Performance of ODDM with Imperfect Channel Estimation

The orthogonal delay-Doppler division multiplexing (ODDM) modulation is a newly proposed multi-carrier modulation that features a realizable pulse orthogonal with respect to the delay-Doppler (DD) plane's fine resolutions. In this paper, we investigate the performance of the ODDM system with three detectors, namely the message passing algorithm (MPA) detector, iterative maximum-ratio combining (MRC) detector, and successive interference cancellation with minimum mean square error (SIC-MMSE) detector. Our study presents a comprehensive comparison of these algorithms on their detection performance, taking into account bit error rate, convergence characteristics, and impacts of imperfect channel state information (CSI). We demonstrate that the MPA detector is more sensitive to imperfect CSI. With high channel estimation errors, both MRC and SIC-MMSE can outperform MPA in terms of BER performance.