Pulse or digital communications – Bandwidth reduction or expansion – Television or motion video signal
Reexamination Certificate
1998-01-28
2001-01-30
Vo, Don N. (Department: 2734)
Pulse or digital communications
Bandwidth reduction or expansion
Television or motion video signal
C375S316000, C375S350000
Reexamination Certificate
active
06181744
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Technical Field
The present invention relates to a method and system for signal processing in general, and in particular to a method and system for processing pulsed signals. Still more particularly, the present invention relates to a method and system for improving process shadow time within a pulsed signal processing system.
2. Description of the Prior Art
In military defense, once a new weapon is developed, typically another weapon will be invented to counteract the first weapon. For example, since the introduction of radar in World War II, many different strategies have been developed to interfere with and to defeat radar effectiveness. These strategies are often referred to as electronic countermeasures (ECMs). Some successfully developed ECMs that have been popularized over the years to inhibit radar effectiveness include, inter alia, chaffs and jammers.
But with the improvement of radar technology and the increasing complexity of the electronic signal environment, not only are there more radars in operations today, the radar signals themselves are also more sophisticated than their predecessors. Not surprisingly, more sophisticated ECMs have been developed as a result. For example, an electronic warfare receiver, commonly referred to as an intercept receiver, has been developed to detect the existence of radar signals from a hostile source. Even so, because detailed information about the radar system from a hostile source is seldom available, it is almost impossible to design an intercept receiver as effective as the radar receiver in the radar system. Fortunately, due to the fact that the distance travelled by the radar signal from the radar system source to the intercept receiver is half the distance from the same radar system source to the radar receiver, the signal strength at the input of the intercept receiver is much stronger than the signal strength at the radar receiver. Therefore, if an intercept receiver is properly designed, the intercept receiver can effectively detect the radar signal from a hostile source.
Generally speaking, an intercept receiver is a pulsed signal processing system. A pulsed signal processing system processes each radar signal pulse as the radar signal pulse is being detected. The timeframe after a radar signal pulse detection in which the pulsed signal processing system cannot (or is not ready) to detect another radar signal pulse is referred to as “shadow time.” One main drawback of prior art pulsed signal processing systems is that these pulsed signal processing systems must wait for a long period of time for the radar signal level to decay below the system threshold level in order to process a subsequent pulse, even though the radar signal may have already ended. In other words, these pulsed signal processing systems have a very long process shadow time. With a very long process shadow time, any of the following problems can occur: (1) system processing throughput is limited by the incapability to handle dense pulsed signal environments; (2) pulse signals that occur within the process shadow time of a previous pulse signal will go undetected; and (3) pulse signal widths will be measured inaccurately when portions of the pulse signal fall within the process shadow time of a previous pulse signal. Consequently, it would be desirable to provide a method to improve process shadow time within a pulsed signal processing system.
SUMMARY OF THE INVENTION
In view of the foregoing, it is therefore an object of the present invention to provide an improved method and system for signal processing.
It is another object of the present invention to provide an improved method and system for processing pulsed signals.
It is yet another object of the present invention to provide an improved method and system for improving process shadow time within a pulsed signal processing system.
In accordance with a preferred embodiment of the present invention, an electrical signal receiving system comprises a receiver, a digitizer, and a processor. The receiver generates video signals from radio-frequency signals collected by an attached antenna. The digitizer, coupled to the receiver, converts the video signals to digital signals. The digitizer includes a bandwidth switch for reducing a shadow time of the video signals. Finally, the processor analyzes the digital signals in order to extract any useful information.
All objects, features, and advantages of the present invention will become apparent in the following detailed written description.
REFERENCES:
patent: 3623098 (1971-11-01), Jones et al.
patent: 3701059 (1972-10-01), Nyswander
patent: 3767939 (1973-10-01), Chamran et al.
patent: 3898573 (1975-08-01), Sherman
patent: 4370652 (1983-01-01), Lucchi
patent: 4481675 (1984-11-01), Ichikawa et al.
patent: 4739189 (1988-04-01), Kellogg
patent: 4857778 (1989-08-01), Hague
patent: 5324999 (1994-06-01), Hunley et al.
patent: 5418409 (1995-05-01), Kuhn
patent: 5463346 (1995-10-01), Brooks
patent: 5602876 (1997-02-01), Noneman et al.
Antonaitis David John
Showers Chad Matthew
Smith Justin Derek
Felsman Bradley Vaden Gunter & Dillon, LLP
Lockheed Martin Corporation
Vo Don N.
LandOfFree
Method and system for improving process shadow time within a... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Method and system for improving process shadow time within a..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Method and system for improving process shadow time within a... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2469269