Semi-Coherent Detection for Differential Space-Time Codes

Differential space-time coded (DSTC) modulation is a viable scheme for MIMO communication systems that do not utilize channel information at the receiver either because of rapid channel variation and/or limited training data. The drawback of DSTC is the 3 dB performance loss because of incoherent detection. In order to alleviate this performance loss, we develop a semi-coherent receiver structure in which partial channel information is acquired and utilized to generalize the traditional non-coherent receiver. This partial channel information takes the form of a subspace where the channel parameter vector must reside in. It is blindly extracted from the receive data without additional pilot assistance.