Transmit antenna diversity in Ricean fading MIMO channels with co-channel interference

Transmit antenna diversity using closed loop and open loop modes are compared in environments with line of sight propagation and spatially and temporally non-white noise. The connection between the feedback channel capacity in closed loop modes and the channel coherence time is investigated. It is shown that in LOS environments, the requirements on the feedback channel bit rate is lower. Furthermore, we derived the beamforming vector in closed loop transmit diversity with directional interference and showed how this gives an equivalent gain in SNR of about 3 dB at the receiver, even at a beamforming weight phase resolution of 90 .