A Novel ISAC Waveform Based on Orthogonal Delay-Doppler Division Multiplexing With FMCW

2026-02-02

IEEE Transactions on Wireless Communications

AI Summary

This work addresses the challenges of high peak-to-average power ratio (PAPR) and the inherent trade-off between sensing and communication performance in conventional frequency-modulated continuous-wave (FMCW) waveforms for integrated sensing and communication (ISAC) systems. To overcome these limitations, the authors propose a novel ODDM-FMCW waveform that integrates square-root Nyquist-filtered FMCW (SRN-FMCW) with orthogonal time-delay–Doppler division multiplexing (ODDM). Sensing symbols are directly embedded in the delay–Doppler domain, forming a DD-SRN-FMCW frame superimposed onto the ODDM data frame. A tailored chirp-compression receiver and Cramér–Rao bound analysis are developed to ensure robust performance. Experimental results demonstrate that the proposed scheme significantly reduces PAPR while achieving high parameter estimation accuracy, excellent bit error rate performance, and favorable spectral characteristics.

Technology Category

• Search and Optimization: Mixed Discrete/Continuous Search
• Planning, Routing, and Scheduling: Optimization of Spatio-temporal Systems
• Constraint Satisfaction and Optimization: Distributed CSP/Optimization

Application Category

• Systems and Infrastructure for Web, Mobile and WoT: Data management and stream processing for Web, mobile and wireless applications
• Security and Privacy: Large-scale security measurements
• Search and Retrieval-Augmented AI: Vertical and domain-specific search

Abstract

In this work, we propose the orthogonal delay-Doppler (DD) division multiplexing (ODDM) modulation with frequency modulated continuous wave (FMCW) (ODDM-FMCW) waveform to enable integrated sensing and communication (ISAC) with a low peak-to-average power ratio (PAPR). We first propose a square-root-Nyquist-filtered FMCW (SRN-FMCW) waveform to address limitations of conventional linear FMCW waveforms in ISAC systems. To better integrate with ODDM, we generate SRN-FMCW by embedding symbols in the DD domain, referred to as a DD-SRN-FMCW frame. A DD chirp compression receiver is designed to obtain the channel response efficiently. Next, we construct the proposed ODDM-FMCW waveform for ISAC by superimposing a DD-SRN-FMCW frame onto an ODDM data frame. A comprehensive performance analysis of the ODDM-FMCW waveform is presented, covering peak-to-average power ratio, spectrum, ambiguity function, and Cramér-Rao bound for delay and Doppler estimation. Numerical results show that the proposed ODDM-FMCW waveform delivers excellent ISAC performance in terms of root mean square error for sensing and bit error rate for communications.

Problem

• Integrated Sensing and Communication
• FMCW
• Peak-to-Average Power Ratio
• Waveform Design
• Delay-Doppler Domain

Innovation

• ODDM-FMCW
• Integrated Sensing and Communication
• Delay-Doppler Domain
• Low PAPR Waveform
• Chirp Compression Receiver