Patent ID: 7042854
Filing Date: 2006-05-09
Classification: H04B,H04J,H04L

Abstract:
1. A method of acquiring a communication signal, the communication signal comprising a plurality of frames, each frame comprising a plurality of time slots, at least one time slot in each frame having synchronization data with a unique word signal contained therein, the method comprising: (a) setting the gain of an automatic gain control circuit based on the maximum power measured in continuous time intervals being less than the duration of one time slot of each frame; (b) correlating at least one frame with a locally generated unique word signal at at least one of a plurality of possible frequencies; (c) storing a correlation value for each of said possible frequencies; (d) setting a numerically controlled oscillator (NCO) frequency based on a desired correlation value of said possible frequencies; (e) repeating steps (a)–(d) while the correlation value is below a frequency acquisition threshold, and when said correlation value is at least equal to said frequency acquisition threshold, performing the steps of: (f) determining an arrival time of the unique word signal in a first frame; (g) estimating an estimated arrival time of the unique word signal in a second frame based on the arrival time of the unique word signal in said first frame; (h) determining the actual arrival time of the unique word signal in said second frame; (i) calculating a difference between the estimated arrival time and the actual arrival time; (j) adjusting a voltage controlled oscillator (VCO) frequency based on said difference; (k) repeating steps (f)–(j) while said difference is not below a timing acquisition threshold to determine acquisition of said communication signal.