Equivalent Sampling Frequency Offset in Transceivers: Minimization and Compensation for Broadband Photonics-Aided THz Wireless Transmission Systems

This paper addresses a critical challenge in high-speed THz systems: sampling frequency offset (SFO) from both intrinsic device characteristics and critically, artificial introduction during system operation. We present a comprehensive study that uniquely examines operation-induced SFO alongside conventional device SFO through a novel sample-per-symbol (sps) framework. Our analysis reveals how artificial SFO, often undetected in standard system calibration, can significantly degrade performance beyond typical device limitations. The developed theoretical model precisely quantifies both SFO sources and their combined impact. Experimental validation in a photonics-aided THz-over-fiber polarization-division-multiplexing system demonstrates our method's effectiveness, successfully mitigating both device and artificially introduced SFO to achieve stable 60-GBaud transmission at 0.32-THz. This implementation establishes a record 576-Gbps/λper-channel capacity while providing crucial insights into preventing artificial SFO in practical deployments. The work offers researchers essential tools for identifying and correcting human-induced sampling errors in next-generation THz systems.