Bit error rate of a digitally modulated signal
Upper curve : Bit error rate versus C/N for a 128 QAM / 28 MBaud signal, in presence of non linearities and interferers. The noise power N is defined in the Nyquist bandwidth (28 MHz). C is the maximum power within the constellation of modulation states.
Lower curve : Theoretical bit error rate, without non-linearities and interferences.

Other examples : Fresnel plan Eye diagram Group delay of a feeder
Group delay of a filter
Interferences Multicarrier amplification Constellation Differential gain