THz-Over-Fiber System With Orthogonal Chirp Division Multiplexing for Integrated Sensing and Communication
Lianyi Li, Lu Zhang, Hongqi Zhang, Zhidong Lyu, Zuomin Yang, Xiaodan Pang, Vjačeslavs Bobrovs, Oskars Ozoliņš, Hangbin Zhao, Feng Li, Changming Zhang, Xianbin Yu
Abstract
To achieve integrated sensing and communication (ISAC) applications with high data rates and high resolution, the terahertz-over-fiber (ToF) system has been recognized as a promising solution. However, the frequency-selective fading would deteriorate the performance of the ToF-based ISAC systems. In this work, we propose the orthogonal chirp division multiplexing (OCDM) waveform-based ToF system for high-performance ISAC applications. The system encodes data with the phase of the sub-chirps and obtains radar images by processing echoes with the zero-padded matched filtering algorithm. We experimentally demonstrate a proof-of-concept OCDM-ToF system, which simultaneously achieves a 32 Gbit/s data rate and 1.875 cm range resolution after transmission over a 10 km optical fiber and a 3.14 m wireless link at the THz band, for the first time. The experimental results indicate that the OCDM-ToF system can enhance robustness against the frequency-selective fading issue, as a benefit improving communication performance with high data rates while preserving the high sensing resolution of OFDM in the THz ISAC applications.