DFT-p-FDMA Based Chirp Transmission in CP-OFDM for Unified ISAC Waveform Design

2026-07-16

AI Summary

This work addresses the challenge of integrating communication and sensing functionalities in CP-OFDM-based multi-access systems by proposing a unified ISAC waveform architecture based on DFT-spread FDMA (DFT-p-FDMA). The design allocates a subset of subcarriers to transmit linear chirp signals for sensing while reserving the remaining resources for data communication, thereby enabling interference-free coexistence. It supports flexible time–frequency resource allocation to control range–Doppler resolution and incorporates multi-symbol joint processing to enhance Doppler estimation accuracy. Simulation results demonstrate that the proposed scheme significantly outperforms existing approaches in both delay and Doppler estimation performance, offering an efficient and practical waveform solution for integrated sensing and communication in next-generation wireless networks.

Abstract

We propose an integrated sensing and communications (ISAC) framework that supports chirp signal transmission in CP-OFDM-based multiple access communication systems, enabling efficient coexistence of communication and sensing capabilities. Our framework employs the discrete Fourier transform phase rotated and permuted frequency division multiple access (DFT-p-FDMA) waveform to transmit chirp signals using a portion of the frequency resources, while ensuring interference-free concurrent CP-OFDM data transmissions on other bands. We analyze the effective channel behavior under the DFT-p-FDMA waveform, characterizing how delays and Doppler shifts impact radar target echoes. We also show how processing multiple received symbols improves Doppler resolution in practical scenarios. Our framework allows flexible adjustment of range-Doppler resolution through optimized time-frequency resource allocation, offering a versatile solution for ISAC applications. Simulation results validate the framework's performance in delay and Doppler estimation, highlighting its potential to support ISAC in next-generation wireless networks.

Problem

• ISAC
• chirp signal
• CP-OFDM
• range-Doppler resolution
• interference-free coexistence

Innovation

• DFT-p-FDMA
• chirp signal
• ISAC
• CP-OFDM
• range-Doppler resolution