V-BLAST outage probability: analytical analysis

An analytical approach to the performance analysis of the V-BLAST algorithm is discussed in this paper. It is based on closed-form analytical models of the three key algorithm components: interference cancellation, interference nulling and optimal ordering. The closed-form analytical model of the Gram-Schmidt orthogonalization process is a key component of the proposed analysis method. It allows us to derive closed-form expressions for the signal at each detection step, to perform analytically statistical analysis for a Rayleigh-fading channel (i.e., diversity order etc.) and to obtain closed-form expressions for outage probabilities in the case of two Tx antennas. In particular, it is demonstrated that the optimal ordering does not result in increased diversity order, but only in a fixed SNR gain. Generalized versions of the V-BLAST algorithm proposed recently can be analyzed in a similar way.