Signal representing data, method and device for generating such signal and method and device for determining the represented data from such signal
A method and a device are described for generating a signal representing data. The method for generating a signal has a step of modulating a portion ( 1 P, 2 P) of the data using phase shift keying and spreading the modulated portion over the at least one frequency base band using at least one highly auto-correlated spread code sequence ( 1 C, 2 C) associated with the frequency base band. The method for further has a step of delaying, according to a delay determined using a remainder ( 1 R, 2 R) of the data (ID), the at least one spread code sequence ( 1 C, 2 C) by a time delay wherein the modulated portion ( 1 MP, 2 MP) is spread according the delayed spread code sequence ( 1 DC, 2 DC).
1. A method for generating a signal spread over at least one frequency base band, the signal representing data, the method comprising:
modulating a portion of the data using phase shift keying and spreading the modulated portion over the at least one frequency base band using at least one highly auto-correlated spread code sequence associated with the frequency base band, characterized by
delaying, according to a delay determined using a remainder of the data, wherein the portion of the data is complementary to the remainder of the data, the at least one spread code sequence by a time delay wherein the modulated portion is spread according to the delayed spread code sequence wherein at least one of the following holds:
(i) the signal comprises the portion modulated on the at least one baseband as one of an I component and a Q component according to offset quadrature phase shift keying and the signal comprises further data of which a portion is modulated on the at least one baseband as the other of the I component and the Q component, the other component being spread with a further spread code time sequence selected from a set of predetermined spread code sequences and delayed by a further delay determined according to a remainder of the further data, and
(ii) the signal comprises the portion modulated on different frequency base bands, wherein, for each frequency base band, a different spread code is used, and wherein the different spread codes differ not only by delays.
2. The method according to claim 1 , the data being Viterbi encoded.
3. A device for generating a signal spread over at least one frequency base band, the signal representing data, the device comprising:
means for modulating a portion of the data using phase shift keying and means for spreading the modulated portion over the at least one frequency base band using at least one highly auto-correlated spread code sequence associated with the frequency base band, characterized by
means for delaying, according to a delay determined using a remainder of the data, wherein the portion of the data is complementary to the remainder of the data, the at least one spread code sequence by a time delay wherein the modulated portion is spread according to the delayed spread code sequence wherein the device is configured such that at least one of the following holds
(i) the signal comprises the portion modulated on the at least one baseband as one of an I component and a Q component according to offset quadrature phase shift keying and the signal comprises further data of which a portion is modulated on the at least one baseband as the other of the I component and the Q component, the other component being spread with a further spread code time sequence selected from a set of predetermined spread code sequences wherein the predetermined spread code sequences differ not only by delays and delayed by a further delay determined according to a remainder of the further data, and
(ii) the signal comprises the portion modulated on different frequency base bands, wherein, for each frequency base band, a different spread code is used, and wherein the different spread codes differ not only by delays.
4. The device according to claim 3 , the data being Viterbi encoded.