Basic knowledge about Communication Engineering: A Bright Carrier Scope In Globally
The introductory tutorial on the analog and digital communication engineering and we will see some basic terminologies and basic block diagram of the communication engineering. So, in a very basic sense the communication is the exchange of information between the two points and in electronics point of view using the electronic gadgets and the devices the information can be exchanged between the two points which are far away from each other.
So, this exchange of information could be wired or the wireless. The communication could be point-to-point communication or point to multi-point or even it could be in the network also and many times this communication could be even the broadcast also where from one station the information is broadcasted. Such example is the FM transmission where a reduced station broadcasts the information at a particular frequency and anyone can tune the receiver to the particular frequency. The channel to receive the information and in fact using the gadgets we are sending and receiving the information every day like talking on a smart phone or sending a text massage to someone. So, through a basic block diagram of the communication system let us understand how the information is exchange between the two points.
Block diagram of communication system
In block diagram, the first block is the source itself from where the method signal is generated so this message could be voice email or the television signal. It could be even some data signal. If this message is not in electric form then using the transducer to converted into the electrical signal. The microphones, camera and the computer keyboard are the examples of the transducer. For exam using the microphone our voice can be converted into the electrical signal and using the camera the picture or the motion can be converted into the digital signal. After this transducer the electrical signal which we have is known as the input signal then after this transducer the next block is the transmitter so this transmitter modifies the input signal for the efficient transmission. This transmitter module also contains several subsystems like the modulator the analog to digital converter and the encoder and many times it also contains the amplifier system.
About communication engineering
Analog signal is sample at the regular intervals and then it is quantized and after the quantization using the analog to digital converter. Now it is converted into the digital form and later it can be encoded in a particular format using the encoder and usually for the efficient transmission the signal is modulated using the particular scheme. The modulation is the process where the property of the periodic signal like the amplitude phase or the frequency is altered according to the input signal. now when we talk about the transmitted signal then we need to know certain characteristic of this transmitted signal like whether it is analog or the digital signal what is the frequency of the signal if it contains multiple frequencies then what is the range of frequencies in the transmitted signal or in other way what is the bandwidth of the transmitted signal. If the signal is transmitted in the digital form then at which rate the data is transmitted or in other words what is the data rate or the bit-rate of the transmitted signal.
The important aspect is the power level of the signal because that will decide how long the signal can be transmitted over a particular medium faithfully. So these are the some of the aspects which are very important for the transmitted signal and one needs to see these aspects while designing the communication. The signal is sent over the particular channel. A channel is the medium over which the signal is transmitted over the certain distance so this channel could be a physical channel. These channels are optical fiber or coaxial cable.
The channel partly behaves like a filter and attenuates the different frequencies of the transmitted signal differently. When the transmitted signal passes through the channel and gets received. At the receiver gets attenuated as well as the distorted moreover. The noise also gets superimposed over the transmitted signal. If this is the transmitted signal at the transmitter end and at the receiver we may receive the attenuated as well as the distorted signal and by what amount the signal will get attenuated and the distorted will depend on the length of the channel.
So if the signal travels longer in a particular medium then the attenuation and the distortion of the signal will be more but the detector or the receiver should be able to recover the message signal from this distorted signal which is affected by noise in channel. Whether the detector is able to recover the signal or not it depends on the signal-to-noise ratio.
Signal to noise ratio
Signal to noise ratio is a very important parameter in the communication system. This parameter is the ratio of the signal power to the noise power. By increasing the signal power the signal-to-noise ratio can be improved and the signal can be transmitted over a longer distance faithfully. Now many times the signal needs to be transmitted over much longer distance and it is not possible to increase the signal power beyond the certain limit so in such case regenerative repeaters are used after the certain distance. This regenerative repeater detects the distorted and the noisy signal and generates the fresh copy of the transmitted signal and that signal he is once again transmitted over the particulars channel. so this is another way to increase the distance over which the signal can be transmitted apart from that for the digital signals using the error correction mechanism and by adding the redundancy in the message signal. The error in the received signal can be reduced so for a transmitting medium or a channel perspective following are the important specifications. And the specification is what is the length of the channel or a distance for which the signal can be transmitted faithfully? Then another important specification is the bandwidth of the channel so it is the range of the frequencies which is supported by the channel with reasonable fidelity. For example if a particular tenor can transmit the signal in the range of 0 to 20 kilohertz then we can say that the bandwidth of the channel is 20 kilohertz and if the signal is transmitted in the digital form then for the digital signal.
The another important aspect is the data rate that is the maximum supported data rate by the particular channel. so these are the some of the important aspect for the channel perspective now at the receiver these received signal is be modulated and if the signal is in digital form then first of all it is decoded and then using the digital to analog converter. The output of transducer could be a speaker or it could be when a display screen of the Smartphone or the monitor so this is the basic block diagram of the communication system and a little overview of how the information or the message is transmitted from one point to the another point so in the upcoming videos we will see how to represent the signal using the Fourier series. in the Fourier transform and then we will also talk about the different modulation schemes and in the digital communication we will also see how the analog signal can be digitized and encoded so we will discuss about the source coding then we will discuss about some much flexing skills and we’ll also see different error correction mechanisms which is used in the communication so these are the some of the topics we will discuss in the upcoming tutorial but I hope in this tutorial you got the basic overview of the analog and the digital communication so if you have any question or suggestion do let me know here in the comment section below.
WHAT IS MODULATION?
The modulation is the process where the property of the periodic signal like the amplitude phase or the frequency is altered according to the input signal.
what is amplitude modulation?
Amplitude modulation is a technique in which the signal is transmitted by modulating the amplitude of signal. In amplitude modulation the amplitude of carrier signal is changes in accordance with instantaneous amplitude of the massage signal.
The network topology is the arrangement of network in a various way is a network topology. the some example of network topology is
- Bus topology
- Ring topology
- Mesh topology
- Star topology