A new differential space-time modulation scheme for MIMO systems with four transmit antennas

In this paper, a new differential space-time modulation (DSTM) scheme for 4×4 multiple input multiple output (MIMO) systems is proposed. This scheme is used for MIMO systems where the channel coefficients are not available at both the transmitter and the receiver. The transmission matrices used in this scheme belong to the Weyl group. Simulation results show that this new scheme with four transmit antennas outperforms the well-known Tarokh´s differential space-time block coding (DSTBC) scheme. The spectral efficiency of this scheme can be up to 3 bit/s/Hz.