Low Complexity Hybrid Precoding and Combining for Millimeter Wave Systems

In millimeter-wave (mmWave) systems, hybrid precoding/combining architectures are an attractive low-complexity alternative to the use of fully digital precoding. This is because of the reduction in the number of Radio-Frequency (RF) and mixed-signal hardware components. Hybrid precoding/combining design involves a combination of analog and digital processing that enables both beamforming and spatial multiplexing gains in mmWave systems. This paper presents an algorithm for hybrid precoding and combining designs in mmWave systems. The proposed design does not depend on the antenna array geometry, unlike the orthogonal matching pursuit (OMP) hybrid precoding/combining approach. Moreover, this algorithm allows hybrid precoders/combiners to perform close to the known optimal performance of unconstrained digital precoders and combiners. Simulation results verify that the proposed hybrid precoding/combining scheme outperforms the previous methods in the literature in terms of bit error rate (BER) and achievable spectral efficiency with lower complexity.