BER-Based Codebook Construction for MIMO-OFDM Precoded Spatial Multiplexing Systems

This paper deals with design and performance analysis of transmit precoder optimization for MIMO-OFDM systems with limited feedback of channel state information (CSI). We assume that the receiver has perfect channel knowledge while the transmitter has only partial channel knowledge from limited feedback. We present a BER-based optimal codebook construction algorithm for MIMO-OFDM systems under average power constraint using the Lloyd algorithm. The proposed optimal precoder has the structure of joint precoding and power allocation. Closed form solution has been derived for power allocation in the sense of minimum BER for the MIMO-OFDM systems. Simulation results show that the BER-based codebook construction algorithm with hybrid design of power allocation and multi-mode beamforming can achieve better performance than those of equal power allocation based codebooks in literature.