Explain Block Diagram of Communication system

   communication system 

The word "communication" means exchange of information. from ancient times human being were using this technology to convey one's thoughts , ideas and feelings .  the rapid development in  electronic field have the change the mode of communication from human messengers and birds to radio , tv , telephone ,mobile , WI-FI , LI-FI , internet of things and so on . the application domain of communication system is so developed and have became so common that we often take it for granted the powerful technologies that allows us to communicate nearly instantaneously . it is almost impossible to imagine our society without communication system . the rapid development in communication system is playing a vital role in globalization thus stimulating a bursting growth of complex social and economic activities . The growth of communication industry has no end since people had a natural desire and need to communicate rapidly to any one at any time and at any location . Number of users utilizing communication system are increasing day- by- day . To accommodate them and to fulfill the above three requirement , continuous updation in communicating devices and technologies is required in the field of communication .

Elements of communication system :)

The communication system convey information from one place to another place . Thus system must have information source at ane end and destination at the other end. Source generates the information (a human voice , video, digital data from computer etc . ) 

Basic blocks of communication system : 

1:  source

2: Transmitter 

3: Transmission channel

4: Receiver 5: User 

6: Noise

BLOCK  DIAGRAM OF COMMUNICATION SYSTEM :)

The role of  each block in information transmission :

1. SOURCE: 

The source generates the information . The information can be audio, video, digital data , text etc.  depending upon the type of information signal ,communication system , application differs . e.g. radio communication transmit the audio signal, TV communication transmit the audio and video signal , mobile communication has audio ,video, text, digital data etc.

* further the type of information signal can be analog or digital.

 

2. TRANSMITTER:

The information sent via the communication link originates at the source. Since information can have various forms , it may not be suitable for transmission at it is. The job of transmitter is to process the information of to produce a signal suited for the transmission through the transmission channel. processing may involve amplification, signal conversion, modulation, encoding , encryption , multiplexing etc. The last element of transmitter is antenna. Antenna is responsible for conversion of electrical signals into electromagnetic signals and linked to transmission channel.

3. TRANSMISSIONN CHANNEL: 

   This is the physical transmission medium over which the information is sent. During travel through channel, some amount of transmission loss or attenuation is observed. So the information signal strength decrease with increasing distance. Depending upon transmission channel, communication system is divided in two types:

3.1:wired communication  :

3.1.1: co-axial cable :

co-axial cable has two conductors arranged in concentric manner and are separated by an insulating material. co-axial cable widely used for long-distance telephone communication but now have largely been replaced by by optic fiber cable because of several advantages.

3.1.2: Optic fiber cable :

optic fiber cable transmit the information in terms of light waves. it consist of core and clad material having different refractive indices. The light travel through the optical -phenomenon - total internal reflection. 

Advantages of optical fiber cable :

a) Immunity to crosstalk.

b) Immunity  to static interference. 

c) Durability and reliability. 

d) Smaller size and light weight.

3.2: Wireless communication :

In wireless transmission, information is sent and received as electromagnetic waves from one point to another point through the atmosphere or free space. Different layer of the atmosphere are used for propagating electromagnetic waves. the layer selection is dependent upon frequency of information and range of coverage.

4. RECEIVER :

Receiver is the block which accept the transmitted and propagated signal through it's antenna and convert it back into original information. It performs many operation on the received signal to extracts original information. The operation includes amplification , demodulation, decoding, to reverse signal processing performed at the transmitter, decryption, etc. 

5. USER :

The user is a recipient of the information.

6. NOISE:

Noise is a unwanted electrical signal superimposing on original information signal.

This superimposing of noise signal either partially corrupts  or totally  modifies the original information. Identification of the  information at the receiver depend upon the amount of noise accompanied by the information during the process of communication. in the absence of noise identification of information at the receiver is the perfect.