Low-complexity hop timing synchronization in frequency hopping systems

This paper considers the problem of synchronization in frequency hopping systems. A simple digital signal processing block along with the existing RF circuits forms a phase detector that generates a signal corresponding to the phase difference between the hop timings of the local and received signals. The two hop-timing acquisition algorithms proposed in this paper - based on energy detection - utilize the phase detector and result in low-complexity implementations. In the first one, a simple cost function relying on the power sum definition estimates the hop timing. This estimator allows for only a limited acquisition range. Based on this study, we propose a hop-timing estimator with a full acquisition range which still maintains low-complexity. Furthermore, this paper analyzes the optimal threshold to detect the signal existence based on the maximum likelihood detection rule