Predictive vector quantization with input control circuit

摘要

In a vector quantizer device including an input vector quantizer (11) for a current input vector of an input vector sequence to produce a first quantized vector and a predicted vector quantizer (13) responsive to the input vector sequence for quantizing into a second predicted vector a predicted vector predictive of the current input vector with quantization, a predicting unit (37) produces the predicted vector in response to a predetermined number of output vectors including such first and second quantized vectors. Responsive to a prediction error vector between the current input and the predicted vectors, a control circuat (35) controls, at a time, input and output switches (31, 33) to supply the input vector sequence to only one selected quantizer of the input and the predicted vector quantizers and to produce as one of the output vectors one of the first and the second quantized vectors that is produced by the selected quantizer. The first and the second quantized vectors are produced as two of the output vectors when the prediction error vector is greater and smaller than a threshold value, respectively. <MATH>