Reduced-Complexity Near-ML Detector for a Coded DSTTD-OFDM System

This letter introduces an efficient near-maximum likelihood (NIL) detector for a coded double space-time transmit diversity-orthogonal frequency division multiplexing (DSTTD-OFDM) system. The proposed near-ML detector constructs a candidate vector set through a relaxed minimization method. It reduces computational loads from O(2|A|(2)) to O(|A|(2)). where |A| is the modulation order. Numerical results indicate that the proposed near-ML detector provides both almost ML performance and considerable complexity savings.