On Performance of Sphere Decoder Joint Detection Algorithm for MIMO LAS-CDMA System

This paper proposes a new reduced-complexity joint detection algorithm based on sphere decoder for MIMO LAS-CDMA system. This algorithm can approach ML performance in polynomial complexity. Special zero correlation window property of LAS code can reduce complexity of this algorithm greatly. Simulation indicates it is more insensitive to the choice of initial radius. Thus, by making the choice of radius sufficiently large, the ML solution is guaranteed with low complexity, even for large constellations. We compare this algorithm with MMSE, ZF multicode detectors. Numerical results show performance of this algorithm is good even at very high speed such as 160 Km/h, this give us some insights on developing high efficient practical joint detection algorithm for further LAS-CDMA system.