OTFS based Joint Radar and Communication: Signal Analysis using the Ambiguity Function

TL;DR

This paper analyzes the ambiguity function of OTFS waveform for joint radar and communication, revealing how data modulation impacts radar accuracy and comparing its performance with OFDM.

Contribution

It derives the AF of OTFS, characterizes its distribution, and evaluates its radar performance relative to OFDM, providing insights into OTFS's suitability for joint systems.

Findings

AF of OTFS depends on data modulation distribution

Approximate AF distribution by Rice distribution

OTFS shows comparable or improved radar performance over OFDM

Abstract

Orthogonal time frequency space (OTFS) modulation has recently been identified as a suitable waveform for joint radar and communication systems. Focusing on the effect of data modulation on the radar sensing performance, we derive the ambiguity function (AF) of the OTFS waveform and characterize the radar global accuracy. We evaluate the behavior of the AF with respect to the distribution of the modulated data and derive an accurate approximation for the mean and variance of the AF, thus, approximating its distribution by a Rice distribution. Finally, we evaluate the global radar performance of the OTFS waveform with the OFDM waveform.