Mark D Whitaker

US Patent:

56278608, May 6, 1997

Filed:

Jun 1, 1995

Appl. No.:

8/456510

Inventors:

Carol A. McKinny - Delray Beach FL
Christopher B. Rausch - Boynton Beach FL
Mark L. Oliboni - Boynton Beach FL
Mark R. Whitaker - Pflugerville TX
Mark H. Babcock - Austin TX
Tuan S. Hoang - Austin TX

Assignee:

Motorola, Inc. - Schaumburg IL

International Classification:

H04L 2506

US Classification:

375317

Abstract:

A peak and valley detection system and method are shown for a selective call receiving device (10). The peak and valley detection system quickly and accurately detects and tracks to the peak and valley of a two level and/or four-level signal. A signal value representing a received signal is compared by a CPU (28) to the sum of a peak variable and attack constant. The peak variable is updated to a first value if the received signal value is less than the sum and is updated to a second value if the received signal value is not less than the sum. Similarly, the received signal is compared by the CPU (28) to a difference between a valley variable and attack constant. The valley variable is updated to a third value if the received signal value is greater than the difference value and updated to a fourth value if the received signal value is not greater than the difference value. The peak and valley variables attack and decay at non-constant rates and independently of one another.