Blind iterative maximum likelihood-based frequency and transition time estimation for frequency hopping systems

Timing synchronisation and frequency estimation are two major estimation problems for frequency-hopping spread spectrum systems. We present a blind scheme for estimating frequency and transition time in an iterative fashion: the iterative disassemble and assemble algorithm. The proposed scheme does not require initial random guesses as with common iterative algorithms. Improper initial guesses may suffer from the problem of convergence to the local maximum. The proposed approach can converge to the global maximum in order to achieve the solution. The proposed scheme offers a much lower computational complexity than that of the maximum-likelihood greedy search algorithm. Moreover, it also outperforms existing schemes with comparable complexity. The simulation results demonstrate the efficacy of the proposed approach.