A novel soft-extension of fixed-complexity sphere decoding (FSD) algorithm is proposed, taking Soft FSD (SFSD)1 algorithm as a starting point, which suffers from the multiple-tree-search problem, and the so called iteration problem, that is, its performance degrades as the number of the receiver iteration increases. The proposed parallel SFSD (PSFSD) performs a single tree search by taking partial best nodes to generate counter-hypotheses. To make use of priori information in tree search to overcome the iteration problem, soft-hard combination (SHC) enumeration method is presented as a low complexity algorithm to find the best child with prior term added. The proposed scheme is suitable for hardware implementations and can be easily extended to other tree search schemes.