Predictive signal coding with partitioned quantization

Claim 1

A predictive signal .[.communication.]. .Iadd.processing .Iaddend.system comprising means for analyzing an input signal in successive time intervals to generate a set of prediction signals for each interval; means jointly responsive to the input signal and the interval prediction signals for producing a predictive residual signal; means for generating a quantized signal corresponding to said predictive residual signal; and means for encoding said quantized signal; characterized in that said quantized signal generating means (160, 164, 166, 111, 168) comprises means (160) responsive to .[.said interval prediction signals,.]. said predictive residual signal and said quantized signal for producing an adaptively varying threshold level signal, means (164) responsive to said adaptively varying threshold level signal for dividing said predictive residual signal into a first distinct portion below said threshold level signal and a second distinct portion at and above said threshold level signal, and means (111) responsive to said first and second distinct portions for producing first and second sets respectively of quantized signals.

Claim 5

A method for processing a predictive type signal .[.in a communication arragement.]. comprising the steps of: analyzing an input signal in successive time intervals to generate a set of prediction signals for each interval; producing a predictive residual signal jointly responsive to said input signal and the interval prediction signals; generating a quantized signal corresponding to the predictive residual signal; and encoding the quantized signal; characterized in that the generation of said quantized signal comprises producing an adaptively varying threshold level signal responsive to .[.said interval prediction signals,.]. said predictive residual signal and said quantized signal, dividing said predictive residual signal into a first distinct portion below said threshold level signal and a second distinct portion at and above said threshold level signal responsive to said adaptively varying threshold level signal, and producing first and second sets of quantized signals responsive to said first and second distinct portions respectively.

Claim 6

A method for processing a predictive type signal .[.in a communication arragement.]. comprising the steps of: analyzing an input signal in successive time intervals to generate a set of prediction signals for each interval; producing a predictive residual signal jointly responsive to said input signal and the interval prediction signals; generating a quantized signal corresponding to the predictive residual signal; and encoding the quantized signal; characterized in that the generation of said quantized signal comprises producing an adaptively varying threshold level signal responsive to .[.said interval prediction signals,.]. said predictive residual signal and said quantized signal, dividing said predictive residual signal into a first distinct portion below said threshold level signal and a second distinct portion at and above said threshold level signal responsive to said adaptively varying threshold level signal, and producing first and second sets of quantized signals responsive to said first and second distinct portions respectively.

Claim 7

A method of processing a predictive type signal .[.in a communication system.]. according to claim .[.8.]. .Iadd.4 characterized in that said input signal is a speech signal.