A Phase-Coded Time-Domain Interleaved OTFS Waveform with Improved Ambiguity Function

TL;DR

This paper introduces a novel TICP4-OTFS waveform that enhances sensing and communication performance by improving the ambiguity function, achieving better resolution, lower sidelobes, and improved bit error rates in low SNR conditions.

Contribution

The paper proposes a new TICP4-OTFS waveform with an improved ambiguity function and better sensing and communication performance compared to traditional OTFS.

Findings

Outperforms OTFS with narrower mainlobe and lower sidelobes in ambiguity functions.

Provides higher resolution in range estimation via pulse compression.

Achieves better bit error rate performance in low SNR scenarios.

Abstract

Integrated sensing and communication (ISAC) is a significant application scenario in future wireless communication networks, and sensing capability of a waveform is always evaluated by the ambiguity function. To enhance the sensing performance of the orthogonal time frequency space (OTFS) waveform, we propose a novel time-domain interleaved cyclic-shifted P4-coded OTFS (TICP4-OTFS) with improved ambiguity function. TICP4-OTFS can achieve superior autocorrelation features in both the time and frequency domains by exploiting the multicarrier-like form of OTFS after interleaved and the favorable autocorrelation attributes of the P4 code. Furthermore, we present the vectorized formulation of TICP4-OTFS modulation as well as its signal structure in each domain. Numerical simulations show that our proposed TICP4-OTFS waveform outperforms OTFS with a narrower mainlobe as well as lower and more distant sidelobes in terms of delay and Doppler-dimensional ambiguity functions, and an instance of range estimation using pulse compression is illustrated to exhibit the proposed waveform\u2019s greater resolution. Besides, TICP4-OTFS achieves better performance of bit error rate for communication in low signal-to-noise ratio (SNR) scenarios.