Delay-Doppler Reversal for OTFS System in Doubly-selective Fading Channels

The recent proposed orthogonal time frequency space (OTFS) modulation shows significant advantages than conventional orthogonal frequency division multiplexing (OFDM) for high mobility wireless communications. However, a challenging problem is the development of efficient receivers for practical OTFS systems with low complexity. In this paper, we propose a novel delay-Doppler reversal (DDR) technology for OTFS system with desired performance and low complexity. We present the DDR technology from a perspective of two-dimensional cascaded channel model, analyze its computational complexity and also analyze its performance gain compared to the direct processing (DP) receiver without DDR. Simulation results demonstrate that our proposed DDR receiver outperforms traditional receivers in doubly-selective fading channels.