| The GPS signal is a direct sequence spread spectrum (DSSS) signal, which is binary phase shift keying (BPSK) modulated by the input data. A delay lock loop is used for tracking the propagation delay, which occurs when a GPS signal is transmitted from the GPS satellite to the GPS receiver. However, multipath is a key issue of Global positioning system (GPS) receivers, which will be studied throughout this thesis, since a satellite signal maybe reflected from some surface before reaching the GPS receiver antennas, causing multipath error. This thesis analyzes the behavior of multipath error elimination algorithm to eliminate multipath propagation in the GPS signal. This technique [1]uses the least squares estimate technique to implement the channel estimator and a deconvolution approach to estimate the multipath error. Moreover, this thesis studies Doppler effects with multipath error on delay lock tracking loop. |
