다중 입출력 시스템을 위한 선부호화 궤환양 감소에 관한 연구

Abstract

It has been known that the lattice-reduction-aided precoding (LRP) provides near- capacity with the use of the low complexity linear receivers. However, the number of feedback bits increases exponentially with respect to the number of spatial streams; thus, the scheme has been unsuitable for the practical systems often based on a few number of feedback bits. In this paper, for a given number of feedback bits, a codebook- based LRP scheme is proposed by modifying the precoding matrices to have specific forms that are predefined in a codebook set. The codebook for the binary precoding matrix is designed statistically such that the achievable rate is maximized. By using the proposed scheme, the performance of the linear detectors can be dramatically improved only with one or two feedback bits if the number of transmit antennas is small.