Optimum power allocation for a V-BLAST system with two antennas at the transmitter

In this letter we propose a power optimization scheme for 2×N (where N is the number of receive antennas) Vertical Bell Laboratories Layered Space-Time (V-BLAST) systems. The proposed scheme minimizes the uncoded probability of vector error for each channel realization, considering error propagation. Simulation results show that this approach can yield SNR gain of up to about 3 dB for a 2×2 system at probability of vector error 10^-3 and can partially compensate for the performance loss due to error propagation.