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Time Delay Estimation Based on Double Dynamic Threshold in Indoor Multipath Environment

In order to reduce the impact of multipath environment on time delay estimation and improve indoor positioning accuracy, a time delay estimation algorithm based on double dynamic thresholds is proposed in this paper. Firstly, constant false alarm rate (CFAR) detection method is introduced to construct the first dynamic threshold, which effectively suppresses the false alarm of the first path detection caused by noise. Then, combined with the adaptive threshold based on the strongest path, a double dynamic threshold decision method is designed to further reduce the false alarm of the first path detection caused by multipath in the correlation results, so as to improve the detection probability of the first path and obtain more accurate time delay estimation results. The simulation results show that the proposed algorithm can effectively improve the accuracy of time delay estimation compared with the time delay estimation algorithms based on correlation.