Performance analysis for V-BLAST system using OSIC receiver in correlated channel

Vertical-Bell Labs Layered Space–Time (V-BLAST) system is an emerging spatial multiplexing scheme that can achieve high spectral efficiency. Ordered successive interference cancellation (OSIC) detection algorithm is suitable for V-BLAST system because it can afford a reasonable trade-off between complexity and performance. However, the correlation of a real-world wireless channel may result in a substantial degradation of the OSIC performance. In this paper, the performance of OSIC under correlated fading is analyzed. We obtain the closed-form expression of post-processing signal-to-noise ratio (SNR) for each sub-stream based on V-BLAST architecture, and then derive the distribution of post-processing SNR based on multivariate statistical theory. The upper bound of the average probability of error (APE) is derived by the nearest neighbor union bound theory. From the expression of APE for each sub-stream, it is shown that the diversity gain at the ith processing step is (N − M + i), where N and M are the number of receive and transmit antennas, respectively. Correlation can decrease the effective post-processing SNR rather than the diversity gain, and the decreased amount of the effective post-processing SNR is accurately measured by the corresponding diagonal element of the inverse of the transmit correlation matrix. The optimal ordering can improve the performance and this advantage vanishes gradually as the scattering angle decreases. Copyright © 2010 John Wiley & Sons, Ltd.