# Frequency Division Multiplexing - Mastergroup 3 - Topic on telecomms

1. Apr 8, 2013

### Equilibrium

Frequency Division Multiplexing - "Mastergroup 3" - Topic on telecomms

1. The problem statement, all variables and given/known data
What is the frequency output of the mastergroup combining network for a signal of 552kHz to be translated using mastergroup 3?

2. Relevant equations
Mastergroup Spectrum:
For AT&T = 564 - 3084 kHz
For ITU-T = 812 - 2044 kHz
Mastergroup Bandwidth
For AT&T = 2.52 MHz
For ITU-T = 1.232 MHz
Mastergroup VoiceBand
For AT&T = 600 voicebands
For ITU-T = 500 voicebands

$f_{out}=f_{c}-f_{i}$

3. The attempt at a solution
The problem has already been solved by our instructor but i am having a problem understanding, Here is the solution posted:
For mastergroup 3,
$f_{c}=8848kHz$

$f_{out}=f_{c}-f_{i}$ (LSB - Lower SideBand)
$f_{out}=8848kHz-552kHz$
$f_{out}=8296kHz$

1. What i'm having trouble is how did he get 8848kHz,? I've already listed what mastergroup consist of but i don't know if it relates to getting that value.
2. Why did he let the frequency be translated to the lower side band?
Thanks

Last edited: Apr 8, 2013