Patent ID: 6084922
Filing Date: 2000-07-04
Classification: H04B,H04W,Y02D

Abstract:
A waiting circuit incorporated within a portable terminal of a mobile communication system, for detecting a predetermined signal from a base station to start other circuits which are in a sleep mode, said predetermined signal being generated in said base station having a speed corresponding to a predetermined symbol rate, said predetermined signal being modulated in said base station to be an intermediate frequency signal having a frequency higher than a frequency of said symbol rate, comprising:a sub-sampling circuit for sampling said intermediate frequency signal in response to a sampling clock having a speed equal to an integer times said symbol rate;a matched filter for multiplying said sampled intermediate frequency signal by a predetermined sequence of coefficients corresponding to said intermediate frequency signal, and producing a produces a matched filter signal; anda control circuit for starting said other circuits when said matched filter signal indicates that said predetermined signal is received.