An apparatus: obtains K downlink channel weight matrices based on K pieces of downlink channel information sent by K UEs, where the downlink channel information is fed back by the UE in response to a preset reference signal sent by the base station, the downlink channel weight matrix is an N.sub.T×rank-dimensional matrix, and rank is a quantity of signal streams received by the UE; obtains K×rank first initial phase difference matrices and K×rank second initial phase difference matrices based on the K downlink channel weight matrices and a first polarization direction and a second polarization direction of transmit channels of the base station; obtains a cell initial phase difference matrix based on the K×rank first initial phase difference matrices and the K×rank second initial phase difference matrices; and implements initial phase correction of the transmit channels based on the cell initial phase difference matrix.

A communication system includes a base station including a plurality of antennas that separate from each other and a mobile station. The base station maps a plurality of reference signals separable from each other onto the antennas to transmit the mapped reference signals. The mobile station determines, using the received reference signals, reception quality in consideration of gain of beam-forming transmission performed by the base station with the antennas, and notifies the base station of the determined reception quality.

A transmission apparatus that (i) generates a Quadrature Phase Shift Keying (QPSK) modulation signal s1(t) by applying a QPSK modulation scheme to a first data sequence, (ii) generates a 16-Quadrature Amplitude Modulation (QAM) modulation signal s2(t) by applying a 16-QAM modulation scheme to a second data sequence, (iii) generates a transmission signal z1(t) and a second transmission signal z2(t) by applying a phase hopping process, a precoding process, and a power adjust process to the QPSK modulation signal s1(t) and the 16-QAM modulation signal s2(t), wherein an average transmission power of the 16-QAM modulation signal s2(t) being the same as an average transmission power of the QPSK modulation signal s1(t), and (iv) transmits the transmission signal z1(t) from a first antenna at a first time and a first frequency and the second transmission signal z2(t) from a second antenna at the first time and the first frequency.

A signaling transmission method and apparatus for a Multiple-Input Multiple-Output MIMO system are provided. The method includes the following steps. Channel-Related Information CRI about a combined channel is formed according to CRI between all receiving antenna ports in a receiving network and a sending antenna port in a sending network. The CRI about the combined channel is sent to the sending network. Herein, the CRI includes one or more of the following: channel information, Channel State Information CSI, and a CSI Reference Signal CSI-RS.

[Object] To enable more appropriate recognition of an interference situation of a directional beam.

[Solution] Provided is an apparatus including: an acquisition unit that acquires a weight set for forming a directional beam; and a control unit that multiplies a reference signal for channel quality measurement by the weight set. The weight set is a weight set that is able to be generated from a first weight set for acquiring directivity in a first direction, a second weight set for acquiring directivity in a second direction, and a third weight set for phase adjustment of dual layer multiple-input multiple-output (MIMO). The third weight set is a specific one of a plurality of weight sets for phase adjustment of dual layer MIMO.

A method for operating a user equipment (UE) comprises receiving information about a channel state information (CSI) report, the information including information about a parameter α, wherein the parameter α is a rational number≤1; determining a value of K.sub.1 based on the parameter α; selecting K.sub.1 CSI reference signal (CSI-RS) ports from a total of P CSI-RS ports; determining the CSI report including an indicator indicating the selected K.sub.1 CSI-RS ports; and transmitting the CSI report including the indicator indicating the selected K.sub.1 CSI-RS ports.

Provided are a method and an apparatus for performing communication based on hybrid beamforming in a wireless communication system. Specifically, a user equipment (UE) transmits a dedicated scheduling request to a base station (BS). The dedicated scheduling request indicates a first scheduling request that is a request to transmit beam state information, multiplexed on an uplink data channel, or a second scheduling request that is a request to allocate a resource for a reference signal for beam refinement information. When the dedicated scheduling request indicates the first scheduling request, the UE receives an uplink grant including a response to the first scheduling request from the BS. The UE feeds the BSI back multiplexed on the uplink data channel to the BS.

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. A terminal apparatus that communicates with a base station apparatus, includes a higher layer processing unit for which a CSI process that is a configuration relating to reporting of channel state information (CSI) is configured by the base station apparatus, and a transmission unit that transmits the CSI based on the CSI process, in which the CSI information includes a configuration of a CSI reference signal and a configuration relating to two different code books.

A method of a user equipment (UE) for a channel state information (CSI) feedback in a wireless communication system is provided. The method comprises receiving, from a base station (BS), CSI feedback configuration information including a number (K.sub.0) of coefficients for the CSI feedback, deriving, based on the CSI feedback configuration information, the CSI feedback including K.sub.1 coefficients that are a subset of a total of Q coefficients, wherein K.sub.1≤K.sub.0 and K.sub.0<Q, and transmitting, to the BS, the CSI feedback including the K.sub.1 coefficients over an uplink channel.

Aspects of the subject disclosure may include, for example, determining a coherence block for each user equipment (UE) of a plurality of UEs being served by the first cell, resulting in a plurality of coherence blocks, responsive to the determining, identifying a smallest coherence block from the plurality of coherence blocks, identifying a pilot sequence length based on the smallest coherence block, determining a plurality of orthogonal pilot sequences based on the identifying the pilot sequence length, designating, from the plurality of orthogonal pilot sequences, a first group of orthogonal pilot sequences for use in the first cell, and distributing, to each neighboring cell of a plurality of neighboring cells adjacent to the first cell, a respective group of orthogonal pilot sequences from a remainder of the plurality of orthogonal pilot sequences, to prevent pilot contamination between the first cell and the plurality of neighboring cells. Other embodiments are disclosed.