Transform encoding/decoding of harmonic audio signals

A User Equipment (UE) comprising:

• radio circuitry configured to transmit radio signals;
• a microphone configured to generate an audio signal;
• and
• processing circuitry configured to adapt encoding of the audio signal for radio transmission in dependence on detecting whether the audio signal is a harmonic audio signal or a non-harmonic audio signal, and output an encoded audio signal to the radio circuitry for transmission as a radio signal;
• wherein the encoding of the audio signal includes digitizing the audio signal, generating frequency transform vectors corresponding to time domain segments of the digitized audio signal, and wherein the processor is configured to adapt the encoding by using a first encoding process in response to detecting that the audio signal is harmonic audio signal, the first encoding process comprising the processing circuitry encoding coefficients of the frequency transform vectors corresponding to spectral peaks of the audio signal, encoding coefficients of the frequency transform vectors that are outside of the spectral peaks but below a cutoff frequency, and, for coefficients of the frequency transform vectors that are outside of the spectral peaks and above the cutoff frequency, determining a noise floor gain to be used for noise filling at a decoder.