Modified GML algorithm with simulated annealing for estimation of signal arrival time

A modified generalized maximum-likelihood (GML) algorithm with simulated annealing for estimating the signal arrival time is presented. In a multipath environment, the GML algorithm can be used for the time-of-arrival (TOA) estimation; nevertheless, the GML algorithm usually takes up a long period of processing time, and sometimes fails to converge. To mitigate the effects from dense multipath interference and to reduce the computational complexity of the algorithm, methods of threshold settings based on the minimum root mean square error (RMSE) criteria are discussed. Instead of performing a full-scale search of adequate threshold settings, the simulated annealing process is adopted for finding the best pair of thresholds for use in the modified GML algorithm. Simulation results show that in the line-of-sight (LOS) short-range propagation environment, the proposed scheme achieves better performance than other statistical schemes in terms of the root mean square error of signal arrival time.