Pulse amplitude modulation

pulse amplitude modulation

1. SUBMITTED BY 1 st BATCH STUDENTS III – B.Sc, PHYSICS . P ULSE A MPLITUDE M ODULATION

2. DEFINITION OF PAM P ulse A mplitude M odulation (PAM) is the transmission of data by varying the amplitude s ( voltage or power levels) of the individual pulses in a regularly timed sequence of electrical or electromagnetic pulses. The number of possible pulse amplitudes can be infinite (in the case of analog PAM), but it is usually some power of two so that the resulting outputsignal can be digital .

3. BLOCK DIAGRAM OF PAM

4. TYPES OF PAM There are two types of pulse amplitude modulation: Single polarity PAM: In this a suitable fixed DC bias is added to the signal to ensure that all the pulses are positive. Double polarity PAM: In this the pulses are both positive and negative .

5. GENERATION OF PAM Pulse amplitude modulation is the basic form of pulse modulation in which the signal is sampled at regular and each sample is made proportional to the amplitude of the modulating signal at the sampling instant. The Fig shows the generation of PAM signal from the sampler which has two inputs i.e. modulating signal and sampling signal or carrier pulse.

6. Thus the amplitude of the signal is proportional to the modulating signal through which information is carried. This is Pulse amplitude modulation signal. Pulse Modulation may be used to transmitting analog information, such as continuous speech signal or data.

7. REFERENCES http://whatis.techtarget.com/definition/pulse-amplitude-modulation-PAM https://en.wikipedia.org/wiki/Pulse-amplitude_modulation http://www.ques10.com/p/11460/explain-generation-and-demodulation-of-pam-ppm-and/

8. THANK YOU