from a base station; and constructing a codebook using the parameters for constructing the codebook, wherein the parameters for constructing the codebook may include a phase value () of a first code vector forming the codebook, a phase difference () between code vectors that are adjacent to one another within the codebook, and the number of bits () that is required when feeding back a code vector selected thin the codebook.

Various aspects of the disclosure relate to a codebook design that defines phase rotation on one or more layers of a codebook. This codebook may be used, for example, for sparse code multiple access (SCMA) encoding. One feature pertains to a method of communication that includes receiving at least one input signal, and mapping each of the at least one input signal to a corresponding layer of a codebook, where the codebook defines phase rotation between the layers. The method may further include generating a coded signal for each of the at least one input signal on each corresponding layer based on the codebook, and generating an output signal based on each generated coded signal.

Various solutions with respect to codebook-based uplink transmission in wireless communications are described. A user equipment (UE) generates a codebook comprising a plurality of precoders. The UE processes information using the codebook and transmits the processed information to a network node of a wireless network. In generating the codebook, the UE selects a candidate precoder from a single-stage codebook or a dual-stage codebook and performs a permutation on the candidate precoder.

A method and apparatus for allowing a UE to transmit uplink signals using a MIMO scheme are disclosed. In order to maintain good Peak power to Average Power Ratio (PAPR) or Cubic Metric (CM) properties when the UE transmits uplink signals using the MIMO scheme, the UE uses a precoding scheme based on a precoding matrix established in a manner that one layer is transmitted to each antenna in specific rank transmission.

The present invention provides a terminal device that allows constraints on user allocation to be prevented and spread codes to be allocated in a scheduler when non-adaptive HARQ is employed using a PHICH. A codeword generator (103) generates code words (CW) by encoding data, a layer mapping unit (108) places each CW in one or a plurality of layers, a DMRS generator (110) generates a reference signal for each layer in which a CW is placed by using any resource among a plurality of resources defined by a mutually orthogonal plurality of OCCs, and an ACK/NACK demodulator (102) receives a response signal indicating a retransmission request. When a response signal requesting retransmission of only a CW placed in a plurality of layers is received, the DMRS generator (110) uses each resource having the same OCC among the plurality of resources for the reference signals generated in the corresponding layers.

Efficient techniques to signal codebook subset restriction bit maps are provided. In some embodiments, a method of operation of a node of a cellular communications network includes determining a codebook restriction for a wireless device. The codebook restriction reduces a full codebook of the wireless device to a reduced codebook. The method also includes providing the codebook restriction to the wireless device with an indication of one or more ranks to which the codebook restriction applies. In some embodiments, this enables reduced signaling overhead from upper layers, improving the throughput of data traffic channels. This may also enable reduced RRC signaling message failures and also reduced latency.

Various embodiments disclosed herein provide for a base station device that can determine which layers should be mapped to codewords in a multi-layer, multi-antenna transmission. The base station device can transmit reference signals to a user equipment device, with each reference signal associated with a respective codeword to layer mapping combination, and the user equipment can send channel state information associated with each reference signal back to the base station device, and the base station device can rank each combination in terms of spectral efficiency or capacity and/or throughput. The base station device can inform the user equipment of the ranked combinations by sending a bit map with the ranked combinations to the user equipment device.