In this paper, we investigate the impacts of transmitter and receiver windows on orthogonal time-frequency space (OTFS) modulation and propose a window design to improve the OTFS channel estimation performance. Assuming ideal pulse shaping filters at the transceiver, we first identify the role of window in effective channel and the reduced channel sparsity with conventional rectangular window. Then, we characterize the impacts of windowing on the effective channel estimation performance for OTFS modulation. Based on the revealed insights, we propose to apply a Dolph-Chebyshev (DC) window at either the transmitter or the receiver to effectively enhance the sparsity of the effective channel. As such, the channel spread due to the fractional Doppler is significantly reduced, which leads to a lower error floor in channel estimation compared with that of the rectangular window. Simulation results verify the accuracy of the obtained analytical results and confirm the superiority of the proposed window designs in improving the channel estimation performance over the conventional rectangular or Sine windows.

翻译：在本文中,我们调查发射机和接收器窗口对正方位时频空间调节器的影响,并提出改进 OTFS 频道估计性能的窗口设计建议。假设收发器使用理想的脉冲成形过滤器,我们首先确定窗口在有效频道中的作用以及频道宽度减少与传统矩形窗口的作用。然后,我们将窗口对OTFS 调制有效频道估计性能的影响定性为窗口。根据披露的洞察,我们提议在发报器或接收器中应用多尔夫-切尔比谢夫(DC)窗口,以有效提高有效频道的广度。因此,由于分形多普勒的频道扩散率大大降低,导致频道估计层差比矩形窗口低。模拟结果验证了所获得的分析结果的准确性,并确认了拟议窗口设计在改进频道评估常规矩形或辛烷窗口的性能方面的优势。