Patent ID: 7957256

Claim:
A method for modulating information bits over a radio frequency communication channel, comprising: allocating selected ones of a set of information bits into two or more groups of code bits, based on the two or more groups of code bits, choosing one of M modified orthogonal codes, each of the M modified orthogonal codes based on an orthogonal code and a complimentary code combination, and modulating, by a transmitter, the phase of a complex carrier signal in accordance with the chosen modified orthogonal code, wherein the chosen one of the M modified orthogonal codes is defined according to the expression: c={e j(Φ1+Φ2+Φ3+Φ4) , e j(Φ1+Φ3+Φ4) , e j(Φ1+Φ2+Φ4) , −e j(Φ1+Φ4) , e j(Φ1+Φ2+Φ3) , e j(Φ1+Φ3) , −e j(Φ1+Φ2) , e jΦ1}, where Φi correspond to phase angles of code bits associated with the ith group of code bits.