In orthogonal time frequency space (OTFS) systems, the impact of frequency-dependent Doppler which is referred to as the Doppler squint effect (DSE) is accumulated through longer duration, whose negligence has prevented OTFS systems from exploiting the performance superiority. In this paper, practical OFDM system using cyclic prefix time guard interval (CP-OFDM)-based OTFS systems with DSE are adopted. Cyclic prefix (CP) length is analyzed while the input-output relation considering DSE is derived. By deploying two prefix OFDM symbols, the channel estimation can be easily divided into three parts as delay detection, Doppler extraction and gain estimation. The linear equalization scheme is adopted taking the block diagonal property of the channel matrix into account, which completes the low-complexity receiver design. Simulation results confirm the significance of DSE and the considerable performance of the proposed low-complexity receiver scheme considering DSE.

翻译：在正交时频空间(OTFS)系统中，频率相关多普勒效应（即多普勒弯曲效应，DSE）随长持续时间累积，忽视该效应将使OTFS系统难以发挥性能优势。本文采用基于循环前缀-正交频分复用(CP-OFDM)且考虑DSE的实用OTFS系统。分析了循环前缀(CP)长度，并推导了考虑DSE的输入输出关系。通过部署两个前导OFDM符号，信道估计可简洁地分为时延检测、多普勒提取和增益估计三部分。利用信道矩阵的块对角特性，采用线性均衡方案，从而完成低复杂度接收机设计。仿真结果验证了DSE的重要性以及所提考虑DSE的低复杂度接收机方案的显著性能优势。