JAMMING DETECTOR AND JAMMING DETECTING METHOD

• US 20090104869A1
• Filed: 10/18/2007
• Published: 04/23/2009
• Est. Priority Date: 10/18/2007
• Status: Active Grant

• Current Assignee: MediaTek, Inc.
• Original Assignee: MediaTek, Inc.
• Inventors: Li, Kuan-i
• Granted Patent: US 7,835,687 B2
• Time in Patent Office: Days
• US Class Current: 455/1
• CPC Class Codes: G01S 19/21 Interference related issues ; Issues related to cross-correlation, spoofing or other methods of denial of service
• CPC Class Codes: H04B 1/7097 Interference-related aspects
• CPC Class Codes: H04B 2201/70715 with application-specific features
• 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 jamming detector and jamming detecting method are disclosed. In accordance with the present invention, distribution of a received signal is compared with a reference distribution of a specific signal model. Deviation of the signal distribution from the reference distribution can be obtained according to the comparison results. The existence of jamming is determined according to the deviation. If the signal distribution significantly deviates from the reference distribution, it means that jamming exists. An anti-jamming circuit or algorithm can be activated only when jamming is detected, thereby power consumption is reduced.

Claims

1. A jamming detector for a CDMA-like receiver, said jamming detector comprising:

a distribution measurement part measuring a signal distribution of the received signal; and

a jamming detection part comparing the signal distribution measured by the distribution measurement part with a reference distribution and determining whether there is jamming according to the comparison result.

2. The jamming detector of claim 1, wherein the reference distribution is divided into a plurality of groups, and the signal distribution is measured based on the groups.

3. The jamming detector of claim 2, wherein said distribution measurement part comprises a plurality of counters, each of which counts samples obtained by sampling the signal and meeting a specific condition of one of the groups to obtain a sample number, and said jamming detection part compares the respective sample numbers with reference values of the respective groups for the reference distribution to determine whether there is jamming.

4. The jamming detector of claim 3, wherein the reference distribution is divided into the groups according to signal amplitudes.

5. The jamming detector of claim 4, wherein each group has a predetermined range, and the counters respectively count samples falling in the respective ranges of the groups.

6. The jamming detector of claim 2, wherein the jamming detection part compares a measured result of the signal in each group with a reference value of the reference distribution for the group.

7. The jamming detector of claim 6, wherein the jamming detection part uses one selected from a group at least consisted of difference between measured results of the respective groups, ratio between measured results of the respective groups, square of differences between measured results of the respective groups and chi-square test for measured results of the respective groups to compare with the reference distribution.

8. The jamming detector of claim 1, wherein the reference distribution is of Gaussian signal model.

9. The jamming detector of claim 1, wherein the reference distribution is of single-tone sine wave signal model.

10. A jamming detecting method comprising steps of:

measuring distribution of a received signal;

comparing distribution of the signal with a reference distribution; and

determining if there is jamming in the signal according to the comparison result.

11. The method of claim 10, further comprising:

dividing the reference distribution into a plurality of groups;

determining an ideal value of samples for each group;

sampling the signal; and

counting actual samples of a signal falling in each step to obtain an actual sample number of each group,

wherein the actual sample numbers are respectively compared with the corresponding reference values of the respective groups in the comparing step.

12. The method of claim 11, wherein the reference distribution is divided into the groups according to signal amplitudes.

13. The method of claim 11, wherein each group has a predetermined range, and the samples falling in the respective ranges of the groups are respectively counted.

14. The method of claim 11, wherein measured result of the signal in each group is compare with the reference value of the reference distribution for the group.

15. The method of claim 11, wherein one selected from a group at least consisted of difference between measured results of the respective groups, ratio between measured results of the respective groups, square of differences between measured results of the respective groups and chi-square test for measured results of the respective groups is used to compare with the reference distribution.

16. The method of claim 11, wherein ratio between measured results of the respective groups are used to compare with the reference distribution.

17. The method of claim 10, wherein the reference distribution is of Gaussian signal model.

18. The method of claim 10, wherein the reference distribution is of single-tone sine wave signal model.