Multiuser detection in massive spatial modulation (SM-) MIMO with low-resolution ADCs

In this work, we research the multiuser detection (MUD) in a new Single Carrier (SC) massive Spatial-Modulation-Multiple-Input-Multiple-Output (SM-MIMO) system, where the Base Station (BS) is equipped with massive antennas connecting to independent Radio-Frequency (RF) chains designed by low-resolution Analog-to-Digital Converters (ADCs). Different User Equipments (UEs) possess multiple Transmit Antennas (TAs) but only one RF chain, and transmit data-bits to the BS by Cyclic-Prefix Single-Carrier (CP-SC) SM. We construct a new Message Passing De-Quantization Detector (MPDQD) based on the MPDQ algorithm in Compressed Sensing (CS). MPDQD exploits both the special structures (e.g., sparsity) and prior probability distribution of the transmitted signal, so it reaches superior detection performances. It involves the parallelized matrix-vector multiplication as the most complex operation, so it has low complexity and is suitable for hardware implementation. Simulation results show that MPDQD outperforms the linear detectors, and can approach the performance of the un-quantized system even when ADC resolution is low (e.g., 4bits).