A low complexity grouping multi-user detection algorithm for the LDS multiple access system

The complexity of the multiuser detection algorithm of the low-density spreading multiple access system is need to reduced. Based on the difference in the channel quality and signal power at the base station of each user in the uplink system, we propose a multi-user detection algorithm that reduces the computational complexity. This algorithm adopts group detection based on the users instantaneous channel quality, and presents design criteria for user grouping and the corresponding indication matrix. The computational complexity of the algorithm is analyzed and the algorithm is simulated under different channel conditions. The simulation results show that the computational complexity of the algorithm is effectively reduced with a very small loss of user performance.