Method for realtime digital processing of communications signals

Abstract

In a communications or jamming system, accurate timing of the transmission of digitally processed signals is accomplished through the use of standard off-the-shelf components. In order to eliminate the need for high-cost, difficult to develop, specific digital hardware or realtime synchronous software not available from the standard off-the-shelf components, the output from the non-real time components is coupled to a realtime interface that assures nanosecond timing accuracy regardless of timing errors introduced by the off-the-shelf components. In one embodiment, the signals to be transmitted are digitized and then packetized, with the data to be transmitted reconstructed using non-real time digital processing. In order to establish the exact time for transmission, the packet is given a time stamp in the form of a header which indicates the exact time at which the packet is to be transmitted by the communications system, with the packet with header being transmitted to a storage buffer, the output of which is coupled to a realtime interface including a precise time output gate, the timing of which is controlled by a precision time reference having nano-second accuracy.

Description

RELATED APPLICATIONS[0001]This is a continuation of co-pending U.S. Patent Application Ser. No. 10 / 225,707 filed Aug. 22, 2002 entitled Method For Realtime Digital Processing Of Communications Signals, the contents of which are incorporated herein by reference.FIELD OF INVENTION[0002]This invention relates to communications systems and more particularly to a method and apparatus for accurately controlling the transmission of communications signals.BACKGROUND OF THE INVENTION[0003]When building either a communications system or, for instance, a jamming system, it is important that a particular pattern of RF energy be transmitted and that this transmission be made to occur at a precise time. The signals to be transmitted are usually reconstructed from an original signal after the original signal has been processed. Whether the transmission contains analog or digital information, it is important that the reconstructed signal be transmitted at a particular point in time.[0004]This is es...

AI Technical Summary

Benefits of technology

This approach enables accurate transmission of signals at precise times without the need for expensive, specialized hardware, using standard off-the-shelf components and reducing timing errors, applicable in communications, jamming, and radar systems.

Problems solved by technology

Thus the problem is that there must be real time processing throughout all of the components used in generating the signal.

Achieving such realtime accuracy is an expensive costly process involving specialized hardware that is developed for each and every application.

The dominant source of timing error thus resides in the digital processing circuitry, with millisecond accuracies being insufficient for many applications.

The result is that common digital processing units such as general-purpose processors do not provide for the transmission of signals at the precise point in time required.

While general purpose processors are in fact quite common and inexpensive, these processors cannot without massive specialized reconfiguration be used to create accurately timed transmissions.

In short, the problem in the past is that the elements making up the communications system must themselves be controlled to nanosecond accuracies to provide the real time result.

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