Exploring the Limitations of Phase Modulation in Practical Broadcasting

In summary, PM (phase modulation) transmitters are not commonly used for practical broadcasting due to the complex receiver required to deal with phase ambiguity and difficulty in distinguishing high level modulations. Additionally, multipath propagation can also cause phase related issues. PM is more suited for transmitting discreet phase states for digital data, with the most widely used modulation being QAM (quadrature amplitude modulation) for applications such as cable modem, satellite TV, and digital cable TV.
  • #1
saikatmajumder
Hello,
I want to know why phase modulation (PM) transmitters are not used for practical broadcasting, though its almost similar partner frequency modulation (FM) is used widely for broadcasting.
 
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  • #2
PM has been used in two-way radios for many years. Probably not anymore, but at one time was common.
 
  • #3
re

pm is more suited to transmit discreet phase states usually for digital data. Probably the most widely used modulation is QAM (quadriture amplitude modulation) which combines amplitude and phase shift keying to trasmit large amonts of data very quickly. The most common application is the cable modem, satellite tv, and digital cable tv.
 
  • #4
Response to Phase Modulation by Jha,Shambhu Nath

saikatmajumder said:
Hello,
I want to know why phase modulation (PM) transmitters are not used for practical broadcasting, though its almost similar partner frequency modulation (FM) is used widely for broadcasting.
:zzz:

hi,

I am Telecom Engineer at Nepal Telecom,Nepal.
Response to above query:

The phase modulation necessitates complex receiver due to phase ambiguity in comparision to frequency modulation.So it is not preferred for transmmiting broadcasting.

Thanks
Jha,Shambhu Nath
e_shambhu@rediffmail.com
 
  • #5
It should be, Mr. Shambhu

Thank you Mr. Shambhu,
I think it should be the reason. What I think is that if modulating signal amplitude is increased beyond certain amplitude, phase will exceed pi or 2*pi and it will be difficult to distinguish it. Thus high level modulation will be somewhat difficult.
Moreover I think multipath propagation will bring a lot of phase related problems.

its
saikat m
ec04m016@nitc.ac.in
 

Related to Exploring the Limitations of Phase Modulation in Practical Broadcasting

1. Why is phase modulation not used as frequently as other modulation techniques?

Phase modulation is not as commonly used as other modulation techniques, such as amplitude or frequency modulation, because it is more complex and requires more precise equipment to implement. Additionally, phase modulation can be more susceptible to interference and noise, making it less reliable for certain applications.

2. What are the main advantages of phase modulation?

The main advantage of phase modulation is its ability to carry a larger amount of information compared to other modulation techniques. This is because it encodes information in the phase of the signal, rather than its amplitude or frequency. Phase modulation is also less affected by amplitude variations, making it a more robust option in certain environments.

3. Is phase modulation used in any communication systems?

Yes, phase modulation is used in various communication systems, including satellite and digital radio communications. It is also commonly used in modern digital communication technologies, such as Bluetooth and Wi-Fi.

4. How does phase modulation differ from frequency modulation?

Phase modulation and frequency modulation are both forms of angle modulation, where the information is encoded in the variation of a specific parameter of the carrier wave. However, in frequency modulation, the frequency of the carrier wave is varied, while in phase modulation, the phase of the carrier wave is varied.

5. Can phase modulation be used for analog signals?

Yes, phase modulation can be used for both analog and digital signals. In analog phase modulation, the phase of the carrier wave is varied in proportion to the amplitude of the input signal, resulting in a continuous change in the phase of the wave. In digital phase modulation, the phase of the wave is varied in discrete steps, depending on the digital data being transmitted.

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