High pilot overhead and peak-to-average power ratio (PAPR) are challenging issues in channel estimation for orthogonal time frequency space (OTFS) systems. ZP-OTFS is a modified OTFS system where multiple rows along the delay axis are zero. We propose a two-step channel estimation method for the ZP-OTFS system. The proposed method inserts pilot sequences in the zero bins of the ZP-OTFS system, resulting in low overhead and PAPR. Our simulation results demonstrate the effectiveness of the proposed method and show that it outperforms embedded pilot estimation in terms of normalized mean square error (NMSE) at the same bit error rate (BER).

翻译：高导频开销和峰均功率比（PAPR）是正交时频空间（OTFS）系统中信道估计面临的挑战性问题。ZP-OTFS是一种改进的OTFS系统，其沿延迟轴的多个行设置为零。我们针对ZP-OTFS系统提出了一种两步信道估计方法。所提方法将导频序列插入ZP-OTFS系统的零值区间中，从而实现了低开销和低PAPR。仿真结果验证了该方法的有效性，并表明在相同误码率（BER）条件下，该方法在归一化均方误差（NMSE）方面优于嵌入式导频估计方法。