DECODING METHOD OF ADAPTABILITY FORECASTING TYPE DIFFERENTIAL PULSE CODE AND ITS UNIT

摘要

PURPOSE:To warrant the stability completely even with transmission error taken place with a simple circuit and to enable to remarkably improve the S/N, by providing quantizer and predictor. CONSTITUTION:The coder at the transmission section quantizes amd delivers the difference between the signal xj and the forecast value xj' at the quantizer 20, the output ej' is inputted to the predictor 50, which obtains the predict value xj' at time j by equation (8). (Where; Bij is the coefficient sequentially corrected, Ej' is forecast residual signal) In the reception section, the forecast sognal ej' quantized is inputted to the forecast unit 150, which outputs the forecast value xj' from equation (8), and the adder 160 outputs the reproduction signal xj'' by adding the forecast residual signal ej' to the forecast value xj'. Thus, by selecting the number of dimension as around 7, and setting practical delta (positive and sufficiently smaller value than 1, and used to cancel the effect of transmission error), the degree of improvement of S/N to PCM system can be taken more than 10dB at audio signal input.