VCM Example:
Minimize Bandwidth
•
The network now has an average BW of 10.7 Msps
(14.41Mhz). Each zone gets an unequal share of the
BW.
46
Site A Site B Site C
Modulation / Coding 16-APSK 2/3 8-PSK 2/3 QPSK 4/5
Spectral Efficiency 2.64 bits/Hz 1.98 bits/Hz 1.59 bits/Hz
Es/No Required >= 9.0 dB 6.6 –
9.0 dB 4.7 –
6.6 dB
User Data Rate 21.2 Mbps 21.2 Mbps 21.2 Mbps
Symbol Rate required
= BW Required w/o
spacing
8.0 Msps
(10.8 Mhz)
10.7 Msps
(14.4 Mhz)
13.33 Msps
(18 Mhz)
