Low Complexity Soft-input Soft-output Group Detection for Massive MIMO Systems

In this paper, we present a novel soft-input soft-output detector for large-scale MIMO systems that offers substantial complexity reduction over the existing detectors and performance close to the full dimensional symbol detector. The proposed algorithm, termed soft-input soft-output successive group (SSG) detector, detects a subset of symbols successively with an aid of the preprocessing designed to suppress the inter-group interference. In fact, the proposed preprocessor mitigates the effect of interfering symbol groups using a priori information of the undetected groups and a posteriori information of the detected groups. Simulation results performed on large-scale-multi-input multi-output (MIMO) systems demonstrate that the proposed SSG detector achieves significant complexity reduction over the conventional approaches with negligible performance loss.