Digital demodulator for amplitude or angle modulation using truncated

Abstract

A digital demodulator for demodulating baseband signals in a radio receiver. The demodulator includes a digital signal processing module for forming a mathematical series adapted for generating demodulation functions. The selection of coefficients for this series is controlled to provide specific demodulation functions as required for the demodulation of different kinds of signals such as amplitude modulated or angle modulated signals using one computational block or element. When demodulating amplitude modulated signals, the coefficients used in the mathematical series provide an approximation to the square root function. When demodulating phase or frequency modulated signals, the coefficients used provide an approximation to the arctangent function.