A Double-Stage Phase Hit Mitigation Scheme In Microwave Backhaul Links

摘要

The oscillator phase hit (PH) results in a temporary link loss in the communication system and bears an expensive cost on the operator companies. In this work, we propose a double-stage solution to mitigate the PH. In the first stage, we use Neyman-Pearson binary hypothesis testing to develop a low-cost PH detection algorithm, in which a likelihood ratio test is designed, and the optimal detection threshold is analytically calculated. The proposed PH detection scheme entails small real-time computations while using the existing pilot symbols in the system. Hence, no extra pilot overhead is required. In the second stage, the maximum likelihood (ML) estimation is used to develop a PH correction scheme. In particular, the phase noise and the PH are jointly mitigated by solving an ML estimation problem. By applying the proposed correction scheme, the number of remaining erroneous symbols due to PH (if any) is within the error correction capability of modern forward error-correcting codes. Numerical results verify the effectiveness of the proposed scheme in detecting and correcting the PH.