Electronic Communication Systems
Electronic Communication Systems Electronic communications are the transmission, reception, and processing of information between two or more locations with the use of electronic circuits. The basic components of an electronic communications system are the transmitter, communications channel or medium, receiver, and noise. Analog signals (such human voice) or digital signals (binary data) are inputted to the system, processed within the electronic circuits for transmission, then decoded by the receiver. The system is claimed to be reliable and effective only errors are minimized within the process. Examples: Internet, public switched telephone network, intranet and extranet, and television
Different Types of Communication Systems
Analog
Digital
Wired (Line communication)
Wireless (Space communication)
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Communication System
Terms Used In Electronic Communication Systems
Information
Message or information is the entity that is to be transmitted. It is often within the sort of audio, video, temperature, picture, pressure, etc.
Signal
The single-valued function of time that carries the information. For transmission, the information is converted into an electrical form.
Transducer
A device or an arrangement that converts one form of energy to the other. An electrical transducer converts physical variables like pressure, force, temperature into corresponding electrical signal variations. Example: Microphone, Photodetector.
Amplifier
The electronic circuit or device that increases the amplitude or the strength of the transmitted signal is named an amplifier. When the signal strength becomes but the specified value, amplification is often done anywhere in between transmitter and receiver. The amplification is provided by a DC power source.
Modulator
As the original message signal can't be transmitted over an outsized distance due to their low frequency and amplitude, they're superimposed with high frequency and amplitude waves called carrier waves. This phenomenon of superimposing a message signal with a carrier wave is called modulation. And the resultant wave is a modulated wave which is to be transmitted.
Different Types Of Modulation.
i. Amplitude Modulation (AM)
ii. Frequency Modulation (FM)
iii. Phase Modulation (PM)
Transmitter
It is the arrangement that processes the message signal into an appropriate form for transmission and subsequently reception.
Antenna
An Antenna is a structure or a device that radiates and receives electromagnetic waves. So, they are used in both transmitters and receivers.
Channel
It refers to a physical medium such as wire, cables, space through which the signal is passed from transmitter to the receiver.
Noise
Noise is one of the channel imperfections or impairment in the received signal at the destination. External sources include interference, interference generated by natural sources like solar, lightning, or radiation, from automobile generated radiation. The external noise is often minimized and eliminated by the appropriate design of the channel, shielding of cables. Digital transmission external noise is often minimized.
Attenuation
Attenuation is a problem caused by the medium. When the signal is propagating for an extended distance through a medium, counting on the length of the medium the initial power decreases. The loss in initial power is directly proportional to the length of the medium. Using amplifiers, the signal power is strengthened or amplified so on reducing attenuation. Digital signals are comparatively less susceptible to attenuation than analog signals.
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Effect of Attenuation
Distortion
It is also another type of channel problem. The signal may have frequency and bandwidth different from the transmitted signal when the signal is distorted. The variation in the signal frequency can be linear or nonlinear.
Receiver
The message or information from the transmitted signal at the output end of the channel is extracted by an arrangement that is called a receiver and as the original message signal is a receiver it is reproduced in a suitable form.
Demodulator
It is the inverse phenomenon of modulation. The process of separation of message signals from the carrier takes place within the demodulator. The information is retrieved from the modulated wave.
Repeaters
Repeaters are placed at different locations in between the transmitter and receiver. A repeater receives the transmitted signal, amplifies it, and sends it to the next repeater without distorting the original signal.
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Diagram for Repeaters
Fun Facts
There are around 250 billion emails sent every day. Around 80% of these are spam.
Around 20 hours of video are uploaded to YouTube every minute.
Fiber optics are good because they use less energy and are better for the environment than electrical wires. They are also very resistant to weather.
The first telephone pole was built in 1876.
There are over 4 billion cell phones within the world and phones that are thrown away every year are over 100 million.
The first cell phone was invented by a company called Motorola.
Over 3.8 billion people use the internet, which is 40% of the world's population.
The first smiley appeared in 1979, it first looked like this -) then three years later colon was added to it and it took the form of :-) this.
FAQs on Terms Used in Electronic Communication Systems
1. What is an electronic communication system as per the CBSE Class 12 syllabus?
An electronic communication system is a setup designed for the transmission, reception, and processing of information between two or more points using electronic circuits. The goal is to send information, such as voice, audio, video, or data, from a source to a destination. The information is first converted into an electrical signal, processed for transmission, sent through a channel, and then decoded by the receiver.
2. What are the three fundamental elements of any basic communication system?
Every communication system is fundamentally composed of three essential elements as defined in the NCERT curriculum:
- Transmitter: This element processes the original message signal to make it suitable for transmission. It often involves modulation, where the message is superimposed onto a high-frequency carrier wave.
- Channel: This is the physical medium that carries the signal from the transmitter to the receiver. It can be wired (like coaxial cables, optical fibres) or wireless (space/free air).
- Receiver: This element's task is to extract the original message signal from the carrier wave received from the channel. This process is known as demodulation.
3. What is the specific role of a transducer in electronic communication?
A transducer is a device that converts one form of energy into another. In a communication system, its primary role is to convert the original message into a format compatible with the electronic system. For example, a microphone is a transducer that converts sound waves (pressure variations) into an electrical signal, which can then be transmitted.
4. Why is modulation a crucial step for transmitting signals over long distances?
Modulation is crucial because original message signals (like voice) have low frequency and low energy, making them unsuitable for long-distance transmission. They get weakened (attenuated) quickly and require impractically large antennas. Modulation superimposes this low-frequency message signal onto a high-frequency carrier wave. This process provides several key advantages:
- It increases the signal's energy, allowing it to travel much farther.
- It allows the use of smaller, practical-sized antennas for radiation.
- It prevents the mixing of different signals by assigning different carrier frequencies.
5. What is the main difference between an analog and a digital signal?
The main difference lies in how they represent information. An analog signal is a continuous wave that varies smoothly over time, mirroring the information it carries (like the continuous variation in sound pressure). A digital signal, on the other hand, is discrete and represents information as a series of non-continuous values, typically as binary digits (0s and 1s). Digital signals are generally more robust against noise and distortion.
6. How do attenuation and distortion affect a signal in a communication channel?
Attenuation and distortion are two primary forms of signal degradation within a communication channel. Attenuation is the loss of signal strength or amplitude as it travels through the medium. It is a natural consequence of the signal propagating over a distance and is usually compensated for by using amplifiers. Distortion, however, is a change in the waveform or shape of the signal, which can occur if different frequency components of the signal travel at slightly different speeds. This alters the information carried by the signal and is harder to correct.
7. What is the specific function of a repeater, and how does it differ from a simple amplifier?
While both are used to boost signal strength, their functions are distinct. An amplifier simply increases the amplitude of the entire signal it receives, including any noise that has been added along the way. A repeater is a more complex device used in long-distance communication. It receives the weakened signal, demodulates it to retrieve the original information, regenerates the clean signal, and then re-modulates it for further transmission. A repeater is essentially a receiver and a transmitter combined, ensuring the signal is not just amplified but also cleaned of accumulated noise.
8. Explain the terms 'bandwidth' and 'noise' in the context of a communication system.
Bandwidth refers to the range of frequencies that a communication channel can carry. Different types of signals require different bandwidths; for example, a video signal requires a much wider bandwidth than a voice signal. Noise refers to unwanted random electrical signals that get mixed with the desired message signal during transmission. It can originate from sources like atmospheric disturbances or other electronic devices, and it degrades the quality of the received signal.
