Studying the process of analogue and digital modulation

2012

The concept of modulation is a key factor in commun ication, because without an appropriate modulation method or scheme, getting an expected th roug put in such a communication effort would be impossible to achieve. Communication engineers and researchers have not relented in trying to find the best modulation methods aimed at achieving an expected t hroughput, bandwidth/power efficiency, low error performance, etc in digital communication networks. Digital modulation is preferred to the analogue mo dulation due to their error-free capability.Moreso, this cho i e of digital modulation is dependent on the type of communication network that is to be established. Ho wever, trade-offs must be made between the bandwidt h efficiency, power efficiency and the cost of implem ntation of such a network. This paper focuses onsome methods usually employed in the process of modulation in digital communicati on networks. Specifically, binary phase shift keying, quadrature phase shift keying, eigh...

Digital communication is a transfer of information from source to destination in the form of discrete signals. These signals are manipulated by electronic circuits (analog or digital) for making it possible to transmit and receive the data or information. Digital transmission is the physical transfer of data over a point-to-point or point-to-multipoint communication channel such as copper wires (guided and unguided channels), optical fibres, wireless communication channels, and storage media. The data is represented as an electromagnetic signal, such as an electrical voltage, radiowave, microwave, or infrared signal. In communication systems, the noise is an error or undesired random disturbance of a useful information signal, introduced before or after the detector and decoder. The noise is a summation of unwanted or disturbing energy from natural and sometimes man-made sources. If we transmit the baseband signals directly, the signals from different transmitters will get mixed up and the information will be lost. Because of these reasons, we use the technology of modulation, for transmitting message signals effectively for long distances Modulation is the process of varying one or more properties of a high frequency periodic waveform, called the carrier signal, with a modulating signal which typically contains information to be transmitted. The main goal of modulation today is to squeeze as much data into the least amount of spectrum possible. That objective, known as spectral efficiency, measures how quickly data can be transmitted in an assigned bandwidth expressed in terms of bits per second per Hz (b/s/Hz). Multiple techniques have emerged to achieve and improve spectral efficiency. There are various analog and digital modulation techniques used to transmit the signals. Due to various advantages of digital signals over analog signals, digital modulation techniques are preferred widely. This paper presents a brief study of different digital modulation methods and their uses for a particular application.

International Journal of Academic Research in Progressive Education and Development

COVID-19 pandemic hit has raised new challenges for Outcome-Based Education (OBE) system since the normalization of the online education delivery. Still, this era of endemic imposes challenges in satisfying OBE requirements, especially the students' practical assessments. As an essential part of Communication Engineering, Frequency Modulation (FM) fundamental can be theoretically and mathematically explained during the online classes. However, its practical assessment needs to be done experimentally. Since buying the real devices and tools needed to create a complete FM system consumes high cost, software simulation is the best solution to accommodate the learning processes for all students. Hence, aided by the MATLAB simulation and analysis approaches, this paper presents the implementation of FM practical assessment at Universiti Teknologi MARA (UiTM) as an institute of higher education. For this task, students have built the FM system by using both mathematical and Simulink model. The model also emphasized students on the association between FM's important parameters: modulating frequency, modulation index, frequency deviation, and bandwidth, with the type of FM, Narrow Band FM (NBFM) or Wide Band FM (WBFM). Results for all model configurations are recorded and analyzed accordingly. From this practical activity, students have demonstrated a better attainment for this course's Program Outcome (PO) as compared to the conventional assessment methods.

We use the word modulation to mean the systematic alteration of one waveform, called the carrier, according to the characteristic of another waveform, the modulating signal or the message. In Continuous Wave (CW) modulation schemes, the carrier is a sinusoid. We use () c t and (), m t to denote the carrier and the message waveforms respectively. The three parameters of a sinusoidal carrier that can be varied are: amplitude, phase and frequency. A given modulation scheme can result in the variation of one or more of these parameters. Before we look into the details of various linear modulation schemes, let us understand the need for modulation.

Communication plays a vital role in our lives, it is impossible to think life without it. So, it is very important for us to understand the technology behind it which has made our lives so simple and fast. This paper is about the different types of modulation schemes like AM, FM, PM, PAM, PWM, PPM, PCM etc used in the communication system and their importance.

The main objective of this paper is to introduce various modulation techniques in order to have possibility of simultaneous transmission and multiplexing of signals.

IEEE EDUCON 2010 Conference, 2010

Teaching mathematical intensive engineering based courses to undergraduate Information Technology students poses a great challenge to instructors. In this paper we provide an efficient and effective method for teaching digital and analog modulation to undergraduate students enrolled in an Information Technology program which does not require a strong foundation in mathematics as in the case of an Engineering program. The used approach utilizes Matlab packages, Simulink, and Communication Blockset to simulate analog and digital modulation techniques avoiding the derivation of any mathematics formulations and without coding. A survey that was distributed to Information Technology students who were taught using this approach showed a high level of satisfaction in understanding all modulation concepts.

Abstract A MATLAB-based application is introduced here in order to show graphically how radio frequency modulation works. This work show how students of radio frequency courses can learn the different types of modulations varying the most important parameters of each modulation and using different signal sources. The examples presented in the article are a demonstration of how MATLAB can be used to visualize the modulated signals resulting of a radio frequency (RF) modulation.

The simulation focuses on a basic modulation technique known as amplitude modulation. This paper shows the appearance of an information signal which is usually in sinusoidal form as its characteristics are altered to make it more suitable for transmission. The virtual environment of the program will allow the user to manipulate various information signal characteristics related to the said modulation technique. The modulation index, frequency, phase, and amplitude can be changed as desired and the AM envelope will be displayed.

CVR Journal of Science & Technology, 2015

This paper presents step by step procedure for designing analog modulation techniques such as Amplitude Modulation (AM) and Frequency Modulation (FM).These techniques are simulated in Simulink environment. AM and FM broadcasting range is of 550-1650 KHz and 88-108 MHz respectively. Tuning of these frequencies is difficult in implementation. To implement these modulation techniques, MATLAB and Simulink tool has been used. These tools will help the engineers for simulating a complete system before embarking on actual prototype. Simulation results show the capability of adequate system performance. In this paper AM and FM systems are simulated using MATLAB and Simulink and their performance is presented.