OMP-based hybrid precoding and SVD-based hybrid combiner design with partial CSI for massive MU-MIMO mmWave system

摘要

Millimeter-wave (mmWave) communications have been regarded as a key technology for the next-generation cellular systems since the huge available bandwidth can potentially provide the rates of multiple gigabits per second. Conventional precoding and combining techniques are impractical at mmWave scenarios due to manufacturing costs and power consumption. Hybrid alternatives have been considered as a promising technology to provide a compromise between hardware complexity and system performance. In this paper, we propose a hybrid precoder/combiner design through a hierarchical strategy evolving three stages. In the first stage, we incorporate the use of a low complexity and low size discrete Fourier transform based-codebook, which greatly reduces the needs of channel side information of our proposal. The hybrid precoder includes (i) a compress sensing technique, orthogonal matching pursuit(OMP), to take advantage of the channel sparsity at the beamforming selection procedure, (ii) the classical MMSE linear filter to deal with interference system, and (iii) the eigenvectors of the residual user channel to increase their channel gain. On the other hand, the hybrid combiner uses a low complex beamforming selection algorithm and the eigenvectors of their own residual channel. Numerical results in terms of BER and sum-rate illustrate the performance improvements resulting from our proposal in relation to other hybrid precoders/combiners.