New List Sphere Decoding (LSD) Algorithms for MIMO Detection with LDPC FEC

New sphere decoding algorithms are proposed in this paper. In particular an iterative list branch and bound (BB) algorithm based on the basic BB algorithm is proposed in this paper, which can obtain a candidate list to compute soft information that is used in the iterative detector. Furthermore, an improved algorithm is proposed which uses the prior information from the preceding iteration to calculate the lower bound and the candidate list is updated every iteration. Simulation results show that the proposed list BB algorithm can achieve near capacity performance and the improved algorithm achieves good performance with smaller candidate list size.