CONVERSION OF A PCM SIGNAL INTO AN UPWM SIGNAL

摘要

PURPOSE: A method for conversing a PCM(pulse code modulated) signal into an UPWM(uniform pulse width modulated) signal is provided to correct a non-linearity and a noise. CONSTITUTION: To correct the non-linearity and noise in the conversion of a PCM signal into an UPWM signal, a model is made of the known non-linearity in the conversion by dividing a plurality of non-linearity components in the model, where the polynomial components are separately weighted with filter coefficients. The model is used as a basis for the construction of a filter (10) of the Hammerstein type whose non-linear parts consist of a division of the PCM signal into a plurality of powers, and whose linear parts are approximated by means of the model made. With the circuit of the invention it is now possible to construct a purely digital amplifier which has a great efficiency, low weight, etc.