MULTIPLE INPUT MULTIPLE OUTPUT COMMUNICATION SYSTEM FOR ROTATING REFERENCE CODEBOOK INCLUDING CODEDWORDS OF DISCRETE FOURIER TRANSFORMATION CODEBOOK

摘要

The base station and the terminal may calculate the rotation matrix based on any of the code words included in the previous preferred code word and the discrete Fourier transform codebook. At this time, the reference codebook is rotated using the rotation matrix, so that it is converted into a new codebook. The reference codebook also includes the code words of the polar-cap codebook and the code words of the discrete Fourier transform codebook, and the code words of the discrete Fourier transform codebook are still included in the new codebook as elements of the discrete Fourier transform codebook .