×

Waiting circuit

  • US 6,084,922 A
  • Filed: 04/16/1998
  • Issued: 07/04/2000
  • Est. Priority Date: 04/17/1997
  • Status: Expired due to Term
First Claim
Patent Images

1. 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; and

    a control circuit for starting said other circuits when said matched filter signal indicates that said predetermined signal is received.

View all claims
  • 7 Assignments
Timeline View
Assignment View
    ×
    ×