Basic Communication System | Block Diagram, Types, Processes

Basic Communication System

Because of noise and attenuation, the basic communication system consists of information/data transmission from one point to another, with the original/main information signal passing through numerous stages and subsequently undergoing many changes in its direction and properties.

Furthermore, in order to ensure that communication is both safe and quick.

What is Communication

The basic process of transmitting information/data is known as communication.

Communication equipment refers to electronic equipment or materials that are utilized for communication. When various communication equipment/materials are combined, a communication system is formed.

A typical example of the communication system are

  • Line telephony and line telegraphy
  • Computer communication
  • Mobile communication
  • Point-to-point communication
  • Television broadcasting
  • Radiotelephony and radiotelegraphy
  • Radio telemetry
  • Radar communication
  • Radio broadcasting
  • Radio aids to aircraft landing, etc.

What is Communication System

A communication system’s goal is to convey intelligence signals from a source to a destination located at a distance from the source. A communication system is depicted in the figure below as a block diagram. The transmitter, channel, and receiver are the three essential components of this system.

basic communication system 1


The transmitter’s job is to transform the message signal into something that can be sent via the communication channel.

This is referred to as modulation. The purpose of the communication channel is to create a link between the transmitter’s output and the receiver’s input.

The receiver’s task is to decode the received signal and recover the correct message signal. If all of the elements perform their functions correctly, the output signal should equal the input message signal.

Communication Channel

This communication mechanism will be revisited later in this report as we go over the amplitude modulation lesson ideas.

An intelligent message signal can be sent via the communication channel in two ways. Analog and digital are the two options. Both strategies have their own set of benefits and drawbacks. The following are some of the benefits of the digital method:

  1. Increased tolerance to noise in the communication channel and outside interference that is impossible to avoid.
  2. Because of the technology in the digital system, the system may operate in a more flexible manner.
  3. The transmitter can implement different forms of message signals in the same format, such as speech data, video data, or computer data.
  4. Sensitive data can be protected by encrypting message signals.

The downsides of digital technology include the complexity of the communication system and the cost of communication channels such as satellite channels and optical fibers.

Analog provides two significant advantages. The first is that the analog communication mechanism is fairly basic. The analog method’s second advantage is that it is inexpensive due to the usage of simple technology.

It may eventually be replaced by the digital technique as communication systems become more simple as technology advances and more communication channels become available for the digital approach.

Many broadcasting systems, such as the radio, still employ the analog approach to convey signals. The analog approach is still used in some of our telephone networks.

Analog will continue to exist for some time, thus learning both the analog and digital methods is a smart idea.

Before we can transmit a message signal through a communication channel, we must first convert the signal into a format that is acceptable for transmission.

Modulation is the term we used to describe the process of changing the communication signal. This modulation procedure includes changing some properties of a carrier wave in response to the message signal, resulting in a wave that matches the bandwidth of the communication channel.


The receiver of the communication system will have to go through the demodulation process, which is the inverse of the modulation process, in order to retrieve the message signal.

One could ask why a message signal needs to be altered in order to be transmitted. One of the reasons, as previously said, is to modify the message signal to match the bandwidth of the channel.

Other reasons exist for modulating a communication transmission. Modulation allows for multiplexing, which is one of these reasons. Multiplexing refers to the ability to send many message signals over the same channel at the same time.

Another reason for modulation is to make the message signal noise and interference resistant. This will allow for a good transmission without having to worry about noise.

The message signal is encoded in a carrier wave during the modulation process. A sinusoidal wave is the carrier wave.

This carrier wave, also known as a sinusoidal wave, contains three independent parameters that can be changed in response to the message signal. Amplitude, phase, and frequency are the three parameters.

Amplitude modulation is the variation of the amplitude (AM). Frequency modulation (FM) is the process of changing the carrier wave’s frequency in response to the message signal.

Phase modulation is the final type of modulation. It is accomplished by altering the carrier wave’s phase in response to the message signal.

AM and FM are terms that most of us are already familiar with. Radio communications are widely used in our daily lives.

Types of Basic Communication System

There are two fundamental modes of communication:

  1. Point-to-Point (P2P)

Communication occurs across a link between a single transmitter and a single receiver in the point-to-point communication mode. One example of such a means of communication is telephony.

  1. Broadcast

In broadcast mode, a single transmitter is accompanied by a huge number of receivers. The broadcast mode of communication is exemplified by radio and television.

Read also : Digital and Analog I/O

Components of Basic Communication System Processing

Communication, in its most basic form, entails the transmission of information/data from one point to another via a series of processes such as those described below:

  1. The creation of a mental image in the mind of the creator.
  2. In the recipient’s mind, a reproduction of the original thought image with a defined deterioration in quality.
  3. A set of verbal-visual symbols that describe the image with a particular degree of precision.
  4. The delivery of the encoded symbols to the desired location.
  5. The process of encoding these symbols in a format suitable for transmission across a physical medium.
  6. The actual symbols are decoded and reproduced.

Block Diagram of Basic Communication System

The block diagram of a basic communication system is shown below, with the various functional aspects represented by blocks.

basic communication system 2

An information source, input transducer, transmitter, communication channel, receiver, and destination are all required components of a communication system.

Now we’ll have a look at how these blocks work.

1. Information Source

A communication system, as we all know, is used to send a message, information, or data. This data/information comes from the information source.

In general, communications can take the shape of words, groupings of words, code, symbols, sound signals, and so on. However, only the desired message is picked and communicated from among these messages.

As a result, we may argue that the information source’s function is to generate the required message that must be conveyed.

2. Input Transducer

The input can be in any energy form (temperature, pressure, light), but it must be transformed to electrical energy for transmission. This is done by the transducer.

  1. In an electronic communication system, we frequently encounter devices that have electrical inputs or outputs.
  2. A transducer is any device that transfers one form of energy/power into another.
  3. An electrical transducer is a device that translates a physical variable (such as pressure, force, or temperature) into equivalent fluctuations in an electrical signal at its output.

3. Transmitter

It turns data and information into a signal that may be transmitted via the media. The transmitter amplifies the signal and provides interfaces that correspond to the transmission medium, such as an antenna interface, fiber interface, and so on.

The transmitter’s job is to analyze the electrical signal from various angles. In radio transmission, for example, the electrical signal obtained from the sound signal is commonly amplified and processed to limit its range of audio frequencies (up to 5 kHz AM radio broadcast).

4. Channel

A channel is just the conduit through which an electrical signal passes in a basic communication system. These media can be divided into two categories: guided and unguided.

Through the use of connective cables, guided media can be directed from a source to the receiver. An optical fiber is a medium in OFC-optical fiber communication. Telephone wire, coaxial cable, and twisted pairs, among other things, may be used as additional guided media.

The second sort of media is unguided media, which is a communication route that creates space between the source and receiver. The medium of RF (radio frequency) transmission is space, which is also known as air.

It is the only thing that connects the source and the receiver, however in other circumstances, such as sonar, the medium is usually water since sound waves travel far and wide across liquid media. Because there are no connecting cables between the source and the receiver, the two forms of media are measured unguided.

5. Noise

Communication engineers face a difficult task when dealing with noise. Nature is unexpected and random. The unwanted electric energy that enters the communication system and interferes with the desired signal is referred to as noise.

  • Noise is generated at all levels, including the transmitter, channel, and receiver.
  • It can be both artificial and natural.
  • Lightning, solar radiation, and thermal noise are examples of natural noise.
  • Welding, sparking, motors, car ignition, tube lights, electronic fan regulators, and other man-made devices
  • Unwanted signals that disrupt the transmission and processing of message signals in a communication system are referred to as noise.
  • The cause of the noise could be either inside or outside the system.

6. Receiver

From the received signals at the channel output, a receiver extracts the desired message signals.

  • With noise, it receives the required signal (undesired).
  • Despite the noise, it recovers the original signal.
  • Amplifiers, filters, mixers, oscillators, demodulators, and transducers are all part of this system.
  • The receiver is made up of the same block schematics as the sender.
  • In the receiver, whatever was done in the transmitter will be undone.
  • For example, modulation in the transmitter will be matched by demodulation in the receiver, and A to D in the transmitter will be undone by D to A in the receiver, and so on.

Output Transducer

The final stage in the conversion of an electrical communication signal back to its original form is the output.

In radio broadcasting, for example, the output is a loudspeaker that acts as a transducer, converting an electrical signal into the original sound signal.

Basic Communication System Applications

The following are some of the most important applications of communication systems:

  1. It’s utilized for secure communication and missile guidance in military applications.
  2. It’s utilized in pattern recognition, robotic vision, and picture enhancement in image processing.
  3. It’s a component of digital signal processing.
  4. Text messaging and other digital communication tools are utilized in telephony.
  5. It’s used in space communication to send signals to Earth from spacecraft.
  6. It’s a video compression algorithm.
  7. It’s utilized in speech recognition.
  8. It is employed in the transmission of digital audio.
  9. It’s used to compress data.

Frequently Asked Questions

What are the digital communication system’s objectives?

A digital communication system is a model for sending a message from an information source across a transmission medium, such as a channel. The goal is to complete this work in such a way that data is efficiently delivered while maintaining a high level of reliability.

What is analog communication, exactly?

Analog Communication is a method of transferring data in a format that uses continuous data to communicate data such as sound, image, and video. An analog signal is a variable signal that is continuous in time and amplitude and is typically conveyed using modulation.

What is the process of digital communication?

Instead of continuously monitoring digital signals, they can be sampled. The physical transport of data through a Point-to-Point or Point-to-Multipoint communication connection is known as data transmission.

Why is digital communication superior to analog communication?

Because digital signals are less influenced, the effects of distortion, noise, and interference are much less. Digital circuits are easier to design and less expensive to produce than analog circuitry. Digital signals provide a simpler configuration mechanism than analog signals.

What’s the distinction between analog and digital communication?

Analog and Digital Communication: What’s the Difference? Analog signals are time-varying signals that are continuously changing, whereas digital signals are discrete values. Digital communication has several advantages, including immunity to noise and distortion due to its higher signal-to-noise ratio.

What makes analog superior to digital?

The smooth analog signal better resembles the recorded sound wave than the digital recording’s steps. The analog medium on which the recording is imprinted may have minor flaws that create cracking and popping noise.

Why do we make the transition from analog to digital?

Because a digital transmission may be compressed much more than an analog signal, switching from analog to digital allows broadcasters to give improved visual definition. Local stations can offer more programs to their viewers with digital broadcasting than they could with an analog feed.

Is it better to have an analog or digital signal?

Is digital audio superior to analog? In most cases, sound is an analog signal. There are no breaks or impediments in an analog signal because it is continuous. Some audiophiles feel that the analog recording process is better at capturing a true depiction of sound since it is continuous.

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