Spread-spectrum modulation and demodulation
A method for communicating comprises generating at least one generalized Golay code from a concatenation of constituent Golay codes, and spreading at least a portion of a data stream with the at least one generalized Golay code. Generalized Golay codes comprise pseudo-complementary sequences having code lengths that differ from Golay complementary sequences and are characterized by low autocorrelation sidelobes relative to the autocorrelation peak.
1. A method for communication, comprising:
generating a plurality of pseudo-complementary generalized Golay codes by concatenating a plurality of different-length binary complementary Golay codes wherein each of the plurality of pseudo-complementary generalized Golay codes has a length that differs from any binary complementary Golay code; and
modulating at least a portion of a data stream using the plurality of pseudo-complementary generalized Golay codes.
2. The method in claim 1 , wherein the plurality of generalized Golay codes comprises a pair of pseudo complementary generalized Golay codes.
3. The method in claim 2 , wherein the pair of pseudo complementary generalized codes are constructed using complementary constituent Golay codes.
4. The method in claim 1 , wherein the modulator is configured for sending multiple bits per symbol using the plurality of pseudo-complementary generalized Golay codes.
5. The method in claim 1 , wherein modulating a portion of a data stream includes dividing the portion of the data stream into blocks of K bits and encoding each of said blocks into one of the pseudo-complementary generalized Golay codes multiplied by a constellation point.
6. The method in claim 5 , wherein the constellation point is selected from the group consisting of phase shift keying constellation, quadrature amplitude modulation constellation, and combinations thereof.
7. A method for communication, comprising:
receiving a data stream having at least a portion modulated using a plurality of pseudo-complementary generalized Golay codes; and
demodulating the modulated portion with a generalized Golay correlator that employs pseudo-complementary generalized Golay codes constructed by concatenating a plurality of different-length binary complementary Golay codes wherein each of the pseudo-complementary generalized Golay codes has a length that differs from any binary complementary Golay code.
8. The method in claim 7 , wherein the generalized Golay correlator comprises a plurality of efficient Golay correlators.
9. The method in claim 7 , wherein the outputs of the generalized Golay correlator are used to decode the encoded bits of the data stream.
10. The method in claim 7 , wherein the generalized Golay correlator is a serial generalized Golay correlator.
11. The method in claim 7 , wherein the generalized Golay correlator is a parallel generalized Golay correlator.
12. An apparatus for communications, comprising:
a generator for generating a plurality of pseudo-complementary generalized Golay codes by concatenating a plurality of different-length binary complementary Golay codes wherein each of the plurality of pseudo-complementary generalized Golay codes has a length that differs from any binary complementary Golay code; and
a modulator for modulating at least a portion of a data stream using the plurality of pseudo-complementary generalized Golay codes.
13. The apparatus in claim 12 , wherein the plurality of pseudo-complementary generalized Golay codes comprises a pair of pseudo complementary generalized Golay codes.
14. The apparatus in claim 13 , wherein the pair of pseudo complementary generalized codes are constructed using complementary constituent Golay codes.
15. The apparatus in claim 12 , wherein the modulator is configured for sending multiple bits per symbol using the plurality of pseudo-complementary generalized Golay codes.
16. The apparatus in claim 12 , wherein modulating a portion of a data stream includes dividing the portion of the data stream into blocks of K bits and encoding each of said blocks into one of the pseudo-complementary generalized Golay codes multiplied by a constellation point.
17. The apparatus in claim 16 , wherein the constellation point is selected from the group consisting of phase shift keying constellation, quadrature amplitude modulation constellation, and combinations thereof.
18. An apparatus for communications, comprising:
a receiver for receiving a data stream having at least a portion modulated using a plurality of pseudo-complementary generalized Golay codes; and
a demodulator for demodulating the modulated portion with a generalized Golay correlator that employs pseudo-complementary generalized Golay codes constructed by concatenating a plurality of different-length binary complementary Golay codes wherein each of the pseudo-complementary generalized Golay codes has a length that differs from any binary complementary Golay code.
19. The apparatus in claim 18 , wherein the generalized Golay correlator comprises a plurality of efficient Golay correlators.
20. The apparatus in claim 18 , wherein the outputs of the generalized Golay correlator are used to decode the encoded bits of the data stream.
21. The apparatus in claim 18 , wherein the generalized Golay correlator is a serial generalized Golay correlator.
22. The apparatus in claim 18 , wherein the generalized Golay correlator is a parallel generalized Golay correlator.