Power Diversity Scheme for V-BLAST Systems under Rayleigh Fading

As the multimedia applications become more popular, there is an increasing demand for wireless communication technology that supports high transmission rate. Vertical bell laboratories layered space-time (V-BLAST) is one of the most popular multiple-input multiple-output (MIMO) architectures that achieves very high spectral efficiency and thus high transmission rate. In this work, we propose the use of power diversity scheme to minimize the bit error rate (BER) of V-BLAST systems. The essence of power diversity scheme is to intentionally cause different received power from each layer at the receiver. By judiciously allocating the transmitting power to the layers, the performance of the successive interference cancellation at the receiver can be significantly improved. The exact BER of the V-BLAST systems with non-uniform power allocation is analyzed for the Rayleigh fading case. The BER is minimized to determine the optimal power allocation pattern for the V-BLAST systems. Simulations show that our BER analysis is accurate and the proposed power diversity scheme significant improves the performance of the V-BLAST systems by 3 to 3.6 dB.