Joint channel tracking and MAP detection for OFDMA systems in fading channels

In this research, we present a joint channel tracking and maximal a posteriori (MAP) symbol detection method for orthogonal frequency division multiple access (OFDMA) systems in time-varying fading channels. In contrast to some existing joint estimation and detection schemes that perform channel tracking in time-domain, we propose an algorithm that do both channel tracking and symbol detection in frequency domain, thus preventing the performance degradation due to the multiple access interference present in the time domain channel estimation. In conjunction with appropriate frequency allocation for each user, it is shown that a lowcomplexity algorithm can be obtained and, in the mean time, provides good performance in channel tracking.