System and Method for Correcting for Lost Data in a Digital Audio Signal

A method of correcting for missing audio data, the method comprising:

• copying frequency domain coefficients of a digital audio signal from a previous frame;
• using a processor, adaptively adding random noise coefficients to the copied frequency domain coefficients;
• scaling the random noise coefficients and the copied frequency domain coefficients to form recovered frequency domain coefficients, wherein scaling is controlled with a parameter representing a periodicity or harmonicity of a received digital audio signal;
• generating a high band time domain signal by inverse-transforming high band frequency domain coefficients of the recovered frequency domain coefficients;
• generating low band time domain signal;
• estimating an energy ratio between the high band and the low band from a last good frame;
• keeping the energy ratio for following frame-erased frames by applying an energy correction scaling gain to a high band signal, segment by segment in the time domain;
• and
• combining the low band signal and the high band signal to form a final output.

A system for receiving a digital audio signal, the system comprising:

• a processor;
• and
• a computer readable storage medium storing programming for execution by the processor, the programming including instructions to
• generate a high band time domain signal,
• generate low band time domain signal,
• estimate an energy ratio between the high band and the low band from a last good frame,
• keep the energy ratio for following frame-erased frames by applying an energy correction scaling gain to a high band signal segment by segment in the time domain, and
• combine the low band signal and the high band signal into a final output.