Patent ID: 7313193

Claim:
A multi-tone signal communications method for communicating information using N tones, where N is a positive integer greater than one, the method comprising: generating N analog signals, each one of the N analog signals corresponding to a different one of the N tones, wherein each of the N analog signals includes a periodic signal representing a symbol to be transmitted during a symbol transmission period; separately generating N signal prefixes, one signal prefix being generated for each one of the N analog signals from the one of the N periodic signals included in the corresponding one of the N analog signals, each of the N signal prefixes including multiple parts and wherein the step of separately generating N signal prefixes includes, for each one of the N analog signals: i) generating a first cyclic prefix part from the included periodic signal representing the current symbol; and ii) generating a second prefix part from the included periodic signal representing the preceding symbol and from the first cyclic prefix part; and transmitting the N analog signals into a communications channel using M antennas, where M is an integer and where 1<M<N.