A complexity-reduced joint detector for OFDM-CDM systems

Orthogonal frequency division multiplexing with code division multiplexing (OFDM-CDM) is one of the major transmission technologies for the next generation mobile communications. The performance of OFDM-CDM systems can be improved by employing a joint detection scheme such as the maximum likelihood (ML) detector. However, the complexity of the ML detector increases exponentially as the number of codes increases. In this paper, we propose a complexity-reduced ML algorithm that uses a modified Euclidean distance as the soft metric for decoding, providing near optimum ML performance. Finally, the performance of the proposed scheme is verified by computer simulation.