Multisine excitation for ACPR measurements

We use a simulator to compare adjacent-channel power ratio (ACPR) measurements of a nonlinear device excited with various multisine signals to ACPR measurements of the same device excited with pseudorandom digital modulation. We examine four common types of multisine excitation, each with identical numbers of tones, tone-spacings, and nominal power levels, but with different magnitude and phase relationships between tones. We show that use of some common multisines may result in significant overestimation of the actual ACPR from the digitally modulated nonlinear device.