Comtech EF Data CDM-550T - Manual (Page 145)

Appendix B. E
b
/N
o
MEASUREMENT
Although the CDM-550T calculates and displays the value of receive E
b
/N
0
on the front panel of
the unit, it is sometimes useful to measure the value using a spectrum analyzer, if one is available.
The idea is to accurately measure the value of (C+N)/N, (Carrier density + Noise density/Noise
density). This is accomplished by tuning the center frequency of the Spectrum analyzer to the signal
of interest, and measuring the difference between the peak spectral density of the signal (the flat
part of the spectrum shown) and the noise density.
B–1