U.S. patent application number 10/613488 was filed with the patent office on 2004-01-08 for detector of commercial jammer.
Invention is credited to Cervinka, Alexandre, Gauvreau, Jean-Louis.
Application Number | 20040005858 10/613488 |
Document ID | / |
Family ID | 29783901 |
Filed Date | 2004-01-08 |
United States Patent
Application |
20040005858 |
Kind Code |
A1 |
Cervinka, Alexandre ; et
al. |
January 8, 2004 |
Detector of commercial jammer
Abstract
The present invention relates to a method and device for
detecting a communication-interfering jammer in the proximity of a
communication equipment normally receiving an intelligible signal.
As a first operation, an absence of reception of the intelligible
signal by the communication equipment is detected. A discrimination
of the detection of a communication-interfering jammer in the
proximity of the communication equipment from at least one other
cause for the absence of reception of the intelligible signal by
the communication equipment is then conducted. A
communication-interfering jammer is finally detected in the
proximity of the communication equipment when the discrimination
indicates that there exists no other cause for the absence of
reception of the intelligible signal by the communication
equipment.
Inventors: |
Cervinka, Alexandre;
(Montreal, CA) ; Gauvreau, Jean-Louis; (La
Prairie, CA) |
Correspondence
Address: |
TESTA, HURWITZ & THIBEAULT, LLP
HIGH STREET TOWER
125 HIGH STREET
BOSTON
MA
02110
US
|
Family ID: |
29783901 |
Appl. No.: |
10/613488 |
Filed: |
July 3, 2003 |
Current U.S.
Class: |
455/1 ;
455/423 |
Current CPC
Class: |
G08B 25/08 20130101;
H04K 3/65 20130101; H04K 3/90 20130101; H04K 2203/16 20130101; H04K
2203/22 20130101; H04W 4/029 20180201; H04K 3/222 20130101; H04W
4/02 20130101; H04K 2203/18 20130101 |
Class at
Publication: |
455/1 ;
455/423 |
International
Class: |
H04K 003/00 |
Foreign Application Data
Date |
Code |
Application Number |
Jul 3, 2002 |
CA |
2,392,326 |
Claims
What is claimed is:
1. A device for detecting a communication-interfering jammer in the
proximity of a communication equipment normally receiving an
intelligible signal, comprising: means for detecting an absence of
reception of the intelligible signal by the communication
equipment; means for discriminating the detection of a
communication-interfering jammer in the proximity of the
communication equipment from at least one other cause for the
absence of reception of the intelligible signal by the
communication equipment; and means for detecting a
communication-interfering jammer in the proximity of the
communication equipment when the discriminating means indicates
that there exists no other cause for the absence of reception of
the intelligible signal by the communication equipment.
2. A method for detecting a communication-interfering jammer in the
proximity of a communication equipment normally receiving an
intelligible signal, comprising: detecting an absence of reception
of the intelligible signal by the communication equipment;
discriminating the detection of a communication-interfering jammer
in the proximity of the communication equipment from at least one
other cause for the absence of reception of the intelligible signal
by the communication equipment; and detecting a
communication-interfering jammer in the proximity of the
communication equipment when the discrimination indicates that
there exists no other cause for the absence of reception of the
intelligible signal by the communication equipment.
3. A method for detecting a communication-interfering jammer as
defined in claim 2, wherein discriminating the detection of a
communication-interfering jammer comprises: discriminating the
detection of a communication-interfering jammer in the proximity of
the communication equipment from an out-of-coverage situation.
4. A method for detecting a communication-interfering jammer as
defined in claim 2, wherein discriminating the detection of a
communication-interfering jammer comprises: discriminating the
detection of a communication-interfering jammer in the proximity of
the communication equipment from a situation of interference.
5. A method for detecting a communication-interfering jammer as
defined in claim 2, wherein the communication equipment comprises
at least one common control channel and wherein discriminating the
detection of a communication-interfering jammer comprises:
discriminating the detection of a communication-interfering jammer
in the proximity of the communication equipment from a situation of
interference on said at least one common control channel.
6. A method for detecting a communication-interfering jammer as
defined in claim 3, wherein the communication equipment comprises
at least one common control channel, and wherein discriminating the
detection of a communication-interfering jammer in the proximity of
the communication equipment from an out-of-coverage situation
comprises: comparing an average power level on the common control
channel of the communication equipment with a predicted noise
floor.
7. A method for detecting a communication-interfering jammer as
defined in claim 6, wherein discriminating the detection of a
communication-interfering jammer in the proximity of the
communication equipment from an out-of-coverage situation
comprises: detecting an out-of-coverage situation when the
comparison between the average power level and the predicted noise
floor indicates that a difference between said average power level
and said predicted noise floor is lower than a given threshold.
8. A method for detecting a communication-interfering jammer as
defined in claim 6, wherein, when the comparison between the
average power level and the predicted noise floor indicates that a
difference between said average power level and said predicted
noise floor is higher than a given threshold, discriminating the
detection of a communication-interfering jammer in the proximity of
the communication equipment from an out-of-coverage situation
comprises: detecting either a communication-interfering jammer in
the proximity of the communication equipment or a situation of
interference on the common control channel.
9. A method for detecting a communication-interfering jammer as
defined in claim 6, wherein, when the comparison of the average
power level with the predicted noise floor indicates that the
difference between said average power level and said predicted
noise floor is approximately equal to a given threshold,
discriminating the detection of a communication-interfering jammer
in the proximity of the communication equipment from an
out-of-coverage situation comprises: waiting for a short period of
time; after said short period of time has elapsed, detecting
whether there is still an absence of reception of the intelligible
signal by the communication equipment; and in the absence of
reception of the intelligible signal by the communication
equipment, repeating said comparison of the average power level on
the common control channel of the communication equipment with the
predicted noise floor.
10. A method for detecting a communication-interfering jammer as
defined in claim 3, wherein the communication equipment comprises a
set of channels, and wherein discriminating the detection of a
communication-interfering jammer in the proximity of the
communication equipment from a situation of interference comprises:
comparing to each other power levels of at least a portion of the
channels of said set.
11. A method for detecting a communication-interfering jammer as
defined in claim 10, wherein discriminating the detection of a
communication-interfering jammer in the proximity of the
communication equipment from a situation of interference further
comprises: detecting a situation of interference when the
comparison of the power levels indicate that the power levels of
said at least a portion of the channels are different from each
other.
12. A method for detecting a communication-interfering jammer as
defined in claim 10, wherein detecting a communication-interfering
jammer in the proximity of the communication equipment comprises:
detecting a communication-interfering jammer in the proximity of
the communication equipment when the comparison of the power levels
indicate that the power levels of said at least a portion of the
channels are similar to each other.
13. A device for detecting a communication-interfering jammer in
the proximity of a communication equipment normally receiving an
intelligible signal, comprising: a detector of an absence of
reception of the intelligible signal by the communication
equipment; a discriminator of the detection of a
communication-interfering jammer in the proximity of the
communication equipment from at least one other cause for the
absence of reception of the intelligible signal by the
communication equipment; and a detector of a
communication-interfering jammer in the proximity of the
communication equipment when the discrimination means indicates
that there exists no other cause for the absence of reception of
the intelligible signal by the communication equipment.
14. A device for detecting a communication-interfering jammer as
defined in claim 13, wherein the discriminator comprises: a
detector of an out-of-coverage situation, the out-of-coverage
situation constituting said at least one other cause for the
absence of reception of the intelligible signal by the
communication equipment.
15. A device for detecting a communication-interfering jammer as
defined in claim 13, wherein the discriminator comprises: a
detector of a situation of interference, said situation of
interference constituting said at least one other cause for the
absence of reception of the intelligible signal by the
communication equipment.
16. A device for detecting a communication-interfering jammer as
defined in claim 13, wherein the communication equipment comprises
at least one common control channel and wherein the discriminator
comprises: a detector of a situation of interference on the common
control channel, said situation of interference on the common
control channel constituting said at least one other cause for the
absence of reception of the intelligible signal by the
communication equipment.
17. A device for detecting a communication-interfering jammer as
defined in claim 14, wherein the communication equipment comprises
at least one common control channel, and wherein the discriminator
further comprises: a comparator of an average power level on the
common control channel of the communication equipment with a
predicted noise floor.
18. A device for detecting a communication-interfering jammer as
defined in claim 17, wherein the detector an out-of-coverage
situation comprises: means for detecting an out-of coverage
situation when the comparison between the average power level and
the predicted noise floor indicates that a difference between said
average power level and said predicted noise floor is lower than a
given threshold.
19. A device for detecting a communication-interfering jammer as
defined in claim 17, wherein the discriminator comprises means for
detecting, when the comparison between the average power level and
the predicted noise floor indicates that a difference between said
average power level and said predicted noise floor is higher than a
given threshold, either a communication-interfering jammer in the
proximity of the communication equipment or a situation of
interference on the common control channel.
20. A device for detecting a communication-interfering jammer as
defined in claim 17, wherein the discriminator comprises, when the
comparison between the average power level and the predicted noise
floor indicates that the difference between said average power
level and said predicted noise floor is approximately equal to a
given threshold: a timer for generating a short period of time; the
detector of an absence of reception comprises means for detecting,
after said short period of time has elapsed, whether there is still
an absence of reception of the intelligible signal by the
communication equipment; and the comparator comprises means for
repeating, in the absence of reception of the intelligible signal
by the communication equipment, the comparison of the average power
level on the common control channel of the communication equipment
with the predicted noise floor.
21. A device for detecting a communication-interfering jammer as
defined in claim 15, wherein the communication equipment comprises
a set of channels, and wherein the discriminator comprises: a
comparator of power levels of at least a portion of the channels of
said set to each other.
22. A device for detecting a communication-interfering jammer as
defined in claim 21, wherein the discriminator comprises: a
detector of a situation of interference when the comparison of the
power levels indicate that the power levels of said at least a
portion of the channels are different from each other.
23. A device for detecting a communication-interfering jammer as
defined in claim 21, wherein the detector of a
communication-interfering jammer in the proximity of the
communication equipment comprises: means for detecting a
communication-interfering jammer in the proximity of the
communication equipment when the comparison of the power levels
indicate that the power levels of said at least a portion of the
channels are similar to each other.
Description
FIELD OF THE INVENTION
[0001] The present invention relates to a device for detecting a
communication-interfering jammer, in particular but not exclusively
a commercial jammer.
BACKGROUND OF THE INVENTION
[0002] In order to interfere with communications, a commercial
jammer typically transmits a pseudo-random noise over a whole
downlink frequency bandwidth of a communications system or network.
Normally, the pseudo-random noise has a substantially constant
amplitude over the whole downlink frequency bandwidth. When this
substantially constant amplitude of the pseudo-random noise is
sufficiently high, any communication mobile or terminal in close
proximity to the jammer will be prevented to receive any
intelligible signal from the communication system or network.
SUMMARY OF THE INVENTION
[0003] According to the present invention, there is provided a
method for detecting a communication-interfering jammer in the
proximity of a communication equipment normally receiving an
intelligible signal, comprising: detecting an absence of reception
of the intelligible signal by the communication equipment;
discriminating the detection of a communication-interfering jammer
in the proximity of the communication equipment from at least one
other cause for the absence of reception of the intelligible signal
by the communication equipment; and detecting a
communication-interfering jammer in the proximity of the
communication equipment when the discrimination indicates that
there exists no other cause for the absence of reception of the
intelligible signal by the communication equipment.
[0004] The present invention also relates to a device for detecting
a communication-interfering jammer in the proximity of a
communication equipment normally receiving an intelligible signal,
comprising: means for detecting an absence of reception of the
intelligible signal by the communication equipment; means for
discriminating the detection of a communication-interfering jammer
in the proximity of the communication equipment from at least one
other cause for the absence of reception of the intelligible signal
by the communication equipment; and means for detecting a
communication-interfering jammer in the proximity of the
communication equipment when the discriminating means indicates
that there exists no other cause for the absence of reception of
the intelligible signal by the communication equipment.
[0005] Further according to the present invention, there is
provided a device for detecting a communication-interfering jammer
in the proximity of a communication equipment normally receiving an
intelligible signal, comprising:
[0006] a detector of an absence of reception of the intelligible
signal by the communication equipment;
[0007] a discriminator of the detection of a
communication-interfering jammer in the proximity of the
communication equipment from at least one other cause for the
absence of reception of the intelligible signal by the
communication equipment; and
[0008] a detector of a communication-interfering jammer in the
proximity of the communication equipment when the discrimination
means indicates that there exists no other cause for the absence of
reception of the intelligible signal by the communication
equipment.
[0009] The foregoing and other objects, advantages and features of
the present invention will become more apparent upon reading of the
following nonrestrictive description of an illustrative embodiment
thereof, given by way of example only with reference to the
accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] In the appended drawings:
[0011] FIG. 1 is a schematic block diagram of the non-restrictive,
illustrative embodiment of the device according to the present
invention, for detecting a communication-interfering jammer in the
proximity of a communication equipment; and
[0012] FIG. 2 is a schematic flow chart showing the operation of
the nonrestrictive, illustrative embodiment of the method according
to the present invention, for detecting a communication-interfering
jammer in the proximity of a communication equipment.
DETAILED DESCRIPTION OF THE ILLUSTRATIVE EMBODIMENT
[0013] The non-restrictive, illustrative embodiment of the
jammer-detecting device in accordance with the present invention
constitutes a standalone functionality designed for detecting the
presence of a commercial jammer in a frequency bandwidth of
interest.
[0014] Although the non-restrictive, illustrative embodiment of the
method and device of the present invention will be described in
relation to a cellular communication system or network, it should
be kept in mind that the present invention applies as well to other
types of communication systems or networks.
[0015] When a mobile or terminal receives no intelligible signal
from a cellular communication system or network, an algorithm is
required to discriminate jammer detection from two other cases
(hereinafter the first and second cases). Of course, the
non-restrictive, illustrative embodiment of the jammer-detecting
method and device incorporates such an algorithm.
[0016] The first case is an out-of-coverage case. This out-of
coverage case happens when a mobile or terminal is out-of-coverage,
for example when the mobile or terminal is outside cellular
coverage in fringe areas or inside a building with high penetration
loss.
[0017] The second case is met when the mobile or terminal is
located in an area with strong cellular interference on the common
control channel(s). More specifically, this situation is met in
locations where strong common control channel(s) is (are) received,
these strong common control channel(s) originating from multiple
cellular base stations operating at the same frequency (for FDMA
(Frequency Division Multiple Access) systems) or with the same code
(for CDMA (Code Division Multiple Access) systems).
[0018] The structure and operation of the non-restrictive,
illustrative embodiment of the jammer-detecting method and device
according to the present invention will now be described with
reference to FIGS. 1 and 2 of the appended drawings. It should be
mentioned here that the references 101-107 (including 104a) refer
to FIG. 1 while the references 201-207 (including 204a) refer to
FIG. 2.
[0019] Discrimination of the Out-of-Coverage Case
[0020] Operation 201
[0021] The non-restrictive, illustrative embodiment of the
jammer-detecting device comprises a mobile or terminal reception
detector 101 for detecting that the mobile or terminal no longer
receives an intelligible signal from the cellular communication
system or network.
[0022] When a mobile or terminal no longer receives an intelligible
signal from the cellular system or network, the out-of-coverage
discrimination is first executed. Detection that the mobile or
terminal no longer receives an intelligible signal can be carried
out through conventional methods well known to those of ordinary
skill in the art. An example is the detection of a signal-to-noise
ratio lower than a given threshold.
[0023] Operation 202
[0024] The out-of-coverage discrimination first comprises a
comparison of the average power level on at least one common
control channel with a predicted noise floor. This comparison is
conducted by the signal and noise comparator 102.
[0025] As well known to those of ordinary skill in the art, the
predicted noise floor is a function of the mobile or terminal noise
figure and the frequency bandwidth of concern.
[0026] Operation 203
[0027] If the difference between the average power level of the
common control channel and the predicted noise floor as determined
by the signal and noise comparator 102 is lower (for example by 10%
lower) than the signal-to-noise ratio required for proper operation
of the mobile or terminal plus a certain margin to take into
consideration normal co-channel interference, the cellular system
or network is then considered as out-of-coverage. This condition is
detected by the out-of-coverage detector 103.
[0028] The signal-to-noise ratio required for proper operation of
the mobile or terminal plus the above-mentioned margin will be
referred to as the "threshold" in the following description.
[0029] If the difference between the average power level of the
common control channel and the predicted noise floor as determined
by the signal and noise comparator 102 is higher (for example by
10% higher) than the threshold, the cellular system or network is
either jammed or in interference on the common control channel. The
procedure then goes to operation 205 in order to perform the
discrimination of the common channel interference case.
[0030] Operation 204
[0031] The first time (104a and 204a) the average power level on
the common control channel is compared to the predicted noise
floor, the difference between this average power level of the
common control channel and the predicted noise floor is
approximately equal to the threshold (for example equal to the
threshold .+-.10%), the jammer-detecting device waits for a short
period of time generated by the timer 204, for example a few
seconds.
[0032] After this waiting period, as the difference between the
average power level of the common control channel and the predicted
noise floor is approximately equal to the threshold, the reception
may correctly resume. If not, discrimination of the out-of-coverage
case is performed a second time with the following result:
[0033] If the difference between the average power level of the
common control channel and the predicted noise floor is lower (for
example by 10% lower) than the threshold, the out-of-coverage
detector 103 detects an out-of-coverage condition of the cellular
system or network (Operation 203);
[0034] If the difference between the average power level of the
common control channel and the predicted noise floor is higher (for
example by 10% higher) than the threshold, the cellular system or
network is either jammed or in interference on the common control
channel, and the procedure then goes to Operation 205; and
[0035] If the difference between the average power level of the
common control channel and the predicted noise floor is
approximately equal (for example equal to the threshold .+-.10%) to
the threshold as a result of the second (104a and 204a)
out-of-coverage discrimination (104a and 204a), the cellular system
or network is either jammed or in interference on the common
control channels, and the procedure then goes to Operation 205.
[0036] Discrimination of the Common Channel Interference Case
[0037] At this stage, the jammer-detecting method and device
considers the cellular system or network as being jammed or in
cellular interference on the common control channel.
[0038] Operation 205
[0039] Discrimination of the common channel interference case is
conducted by first comparing to each other the respective RF (Radio
Frequency) power levels of a random set of channels within the
relevant frequency bandwidth. The nonrestrictive, illustrative
embodiment of the jammer-detecting device comprises a random
channels power level scanner 105 for performing this
comparison.
[0040] In FDMA systems or networks, this comparison is made by
scanning different frequencies corresponding to a set of channels.
In CDMA systems or networks, the comparison is made by scanning
different codes corresponding to different common channels.
[0041] Operation 206
[0042] If the average RF power levels of the various channels are
different, an interference detector 106 of the non-restrictive,
illustrative embodiment of the jammer-detecting device detects that
the mobile or terminal is victim of cellular interference on the
common control channel(s).
[0043] Detection of the Presence of a Jammer, in Particular but not
Exclusively a Commercial Jammer
[0044] Operation 207
[0045] It the average RF power levels of the various channels are
similar, the non-restrictive, illustrative embodiment of the
jammer-detecting device comprises a jammer detector 107 indicating
that the mobile or terminal is being jammed, that is under the
influence of a jammer.
[0046] Those of ordinary skill in the art will appreciate that,
prior to detecting the presence of a jammer, the non-restrictive
illustrative embodiment of the jammer-detecting device according to
the present invention first determines whether the absence of
reception of an intelligible signal by the cellular mobile or
terminal is caused by either out-of-coverage or interference.
[0047] Although the present invention has been described in the
foregoing specification by means of a non-restrictive illustrative
embodiment thereof, this illustrative embodiment can be modified as
will, within the scope of the appended claims without departing
from the spirit and nature of the subject invention.
* * * * *