Differential en/decoding using APSK signals for distributed MIMO

This paper proposes a differential modulation scheme using amplitude-phase shift keying (APSK) signals for distributed MIMO systems where neither the transmitter nor the receiver knows channel knowledge. The bandwidth efficiency of the proposed scheme is the same as V-BLAST scheme, and it can be applied to the systems with any number of transmit and receive antennas. Simulation results show that the bit error rate (BER) performance is not same in different channel propagation delay cases, and the optimum delay time for two transmit antenna system is about 0.6 T_s (where T_s is symbol period).