Method and arrangements for coding audio signals

An audio signal encoder, comprising:

• an excitation signal generator that comprises:
• an adaptive code book that temporally continuously stores sampled excitation values being already generated,
• a noise generator that continuously generates random sampled values,
• a selection unit that selects a sequence of the sampled excitation values based on an audio basic frequency parameter that predetermines a time interval between a time of the sequence to be selected and current time, and
• a mixing unit coupled to the noise generator and the adaptive code book that generates an excitation signal by mixing the selected sequence of the sampled excitation values with a random sequence of the random sampled values containing random sampled values of the noise generator at the current time and outputs the excitation signal;
• an audio synthesis filter to be excited by the excitation signal that generates a synthetic audio signal;
• and
• a comparison unit that aligns the synthetic audio signal with an audio signal to be transmitted;
• and
• wherein the noise generator is coupled to the mixing unit by an interpolator for inserting intermediate sampled values between the random sampled values.