Mitigating self-induced co-channel interference in PSAP-RoF systems with photonic-based phase-controlled ring interferometer

In the quest to elevate the performance of public safety answering points (PSAPs), integrating cutting-edge technologies such as radio over fiber (RoF) and in-band full duplex communication (IBFD) is proving transformative. These technologies ensure high-bandwidth, low-latency connections crucial for real-time emergency responses and reliable communication in remote areas. However, a persistent challenge is mitigating self-induced co-channel interference (SICI), which can disrupt crucial communications. This paper introduces a novel solution: a photonic-based phase-controlled ring interferometer (PCRI) designed to combat SICI within IBFD systems. By leveraging coherent detection, the PCRI enhances spectral efficiency and receiver sensitivity, significantly improving signal quality. Test results demonstrate that the PCRI effectively cancels SICI, with a notable cancellation depth of 30.56 dB, and optimizes performance across a broad frequency range (10 GHz–22 GHz). The system’s efficiency is highlighted by improved signal-to-noise ratio (SNR) and bit error rate (BER) performance over varying distances, showcasing its potential for advancing PSAPs in real-time communication and interoperability.