20-07-2013, 02:46 PM
TIME DIVISION MULTIPLEXING
Aim:
To design and demonstrate the working of time division (for) multiplexing for Pulse Amplitude Modulated
Signals using discreet components.
Components Required:
Resisters 22K-2, 1k- 2, transistor SL 00 – 2, IC 4051-2
THEORY:
Time-division multiplexing (TDM) is a type of digital or (rarely) analog multiplexing in which two or
more signals or bit streams are transferred apparently simultaneously as sub-channels in one communication channel, but
are physically taking turns on the channel. The time domain is divided into several recurrent timeslots of fixed length,
one for each sub-channel. A sample byte or data block of sub-channel 1 is transmitted during timeslot 1, sub-channel 2
during timeslot 2, etc. One TDM frame consists of one timeslot per sub-channel. After the last sub-channel the cycle
starts all over again with a new frame, starting with the second sample, byte or data block from sub-channel 1, etc.
PROCEDURE:-
1. Rig up the circuit with input of 1 KHz Square wave of 5V amplitude as per the circuit diagram make
the connections carefully.
2. Signal generator inputs 5V, 3V & 200Hz frequency is provided to collectors of T1 & T2 respectively.
3. sampled signals M0 & M1 is obtained at the emitter of T1 & T2, which is provided as inputs to pin 13
and pin 14 of IC -4051 Mux circuit
4. TDM output is fed as input to Pin 3 of Demux circuit. The signals M0 and M1 are retrieved back at pin
13 and Pin 14.