Abstract: A method for displaying a plurality of error measures for an error-containing digitally modulated signal formed of a first and a second orthogonal component includes: determining for each digital value a value for an error-free version of the modulated signal; determining for each digital value a value for the error-containing version of the modulated signal; determining for each digital value a vector difference between the value for the error-containing version of the modulated signal and the respective value for the error-free version of the modulated signal; and displaying the vector differences on a two-dimensional display, each difference being displayed with respect to the respective value for the error-free version of the modulated signal, the display providing the plurality of error measures.

Abstract: A method for measuring amplifier gain compression in an OFDM signal includes measuring the signal as a function of time to provide an observed time magnitude, demodulating the OFDM signal to determine an estimate of the ideal signal constellation points, performing an inverse FFT on the estimate of the ideal constellation points to produce an estimated ideal time magnitude, comparing the observed time magnitude to the estimated ideal time magnitude to provide a measure of amplifier gain compression.