Comtech EF Data SLM-5650A User Manual
Page 320
SLM5650A_CDM625 Satellite Modem
Revision 8
DoubleTalk
Carrier-in-Carrier Option
MN-SLM5650A
15–22
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 + 10log(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
– 10log(B) [where B is bandwidth in Hz]
E
b
/N
o
= C/N
o
– 10log(DR) [where DR is data rate in bits/sec]
= C/N + 10log(B) – 10log(DR)
= C/N – 10log(SE) [where SE is Spectral Efficiency]
E
b
/N
o
= 10log (10
((Co+No/No)/10)
– 1) – 10log(SE) [where SE is Spectral Efficiency]
[
Note: Spectral Efficiency is in bps / Hz]
Power Spectral Density (PSD)
Power Spectral Density (PSD) is the signal power per unit bandwidth: dBW / Hz or dBm /
Hz
For example: Signal power = 20 dBm
Signal bandwidth = 5 MHz
PSD = 20 – 10 *log (5,000,000) = -46.99 dBm / Hz