| 主权项 |
1. A computer system for estimating time of arrival of electromagnetic signals affected by multipath, the computer configured to perform the steps of:
a) sampling, by the computer, an electromagnetic signal received by an antenna, wherein the sampling is performed, by the computer, using a sampling step (p>0) and produces 2k+1 samples where k is a positive integer; b) calculating, by the computer, an autocorrelation function of a sampled electromagnetic signal; c) calculating, by the computer, a first set of abscissa distance values (Tm) for an impulse of the electromagnetic signal of M values, between an intersection point and a maximum point of the autocorrelation function; d) calculating, by the computer, second set of abscissa distance values (TS1,1 . . . TSM,L) from an ideal electromagnetic signal; e) individuating, by the computer, among all the second set of abscissa distance values, particular second set of abscissa distance values that are closer to values of the first set of abscissa distance values obtained in step c) thereby indicating relevance; f) associating, by the computer, the first set of abscissa distance values with estimation errors relevant to the second set of abscissa distance values; g) utilizing, by the computer, a statistical analysis of a distribution of the estimation errors obtained in step f) to reduce standard deviation of the distribution and select a subset of estimation values most close to each other; and h) performing, by the computer, an average of the subset of estimation values thereby obtaining an average value, the average value being assumed as the estimation error of said electromagnetic signal received by the antenna. |
