Exact Outage Probability Analysis of Dual-Transmit-Antenna V-BLAST with Optimum Ordering

An exact outage probability analysis of zero-forcing V-BLAST technique with two transmit antennas and r receive antennas (r ≥ 2) is provided under a decoding order that is optimum in the sense of minimizing the outage probability. Different from the earlier approximated analyses, an exact closed-form expression on the outage probability is attained without neglecting the effect of error propagation. Assuming a one-bit feedback from the receiver to the transmitter, the optimal power and rate allocation values are numerically computed based on the exact outage probability expression under different objective functions. The presented results are also applicable for the corresponding dual scenarios that may involve antenna selection and/or user scheduling.