Iterative Signal Detection Based on LRE-CG Method for Uplink Massive MIMO Systems

The minimum mean square error (MMSE) algorithm is known to be a near-optimal to uplink the large-scale multiple-input-multiple-output (MIMO) systems, however, there are some complexities involved in the procedure in relation to the matrix inversion. This paper proposes that long recurrence enlarged conjugate gradient (LRE-CG) method could be exploited for iteratively realizing the MMSE algorithm while avoiding the matrix inversion complexities. It has been verified by the simulation results that the proposed method outperforms the conventional methods in the literature including the Neumann series approximation-based approach and Gauss-Siedel iterative (GS) methods. The proposed algorithm succeeds to attain near-optimal performance of a typical MMSE algorithm with minimal level of iterations.