Systems and methods for using coherent noise filtering

Patent metadata

Field	Value
Publication number	US-10036800-B2
Application number	US-201514819813-A
Country	US
Kind code	B2
Filing date	Aug 6, 2015
Priority date	Aug 8, 2014
Publication date	Jul 31, 2018
Grant date	Jul 31, 2018

Abstract

Systems and methods are provided for the filtering of coherent noise signals. In an illustrative embodiment, a pulsed electronic signal receives varying phase shifts for each of its pulses prior to transmission. When coherent noise interferes with the transmitted signal, received signal receives a phase shift opposite of that applied prior to transmission such that the electronic signal is restored and the coherent noise becomes non-coherent. In another embodiment, width of each transmitted pulses can be varied prior to transmission, but a constant midpoint-to-midpoint time is maintained. After receiving a signal with coherent noise interference, the midpoints of the pulses are aligned causing the coherent noise to become non-coherent.

First claim

The invention claimed is:

1. A platform or mobile system including system for coherent noise filtering, said system including:
an exciter, wherein said exciter generates a first electronic signal, wherein said first electronic signal includes a first plurality of pulses;
a controller, wherein said controller applies a first plurality of phase shifts comprising a varying phase shift to each of said first plurality of pulses in said first electronic signal such that each one of said first plurality of pulses receives a different phase shift as other said first plurality of pulses;
an antenna, wherein said antenna transmits said first electronic signal after said controller applies said first plurality of phase shifts comprising said varying phase shift to said first electronic signal, wherein said antenna is configured to receive said at least one coherent noise signal generated from a coherent noise source and said first electronic signal after said first electronic signal is reflected back to said antenna and received as a second electronic signal comprising a second plurality of pulses, wherein said coherent noise source interferes with said second electronic signal;
a receiver, wherein said receiver receives said second electronic signal and said coherent noise from said antenna, wherein said receiver interfaces with said controller to apply a second plurality of phase shifts comprising an inverse of each said first plurality phase shifts respectively to each pulse in said second electronic signal and said coherent noise, wherein said coherent noise becomes non-coherent to produce a filtered output upon application of said second plurality of phase shifts; and
a Doppler processing and detection processing section that is configured to receive said filtered output, said Doppler processing and detection processing system is further configured to output detection data to a vehicle control signals section and an operator alert System Section based on said filtered output, wherein the vehicle control signals section outputs control data to a navigation system, an anti-lock brake system, a steering control system, or a safety restraints system associated with said system or platform, wherein the operator alert system is configured to generate another outputs to a system speaker comprising an audio warning or operator instruction as well as a user interface comprising a heads-up display based on said filtered output and said detection data.

2. The platform or system of claim 1 , wherein said first electronic signal comprises a radar signal.

3. The platform or system of claim 1 , wherein said varying phase shift is applied using a random number generator to calculate a pseudo-random phase shift for each of said first plurality of pulses.

4. The system or platform as in claim 1 , wherein said controller comprises a field programmable gate array (FPGA) comprising programmable logic blocks configured to generate control signals for said exciter or transmitter used to modulate or generate said first plurality of pulses, wherein said controller further comprises a first phase shifter configured to control applying said phase shifts.

5. The system or platform as in claim 4 , wherein said varying phase shift applied to each of said pulses in said first electronic signal are stored as varying phase shift data in said controller or FPGA, wherein said varying phase shift data are passed as control signals to said exciter or transmitter that then generates said first electronic signal through said antenna.

6. The system or platform as in claim 1 , wherein said pulses comprises a radio frequency (RF), electromagnetic signal, or radar signal's pulses or continuous wave segments comprising a first plurality of wave shifted outputs.

7. A method for using coherent noise filtering, comprising:
providing a system for coherent noise filtering, said system including:
an exciter, wherein said exciter generates a first electronic signal, wherein said first electronic signal includes a first plurality of pulses;
a controller, wherein said controller applies a varying phase shift to each of said pulses in said first electronic signal such that each of said first plurality of pulses does not receive the same phase shift as all of the other said first plurality of pulses;
an antenna, wherein said antenna transmits said first electronic signal after said controller applies said varying phase shift to said first electronic signal, wherein said antenna is configured to receive said first electronic signal after said first electronic signal is reflected back to said antenna and received as a second electronic signal comprising a second plurality of pulses, wherein said antenna further receives said second electronic signal and at least one coherent noise generated from a coherent noise source that interferes with said second electronic signal; and
a receiver, wherein said receiver receives said second electronic signals and said coherent noise from said antenna, wherein said receiver interfaces with said controller to apply a phase shift to said second electronic signal and said coherent noise that is the opposite of said varying phase shift, wherein said coherent noise becomes non-coherent to produce a filtered output; and
a Doppler processing and detection processing section that is configured to receive said filtered output, said Doppler processing and detection processing system is further configured to output detection data to a vehicle control signals section and an operator alert System Section based on said filtered output, wherein the vehicle control signals section outputs control data to a navigation system, an anti-lock brake system, a steering control system, or a safety restraints system associated with said system or platform, wherein the operator alert system is configured to generate another outputs to a system speaker comprising an audio warning or operator instruction as well as a user interface comprising a heads-up display based on said filtered output and said detection data;

generating said first electronic signal using said exciter;
applying said varying phase shift using said controller to each of said pulses in said first electronic signal such that each of said pulses does not receive the same phase shift as all of the other said pulses;
transmitting said first electronic signal using said antenna after said varying phase shift is applied;
receiving said second electronic signal and said coherent noise using said antenna and said receiver;
applying a reverse phase shift to said second electronic signals, using said receiver interfacing with said controller, that is opposite of said varying phase shift such that said coherent noise becomes non-coherent to produce said filtered output; and
operating said Doppler processing and detection processing section that is configured to receive said filtered output, generating and outputting detection data from said Doppler processing and detection processing system and providing said detection data to said vehicle control signals section and an operator alert system section based on said filtered output, generating and outputting control data from said vehicle control signals section to said navigation system, said anti-lock brake system, said steering control system, or said safety restraints system associated with said system or platform, generating and outputting another output from said operator alert system to a system speaker comprising an audio warning or operator instruction as well as a user interface comprising a heads-up display based on said filtered output and said detection data.

8. The method of claim 7 , wherein said first electronic signal comprises a radar signal.

9. The method of claim

Assignees

• Us Navy
• Us Navy

Inventors

• Schofield Iii John Paul
• Fulton Jr Jack Eugene
• Lockridge Terry Wayne

Classifications

• G01S13/288

  phase modulated · CPC title

• G01S13/282

  using a frequency modulated carrier wave (G01S13/286 takes precedence) · CPC title

• G01S7/023 Primary

  Interference mitigation, e.g. reducing or avoiding non-intentional interference with other HF-transmitters, base station transmitters for mobile communication or other radar systems, e.g. using electro-magnetic interference [EMI] reduction techniques (auxiliary means for detecting or identifying radar signals or the like G01S7/021; means for anti-jamming G01S7/36) · CPC title

• G01S13/52

  Discriminating between fixed and moving objects or between objects moving at different speeds · CPC title

• G01S2013/9318

  Controlling the steering · CPC title