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Fig. 3.16 is a typical CCDF measurement graph. In the figure, the horizontal coordinate of the curve represents the
probability in %; the vertical coordinate represents the peak-to-average power ratio in dB. The pink curve Ref represents
the reference curve. The Ref curve can be saved as the reference curve by selecting “CHA” or “CHB” below the [Ref
Line] soft menu. The blue curve Gauss refers to the Gauss curve which represents the probability density distribution
function of Gauss noise.
Fig. 3.16 CCDF Display
The yellow trace is the CCDF graph of the measured signal. Mark 1 and Mark 2 indicate the corresponding probability
of the current peak-to-average ratio as shown in Fig. 3.15. Mark 1 has a horizontal coordinate of 2 dB and its probability
of occurrence is 50.00%, which means the probability that the peak-to-average ratio is greater than 2 dB is 50.00%;
similarly, Mark 2 means the probability that the peak-to-average ratio is greater than 3.5 dB is 10.00n% (“n” stands for
10-9, which means the probability of occurrence is infinitely small). Based on the definition of CCDF, the number of
sampling points that are greater than the peak power level is 0, so the maximum peak-to-average ratio occurs at 0%.
3.10.2 Operation of CCDF power statistic trace
In this section, the detailed operation steps of CCDF waveform display is introduced. Take Channel A as an example.
The detailed operational description is as follows:
1) After properly connecting the peak power sensor to the instrument with the accompanied 12-core cable, power on
the instrument for start.
2) Press [Cal]>[Channel A] >[Zero+Cal] to start the automatic calibration program of Channel A;
3) Press [Back]for several times, press [Preset] , select “Default”, and press [Ok] to exit from the preset interface;
4) Press [Menu]>[Display]>[Disp Type]>[Next Page] >[Stat Trace], and the system will enter the CCDF statistic
measurement window;
5) Scale setting: Press [Scale Set] >[X scale], enter 1.2 through the numeric key, set the X scale to 1.2 dB/div; press
[Max Prob], and set the maximum percentage scale in the Y-direction; press [Scale Set] >[100%], [Decades], enter
