Patent ID: 8611470

Claim:
A method comprising: utilizing a computer system to perform a plurality of operations including: operating on a signal {x(n)} to generate a plurality of baseband signals based on a corresponding plurality of overlapping frequency bands having distinct center frequencies, wherein each of the baseband signals is generated by frequency-translating the signal {x(n)} based on a center frequency of the corresponding frequency band to obtain a corresponding frequency-translated signal and by low-pass filtering the corresponding frequency-translated signal; identifying which one or more of the overlapping frequency bands are spectrally occupied; analyzing the baseband signal corresponding to each of the one or more spectrally-occupied frequency bands in order to classify the spectrally-occupied frequency band as not containing a GSM signal, as containing a GMSK-modulated GSM signal, or as containing a PSK-modulated GSM signal; estimating a respective value of carrier frequency offset for each of the one or more spectrally-occupied frequency bands that have been classified as containing a GMSK-modulated GSM signal, based on the corresponding baseband signal; applying a frequency correction to each of the one or more baseband signals that correspond to the one or more spectrally-occupied frequency bands that have been classified as containing a GMSK-modulated GSM signal, based on the corresponding respective estimated value of carrier frequency offset; and identifying one of the one or more frequency corrected signals as corresponding to a GSM beacon channel by determining which of the one or more frequency corrected signals includes a known extended training sequence and a known frequency correction burst.