Various techniques are provided for determining, by a base station, a beam coverage in a cell, the beam coverage including angle range for an azimuth and an angle range for an elevation, determining, by the base station, an angle quantization step, generating, by the base station, a grid of narrow beams based on the angle range and the angle quantization step, computing, by the base station, a beam index matrix based on the grid of narrow beams, generating, by the base station, a wide beam codebook based on the grid of narrow beams, and transmitting, by the base station, at least one of a CSI-RS resource and a SSB resource using multiple-TX-directions wide beams based on the wide beam codebook.

A codebook generation method and an electronic apparatus are provided. The codebook generation method includes: collecting a plurality of pieces of electric field information of a plurality of antenna units in at least one millimeter-wave antenna module based on an initial codebook; correspondingly generating a full chain codebook (Full Chain Codebook) based on the electric field information; then, extendedly generating a sub chain codebook (Sub Chain Codebook) based on the full chain codebook; and finally generating, based on the full chain codebook and the sub chain codebook, an optimized codebook (Optimized Codebook) by using a power saving algorithm or a cumulative distribution function 50% gain loss algorithm. Therefore, the electronic apparatus using the optimized codebook is more excellent in power saving efficiency and overall efficiency performance.

Channel state information (CSI) feedback in a wireless communication system is disclosed. User equipment transmits a CSI feedback signal via a Physical Uplink Control CHannel (PUCCH). If the UE is configured in a first feedback mode, the CSI comprises a first report jointly coding a Rank Indicator (RI) and a first precoding matrix indicator (PMI1), and a second report coding Channel Quality Indicator (CQI) and a second precoding matrix indicator (PMI2). If the UE is configured in a second feedback mode, the CSI comprises a first report coding RI, and a second report coding CQI, PMI1 and PMI2. The jointly coded RI and PMI1 employs codebook sub-sampling, and the jointly coding PMI1, PMI2 and CQI employs codebook sub-sampling.

Channel state information (CSI) feedback in a wireless communication system is disclosed. User equipment transmits a CSI feedback signal via a Physical Uplink Control CHannel (PUCCH). If the UE is configured in a first feedback mode, the CSI comprises a first report jointly coding a Rank Indicator (RI) and a first precoding matrix indicator (PMI1), and a second report coding Channel Quality Indicator (CQI) and a second precoding matrix indicator (PMI2). If the UE is configured in a second feedback mode, the CSI comprises a first report coding RI, and a second report coding CQI, PMI1 and PMI2. The jointly coded RI and PMI1 employs codebook sub-sampling, and the jointly coding PMI1, PMI2 and CQI employs codebook sub-sampling.

A codebook generation method and an electronic apparatus are provided. The codebook generation method includes: collecting a plurality of pieces of electric field information of a plurality of antenna units in at least one millimeter-wave antenna module based on an initial codebook; correspondingly generating a full chain codebook (Full Chain Codebook) based on the electric field information; then, extendedly generating a sub chain codebook (Sub Chain Codebook) based on the full chain codebook; and finally generating, based on the full chain codebook and the sub chain codebook, an optimized codebook (Optimized Codebook) by using a power saving algorithm or a cumulative distribution function 50% gain loss algorithm. Therefore, the electronic apparatus using the optimized codebook is more excellent in power saving efficiency and overall efficiency performance.