Patent ID: 8040935

Claim:
A spreading and modulation method, comprising a step for spreading an original signal with spread spectrum codes and a step for modulating said spread data in a QPSK format, characterized in that: said spreading step comprises: generating spread spectrum code chips by modulating an arbitrary pair of Golay complementary codes onto two orthogonal channels to obtain a complex complementary code as said spread spectrum code chips; and spreading said original signal with said complex complementary code; said complex complementary code comprises a real component and an imaginary component, which are orthogonal to each other, as an in-phase spread spectrum code and a quadrature spread spectrum code respectively; and in the step of spreading said original signal with said complex complementary code, spreading an in-phase sub-channel of said original signal with said in-phase spread spectrum code and spreading a quadrature sub-channel of said original signal with said quadrature spread spectrum code.