Performance analysis of the V-BLAST algorithm: an analytical approach

An analytical approach to the performance analysis of the V-BLAST (vertical Bell Labs layered space-time) algorithm is presented. The approach is based on the analytical model of the Gramm-Schmidt process. Closed-form analytical expressions of the vector signal at the i-th processing step and its power are presented. A rigorous proof is given that the diversity order at the i-th step (without optimal ordering) is (n-m+i), where n and m are the number of receiver and transmitter antennas respectively. It is shown that the optimal ordering is based on the least correlation criterion and that the after-processing signal power is determined by the channel correlation matrices in a fashion similar to the channel capacity.