SYSTEM AND METHODS FOR OCDM-BASED OPTICAL ENCRYPTION USING SUBSETS OF PHASE-LOCKED FREQUENCY LINES

• US 20110228939A1
• Filed: 03/16/2010
• Published: 09/22/2011
• Est. Priority Date: 03/16/2010
• Status: Abandoned Application

• Current Assignee: Telcordia Technologies Incorporated (Telefonaktiebolaget LM Ericsson)
• Original Assignee: Telcordia Technologies Incorporated (Telefonaktiebolaget LM Ericsson)
• Inventors: Menendez, Ronald, Galli, Stefano, Izadpanah, Hossein, Etemad, Shahab, Jackel, Janet
• Application Number:
  US12/724,631
• Publication Number:
  US 20110228939A1
• Time in Patent Office: Days
• US Class Current: 380/256
• CPC Class Codes: H04B 10/516 Details of coding or modulation
• CPC Class Codes: H04B 10/60 Receivers
• CPC Class Codes: H04B 10/85 Protection from unauthorised access, e.g. eavesdrop protection
• CPC Class Codes: H04K 1/04 by frequency scrambling, i.e. by transposing or inverting parts of the frequency band or by inverting the whole band

Abstract

A method for optical signal processing includes receiving an optical signal containing a plurality of frequency lines, defining at least two wavesets including an updatable random subset of the frequency lines, receiving a data stream, modulating the optical signal with the data stream, encrypting the data stream by extracting the subset of the frequency lines of the at least two wavesets from the modulated optical signal, and phase coding the subset of frequency lines of the at least two wavesets in the modulated optical signal.

Claims

1. A method of optical signal processing, comprising the steps of:

receiving an optical signal including a plurality of frequency lines;

defining at least two wavesets including an updatable random subset of the frequency lines;

receiving a data stream;

modulating the optical signal with the data stream;

encrypting the data stream by extracting the subset of the frequency lines of the at least two wavesets from the modulated optical signal; and

phase coding the subset of frequency lines of the at least two wavesets in the modulated optical signal.

2. The method of claim 1, wherein the step of defining further comprises the step of:

randomly defining at least a first waveset and a second waveset that do not have any of the frequency lines in common.

3. The method of claim 2, wherein frequency lines of the first waveset and frequency lines of the second waveset are intermingled.

4. The method of claim 2, further comprising the steps of:

inverse multiplexing the data stream into a plurality of sub-streams;

modulating individual copies of the optical signal with individual ones of the sub-streams; and

phase coding the modulated individual copies of the optical signal.

5. The method of claim 4, wherein the step of phase coding the modulated individual copies of the optical signal further comprises the steps of:

phase coding frequency lines of the first waveset in a copy of the optical signal modulated by a first of the sub-streams with a first phase code; and

phase coding frequency lines of the first waveset in a copy of the optical signal modulated by a second of the sub-streams with a second phase code,

wherein the first phase code is orthogonal to the second phase code.

6. The method of claim 4, wherein the step of phase coding the modulated individual copies of the optical signal further comprises the steps of:

phase coding frequency lines of the first waveset in a copy of the optical signal modulated by a first of the sub-streams with a first phase code; and

phase coding frequency lines of the second waveset in a copy of the optical signal modulated by a second of the sub-streams with a second phase code,

wherein the first phase code is not orthogonal to the second phase code.

7. The method of claim 4, further comprising:

combining the phase coded and modulated individual copies of the optical signal; and

phase scrambling the combined optical signal.

8. The method of claim 1, wherein:

the step of modulating further comprises the step of modulating a copy of the optical signal with a random data stream to obscure the data stream; and

the step of phase coding further comprises the step of phase coding the subset of frequency lines of the at least two wavesets in the copy of the modulated optical signal.

9. The method of claim 1, wherein the step of receiving further comprises the step of:

receiving the optical signal from a mode locked laser.

10. The method of claim 1, wherein the step of modulating is processed according to at least one of:

on-off keying (OOK), duobinary, differential phase shift keying (DPSK), or multi-amplitude/phase constellations.

11. The method of claim 1, wherein the data stream is a first data stream and the optical signal is a first optical signal, the method further comprising the steps of:

receiving a second data stream from a different source than the first data stream;

modulating the first optical signal with the first data stream;

modulating a second optical signal with the second data stream; and

phase coding frequency lines of the same waveset in the first modulated optical signal and the second modulated optical signal.

12. The method of claim 1, wherein the step of phase coding applies a binary phase shift.

13. The method of claim 1, further comprising the step of:

sending an identification of the frequency lines of the at least two wavesets to a receiver.

14. A transmitter for optical signal processing, comprising:

at least one modulator configured to receive a data stream and an optical signal, the optical signal including a plurality of frequency lines, the at least one modulator further configured to modulate the optical signal with the data stream; and

at least one phase coder configured to;

define at least two wavesets including an updatable random subset of the frequency lines;

encrypt the data stream by extracting the random subset of the frequency lines of the at least two wavesets from the modulated optical signal; and

phase code the subset of frequency lines of the at least two wavesets in the modulated optical signal.

15. The transmitter of claim 14, wherein the at least one phase coder is further configured to:

randomly define at least a first waveset and a second waveset that do not have any of the frequency lines in common.

16. The transmitter of claim 15, wherein frequency lines of the first waveset and frequency lines of the second waveset are intermingled.

17. The transmitter of claim 15, further comprising a converter configured to inverse multiplex the data stream into a plurality of sub-streams, wherein:

the at least one modulator is further configured to modulate individual copies of the optical signal with individual ones of the sub-streams; and

the at least one phase coder is further configured to phase code the modulated individual copies of the optical signal.

18. The transmitter of claim 17, wherein the at least one phase coder is further configured to:

phase code frequency lines of the first waveset in a copy of the optical signal modulated by a first of the sub-streams with a first phase code; and

phase code frequency lines of the first waveset in a copy of the optical signal modulated by a second of the sub-streams with a second phase code,

wherein the first phase code is orthogonal to the second phase code.

19. The transmitter of claim 17, wherein the at least one phase coder is further configured to:

phase code frequency lines of the first waveset in a copy of the optical signal modulated by a first of the sub-streams with a first phase code; and

phase code frequency lines of the second waveset in a copy of the optical signal modulated by a second of the sub-streams with a second phase code,

wherein the first phase code is not orthogonal to the second phase code.

20. The transmitter of claim 17, further comprising a phase scrambler configured to:

receive a combined optical signal of the phase coded and modulated individual copies of the optical signal; and

phase scramble the combined optical signal.

21. The transmitter of claim 14, wherein:

the at least one modulator is further configured to modulate a copy of the optical signal with a random data stream to obscure the data stream; and

the at least one phase coder is further configured to phase code the subset of frequency lines of the at least two wavesets in the copy of the modulated optical signal.

22. The transmitter of claim 14, further comprising a mode locked laser configured to provide the optical signal.

23. The transmitter of claim 22, wherein the at least one modulator is configured to operate according to at least one of:

on-off keying (OOK), duobinary, differential phase shift keying (DPSK), or multi-amplitude/phase constellations.

24. The transmitter of claim 14, wherein the data stream is a first data stream and the optical signal is a first optical signal, wherein the at least one modulator is further configured to:

receive a second data stream from a different source than the first data stream;

modulate the first optical signal with the first data stream; and

modulate a second optical signal with the second data stream,

wherein the at least one phase coder is further configured to phase code frequency lines of the same waveset in the first modulated optical signal and the second modulated optical signal.

25. The transmitter of claim 14, wherein the phase coder is further configured to apply a binary phase shift.

26. The transmitter of claim 14, wherein the transmitter is configured to send an identification of the frequency lines of the at least two wavesets to a receiver.

27. A receiver for optical signal processing, comprising:

at least one phase decoder configured to receive a phase coded modulated optical signal, identify at least two wavesets including a random subset of frequency lines, and perform phase decoding on the random set of frequency lines of the at least two wavesets in the phase coded modulated optical signal; and

at least one demodulator configured to receive the modulated optical signal after the phase decoder performs the phase decoding and demodulate the modulated optical signal to extract at least one data stream.

28. The receiver of claim 27, wherein the at least one phase decoder is further configured to:

identify at least a first waveset and a second waveset that do not have any frequency lines in common.

29. The receiver of claim 28, wherein frequency lines of the first waveset and frequency lines of the second waveset are intermingled.

30. The receiver of claim 27, further comprising a phase descrambler configured to:

receive a scrambled phase coded modulated optical signal;

descramble the scrambled phase coded modulated optical signal into the phase coded modulated optical signal; and

send the phase coded modulated optical signal to the at least one phase decoder.

31. The receiver of claim 27, wherein the at least one demodulator is further configured to demodulate the modulated optical signal to extract a random data stream, the random data stream obscuring the data stream modulating the optical signal.

32. The receiver of claim 27, wherein the receiver is configured to receiver an identification of the frequency lines of the at least two wavesets from a transmitter.