Multiple symbol detection for differential unitary space-time modulation using a stack algorithm

This paper presents a stack algorithm approach as a fast optimization for multiple-symbol detection of differential unitary space-time modulation. The proposed algorithm has low complexity and is optimal, that is, it is equivalent to maximum-likelihood detection. At high SNR, given a signal constellation of size L with N detected symbols, simulations show that the proposed stack algorithm reduces the complexity required to maximize the decision metric from O(L^NN²) to O(LN²).