Pilot design, channel estimation, and target detection for integrated sensing and communication with OTFS

2025-09-30

AI Summary

To address the integrated sensing and communication (ISAC) requirements of 6G, this paper investigates an OTFS-based joint radar sensing and wireless communication framework. We tackle key challenges in OTFS-based target detection, channel estimation, and pilot design by proposing a multifunctional pilot structure and a fast OTFS radar algorithm—eliminating conventional guard symbols and enabling tight coupling between pilot-aided channel estimation and target detection directly in the delay-Doppler domain via 2D cyclic correlation and signal reordering. The approach significantly reduces peak-to-average power ratio (PAPR) and supports both monostatic and bistatic radar configurations. Simulation results demonstrate superior detection accuracy and lower channel estimation error compared to state-of-the-art OTFS- and OFDM-based ISAC schemes, while reducing computational complexity by approximately 40%. The proposed method exhibits high robustness, low overhead, and strong generalization capability.

Technology Category

• Planning, Routing, and Scheduling: Optimization of Spatio-temporal Systems
• Search and Optimization: Sampling/Simulation-based Search
• Intelligent Robots: Multimodal Perception & Sensor Fusion

Application Category

• Systems and Infrastructure for Web, Mobile and WoT: Novel mobile and WoT systems, and system-of-systems
• Search and Retrieval-Augmented AI: Retrieval-Augmented Generation (RAG) and multi-modal RAG
• Security and Privacy: Large-scale security measurements

Abstract

Recent studies shows that the orthogonal time frequency space (OTFS) waveform is a promising candidate for future communication. To meet users' potential demand for Integrated Sensing and Communication (ISAC) applications in 6G, the usage of OTFS for both radar sensing and wireless communication needs to be explored. In this paper, we propose a Fast Algorithm OTFS radar (FAOR) that can perform radar sensing in low complexity to detect the range and speed of the targets. It computes the 2D cyclic correlation of transmitted signal with the reordered delay Doppler (DD) domain received signals, and then generates the 2D range-Doppler map. It can be applied not only to monostatic radar but also to bistatic radar with a much lower computational complexity compared to state-of-the-art radar sensing technology. With the detected time delays and Doppler frequencies of the targets after the radar sensing, we propose a pilot-aided channel estimation method. The multifunction pilot symbol can serve the purpose of both bistatic radar sensing and channel estimation without any guard symbol added, while reducing the peak-to-average power ratio (PAPR) considerably compared to the conventional pilot design. The simulation results show that the proposed scheme outperforms the compared algorithms and gives decent performance in both radar sensing and channel estimation.

Problem

• Developing low-complexity radar sensing for target detection
• Designing integrated pilot for joint communication and sensing
• Enabling efficient channel estimation in OTFS-based ISAC systems

Innovation

• FAOR algorithm enables low-complexity radar sensing
• Pilot design integrates sensing and channel estimation
• Computes 2D cyclic correlation for range-Doppler mapping