Process for minimising jammer noise in receiver systems

• US 8,902,098 B2
• Filed: 04/16/2009
• Issued: 12/02/2014
• Est. Priority Date: 04/18/2008
• Status: Active Grant

• Current Assignee: BAE Systems Plc
• Original Assignee: BAE Systems Plc
• Inventors: Langsford, Peter Alan
• Primary Examiner(s): Sotomayor, John B
• Application Number:
  US12/988,416
• Publication Number:
  US 20110034141A1
• Time in Patent Office: 2,056 Days
• Field of Search: 342/13, 342 16- 19, 342/159, 342/189
• US Class Current: 342/16
• CPC Class Codes: G01S 7/36 Means for anti-jamming , e.g. ECCM, i.e. electronic counter-counter measures
• CPC Class Codes: H01Q 3/2635 the auxiliary unit being composed of a plurality of antennas
• CPC Class Codes: H04B 1/126 having multiple inputs, e.g. auxiliary antenna for receiving interfering signal aerials in general H01Q
• CPC Class Codes: H04K 3/228 Elimination in the received signal of jamming or of data corrupted by jamming interference suppression in receivers H04B1/10

Abstract

A process is disclosed for minimising jammer noise in receiver systems. The process comprises the use of a primary receiver (10) and a plurality of secondary receivers (11) for receiving signals. The process comprises the steps of:—separately correlating the signal received at each of the plurality of 5 secondary receivers with the signal received at the primary receiver;—determining the magnitude of the correlation between signals received at each of the plurality of secondary receivers with the signal received at the primary receiver; and,—minimising the signal received at the primary receiver using those signals received at the secondary receivers for which the magnitude of the correlation with the signal received at the primary receiver is above a threshold value.

Claims

1. A process for minimising jammer noise in receiver systems, the process comprising the use of a primary receiver and a plurality of secondary receivers for receiving signals, the process comprising the steps of:

separately correlating an output signal received from each of the plurality of secondary receivers with an output signal received from the primary receiver;

determining magnitudes of correlation between the signals output from each of the plurality of secondary receivers with the signal output from the primary receiver; and

minimising the signal output from the primary receiver using those signals output from the secondary receivers for which the magnitude of the correlation with the signal output from the primary receiver is above a threshold value;

wherein only those secondary receivers that experience levels of jammer noise for which the magnitude of correlation with the signal output from the primary receiver is above the threshold are used in the minimisation step.

2. A process according to claim 1, further comprising the step of determining weighting factors for each of the signals output from the secondary receivers.

3. A process according to claim 2, wherein the weighting factors are calculated from data samples taken from each of the secondary receivers, using a sequential decorrelation algorithm.

4. A process according to claim 1, wherein only a correlated signal power output from that secondary receiver having the largest magnitude of power correlation with the signal output from the primary receiver, is used in the minimising step.

5. A process according to claim 4, wherein the minimising step comprises subtracting the correlated signal power, obtained by correlating the signal output from that secondary receiver having the largest magnitude of power correlation with the signal output from the primary receiver, from the signal output from the primary receiver to produce an improved primary signal.

6. A process according to claim 5, wherein the minimising step further comprises subtracting the correlated signal power obtained by correlating the signal output from that secondary receiver having the largest magnitude of power correlation with the signal power output from the primary receiver, from the signal output from each of the secondary receivers to produce modified secondary signals.

7. A process according to claim 6, wherein a weighting factor for each modified signal from each of the secondary receivers is recalculated in dependence upon the level of power correlation of each modified signal with the improved primary signal.

8. A process according to claim 1, wherein the signals output from each of the secondary receivers are sorted in order of the level of power correlation with the signal output from the primary receiver.

9. A process according to claim 1, wherein the minimisation step is terminated if there is no signal from a secondary receiver which comprises a level of power correlation with the primary receiver that is above the threshold value.

10. A process according to claim 1, wherein the threshold value is set to be just above the thermal noise.

11. A process according to claim 1, wherein said process is an iterative process that terminates if the signal output from each secondary receiver comprises a level of power correlation with the signal output from the primary receiver that is below the threshold value.

12. A process according to claim 11 wherein at each stage of the iteration, the signal output from each secondary receiver becomes decorrelated with the signal output from the primary receiver.

13. A process according to claim 1, wherein the receiver system is a RADAR system.

14. A RADAR receiver system comprising processing means for performing the process of claim 1.

15. A RADAR system according to claim 14, wherein the processing means comprises a RADAR management computer.