A MCUR-TS Hybrid Precoding and Combining Algorithm for MIMO-OFDM Systems

As one of the promising technologies for the forthcoming 6G millimeter-wave massive multiple-input multiple-output (MIMO) orthogonal frequency division multiplexing (OFDM) systems, hybrid precoding/combining can achieve trade-off between the achievable rate, the power consumption, and cost. In this paper, a two-stage joint hybrid precoding/combining algorithm based on masterful row and column selection (MCUR) decomposition is proposed for the MIMO-OFDM system with subsystems, named as MCUR-TS. During the first stage, the analog precoder/combiner are found by the MCUR and viewpoint of subsystems, which includes the analog precoding/combining subsystems. Then, using the MCUR and notion of equivalent channel, the digital precoder/combiner are acquired. Different from the existing singular value decomposition (SVD)-based algorithms, the proposed MCUR-based algorithm preserves the sparsity of original data while reducing the computational complexity. Meanwhile, the MCUR with the truncated rotated orthogonal triangular factorization and the gravity centers of column subspaces enhances the performance of hybrid precoding/combining. Furthermore, the phase shifter quantization and imperfect channel state information are applied to decrease energy consumption and improve practicality, respectively. Extensive simulations and theoretical analyses illustrate that the proposed algorithm outperforms other methods in terms of spectral efficiency and achievable sum rate with lower complexity while providing with better robustness to channel errors.