Method and apparatus for noise burst detection in a signal processor

In an adaptive differential pulse code modulation (ADPCM) decoder substantially complying with CCITT Recommendation G.726-1990 for at least one data rate thereof, a method for noise burst detection comprising the steps of:

• receiving an input signal I(k) at an input of the ADPCM decoder;
• forming a signal d.sub.ml (k) in an adaptation speed control block of the ADPCM decoder;
• comparing said signal d.sub.ml (k) to a predetermined energy threshold;
• and
• providing a noise indication if said signal d.sub.ml (k) exceeds said predetermined energy threshold.

A signal processor with noise burst detection, comprising:

• an inverse adaptive quantizer for providing a quantized difference signal d.sub.q (k) in response to an input signal I(k) of the signal processor;
• noise detection means coupled to said inverse adaptive quantizer, for receiving said signal d.sub.q (k), a predetermined number, and a product of a noise threshold and said predetermined number, for calculating a total energy estimate of said signal d.sub.q (k) sampled once for each of said predetermined number of samples of a plurality of samples, and for providing a noise indication in response to said total energy estimate exceeding said product of said noise threshold and said predetermined number;
• and
• output means coupled to said inverse adaptive quantizer, for providing an output signal of the signal processor s.sub.d (k) in response to said quantized difference signal d.sub.q (k);
• said inverse adaptive quantizer and said output means substantially forming a CCITT Recommendation G.726-1990 adaptive differential pulse code modulation (ADPCM) decoder for at least one data rate thereof.

A signal processor with noise burst detection, comprising:

• adaptive pulse code modulation (ADPCM) signal processing means for receiving an input signal I(k) and for providing an output signal s.sub.d (k);
• said ADPCM signal processing means including an adaptation speed control block having an output for providing an output signal d.sub.ml (k);
• and
• noise detection means coupled to said adaptation speed control block, for receiving said signal d.sub.ml (k) and a predetermined energy threshold, for comparing said signal d.sub.ml (k) to said predetermined energy threshold, and for providing a noise indication in response to said signal d.sub.ml (k) exceeding said predetermined energy threshold;
• said ADPCM signal processing means substantially forming a CCITT Recommendation G.726-1990 ADPCM decoder for at least one data rate thereof.