Pulse Amplitude Modulation and
Time Division Multiplexing
Indra Bhushan 2010EE50548
Umang Gupta 2010EE50564
Vivek Mangal 2010EE50566
PAM and Time Division Multiplexing
1. To generate time division multiplexed PAM signal.
2. Channel selection from PAM-TDM signal by demultiplexing.
By Nyquist theorem we know that a signal of Bandwidth W can be regenerated
completely from its time-domain samples that are sampled 1/2w. Hence only this
samples need to be transmitted to transmit the signal. A channel normally has higher
BW than signal and hence most of the spectrum gets wasted. So we can multiplex two
signals in a single time period so that they do not affect each other while transmitting.
This can be achieved by sampling at slightly different times. This actually helps in
utilising the channel in efficient way.
The message can be reconstructed by taking back those samples, or by using a switch
that switches every T sec and hence taking out only the required signal.
Here, we did only demultiplexing of the signal.
Signals can be de-multiplexed by having knowledge about the sampling clock. Also
differnet signals can be sent simultaneously this way.