Patent ID: 7672356

Claim:
A communication device to detect a frequency-hopped communication signal with a frequency coded sequence embedded within said communication signal, wherein said communication signal employs a plurality of frequency hops, said communication device comprising: a processor to receive an incoming signal at a frequency hop of said communication signal and detect the presence of said frequency-hopped communication signal with said frequency coded sequence within said incoming signal, wherein said communication signal includes a reference frequency to form said frequency coded sequence and said frequency coded sequence includes a first frequency shifted by a positive frequency offset from said reference frequency and a second frequency shifted by a negative frequency offset from said reference frequency, said processor including: a detection module to process at said frequency hop of said communication signal each said shifted frequency of said frequency coded sequence embedded within said incoming signal in a respective independent detection path, wherein said detection module includes: an upper frequency module to process at said frequency hop of said communication signal said first shifted frequency of said frequency coded sequence embedded within said incoming signal in a corresponding independent detection path to detect the presence of said frequency coded sequence within said first shifted frequency of said incoming signal and determine a detection of said frequency-hopped communication signal at said frequency hop in response to detecting the presence of said frequency coded sequence within said first shifted frequency of said incoming signal; a lower frequency module to process at said frequency hop of said communication signal said second shifted frequency of said frequency coded sequence embedded within said incoming signal in a corresponding independent detection path to detect the presence of said frequency coded sequence within said second shifted frequency of said incoming signal and determine a detection of said frequency-hopped communication signal at said frequency hop in response to detecting the presence of said frequency coded sequence within said second shifted frequency of said incoming signal; and a filter module to filter said incoming signal and, for each said detection path, to pass said shifted frequency of said frequency coded sequence associated with that detection path and reject remaining ones of said shifted frequencies of said frequency coded sequence associated with other detection paths.