Receiver for acquiring and tracking spread spectrum navigation signals with changing subcarriers

摘要

A receiver acquires and tracks a spread spectrum navigation signal with changing subcarriers. The carrier signal changes between several subcarriers according to a hopping frequency and is modulated with data and a pseudorandom noise code signal. The receiver includes a carrier wipe off unit for down converting a received spread spectrum navigation signal from its carrier frequency to a baseband frequency, a frequency hopping wipe off unit for wiping off the hopping frequency from the received spread spectrum navigation signal, and a replica signal generation unit for generating at least one replica signal of the pseudorandom noise code signal for acquiring and tracking the received spread spectrum navigation signal after carrier wipe off. The generation of the at least one replica signal is performed depending on a sojourn time of the spread spectrum navigation signal at a subcarrier and a selected predetection integration time, and a correlation and integration unit correlates and integrates the received spread spectrum navigation signal after carrier wipe off with the at least one replica signal for the selected predetection integration time.