Ultra-Wide Band TOA Estimation Based on Nonlinear Least Squares Algorithm

Studies an ultra-wide band(UWB) time of arrival(TOA) estimation technique in dense indoor multipath environments. An improved TOA estimation algorithm based on threshold comparison is proposed. Nonlinear least squares algorithm is adopted to estimate the multipath delay and amplitude simultaneously, and iterative algorithm is used to further improve the accuracy of parameter estimation. Multipath searching process is terminated according to the result of decision threshold comparison, and then TOA estimation is deduced. The proposed algorithm is analyzed under indoor multipath channel model, and the threshold setting scheme is presented. Simulation results showed that the proposed algorithm has high estimation accuracy under various SNR when decision threshold is optimized. It can satisfy the requirement of precision positioning.