Signal processing

Patent metadata

Field	Value
Publication number	US-10180500-B2
Application number	US-201414899459-A
Country	US
Kind code	B2
Filing date	Jun 27, 2014
Priority date	Jun 27, 2013
Publication date	Jan 15, 2019
Grant date	Jan 15, 2019

Abstract

A method of processing signal data including an unencrypted portion and an encrypted portion, the method including: receiving, at a receiver, the signal data; processing a sample of the signal data to provide a processed signal sample including data relating to the encrypted portion of the signal data and data relating to the unencrypted portion of the signal data, comparing the unencrypted signal data with at least one reference signal to determine information including at least one of (i) the time at which the signal was sent from the source and (ii) the identity of the source; requesting, based on the determined information, and from a source remote to the receiver, a set of encrypted reference signal samples; comparing, on a processing device remote to the receiver, the set of encrypted reference signal samples with the received encrypted signal data to identify any matching signal samples.

First claim

The invention claimed is:

1. A method of processing signal data comprising an unencrypted portion and an encrypted portion, the method comprising:
(i) receiving, at a receiver, the signal data;
(ii) processing a sample of the signal data to provide a processed signal sample comprising data relating to the encrypted portion of the signal data and data relating to the unencrypted portion of the signal data,
(iii) comparing the unencrypted signal data with at least one reference signal to determine information comprising at least one of (i) the time at which the signal was sent from the source and (ii) the identity of the source;
(iv) requesting, based on the determined information, and from a source remote to the receiver, a set of encrypted reference signal samples;
(v) comparing, on a processing device remote to the receiver, the set of encrypted reference signal samples with the received encrypted signal data to identify any matching signal samples.

2. A method according to claim 1 which is a method of authenticating a source of the signal data and/or content of the signal data, and the signal data source and/or content is authenticated in the event of a match between at least one of the set of encrypted reference signal samples and the received encrypted signal data sample being determined.

3. A method according to claim 1 which is a method of identifying an encrypted data signal, and the method optionally further comprises deriving data based on the identification of matching encrypted signal samples to determine information encoded in the encrypted signal data.

4. A method according to claim 1 which is carried out by at least three entities: a receiver, a remote processing device, and a security module.

5. A method according to claim 4 in which steps (i) and (ii) are carried out by the receiver, and the processed signal sample is then transmitted to the remote processing device for further processing.

6. A method according to claim 5 in which step (iii) is performed by the receiver, and the determined information is, or forms part of, the data relating to the unencrypted signal data which in turn form parts of the processed signal sample.

7. A method according to claim 4 in which the remote processing device uses the received information to request a set of encrypted reference signals from the security module, and/or the security module receives at least the part of the processed signal sample which relates to the encrypted portion of data, and performs step (v).

8. A method according to claim 4 in which the set of encrypted reference signals generated are transmitted from the security module to the remote processing device, which performs step (v).

9. A method according to claim 1 in which the step of processing the signal sample is arranged to reduce the signal sample size prior to transmitting the signal sample.

10. A method according to claim 1 in which the step of processing the signal sample comprises separating the unencrypted and encrypted signals into two streams for processing.

11. A method according to claim 1 which comprises pre-screening the signal received prior to transmission to the remote processing device.

12. A method according to claim 11 in which, if the pre-screening indicates that the captured signal does not meet predetermined standards, the method further comprises one or more of: (i) restarting the method by recapturing a signal, (ii) a user notification being generated, (iii) adapting the capture parameters, (iv) employing anti-interference techniques or (v) aborting signal capture.

13. A method according to claim 11 in which the pre-screening is used to determine the amount of signal that is required to be captured and/or an amount of data compression that may be performed.

14. Apparatus for processing signal data comprising an unencrypted portion and an encrypted portion, the apparatus comprising at least one of each of the following: a receiver, a remote processing device and a security module, wherein:
(i) the security module comprises a reference signal generator arranged to generate a set of encrypted reference signal samples;
(ii) the receiver is arranged to receive signal data and comprises processing circuitry arranged to process signal data to provide a processed signal sample comprising data relating to the encrypted portion of the signal data and data relating to the unencrypted portion of the signal data, and further comprises a transmitter for transmitting the processed signal sample to the remote processing device
(iii) at least one of the remote processing device and the receiver comprises processing circuitry comprising a comparison module for comparing the signal data with reference signal samples, and arranged to compare received unencrypted signal data with at least one reference signal to determine information comprising at least at least one of (i) the time at which signal data was sent from the source and (ii) the identity of a signal data source;
(iv) the remote processing device comprises communication apparatus arranged to request generation of encrypted reference signal samples;
(v) the reference signal generator of the security module generates, based on the request, a set of encrypted reference signal samples;
(vi) at least one of the security module and the remote processing device comprises a comparison module arranged to compare the set of encrypted reference signal samples with the received encrypted signal data to identify any matching signal samples.

15. Apparatus according to claim 14 which is arranged to authenticate a source of the signal data and/or content thereof, and the signal data source is authenticated in the event of a match between the set of encrypted reference signal samples and the received encrypted signal sample.

16. Apparatus according to claim 15 in which the remote processing device comprises an authentication module, arranged to authenticate information output from the comparison module in relation to an unencrypted signal based on the determination that a related encrypted signal portion matches a reference sample.

17. Apparatus according to claim 14 which is arranged to identify an encrypted data signal, and the apparatus is arranged to derive data based on the identification of matching encrypted signal samples to determine information encoded in the encrypted data signal.

18. Apparatus according to claim 14 which is part of a Global Navigation Satellite System (GNSS), and the receiver is a GNSS receiver.

19. Apparatus as claimed in claim 14 , wherein the processing circuitry of part (ii) is arranged to compress the processed signal relative to the received signal size, before the processed signal is transmitted to the remote processing device.

20. Apparatus according to claim 19 which is arranged to capture a received signal for processing at a time determined by processing circuitry, and time at which the signal is captured is varied.

Assignees

• Qinetiq Ltd

Inventors

• Davies Nigel Clement
• Bowden Richard Edward
• Dumville Mark
• Wales Ben Peter
• Aguado Luis Enrique
• Evans Thomas Andrew

Classifications

• G01S19/32 Primary

  Multimode operation in a single same satellite system, e.g. GPS L1/L2 · CPC title

• G01S19/215

  issues related to spoofing · CPC title

• G01S19/09 Primary

  providing processing capability normally carried out by the receiver · CPC title

• H04B7/18523

  Satellite systems for providing broadcast service to terrestrial stations, i.e. broadcast satellite service (arrangements specially adapted for satellite broadcast receiving H04H40/90; picture transmission via satellite H04N1/00103; television transmission via satellite H04N7/20) · CPC title

• G01S19/05

  providing aiding data · CPC title