Robust fixed complexity sphere decoder

In this paper, RFSD (Robust Fixed-complexity Sphere Decoder) based on a new preprocessing algorithm is proposed for MIMO (Multiple Input Multiple Output) detection. Unlike the original FSD (Fixed-complexity Sphere Decoder) ordering which determines the FE (Full expansion) stage by choosing the signal component with greatest post-processing noise amplification on itself, the proposed RFSD determines the FE stage by selecting the signal component with the smallest postprocessing impact on the undetected signal component in following SE (Single Expansion) stage. Besides better performance than the original FSD ordering, RFSD is robust to the configuration of MIMO antennas (both NT NR), which is another advantage over original FSD ordering.