Method and apparatus for receiving a DS / FH signal

摘要

A method for receiving a frequency hopped direct sequence spread spectrum signal comprises: dividing a received signal into a plurality of processing sub-channels each corresponding to one or more hop frequencies; Within each sub-channel: i) removing any subcarrier frequencies from the received signal; Ii) filtering said signal from (i) using a chip-matched filter; Iii) selecting a subset of samples from the filtered signal; iv) acquiring the signal by correlating the sampled signal from step (iii) with a known reference signal to produce at least one correlator output. The output (s) from each subchannel is provided at the input of a corresponding one or more common discrete time Fourier transforms (DTFT), and the output from it having a peak above a predetermined threshold is provided during further processing at the receiver Is selected. Once acquired, the method provides a less computationally costly method of tracking the signal. The present method and system implementing the method can be used to demodulate the appropriately modulated signals and have specific applications in the satellite navigation receivers.