STATISTICS-AIDED CODEBOOK DESIGNS FOR LIMITED FEEDBACK BEAMFORMING SYSTEMS OVER MILLIMETER WAVE CHANNELS

Abstract

In this paper, we consider statistics-aided beamformer code book designs for millimeter wave (mmWave) channels with limited feedback. The dimension of the beamformer, which scales with the number of transmit antenna, is typically large in mmWave systems and a large dimension adds to the difficulty of codebook designs. Two low-cost design methods are proposed. The first one, a VQ based approach, reduces the dimensionality of the codebook design problem by using training AoDs (angles of departure) instead of training channels. The second one, requiring no codebook training, designs the beamformer codebook from the statistics of the channel alone based on spectral analysis of the channel. Simulations are given to demonstrate the usefulness of the proposed methods.