论文标题
在非常高的移动性场景中，延迟多普勒域转换的时间域转换
Time-Domain to Delay-Doppler Domain Conversion of OTFS Signals in Very High Mobility Scenarios
论文作者
论文摘要
在正交时间频率空间（OTF）调制中，信息符号嵌入到延迟多普勒（DD）域中，而不是时间频率（TF）域。 n为了确保与现有OFDM系统（例如4G LTE）的兼容性，大多数先前在OTFS接收器上的工作都考虑了两步转换，其中首先将接收到的时间域（TD）信号转换为时频（TF）信号（使用OFDM解调仪），然后使用此TF DyDddddddddddddddddddddddddd domains。在本文中，我们表明，在非常高的移动性场景中，基于两步转换的接收器的光谱效率（SE）性能降低了多普勒偏移在无人驾驶范围（例如，在无人驾驶飞机系统（UAS系统（UAS））中，多普勒偏移是通信带宽的很大一部分）。因此，我们考虑一种替代转换，其中接收到的TD信号直接转换为DD域。结果显示，所得接收的DD域信号与先前工作中考虑的两步转换中获得的信号不同。替代转换不需要OFDM解调器，并且显示出比两步转换的复杂性低。分析和模拟表明，即使在非常高的迁移率方案中，替代转换实现的SE也是多普勒偏移的不变性，并且显着高于两步转换（随着多普勒偏移的增加而降解）所获得的SE。
In Orthogonal Time Frequency Space (OTFS) modulation, information symbols are embedded in the delay-Doppler (DD) domain instead of the time-frequency (TF) domain. n order to ensure compatibility with existing OFDM systems (e.g. 4G LTE), most prior work on OTFS receivers consider a two-step conversion, where the received time-domain (TD) signal is firstly converted to a time-frequency (TF) signal (using an OFDM demodulator) followed by post-processing of this TF signal into a DD domain signal. In this paper, we show that the spectral efficiency (SE) performance of a two-step conversion based receiver degrades in very high mobility scenarios where the Doppler shift is a significant fraction of the communication bandwidth (e.g., control and non-payload communication (CNPC) in Unmanned Aircraft Systems (UAS)). We therefore consider an alternate conversion, where the received TD signal is directly converted to the DD domain. The resulting received DD domain signal is shown to be not the same as that obtained in the two-step conversion considered in prior works. The alternate conversion does not require an OFDM demodulator and is shown to have lower complexity than the two-step conversion. Analysis and simulations reveal that even in very high mobility scenarios, the SE achieved with the alternate conversion is invariant of Doppler shift and is significantly higher than the SE achieved with two-step conversion (which degrades with increasing Doppler shift).
