1. TIME DIVISON MULTIPLEXING
NAME : MR ABHISHEK KUMAR
REG.ID: 10114008
SEM:FIFTH
STREAM: IT
BTECH(2014-2018)
IIIT KALYANI
EMAIL ID: abhishekseth.3344@gmail.com
2. Why we need multiplexing in
communication system ?
We know that a network
always have limited
amount of bandwidth.
9/6/2018
So, for proper utilization of
bandwidth to achieve a
specific goal we go for
multiplexing.
Like Divide bandwidth of low
level channel to high level
channel
MULTIPLEXING
3. MULTIPLEXING TYPES:
FREQUENCY DIVISON MULTIPLEXING
• Analog Technique
• Channel created based on Frequencies
• Application AM & FM Radio broadcasting
WAVELENTH DIVISON MULTIPLEXING
• Uses high data rate capability of
fibre optic cable
• Channel are created based on
Wavelengths
• Application SONET
4. WHY WE NEED TIME
DIVISON MULTIPLEXING ?
This multiplexing allow to transmit
a signal at high BANDWIDTH through
Channel But not Frequency Division
multiplexing .
TDM is used for multiplexing of Digital
Signal.
TIME DIVISON MULTIPLEXING
Each connection occupies a
portion of time.
In this Figure each signal
occupies ¼ th of shared link to
transfer data.
Under the same communication channel
sample of many signals can be transmitted
and recover the receiving end. This technique
Is knows a TDM.
5. Lets See what
happens inside
TDM system .
LPF1
LPF2
LPF1
LPF2
LPF3
EncoderQuantizer Decoder
. .
LPF3
Commutator
Decommutator
Channel
t1
t2
t3
t1
t2
t3
m1(t)
m3(t)
m2(t)
m1(t)
m2(t)
m3(t)
t1 t2 t3 ts+t1 ts+t2 ts+t3
Ts=time taken by commutator in one rotation
ts
Commutator:- it is a rotating switch. rotate in anticlockwise.
Decommutator:- it is a rotating switch. rotate in clockwise.
Quantizer: purpose of quantizer is rounding up to a quantization level.
Encoder: generate unique binary code.
LPF: low pass filter is used for limiting the bandwidth. Commutator O/P
t1
m1(t)