Maximum signal-to-noise ratio array processing for space-time coded systems

We consider the design of an array processor for space-time coded multi-antenna systems. As an alternative to the previously proposed zero-forcing method, in this paper, the maximum signal-to-noise ratio (SNR) criterion is used to obtain a balance between interference suppression and noise enhancement. Although the same in concept, this work differs from the conventional minimum mean-squared error method in that there is more than one desired signal dimension each corresponding to one of the space--time coded streams. It will be shown that the number of linear filters required by the maximum SNR array processor is no more than the dimension of the signal space or the number of collaborating transmit antennas. The advantages of this design are highly improved performance and reduced decoding complexity. Index Terms--Array processing, diversity, space-time codes.