Modulation Matlab Homework Help


The term that is used for delivering a message to someone or a group of people is known as communication. The primary attraction of the humankind for finding out what is happening around us or the world is communication.

From the beginning of the world, communication (verbally or non-verbally) is the key for interacting with other human beings and in this modern era, there are various sources available for the communication between two people or with number of persons, these various sources include TV, Internet, Mobile phone, and so on.

In the 19th century, we use telephone and letters for communication, the telephone is a wire-based communication system. In this modern era, we communicate through the signals because nowadays the communication industry become wireless or sometimes we use wire for transferring huge amount of data to our data centers and for connecting with the data centers for providing non-stop services to other, where we cannot rely on wireless system.

Signals are the main key to communication. In scientific terms, a function that is used for transferring the message to others in a limited time is known as Signal. Signal is not only used by human’s even birds and animals also uses signals for communication with each other. Signals are majorly divided into two categories which includes:

  1. Analog Signal
  2. Digital Signal

The term analog represents continuous variation in signal concerning the time. In signal terms, it is the variation in signal function as time passes. Sometimes it is also known as continuous signal because of its nature.

The best and common example of analog signal is the human voice, audio signal, and the thermometer. Whenever we measure something for further processing using a system we use some sensors, the specific name of the sensor or the term that is used for sensing is transducer. These transducers convert physical entity value into an analog signal which then further converted for processing.

The term digital represents no continuous variation in signal, sometimes there is a sequence or pattern in a signal. In scientific terms, digital signals are the representation of the physical quantity distinct data set. The digital signals work in only binary numeric system or simple terms its only work in 1 or high and 0 or low form. The best example of the digital signal is the computer, digital phones, and many more.

If we compare the analog signal with digital we find many differences and from those difference some of them include:

  • Analyzing and processing on signal is easy in a discrete signal system rather than an analog signal system.
  • The continuous the signal system the more accuracy gets the signal and gives the best results, therefore, the analog signal system is more accurate for providing the result than the digital signal system.
  • The unwanted signals or noise which makes the system inaccurate doesn’t affect the digital signal while in an analog signal it affects the most.
  • Analog signal requires times for storage while the digital signal is easily stored.


Signal transmission is not an easy task it requires great time and study for developing a system by which signals can be easily transmitted without having any interference of noise.

In the telecommunication industry, they used a process for transmitting a signal and receiving a signal such is known as modulation for transmission of a signal and demodulation for receiving a signal. In simple terms, a process by which we can transmit any information like video, text, image with the help of electrical signal is known as modulation.

Transmitter is the devices that are used for transmitting the signal or information and the basis of transmitter is the modulation process while for receiving a signal or information we use a receiver and the basis of the receiver is the demodulator. By interchanging the carrier or periodic waveform we can attain the process of modulation.

There are many methods and technique available for the modulation and from those techniques and methods some of them are discussed below in two major categories:

  1. Analog Modulation

1.1. Modulation based on Amplitude

1.2. Modulation based on Single Side-band

1.3. Modulation based on Double Side-band

1.4. Modulation based on Angle

1.4.1.  Modulation based on Frequency

1.4.2.  Modulation based on Phase

  • Digital Modulation

2.1. Keying based on Phase Shift

2.2. Keying based on Frequency Shift

2.3. Keying based on Amplitude Shift

2.4. Keying based on off/on

2.5. Modulation based on Quadrature amplitude

2.6. Modulation based on Continuous phase

2.7. Modulation based on Wavelet

2.8. Modulation based on Trellis

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