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US005187471A
United States Patent [19] [11] Patent Number: 5,187,471
Wagai et al. [45] Date of Patent: Feb. 16,1993
[54] RADIO TELECOMMUNICATION
APPARATUS
[75] Inventors: Kiyoshi Wagai, Hino; Tatsuaki
Sekigawa, Hachiioji; Shihoko
Ohyanagi, Kokubunji; Mitsuji
Shiono, Oome, all of Japan
[73] Assignee: Kabushiki Kaisha Toshiba, Kawasaki, Japan
[21] Appl. No.: 698,327
[22] Filed: May 6,1991
Related U.S. Application Data
[63] Continuation of Ser. No. 370,708, Jun. 23, 1989, abandoned.
[30] Foreign Application Priority Data
Jun. 24, 1988 [JP] Japan 63-156471
[51] Int. CI.' H04Q7/00
[52] U.S. CI 340/825.44; 340/825.72;
455/343
[58] Field of Search 340/825.44, 825.47,
340/825.48, 825.69, 825.72, 311.1; 455/343;
379/57, 63
[56] References Cited
U.S. PATENT DOCUMENTS
4,384,361 5/1983 Masaki 455/343
4,618,860 10/1986 Mori 340/825.44
4,642,632 2/1987 Ohyagi et al 340/825.44
4,668,949 5/1987 Akahori et al 340/825.47
4,802,240 1/1989 Yamaguchi et al 340/825.44
4,811,362 3/1989 Yester, Jr. et al 455/343
4,839,639 6/1989 Sato et al 340/825.44
4,860,003 8/1989 DeLuca et al 340/825.44
Primary Examiner—Donald J. Yusko
Assistant Examiner—Peter Weissman
Attorney, Agent, or Firm—Obion, Spivak, McClelland,
Maier & Neustadt
[57] ABSTRACT
A method and apparatus of this invention changes a frequency at which a control circuit (signal processing circuit) operates in accordance with an operational load of a circuit. More specifically, a pager comprises a signal processing circuit for detecting a first signal sequence within received signals by comparing the received signals with codes originated in the pager and for identifying a second signal sequence received in association with the first signal sequence within the received signals, the signal processing circuit being supplied with a first clock signal having a first frequency when the signal processing circuit detects the first signal sequence and being supplied with a second clock signal having a second frequency when the signal processing circuit identifies the second signal sequence. Still, the frequency applied to the signal processing circuit may be changed in accordance with the operational load of the circuit.
27 Claims, 9 Drawing Sheets
