Differential space-time modulation for transmissions over unknown FIR channels

This paper presents a differential space-time transceiver over multiple-input multiple-output (MIMO) time-dispersive channels. The underlying idea is to transform the block Toeplitz received signal structure caused by the finite impulse response (FIR) multipath channels into a block circulant matrix structure by deploying specialized signaling when transmitting through multiple antennas. This structure is then exploited by using the efficient space-time (ST) processing at the receiver for the mitigation of the channel multipath effects. The new, low complexity, transceiver is based on cyclic group codes and a differential ST demodulation. The proposed scheme falls into the category of the deterministic approaches that are able to operate on short sample data and do not face convergence problems. Simulation results verify the robust performance of the scheme over the MIMO-FIR fading channels