In orthogonal time-frequency space communications, the performances of existing on-grid and off-grid channel estimation (CE) schemes are determined by the delay-Doppler (DD) grid density. In practice, multiple real-life DD channel responses might be co-located within a same DD grid interval, leading to performance degradation. A finer grid interval is needed to distinguish these responses, but this could result in a significantly higher CE complexity when traditional methods are used.To address this issue, a grid evolution method for doubly fractional CE is proposed by evolving the initially uniform coarse DD grid into a non-uniform dense grid. Simulation results show that our proposed method leads to improved computational efficiency, and achieves a good trade-off between CE performance and complexity.
@article{arxiv.2409.17584,
title = {Grid Evolution for Doubly Fractional Channel Estimation in OTFS Systems},
author = {Xiangjun Li and Pingzhi Fan and Qianli Wang and Zilong Liu},
journal= {arXiv preprint arXiv:2409.17584},
year = {2024}
}