Systems and methods for securing a digital communications link

• US 8,792,640 B2
• Filed: 01/29/2008
• Issued: 07/29/2014
• Est. Priority Date: 01/29/2008
• Status: Active Grant

• Current Assignee: Sony Corporation (Sony Group Corp.), Sony Electronics Inc. (Sony Group Corp.)
• Original Assignee: Sony Corporation (Sony Group Corp.), Sony Electronics Inc. (Sony Group Corp.)
• Inventors: Kawasaki, Kenichi, Hardacker, Robert
• Primary Examiner(s): Zecher, Cordelia
• Assistant Examiner(s): Su, Sarah
• Application Number:
  US12/021,668
• Publication Number:
  US 20090190756A1
• Time in Patent Office: 2,373 Days
• Field of Search: 380/205, 380/219, 329/304, 329/318, 332/100, 332/103, 455/114.3, 375/298, 375/308
• US Class Current: 380/219
• CPC Class Codes: H04L 25/08 Modifications for reducing interference; Modifications for reducing effects due to line faults ; Receiver end arrangements for detecting or overcoming line faults
• CPC Class Codes: H04L 27/0008 arrangements for allowing a transmitter or receiver to use more than one type of modulation negotiating modulation type for two-way transmission paths H04L5/1453
• CPC Class Codes: H04N 19/85 using pre-processing or post-processing specially adapted for video compression
• CPC Class Codes: H04N 21/2383 Channel coding or modulation of digital bit-stream, e.g. QPSK modulation arrangements for detecting or preventing errors in the information received by adapting the channel coding H04L1/0009; analogue front ends or means for connecting modulators, demodulators or transceivers to a transmission line H04L27/0002
• CPC Class Codes: H04N 21/4382 Demodulation or channel decoding, e.g. QPSK demodulation analog front ends or means for connecting modulators, demodulators or transceivers to a transmission line H04L27/0002
• CPC Class Codes: H04N 7/1675 Providing digital key or authorisation information for generation or regeneration of the scrambling sequence pseudo-random number generators in general G06F7/58

Abstract

A digital data signal, such as a digital video signal, is intentionally pre-distorted before being sent over a network. In one embodiment, this pre-distortion may be performed in accordance with a pre-distortion pattern or algorithm which is shared with only intended receivers. The pre-distortion pattern may be used to vary the pre-distortion on a periodic basis, as frequently as on a symbol-by-symbol basis. The pre-distortion function may include distorting the phase and/or the amplitude of the digital signal'"'"'s modulation.

Claims

1. A method for providing secure digital communications comprising:

receiving a pre-distortion pattern configured to secure a signal transmission prior to receiving a pre-distorted data signal;

receiving the pre-distorted data signal over a network connection corresponding to the signal transmission;

undistorting at least one of a phase and an amplitude of the pre-distorted data signal in accordance with two or more modulation schemes consecutively based on the pre-distortion pattern, thereby securely receiving the signal transmission;

wherein the pre-distortion pattern comprises data representative of how to change from one modulation scheme to another modulation scheme while undistorting the pre-distorted data signal.

2. The method of claim 1, wherein the pre-distorted data signal comprises a video signal, and wherein the method further comprises decoding the pre-distorted data signal following the undistorting in accordance with a video coding standard.

3. The method of claim 1, further comprising demodulating the pre-distorted data signal in accordance with one of a binary phase-shift keying scheme, a quadrature phase-shift keying scheme, and a quadrature amplitude modulation scheme.

4. The method of claim 1, further comprising receiving a preamble over the network, prior to receiving the pre-distorted data signal.

5. The method of claim 4, wherein the preamble is distorted in accordance with the pre-distortion pattern.

6. The method of claim 4, further comprising correcting at least one of a phase and an amplitude of the received pre-distorted data signal for channel-condition-based distortion using the preamble.

7. A method for providing secure digital communications comprising:

providing a pre-distortion pattern to an intended receiver prior to transmitting a pre-distorted data signal, the pre-distortion pattern configured to secure a signal transmission;

distorting at least one of a phase and an amplitude of a data signal corresponding to the signal transmission in accordance with two or more modulation schemes consecutively based on the pre-distortion pattern; and

transmitting, following the distorting, the data signal over a network to the intended receiver, thereby securely transmitting the signal transmission;

wherein the pre-distortion pattern comprises data representative of how to change from one modulation scheme to another modulation scheme while undistorting the pre-distorted data signal.

8. The method of claim 7, wherein the data signal comprises a video signal, and wherein the method further comprises encoding the data signal prior to the transmitting in accordance with a video coding standard.

9. The method of claim 7, further comprising modulating the data signal in accordance with one of a binary phase-shift keying scheme, a quadrature phase-shift keying scheme, and a quadrature amplitude modulation scheme.

10. The method of claim 7, further comprising transmitting an undistorted preamble, prior to the data signal, over the network to the intended receiver.

11. The method of claim 7, further comprising transmitting a preamble, prior to the data signal, over the network to the intended receiver, wherein the preamble is distorted in accordance with the pre-distortion pattern.

12. A receiver comprising:

a network interface configured to couple the receiver to a network; and

a demodulation circuit configured to,

receive a pre-distortion pattern configured to secure a signal transmission prior to receiving a pre-distorted data signal,

receive a pre-distorted data signal over the network corresponding to the signal transmission, and

undistort at least one of a phase and an amplitude of the pre-distorted data signal in accordance with two or more modulation schemes consecutively based on the pre-distortion pattern, thereby securely receiving the signal transmission;

wherein the pre-distortion pattern comprises data representative of how to change from one modulation scheme to another modulation scheme while undistorting the pre-distorted data signal.

13. The receiver of claim 12, wherein the pre-distorted data signal comprises a video signal, and wherein the method further comprises decoding the pre-distorted data signal following the undistorting in accordance with a video coding standard.

14. The receiver of claim 12, further comprising demodulating the pre-distorted data signal in accordance with one of a binary phase-shift keying scheme, a quadrature phase-shift keying scheme, and a quadrature amplitude modulation scheme.

15. The receiver of claim 12, further comprising receiving a preamble over the network, prior to receiving the pre-distorted data signal.

16. The receiver of claim 15, wherein the preamble is distorted in accordance with the pre-distortion pattern.

17. The receiver of claim 15, further comprising correcting at least one of a phase and an amplitude of the received pre-distorted data signal for channel-condition-based distortion using the preamble.