Method and device for feeding back channel state information (CSI) and method and device for determining CSI are provided. The method for feeding back CSI includes feeding back CSI according to a determined structure of the CSI, where the structure of the CSI includes M CSI subsets; an m-th CSI subset among the M CSI subsets includes km channel information components. The M CSI subsets include N CSI subsets, and an n-th CSI subset among the N CSI subsets includes Ln channel information components which are determined by transforming a group of base vectors.

Methods and apparatuses for CSI reporting mechanisms are provided. A user equipment (UE) includes a transceiver and a processor operably connected to the transceiver. The transceiver is configured to receive information indicating a channel state information reference signal (CSI-RS) resource configuration, uplink-related downlink control information (DCI), and a CSI-RS associated with a selected CSI-RS resource in a same subframe as the uplink-related DCI. The processor configured to determine, in response to a CSI request included in the uplink-related DCI, an aperiodic CSI in reference to the CSI-RS. The transceiver is further configured to report the aperiodic CSI by transmitting the aperiodic CSI on an uplink channel.

A transmitter includes an antenna array having a plurality of antennas for a wireless communication with one or more receivers, and a precoder connected to the antenna array, the precoder to apply a set of beamforming weights to the antenna array, the set of beamforming weights selected from a codebook to form by the antenna array one or more transmit/receive beams or nulls pointing in selected directions. The codebook includes a plurality of sets of beamforming weights for a plurality of directions. The beamforming weights in the codebook are based on a first antenna array response matrix, the first antenna array response matrix defined by a second antenna array response matrix and one or more characteristic matrices. The first antenna array response matrix contains first array response vectors of the antenna array, the second antenna array response matrix contains second array response vectors of another antenna array, the other antenna array being different from the antenna array, and the one or more characteristic matrices describing characteristics of the antenna array.

Example embodiments are presented for codebook subset restriction and precoder selection in wireless communications systems. For instance, an example method for codebook subset restriction at a user equipment (UE) is presented. In the example method, the UE can receive, from a network node such as a gNB, codebook subset restriction (CBSR) signaling for a first component common to precoders in a first group of codebooks. In an aspect of the present disclosure, a restriction of the first component maps to a restriction of a second component and the second component is common to precoders in a second group of codebooks. In addition, the example method includes restricting precoders selectable from a codebook in the second group of codebooks based on the second component. Network-side methods are presented, as well as example UEs and network nodes.

Disclosed are a codebook-based signal transmission/reception method in a multi-antenna wireless communication system, and a device for same. Specifically, provided is a method by which a terminal transmits/receives a signal on the basis of a codebook, in a 2-dimensional multi-antenna wireless communication system, comprising the steps of: receiving a channel state information reference signal (CSI-RS) from a base station, via a multi-antenna port; and reporting channel state information to the base station. The channel state information comprises a precoding matrix indicator (PMI) for indicating a precoding matrix. The PMI comprises a first PMI for selecting a precoding matrix set from a codebook, and a second PMI for selecting one precoding matrix from the precoding matrix set. The pair of the first dimensional index and second dimensional index of the precoding matrix belonging to the precoding matrix set is (x, y), (x+2, y), (x, y+1), (x+1, y+1), x and y being whole numbers that are not negative.

A method of user equipment (UE) for channel state information (CSI) feedback in a wireless communication system. The method comprises receiving, from a base station (BS), CSI feedback configuration information for a pre-coding matrix indicator (PMI) feedback indicating a linear combination (LC) pre-coding matrix that corresponds to a linear combination of a plurality of L beams and a plurality of coefficients, determining the first PMI (i.sub.1) and the second PMI (i.sub.2), and transmitting, to the BS, the CSI feedback including the first PMI (i.sub.1) and the second PMI (i.sub.2) over an uplink channel.

The present invention relates to a multi-input and multi-output communication method in a large-scale antenna system. An MIMO transmission method according to the present invention includes: obtaining statistical channel information on at least one terminal, dividing terminals into a plurality of classes and a plurality of groups based on the statistical channel information, wherein the groups depend on the classes; determining a group beam-forming matrix for each of the divided groups; performing a group beamforming transmission by group based on the group beam-forming matrix to obtain instantaneous channel information; and scheduling terminals based on the instantaneous channel information. Thus, it is possible to decrease the complexity in a scheduling and precoding calculation without an increase in the amount of wireless resources that are required for providing feedback for a reference signal and channel status information.

Disclosed are a codebook-based signal transmission and reception method in a multi-antenna wireless communication system and an apparatus therefor. Specifically, a method for transmitting or receiving a signal on the basis of a codebook by a terminal in a 2-dimensional multi-antenna wireless communication system comprises the steps of: receiving a channel state information reference signal (CSI-RS) through a multi-antenna port from a base station; and reporting channel state information to the base station, wherein the channel state information may include a precoding matrix indicator (PMI) for indicating a precoding matrix, the PMI may include a first PMI for selecting a set of precoding matrixes from the codebook and a second PMI for selecting one precoding matrix from the set of precoding matrixes.

Disclosed are a codebook-based signal transmission and reception method in a multi-antenna wireless communication system and an apparatus therefor. Specifically, a method for transmitting or receiving a signal on the basis of a codebook by a terminal in a 2-dimensional multi-antenna wireless communication system comprises the steps of: receiving a channel state information reference signal (CSI-RS) through a multi-antenna port from a base station; and reporting channel state information to the base station, wherein the channel state information may include a precoding matrix indicator (PMI) for indicating a precoding matrix, the PMI may include a first PMI for selecting a set of precoding matrixes from the codebook and a second PMI for determining one precoding matrix applied to a multi-layer from the set of precoding matrixes, the precoding matrix may be configured by a precoding vector applied to each layer, and the precoding vector may be determined in the set of precoding vectors determined by the first PMI.

A wireless communication system includes: a transmission apparatus that transmits a wireless signal including a plurality of wireless transmission signals, by using a plurality of transmitting antenna elements; and a reception apparatus that receives the wireless signal, as a plurality of wireless reception signals, by using a plurality of receiving antenna elements. The reception apparatus generates a plurality of separated reception signals by performing a signal separation process on the plurality of wireless reception signals, generates correlation information about the separated reception signals, and generates phase control information on the basis of the correlation information. The transmission apparatus generates the plurality of synthesized transmission signals by performing the signal synthesis process on the plurality of transmission signals, and adjusts the phase of each of the synthesized transmission signals, by a phase shift amount calculated on the basis of the phase control information.