A novel joint ML detector for transmit diversity systems in frequency selective fading channels

In this paper, a novel joint maximum-likelihood (JML) detector has been proposed for space-time block coded-orthogonal frequency division multiplexing (STBC-OFDM) systems using Alamouti coding scheme. The proposed detector is based on singular value decomposition (SVD) where it effectively uses the unitary matrix property to reduce the complexity of computation. The bit error rate (BER) performance of the proposed SVD based JML detector is investigated under both quasi-static and non-quasi-static conditions. It is also compared with all other detectors in [8], in terms of BER. Simulation result shows that with reduced computational complexity, the SVD based JML detector has the BER performance as like existing JML detector. Also the theoretical BER is derived for the proposed detector under quasi-static condition. In addition, it has been proved that the noise is white even after matched filtering, which reveals another evidence for the complexity reduction.