Patent ID: 7349381

Claim:
A method of obtaining coarse synchronization in a frequency hopped/direct sequence spread spectrum (FH/DSS) time division multiple access (TDMA) data link network, the method comprising: tuning a first receiver to a fixed first frequency out of a plurality of frequencies used in the data link network; observing signal strength of signals received on the fixed first frequency during a sample time period; collecting samples during the sample time period over a plurality of samples on the fixed first frequency to obtain a sample energy pattern; applying a threshold to the sample energy pattern; obtaining a received energy pattern by utilizing a fraction of energy components in the sample energy pattern that exceed the threshold; determining an expected energy pattern on the fixed first frequency corresponding to a time uncertainty window, the expected energy pattern being based upon a known hopping pattern; comparing the received energy pattern to a first portion of the expected energy pattern on the fixed first frequency, the first portion of the expected energy pattern corresponding to a first time period within the time uncertainty window; and determining whether the first time period is a coarse synchronization candidate as a function of the comparison between the received energy pattern and the first portion of the expected energy pattern.