Cross product enhanced harmonic transposition

A system for generating a high frequency component of an audio signal from a low frequency component of the audio signal, comprising:

• an analysis filter bank providing a plurality of analysis subband signals of the low frequency component of the audio signal;
• a non-linear processing unit to generate a synthesis subband signal with a synthesis frequency by multiplying the phase of a first and a second of the plurality of analysis subband signals and by combining the phase-multiplied analysis subband signals;
• and
• a synthesis filter bank for generating the high frequency component of the audio signal from the synthesis subband signal;
• wherein
• the non-linear processing unit comprises a multiple-input-single-output unit of a first and second transposition order generating the synthesis subband signal from the first and the second analysis subband signals with a first analysis frequency ω and a second analysis frequency (ω+Ω), respectively;
• the first analysis subband signal is phase-multiplied by the first transposition order (T-r);
• the second analysis subband signal is phase-multiplied by the second transposition order r;
• T>1;
• 1≦r<T;
• and
• the synthesis frequency is (T−r)·ω+r·(ω+Ω).