Patent ID: 6560270
Filing Date: 2003-05-06
Classification: H04B

Abstract:
A method for tuning a spread spectrum receiver to a frequency of a digital signal within a specified frequency band, the method comprising the steps of:a) coarse tuning the receiver while a preamble of the digital signal is being received, the coarse tuning comprising: i) dividing the specified frequency band into a plurality of first sub-bands; ii) sequentially measuring a received signal strength within each first sub-band until the received signal strength is greater than a predetermined threshold; b) fine tuning the receiver while the preamble of the digital signal is being received, the fine tuning comprising: i) dividing at least one first sub-band which is found to have the received signal strength greater than a predetermined into a plurality of second sub-bands when the received signal strength is greater than the predetermined threshold; ii) sequentially measuring the received signal strength within each second sub-band so as to determine which second sub-band contains a signal having the received signal strength above a predetermined threshold; iii) determining which second sub-band contains the signal with the greatest received signal strength; and c) demodulating the signal, comprising demodulating the signal in the second sub-band which has the greatest received signal strength.