Noise

 

 

       Noise in communication systems refers to any unwanted or random interference that distorts the                transmitted signal, reducing the quality and accuracy of the received information. It can originate

       from external or internal sources and is a critical factor in system performance.

 

      Types of Noise

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     1.Thermal Noise:

        Caused by random motion of electrons in conductors. It is present in all electronic devices and is                proportional to temperature.

       

                                                 N=kTBN = kTBN=kTB

 

         where kkk is Boltzmann's constant,

         TTT is the absolute temperature, and

         BBB is the bandwidth.

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      2.Shot Noise:

         Results from the discrete nature of electric current, prominent in semiconductor devices.

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      3.Interference Noise:

         Caused by external sources like power lines, radio signals, or neighboring communication channels.

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      4.Impulse Noise:

         Consists of short-duration, high-intensity disturbances caused by events like lightning or switching

         in electrical circuits.

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      5.Environmental Noise:

         Includes sounds from natural phenomena, industrial machinery, or urban environments.

 

         Effects of Noise

        •Degrades signal quality.

        •Reduces the signal-to-noise ratio (SNR).

        •Causes errors in data transmission.

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          Noise Reduction Techniques

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          1.Filtering:

            Use of filters to block noise outside the desired frequency band.

 

          2.Shielding:

             Protecting equipment from external electromagnetic interference.

 

         3.Error Correction:

            Employing coding techniques to detect and correct errors.

 

         4.Modulation Techniques:

            Using robust modulation schemes like frequency modulation (FM) to minimize noise impact.

 

          Applications

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         Understanding and managing noise is essential in:

          •Communication systems.

          •Signal processing.

          •Wireless and wired networks.

 

        Noise is an inevitable challenge in any communication system, but effective techniques can

        minimize its impact on signal transmission and reception