Ronald E Krebs

US Patent:

6618696, Sep 9, 2003

Filed:

Jun 14, 1999

Appl. No.:

09/332129

Inventors:

Richard A. Dean - Columbia MD
Steven William Roberts - Columbia MD
Mark George Jacobs - Baltimore MD
Ronald E. Krebs - Bel Air MD

Assignee:

The United States of America as represented by the National Security Agency - Washington DC

International Classification:

G06G 748

US Classification:

703 13, 703 2, 703 6, 380 33, 375225, 702196

Abstract:

The present invention is a method of simulating the effects of a plurality of channels on a signal that includes the steps of acquiring a state transition matrix for each of said plurality of channels; acquiring an error matrix for each of said plurality of channels; selecting the first channel to be simulated; assuming that the signal is in a particular state; receiving the signal; generating a first number; determining the state to which the signal transitions; transitioning the signal to the state determined in the last step; generating a second number; determining what errors, if any, to inject into the signal by comparing the second number to entries in the column of the error matrix of the corresponding channel that matches the state of the signal; if one of the errors determined in the last step is lost signal then discarding the signal, not injecting any other error into the signal, selecting another channel if the user desires, assuming that the next signal selected is in the same state to which the previous signal transitioned, returning to the fifth step if another channel is selected, and transmitting the signal if another channel is not selected; and injecting the errors determined in the tenth step into the signal, selecting another channel if the user desires, returning to the fifth step if another channel is selected, assuming that the next signal selected is in the same state to which the previous signal transitioned, and transmitting the signal if another channel is not selected.