Method and apparatus for providing channel state information report, comprising: receiving configuration information for configuring a measurement window to form a compression matrix of a port selection codebook from a codebook set of vector components, wherein the configuration information defines the size of the measurement window, which is common to all of at least one layer to be reported;

selecting a number of indices of the measurement window based on the configuration information to form the compression matrix from the codebook set of vector components; and remapping the selected indices, associated to vector components of the compression matrix, with respect to an index of a reference vector component, such that the index of the reference vector component is remapped to a first index of the measurement window; reporting channel state information including precoding matrix indicator to a network, the precoding matrix indicator comprising information of the compression matrix after remapping.

An information transmission method and apparatus. In the method, a terminal device generates a first codeword, where the first codeword is obtained based on a second codeword, a quantity of elements included in the second codeword is greater than a quantity of elements included in the first codeword, the second codeword is associated with a first coefficient set of a downlink channel, and the first coefficient set includes an element included in at least one row vector or column vector of a first coefficient matrix; and then the terminal device feeds back the first codeword to a network device. The terminal device can indicate a position and a numerical value of an element in the first coefficient set by reporting only the first codeword. This manner is simple. In addition, a codeword length of the first codeword is shorter than a codeword length of the second codeword.

[Object] To make it possible to further increase a possibility of a success in a handover. [Solution] A first apparatus of the present invention includes: a first communication processing unit configured to transmit reference signals using beamforming; and a second communication processing unit configured to receive a handover message from a source base station of a handover of a terminal apparatus. The handover message includes beam related information related to a beam. The first communication processing unit is configured to receive an access signal of the terminal apparatus based on the beam related information.

Methods, systems, and devices for wireless communication are described. Some wireless communications network may operate in accordance with an open-RAN (ORAN) network specification which may support functional splitting between the ORAN distributed unit (O-DU) and the ORAN radio unit (RU). The O-DU may communicate with the O-RU using control messaging. The control message may include a resource resource element (RE) mask and a resource symbol mask, the resource RE mask indicating frequency resources to be allocated for a reference signal transmission across a set of antenna ports and the resource symbol mask indicating time resources to be allocated for the reference signal transmission. Additionally or alternatively, the O-DU may transmit a control message including a puncturing resource RE mask indicating frequency resources for applying a puncturing pattern and a symbol mask indicating time resources for applying the puncturing pattern during a transmission.

A method performed by a base station of enabling a User Equipment (UE) to determine a precoder codebook in a wireless communication system is provided. The base station transmits, to the UE, information regarding precoder parameters enabling the UE to determine the precoder codebook. The precoder parameters are associated with a plurality of antenna ports of the base station. The precoder parameters relate to a first dimension and a second dimension of the precoder codebook. The plurality of antenna ports comprises a number of antenna ports that is a function of a number of antenna ports in the first dimension, and a number of antenna ports in the second dimension.

A method performed by a wireless device (510, 700, 1100) is disclosed. The wireless device obtains (601) a configuration for a sub-band channel quality indicator (CQI) granularity and a sub-band precoding matrix indicator (PMI) granularity for the wireless device. The wireless device determines (602) channel state information (CSI) feedback according to the configured sub-band CQI granularity and the sub-band PMI granularity. The sub-band PMI granularity corresponds to a first sub-band size and the sub-band CQI granularity corresponds to a second sub-band size. The first sub-band size is smaller than the second sub-band size. The wireless device transmits (603), to a network node (560, 1000), the determined CSI feedback.

Provided is method for generating a precoder in a Multi User Multiple Input and Multiple Output (MU MIMO) communication system. The method involves receiving channel information and quality information of a channel from a plurality of stations. It is determined whether a first condition is satisfied on the basis of the received information, if so, a type of matrix inversion is selected from among a plurality of matrix inversion types for precoding. It is determined whether a second condition is satisfied on the basis of the provided information, and a type of decomposition from a plurality of decomposition types for precoding is selected if the second condition is satisfied. A precoder is generated on the basis of the selected result.

Some embodiments of this disclosure provide a method for determining an index of an orthogonal basis vector and a device. The method includes: receiving position information, where the position information is associated with an orthogonal basis vector; and determining at least one first index set based on the position information, where the first index set represents a set of column indices of a plurality of orthogonal basis vectors in an orthogonal basis matrix.

A codebook subset restriction configuration can be received (410) from a network entity. A set of reference signals can be received (420) from the network entity. A set of frequency domain coefficients can be defined (430). The set of frequency domain coefficients can be an element of a discrete Fourier transform-compression codebook. The set of frequency domain coefficients can be generated (440) based on at least the restriction of the function of the amplitude restriction ratio of each beam in the set of restricted beams. At least one channel state information report containing the set of frequency domain coefficients can be transmitted (450).

A method of performing beam training including obtaining at least one of a probability distribution and a value function for selecting one of a plurality of beams that are used to perform beamforming, selecting a candidate beam from among the plurality of beams based on the at least one of the probability distribution and the value function, the candidate beam being expected to be a best beam among the plurality of beams, performing a present training operation based on the candidate beam and a previous beam selected by at least one previous training operation, and selecting a better one of the candidate beam and the previous beam as a present beam based on a result of the present training operation may be provided.