A comparison of reception schemes for interference suppression in MIMO-OSTBCs system

Current Alamouti's reception scheme for multiple input multiple output (MIMO) communication systems may fail to work when strong interferences exist in the MIMO channel. This paper analyzes and compares three reception schemes for MIMO systems using orthogonal space-time block codes (OSTBCs) suffered directional interferences. These schemes include conventional maximum likelihood decoding (MLD) scheme, simplified MLD scheme, and digital beam-forming (DBF) reception scheme based on minimum mean square error (MMSE) criterion. The analysis shows that both simplified MLD scheme and conventional MLD scheme have the same SER performance. MMSE-DBF reception scheme can also achieve the ML boundary when the constant modulus signals are adopted at the transmitter. Simulation results are given to verify our theoretical analysis.