Biren G Shah

US Patent:

54523311, Sep 19, 1995

Filed:

May 29, 1994

Appl. No.:

8/250301

Inventors:

Mazen M. Shihabi - Pasadena CA
Sami M. Hinedi - Pasadena CA
Biren N. Shah - Sierra Madre CA

Assignee:

The United States of America as represented by the Administrator of the
National Aeronautics and Space Administration - Washington DC

International Classification:

H04L 2722

US Classification:

375324

Abstract:

A symbol lock detector for an incoming coherent digital communication signal which utilizes a subcarrier modulated with binary symbol data, d. sub. k, and known symbol interval T by integrating binary values of the signal over nonoverlapping first and second intervals selected to be T/2, delaying the first integral an interval T/2, and either summing or multiplying the second integral with the first one that preceded it to form a value X. sub. k. That value is then averaged over a number M of symbol intervals to produce a static value Y. A symbol lock decision can then be made when the static value Y exceeds a threshold level. delta.