Spatial Loading in V-BLAST Systems with Limited Feedback and ZF-OSIC Detection

In this paper we propose a new spatial loading scheme for the vertical bell layered space time (V-BLAST) system where the detection of symbols belonging to the same transmitted vector is done by zero-forcing with ordered successive interference cancellation (ZF-OSIC). Assuming no error propagation, the ZF-OSIC detection process decouples the channel matrix into a set of independent parallel sub-channels. In our proposal the data rate and the average power to be allocated on each sub-channel are obtained by minimizing the asymptotic approximation of the average bit error rate for the given desired total data rate and the total average transmitted power. The feedback sent from the receiver to the transmitter consists of the average signal-to-noise ratio and the detection order. Computer simulations are used to demonstrate the effectiveness of our proposal over the conventional V-BLAST.