Introduction to Analog and Digital Communication | The Basic Block Diagram of Communication System
Summary
TLDRThis introductory video on analog and digital communication from the ALL ABOUT ELECTRONICS channel explores the basics of information exchange through electronic devices. It covers the types of communication, the role of transducers in converting non-electrical signals, and the function of transmitters and channels in signal transmission. The video also touches on signal characteristics, the importance of signal-to-noise ratio, and the use of repeaters and error correction in maintaining signal integrity over long distances. Viewers are promised further insights into modulation schemes, signal representation, and error correction mechanisms in upcoming videos.
Takeaways
- 😀 The script introduces the concept of analog and digital communication, explaining the basic terminologies and the block diagram of a communication system.
- 🔌 Communication can be either wired or wireless, and it can be point-to-point, point-to-multipoint, or broadcast, like in the case of FM transmission.
- 📡 The script mentions everyday examples of communication systems, such as using a smartphone, sending emails, and watching television.
- 🔍 The block diagram of a communication system includes a source, a transducer, a transmitter with subsystems like modulator, ADC, and encoder, and a channel for signal transmission.
- 🎤 Transducers convert non-electrical signals like voice or images into electrical signals, which are then processed for transmission.
- 📶 The transmitter modifies the input signal for efficient transmission and may include processes like sampling, quantization, and modulation.
- 📈 Modulation alters properties of a periodic signal like amplitude, phase, or frequency according to the input signal, which will be detailed in future videos.
- 📊 Key characteristics of a transmitted signal include whether it's analog or digital, its frequency, bandwidth, data rate, and power level.
- 🌐 The channel, which can be physical or wireless, acts like a filter, attenuating and distorting the signal, and noise is often added during transmission.
- 🔄 The receiver's ability to recover the message signal depends on the signal-to-noise ratio, a critical parameter for the communication system.
- 🔄 Regenerative repeaters and error correction mechanisms are used to extend transmission distance and reduce errors in the received signal.
- 📚 Upcoming videos will cover topics like signal representation using Fourier series and transform, different modulation schemes, digitization and encoding of analog signals, source coding, multiplexing, and error correction mechanisms.
Q & A
What is the basic definition of communication in the context of electronics?
-In the context of electronics, communication is the exchange of information between two points using electronic gadgets and devices, which can be either wired or wireless.
What are the different types of communication systems mentioned in the script?
-The script mentions point-to-point communication, point-to-multi-point communication, network communication, and broadcast communication, such as FM transmission.
What is the role of a transducer in a communication system?
-A transducer converts non-electrical forms of information, like voice or images, into electrical signals. Examples include microphones, CCD cameras, and computer keyboards.
What happens to the input signal after it passes through the transducer?
-After passing through the transducer, the input signal is modified by the transmitter for efficient transmission. This may involve processes like modulation, analog-to-digital conversion, and encoding.
What is modulation in the context of communication systems?
-Modulation is the process of altering the properties of a periodic signal, such as amplitude, phase, or frequency, according to the input signal to prepare it for efficient transmission.
What are the characteristics of a transmitted signal that are important to consider?
-Important characteristics of a transmitted signal include whether it is analog or digital, its frequency, the range of frequencies (bandwidth), the data rate or bit-rate for digital signals, and the power level.
What is a channel in a communication system and how does it affect the transmitted signal?
-A channel is the medium over which the signal is transmitted, such as optical fiber, coaxial cable, or radio link. It can behave like a filter, attenuating different frequencies of the transmitted signal differently and introducing noise.
Why is the signal-to-noise ratio important in a communication system?
-The signal-to-noise ratio is crucial as it determines the clarity of the received signal. A higher ratio improves the ability of the receiver to recover the message signal from the distorted signal.
What are regenerative repeaters and how do they help in communication systems?
-Regenerative repeaters are devices used to extend the transmission distance. They detect the distorted and noisy signal, regenerate a fresh copy of the transmitted signal, and retransmit it over the channel.
What are the key specifications to consider for a transmitting medium or channel?
-Key specifications include the length of the channel, the bandwidth supported by the channel, and the maximum supported data rate for digital signals.
What happens to the received signal at the receiver in a communication system?
-At the receiver, the received signal is demodulated. For digital signals, it is first decoded and then converted back into an analog signal using a digital-to-analog converter, before being amplified and sent to the output transducer like a speaker or display screen.
Outlines
📡 Introduction to Analog and Digital Communication Systems
This paragraph introduces the concept of communication in electronics, explaining it as the exchange of information between two points using electronic devices. It covers the basics of communication, including the different types such as wired, wireless, point-to-point, multipoint, and broadcast systems. The paragraph also introduces the basic block diagram of a communication system, starting with the source of the message signal, which can be converted into an electrical signal using a transducer. The transmitter's role in modifying the input signal for efficient transmission is discussed, including the subsystems involved like modulators, analog to digital converters, and encoders. The importance of understanding the transmitted signal's characteristics, such as whether it's analog or digital, its frequency, bandwidth, data rate, and power level, is emphasized for effective communication link design.
🔌 Signal Transmission and Reception Challenges
This paragraph delves into the challenges faced during signal transmission and reception. It describes how the transmitted signal gets attenuated and distorted as it passes through the channel, with noise superimposed over it. The importance of the signal-to-noise ratio for the receiver's ability to recover the message signal is highlighted. The paragraph also discusses methods to overcome signal degradation, such as using regenerative repeaters to refresh the signal and error correction mechanisms to reduce errors in digital signals. Furthermore, it outlines important channel specifications like length, bandwidth, and data rate, and explains the process at the receiver end, which includes decoding, converting the signal back to analog, and amplifying it before it's output through a transducer like a speaker or display. The paragraph concludes with a preview of upcoming topics in the video series, such as signal representation using Fourier series and transform, modulation schemes, digitization and encoding of analog signals, source coding, multiplexing, and error correction mechanisms.
Mindmap
Keywords
💡Communication
💡Analog Communication
💡Digital Communication
💡Transducer
💡Transmitter
💡Modulation
💡Signal-to-Noise Ratio (SNR)
💡Repeater
💡Error Correction
💡Channel
💡Bandwidth
💡Data Rate
Highlights
Introduction to analog and digital communication.
Communication is the exchange of information between two points.
Information exchange can be wired or wireless.
Communication can be point-to-point, point-to-multipoint, or broadcast.
FM transmission is an example of broadcast communication.
Daily use of gadgets involves sending and receiving information.
Basic block diagram of a communication system explained.
Transducer converts non-electric signals into electrical signals.
Transmitter modifies the input signal for efficient transmission.
Transmitter includes modulator, analog to digital converter, and encoder.
Signal is sampled, quantized, and converted into digital form.
Modulation alters the properties of a periodic signal according to the input signal.
Characteristics of the transmitted signal include type, frequency, bandwidth, and power level.
Channel acts as a medium for signal transmission and can be physical or wireless.
Signal attenuation and distortion depend on the length of the channel.
Signal-to-noise ratio is crucial for signal recovery.
Regenerative repeaters are used to extend transmission distance.
Error correction mechanisms reduce errors in digital signals.
Channel specifications include length, bandwidth, and supported data rate.
Receiver decodes and converts the signal back to analog form.
Upcoming videos will cover Fourier series, Fourier transform, modulation schemes, digitization, encoding, source coding, multiplexing, and error correction.
Transcripts
Hey friends welcome to the YouTube channel ALL ABOUT ELECTRONICS. So this is the introductory
video on the analog and the digital communication. And we will see some basic terminologies,
and the basic block diagram of the communication system. 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. And 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. And
one 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,
or 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 an email to someone,
and even watching the television are the examples of the different communication system. So through
a basic block diagram of the communication system, let us understand how the information is extent
between the two points. So in this block diagram, the first block is the source itself, from where
the message signal is generated. So this message could be voice, email, or the television signal,
or it could be even some data signal. So if this message is in non-electric form, then
using the transducer, it is converted into the electrical signal. So the microphone, CCD camera,
and the computer keyboard are the examples of the transducer. For example 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. So 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. And 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. For example if the signal
is analog in nature, and it needs to be converted into the digital form, then first it is sample at
the regular intervals. And then it is quantized and after the quantization using the analog
to digital converter, 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. So this 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. And of course in the upcoming videos we will talk in detail about this modulation.
So anyway these are the some of the subsystems of this transmitter module. 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. And 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. Then another 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
link. So the signal after this transmitter is known as the transmitted signal. And this signal
is sent over the particular channel. So a channel is the medium over which the signal is transmitted
over the certain distance. So this channel could be a physical channel, like optical fiber
or the coaxial cable. Or it could be a wireless channel like a radio link. So this channel partly
behaves like a filter and attenuates the different frequencies of the transmitted signal differently.
So once the transmitted signal passes through the channel and gets received at the receiver,
then it gets attenuated as well as the distorted. Moreover the noise also gets superimposed over the
transmitted signal. So 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. And whether the detector is able to recover the signal or not, it depends on the
signal-to-noise ratio. So it is a very important parameter in the communication system. So this
parameter is the ratio of the signal power to the noise power. So 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 a regenerative
repeaters are used after the certain distance. So these regenerative repeaters detects the distorted
and the noisy signal, and generates the fresh copy of the transmitted signal. And that signal
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. The first is what is the length of the channel,
or a distance over 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 channel can transmit
the signal in the range of 0 to 20 kilohertz, then we can say that the bandwidth of the channel is 20
kilo Hertz. 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, it is converted
into the analog signal. And after the proper amplification, this signal is given to the output
transducer. So this output transducer, could be a speaker, or it could be even 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
multiplexing schemes. 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 videos. But I hope
in this video, 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. If
you like this video, hit the like button and subscribe the channel for more such videos.
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