We have started a new series of posts - How To's of Monitoring - in which we provide descriptions and practical examples of monitoring data and plots. We start with CCDF - Complementary Cumulative Distribution Function curves.
Digitally modulated signals are noise-like signals in the Power vs Time domain and require specific statistical tools to extract and analyze and present the signal amplitude distribution over time. The purpose of CCDF is to represent how much time the signal spends at or above a given power level. As a part of AVQ1020 - ActiveCore RF Layer Monitoring Receiver, CCDF plots can be used to analyze the impact of non-linearity of the amplification system. Monitoring the output of a transmitter, CCDF demonstrates the compression of the amplified signal measured at the transmitter output.
AVQ1020 plots two CCDF curves - reference (marked as Ideal CCDF) and actually measured. The reference curve represents the power distribution of an ideal signal measured over a long period of time. The further measured curve from the reference, the more signal is compressed by the transmitter system.
Samples of CCDF

