Differential space-time modulation with transmit-beamforming for correlated MIMO fading channels

While the knowledge of each channel realization is not available in a system with differential space-time modulation, channel correlation can be easily estimated without training at the receiver, and exploited by the transmitter to enhance the error probability performance. We develop a transmission scheme that combines transmit-beamforming with differential space-time modulation based on orthogonal space-time block coding. Error probability is analyzed for both correlated and independent channels. Based on the error probability analysis, we derive power loading coefficients to improve performance.