Comparison of OTFS and OFDM in Ray Launched sub-6 GHz and mmWave Line-of-Sight Mobility Channels
Comparison of OTFS and OFDM in Ray Launched sub-6 GHz and mmWave Line-of-Sight Mobility Channels
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DOI：
10.1109/pimrc.2018.8580850
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发表时间：
2018-09
期刊：
影响因子：
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通讯作者：
Fred Wiffen;Lawrence Sayer;M. Z. Bocus;A. Doufexi;A. Nix
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文献类型：
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作者：
Fred Wiffen;Lawrence Sayer;M. Z. Bocus;A. Doufexi;A. Nix
正交时频空间（OTFS）是最近提出的用于双色散信道的调制方案，其中符号复用和处理在多普勒延迟域而不是传统的时频域中执行。在本文中，OTFS的性能进行了比较，正交频分复用（OFDM）的视线移动汽车信道。射线发射是用来模拟两个不同的动态三维车辆到基础设施的传输环境的信道，使用基尔霍夫模型从粗糙表面的漫散射。然后，针对OFDM和OTFS两者，执行从以13 m/s和31 m/s的速度移动的发射机的传输的比特级仿真。我们发现，与短长度的块码OTFS优于OFDM在所有模拟的情况下，平均降低了50%以上的误块率。与以前的工作不同，模拟在时域中使用实际的矩形脉冲形状，而不是理论上的“理想脉冲”。我们提供了这些脉冲的分析，并推导出相关的表达式的双色散信道的多径延迟和多普勒频移。
Orthogonal Time Frequency Space (OTFS) is a recently proposed modulation scheme for doubly-dispersive channels in which symbol multiplexing and processing is performed in the Doppler-delay domain, rather than conventional time-frequency domain. In this paper, the performance of OTFS is compared to orthogonal frequency division multiplexing (OFDM) for line-of-sight mobility automotive channels. Ray launching is used to simulate the channel for two different dynamic 3D vehicle to infrastructure transmission environments, using a Kirchhoff model for diffuse scattering from rough surfaces. Bit level simulations for transmission from a transmitter moving at speeds of 13 m/s and 31 m/s are then carried out, for both OFDM and OTFS. We find that with short length block codes OTFS outperforms OFDM in all simulated scenarios, reducing the block error rate by more than 50% on average. Unlike previous work, simulations are performed in the time domain using practical rectangular pulse shapes, rather than theoretical ‘ideal pulses’. We provide an analysis of these pulses, and derive relevant expressions for the doubly dispersive channel in terms of the multipath delays and Doppler shifts.