Have you ever wondered why we need to use frequency modulation while transmitting signals?

Of Course, you have. So let us find it here in this informative and authentic article. 

Modulation and demodulation are the processes of encoding and decoding a message, respectively. Lets deep dive into these:

Modulation:

Modulation is a process of converting a baseband message signal into a continuous waveform called a modulated signal. 

It is a method used to encode a message signal (frequency) onto a carrier wave. The message is usually an audio signal such as speech or music which information is represented by varying characteristics of the carrier, such as amplitude, frequency, phase, duration, etc.

It is required in any information system, including telecommunication, to transfer information from one place to another.

Demodulation:

Demodulation is the process of undoing the Modulation. It is brought into use to retain the original information from a modulated signal.

Frequency demodulation focuses on extracting the information contained in a modulated signal. It focuses on information such as audio or video by exploiting the frequency-selective nature of the demodulator.

The same principle underpins both AM and FM receivers. Frequency demodulation is an essential process in telecommunication engineering. It involves converting a signal from one frequency to another frequency.

1. Frequency Modulation: 

The frequency modulation technique is used in computing, radio broadcasting, single processing, telecommunications.

It is widely used in radio broadcasting. Modulation has a larger signal-to-noise ratio in radiofrequency, which rejects radio frequency interference and has better or equal power amplitude modulation.

Most music is broadcast over FM radio for this reason. Frequency modulation is also used in telemetry, radar, EEG, two-way radio systems, seismic prospecting, magnetic-tape recording system, video transmission system, and sound synthesis.

Why is Frequency Modulation Used?

Converting the signal into digital form is often desirable when you need to send analog signals over long distances. You can do it with an A/D converter.

But if the frequency of the original signal is high, an A/D converter will not function. The lack of function is that it takes time for A/D converters to sample and digitize the analog signal.

Frequency modulation, or FM, encodes an information signal by varying the instantaneous frequency of a carrier wave. This modulation technique is used, for example, in radio transmission and magnetic tape-recording systems.

It has several applications. For example, it is used to modulate the frequency of a signal in FM broadcasting.

Frequency modulation is a commonly used technique in digital data transmission.

In frequency modulation, the message to be transmitted is converted into an analog signal. This analog signal or audio message is then passed through a carrier wave whose frequency varies concerning time.

The result is a modulated RF signal receiving and demodulating at the receiver to recover the original audio message.

Tesca Global Frequency Modulation and Demodulation Trainer Kit:

Frequency-Shift Keying (FSK):

It conveys data by changing or shifting an analog signal’s carrier frequency. FSK is widely used for transmitting information via radio signals.

Frequency-shift Keying is a digital modulation scheme in which information is transmitted through discrete frequency changes of a carrier wave. It converts digital data into an analog signal and back again. It is also known as Shift Keying. 

What makes FM a superior modulation to AM?

Here are some of the advantages of Frequency Modulation over Amplitude Modulation:

⮚ Frequency modulation is a communication technique that uses the frequency of the carrier signal to convey information. The main advantage of frequency modulation is that it allows you to send information that would be impractical to send using direct current (DC). 

⮚ Frequency modulation (FM) is a form of signal modulation that conveys information by changing the frequency of a carrier wave. It contrasts with amplitude modulation as in this, the amplitude of the carrier is changed. Whereas in phase modulation, its phase is varied. 

⮚ Frequency modulation is used for both radio broadcasting and telecommunication. The most well-known use of FM broadcasting is in the Radio Data System (RDS).

⮚ The transmitted power used in frequency modulation is prone to be utilized, whereas, in amplitude modulation, the transmitted power in the carrier doesn’t contain information.

⮚ In comparison to amplitude modulation, frequency modulation amplitude is constant.

⮚ Noise in frequency modulation is reduced with the help of the amplitude limiters that help remove the amplitude variation caused by noise. But that’s not the case with Amplitude Modulation as it cannot use amplitude limiters.

⮚ The noise in frequency modulation can further remove by using the deviation and increasing it, which is not feasible in the amplitude modulation.

⮚ When frequency modulation is more than two Signals, it will receive the stronger one and eliminate the weaker signal. In amplitude modulation, it will receive the sign with the same frequency, which will lead to interferences as both the signals will be modulated.

⮚ The noise in frequency modulation is canceled by using the VHF and UFH.

What are the disadvantages of Frequency modulation over Amplitude modulation?

⮚ Frequency modulation has an infinite number of sidebands virus Amplitude Modulation has only two.

⮚ In comparison to amplitude modulation, the channel bandwidth of Frequency modulation is higher.

⮚ In contrast to Amplitude Modulation, the design of the frequency transmitter is rather complex. Amplitude Modulation transmitter and receiver design are simple.

⮚ Compared with Amplitude Modulation, the types of equipment used in frequency modulation transmission and reception are complicated and expensive.

⮚ In comparison to amplitude modulation, the reception of the line of sight and the reception area are smaller in frequency modulation.

2. Delta modulation:

For an immediate transmission of acoustic signals(mainly), a conversion of analog to digital and digital to analog takes place and is most commonly referred to as delta modulation.

Delta modulation is not always about quality. 

Learn More: Delta Modulation & Demodulation.

Things to know about Delta Modulation:

• Delta modulation is a complex representation of surge and plunge in the amplitude of a received or sent signal.
• To achieve the desired signals, oversampling skills are often used.
• It is appraised as a series of different segments.
• Only the increase and decrease in amplitude of the object needs reading in delta modulation.

3. Amplitude Modulation:

Amplitude modulation (also known as AM or amplitude shift keying) is a widely used encoding information.

The amplitude of the carrier wave is varied in proportion to the message signal being transmitted. It is helpful in sending signals over a transmission medium.

In an AM system, the amplitude of the carrier signal is varied in proportion to the amplitude of the modulating signal. It is commonly used for telecommunications and can also carry data on the AC power lines.

It is used for both analog and digital signals. This type of Modulation is used for increasing the range, or bandwidth, of a radio signal.

It works by varying the amplitude (or height) of the carrier wave under the audio signal to be transmitted. 

Amplitude-Shift Keying(ASK):

Amplitude-shift Keying (ASK) is a digital signaling method that transfers data on a communications channel such as a wire, optical fiber, or radio.

It represents digital data as variations in the amplitude of a carrier wave; more precisely, it means the state of the signal as two discrete levels, which are identified by differing amplitudes representing 0 and 1.

It is a type of Modulation that conveys information by changing (or modulating) the amplitude of one or more carrier waves.

A small amount shifts the frequency of each carrier wave. This shift is known as the modulation depth. 

It is a digital modulation scheme that sends data by rapidly switching between two or more distinct signals.

It forms part of the more prominent family of phase-shift keying techniques developed in the 20th century. Amplitude-Shift Keying is a modulation scheme used in digital transmission to send data by changing the amplitude of a sinusoidal carrier wave.

It is one of the oldest and simplest forms of digital Modulation and has been used in telecommunication and data communication applications since forever. 

4. Phase Modulation (PM):

Phase modulation (PM) is a form of signal modulation where the carrier wave phase is varied under the modulating signal.

The receiver can use this phase information to recover the original message signal.

Phase modulation is used in many communications systems, including cell phones and cordless phones, Digital Audio Broadcasting (DAB), Digital Radio Mondiale (DRM), etc. It conveys information by varying the carrier wave phase, while frequency modulation (FM) involves changing the frequency. 

How Phase Modulation is differ from Frequency Modulation:

If we compare phase modulation with frequency modulation, the difference is that in phase modulation, we do not vary the frequency of the carrier wave but its phase.

The phase modulation technique goes to the stage of the carrier wave under the message being sent. It can be used as a form of digital communication that changes the length, speed, and pauses between radio waves or light pulses.

Phase modulation can be used for amplitude modulation, frequency modulation, and phase-shift keying modulation.

Phase-Shift Keying(PSK):

In this modulation scheme, data is conveyed by changing or modulating the phase of a reference signal.

PSK modulates a continuous wave (CW) carrier wave with an information signal and is distinct from amplitude-shift Keying, phase-shift keying, and frequency-shift Keying. It is used for sending information over a communications channel.

PSK modulates the phase of a reference signal which is generated independently of the data being sent. PSK is distinct from on-off Keying because it uses a sinusoidal carrier wave versus an on/off-keyed carrier wave. 

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Frequent Asked Questions

Q: What are the uses of Modulation and Demodulation?

1. Uses of Modulation and Demodulation in Networking:

Modulation and Demodulation in Networking are converting digital data to analog form for transmission over a communication channel and then reconverting it back to digital format at the receiving end. 

Modem means modulation/demodulation; hence modulation & demodulation in networking collectively are also called modem.

Modulation is the process of varying one or more properties of a periodic waveform, also known as the carrier signal, which transmits the information found in the modulating sign. 

2. Utility of Modulation and demodulation in an information exchange system:

There are plenty of reasons why we should go for frequency modulation and demodulation. For instance, if you want to transmit a video without interruption and interference, this is one of the best alternatives available.

It also saves a lot of power and energy as compared to other forms of transmission. Modulation and demodulation encodes a message to be sent over a transmission medium and then decodes it at the receiving end. 

It is about manipulating and processing electromagnetic radio frequency signals to convert the message into digital and analog format.

This process is an essential part of the information system as it converts analog signals to a digital signal and digital signals to an analog signal.

The central concept of Modulation and demodulation is that any information signal can be modulated by using different types of carrier waves to carry the information that we need to send.

This method proves to be very helpful in the inefficient transfer of data between two points that are distant from each other. Transmission of the information in a reliable manner, error detection, and correction is the most common uses of Modulation.

The analog to digital and digital to analog conversion is the most used method and has a wide application in various forms. And that’s when a delta modulation program comes in.