Patent ID: 6122334
Filing Date: 2000-09-19
Classification: H04B

Abstract:
A method for detecting a pilot signal, the method comprising the steps of:generating a pilot energy sample corresponding to said pilot signal;filtering said pilot energy sample in a first branch of a parallel digital filter, said first branch for calculating a weighted historical average of a signal strength of said pilot signal in response to said pilot energy sample;filtering said pilot energy sample in a second branch of said parallel digital filter, said second branch for verifying said pilot energy sample in a state machine, wherein transitions of said state machine between a present state, and an ensuing state are proportional to a magnitude of said pilot energy sample; andgenerating a pilot detection signal if either said weighted historical average exceeds an add threshold, or said ensuing state of said state machine exceeds a maximum value of states of said state machine;wherein said step of filtering said pilot energy sample in a first branch of said parallel digital filter comprises the steps of;determining a number of pilot signals to be searched;calculating a filter length response to said number of pilot signals to be searched; andfiltering said pilot energy sample according to filter coefficients which are based on said calculated filter length.