A Comprehensive Experimental Emulation for OTFS Waveform RF-Impairments

Sensors (Basel). 2022 Dec 21;23(1):38. doi: 10.3390/s23010038.


The orthogonal time-frequency space (OTFS) waveform exceeds the challenges that face orthogonal frequency division multiplexing (OFDM) in a high-mobility environment with high time-frequency dispersive channels. Since radio frequency (RF) impairments have a direct impact on waveform behavior, this paper investigates the experimental implementation of RF-impairments that affect OTFS waveform performance and compares them to the OFDM waveform as a benchmark. Firstly, the doubly-dispersive channel effect is analyzed, and then an experimental framework is established for investigating the impact of RF-impairments, including non-linearity, carrier frequency offset (CFO), I/Q imbalances, DC-offset, and phase noise are considered. The experiments were conducted in a real indoor wireless environment using software-defined radio (SDR) at carrier frequencies of 2.4 GHz and 5 GHz based on the Keysight EXG X-Series devices. The comparison of the performances of OFDM and OTFS in the presence of RF-impairments reveals that OTFS significantly outperforms OFDM.

Keywords: DC-offset; I/Q imbalances; OFDM; OTFS; RF-impairments; carrier frequency offset; phase noise.

Grants and funding

The work of H. Arslan was supported by the Scientific and Technological Research Council of Turkey (TUBITAK) under Grant 120C142.