Exploring Channel Estimation and Signal Detection for ODDM-based ISAC Systems

TL;DR

This paper investigates channel estimation and signal detection in ODDM-based ISAC systems, proposing low-complexity algorithms and demonstrating superior detection performance over other multi-carrier schemes in high-mobility scenarios.

Contribution

It introduces a low-complexity channel estimation algorithm and applies orthogonal approximate message-passing for detection in ODDM ISAC systems, improving performance and efficiency.

Findings

ODDM outperforms other multi-carrier schemes in detection accuracy.

The proposed algorithms achieve near-optimal performance with reduced complexity.

ODDM surpasses OTFS by 2.3 dB at a BER of 10^{-6}.

Abstract

Inspired by providing reliable communications for high-mobility scenarios, in this letter, we investigate the channel estimation and signal detection in integrated sensing and communication~(ISAC) systems based on the orthogonal delay-Doppler multiplexing~(ODDM) modulation, which consists of a pulse-train that can achieve the orthogonality with respect to the resolution of the delay-Doppler~(DD) plane. To enhance the communication performance in the ODDM-based ISAC systems, we first propose a low-complexity approximation algorithm for channel estimation, which addresses the challenge of the high complexity from high resolution in the ODDM modulation, and achieves performance close to that of the maximum likelihood estimator scheme. Then, we employ the orthogonal approximate message-passing scheme to detect the symbols in the communication process based on the estimated channel information. Finally, simulation results show that the detection performance of ODDM is better than other multi-carrier modulation schemes. Specifically, the ODDM outperforms the orthogonal time frequency space scheme by 2.3 dB when the bit error ratio is $10^{-6}$.