Comtech EF Data CDM-760 - Manual (Page 398)

Appendix J Revision 2
CDM-760 Advanced High-Speed Trunking Modem MN-CDM760
J–20
The interfering carrier is the Tx Carrier from Local Modulator and the Desired Carrier is the
carrier from the distant end received by the local demodulator.
At the station transmitting C1:
CnC Ratio (in dB) = PowerC1 (in dBm) – PowerC2 (in dBm)
Eb/No
Ratio of Energy per bit (Eb) to Noise density (No) (unit in dB):
Eb/No = C/No – 10log(DR) (where DR is the Data Rate)
Eb/No = Es/No – 10log(SE) (where SE is Spectral Efficiency)
Es/No
Ratio of Energy per symbol (Es) to Noise density (No) (unit in dB):
Es/No = C/No – 10log(SR) (where SR is the Symbol Rate)
Es/No = Eb/No + 10
log
(SE) (where SE is Spectral Efficiency)
C/N
Ratio of Carrier Power (C) to Noise (N) (unit in dB):
Equivalent to Es/No when calculated in the Symbol Rate
bandwidth.
C/No
Ratio of Carrier Power (C) to Noise Density (N
o
) (unit in dBHz)
Co+No/No
Ratio of Carrier Density (C
o
) + Noise (N
o
) to Noise Density (N
o
) (unit in dB):
C/N = C/N
o
– 10
log
(B) [where B is bandwidth in Hz]
E
b
/N
o
= C/N
o
– 10
log
(DR) [where DR is data rate in bits/sec]
= C/N + 10
log
(B) – 10
log
(DR)
= C/N – 10
log
(SE) (where SE is Spectral Efficiency)
E
b
/N
o
= 10
log
(10 ((Co+No/No)/10) – 1) – 10
log
(SE) (where SE is Spectral Efficiency)
[Note: Spectral Efficiency is in bps / Hz]