Patent ID: 7583582

Claim:
A method for modulating information bits over a radio frequency communication channel, comprising: grouping a number of information bits, based on the grouping, choosing one of M modified orthogonal codes that are produced by modifying an orthogonal code with a complementary code, and modulating, with a modulator, the phase of a complex carrier signal in accordance with the chosen modified orthogonal code, wherein the complementary code is determined according to the expression: c={e i(Φ1+Φ2+Φ3+Φ4) , e i(Φ1+Φ3+Φ4) , e i(Φ1+Φ2+Φ4) , −e i(Φ1+Φ4) , e i(Φ1+Φ2+Φ3) , e i(Φ1+Φ3) , −e i(Φ1+Φ2) , e iΦ1 }, where Φi correspond to phase angles of code bits.