Shannon capacity and eigen-beamforming for space dispersive multipath MIMO channels

This paper considers the information transfer capacity of a space dispersive multipath channel with multiple antenna at the transmitter and receiver. The Shannon capacity is evaluated for such multiple-input multiple-output (MIMO) channels with multi-dimensional space-time modulation. Assuming a non-fading environment and a known channel at the transmitter and receiver, we derive the Shannon capacity under a transmit average power constraint. It is shown that the signal structure achieving capacity corresponds to eigen-beamforming. Capacity is shown to increase with the number of signal propagation paths. The effect of the space-time modulation format on the information-theoretic capacity is also pointed out.