Exponential diversity achieving spatio-temporal power allocation scheme for MIMO fading channels

We analyze optimum (space-time) adaptive power transmission policies for Rayleigh fading MIMO channels when CSIT and CSIR are available. We show that our power allocation policy provides exponential diversity gain/sup 2/ (BER/spl les//spl alpha/e/sup -f(n(t),n(r))/ where /spl alpha/>0 is a constant, and f>0 is an increasing function of n/sub t/&n/sub r/) if perfect CSIT is available. Exponential diversity is lost at high SNR if the quality of CSIT degrades.