Differential Detection Based on Space-Time Block Codes

In this paper we consider the use of differential detection when there aremultiple transmitter and receiver antennas. Our differential scheme is based on the theory ofSpace-Time Block Codes that are used to achieve space-time diversity. Compared to the existingdifferential schemes for multiple antennas our scheme has a much smaller computationalcomplexity. It has the same encoding and decoding complexities as the coherent detection based on space-time block codes and achieves the same rate for up-to 8 transmitterantennas. The performance of the differential detector (which assumes no knowledge of the flat fading channel) is 3 dB less than that of the coherent detector (which uses exact channelstate information for reception). We also show that the proposed receiver is a Maximum Likelihood detector.