Patent ID: 6275523
Filing Date: 2001-08-14
Classification: H04B,H04L

Abstract:
A method for performing in-service nonlinear error measurements on a digitally modulated radio frequency signal wherein signal samples are generated representative of the received digitally modulated radio frequency signal and reference signal samples are generated from estimated transmitted digital symbols of the digital modulation that are time-aligned with the signal samples representative of the received signal, and magnitude values are calculated from the reference signal samples comprising the steps of:a) generating nonlinear error values using the reference signal samples and the received signal samples;b) removing largely deviated nonlinear error values that exceed boundary values in error versus magnitude space;c) deriving coefficients for a nonlinear behavior function using the nonlinear error values within the boundary values; andd) estimating nonlinear error values as a function of the reference magnitude values using the derived coefficients in the nonlinear behavior function.