Full-rate precoding in V-BLAST with angle parameter feedback

In this paper, we present novel precoder designs for V-BLAST systems which achieve full-rate. We first present a precoding scheme based on algebraic lattices over real number fields. We prove that this full-rate scheme achieves full-diversity, assuming availability of full channel state information at the transmitter. We then propose a precoding scheme which achieves full-rate and high orders of diversity with limited feedback. The proposed scheme involves a precoder codebook design consisting of unitary matrices parametrized by a single angular parameter, thereby requiring less feedback overhead. Our simulation results show that the proposed limited feedback precoding scheme provides a performance improvement of 1.5 dB and 2.5 dB at a bit error rate of 10^-3 over existing schemes for 2×2 and 4×4 V-BLAST systems, respectively, using 4-QAM.