Phase Coding Optimization Based on OTFS Waveform in Multi-User Scenarios

The introduction of OTFS technology presents significant advantages for 6G communication, leveraging its time-frequency orthogonality for robust adaptability in complex multipath environments. This waveform also demonstrates its feasibility with radar detection. In scenarios involving multiple user access, high-precision target detection can be achieved through the segmentation and interleaved allocation in the delay-Doppler domain. However, unoptimized OTFS modulation waveforms exhibit elevated sidelobes, resulting in a degradation of the target detection performance. In this paper, an optimization method based on iteratively global exploration and local spiral refinement is designed for the phase coding in the delay-Doppler plane of the OTFS waveform. Element-wise updating is executed during the spiral refinement for the multidimensional phase encoding value. Simulation results confirms that the proposed method for OTFS waveform in radar applications exhibits excellent sidelobe suppression performance compared with traditional optimization.