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 Cramer-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.

翻译：本文提出了一种基于调频连续波的正交时延-多普勒分复用调制波形（ODDM-FMCW），旨在实现低峰均功率比的集成感知与通信。首先，我们提出平方根奈奎斯特滤波的调频连续波波形，以解决传统线性调频连续波在ISAC系统中的局限性。为更好地与ODDM融合，我们通过在时延-多普勒域嵌入符号生成SRN-FMCW，称为DD-SRN-FMCW帧，并设计了时延-多普勒啁啾压缩接收机以高效获取信道响应。随后，通过将DD-SRN-FMCW帧叠加至ODDM数据帧，构建了用于ISAC的ODDM-FMCW波形。本文对该波形进行了全面的性能分析，涵盖峰均功率比、频谱、模糊函数以及时延与多普勒估计的克拉美-罗界。数值结果表明，所提出的ODDM-FMCW波形在感知的均方根误差与通信的误码率方面均展现出优异的ISAC性能。