Single-symbol decodable differential space-time modulation based on QO-STBC

We show that minimum-decoding-complexity quasi-orthogonal space-time block code (MDC-QOSTBC) can be used to form a new differential space-time modulation (DSTM) scheme to provide full transmit diversity with single-symbol decodable complexity. This is the first known single-symbol decodable DSTM not based on orthogonal STBC. We derive the DSTM code design criteria and use them to construct customized constellation sets that provide full diversity and maximum coding gain. Our new DSTM scheme can provide a higher code rate and better decoding performance than DSTM schemes based on rate-1/2 orthogonal STBC. It also has a lower decoding complexity than the other DSTM schemes, as its maximum likelihood decoding only requires the joint detection of two real symbols.