ANALOG, DIGITAL AND PULSE MODULATION TECHNIQUES: AN OVERVIEW

Studying the process of analogue and digital modulation, 2017

The study of communication systems is largely based on signals and systems theory. An important objective in modulation is to produce a signal whose frequency range is suitable for transmission over the communication channel to be used. This paper presents an approach for studying the process of the main types of modulations of low and higher order. By using of computer simulations in MATLAB environment different types of modulation can be deep analyzed. It can be used for educational purposes in engineering education.

IJCSMC, 2019

The digital revolution has emerged the need for storing, processing and communicating data in digital format. Accordingly, all-digital systems have become popular, where no analogue components are included in the circuitry. As the output of these systems is digital, pulse code modulation is employed to establish communications without the need for analogue components. A certain characteristic of the pulse, such as its width, position or amplitude, is adjusted based on the input value. The number of bits transmitted in the channel depends on the number of bits modulated per pulse and the number of pulses outputted from the system per second. However, these parameters are limited by the capabilities of the digital system and communication channel. In this study, a new hybrid communications technique is proposed to allow increasing the bandwidth of digital communication systems, without the need for significant modification to the system. The bits of the input data is split into two sets, one modulated using Pulse Width Modulation and the other is modulated using Pulse Position Modulation. The outputs from these modulators are encoded to the output signal, using one of two possible encoding techniques, amplitude or frequency, depending on the characteristics of the communications channel. The evaluation results show that the proposed method has been able to provide twice the bandwidth the digital system can establish using each of these techniques, solely.

2010

A review of the state-of-art of Modulation Techniques, used for switching the Power electronics inverters and converters, is presented in this paper. It presents a comparison among various modulation strategies and reviewing their advantages and disadvantages. Also it gives a short explanation about the principle of operation of the classic and the advanced modulation techniques starting with the standard PWM and finishing with the invention of the wavelet modulation technique (WM). The output of the wavelet modulated power inverter is found to be the best approximation of the continuous-time sinusoidal reference signal over all other modulation techniques.

MEDITERRANEAN PUBLICATION AND RESEARCH INTERNATIONAL, 2023

The modulation techniques covered include AM, FM, PM, ASK, FSK, PSK, and QAM. Furthermore, the article shed light on the enabling technology in telephony and internet connectivity, specifically in 3G, 4G, 5G, WiFi 5, and WiFi 6. It then concludes that as communication technology continues to evolve, staying updated with modulation techniques and enabling technologies will be essential for optimizing communication systems and ensuring reliable and high-quality information transmission.

The BER for simulated modeled channels agreed with the theoretical results. It was also observed that multipath fading channel characteristic limits the data rate in wireless communication.

2009

Despite being known for many years, Pulse Amplitude Modulation (PAM) technique remains of important and widely used in many engineering applications. That technique takes some advantages of the transmitted data as time division multiplexed (TDM) analog pulses with the amplitude of the information channel pulse being the analog-variable parameter. In this article multi-tone PAM (MT- PAM) is investigated, simulated and implemented in the laboratory using few components. In these investigations three approaches have been used, theoretical, simulation and experimental. Computer simulations have been carried out using Matlab with Simulink. The use of multiple approaches has enabled very good confirmation of achieved result. After the over all investigations it is observed that, the obtained theoretical, simulation and experimental results are very close to each other and have very good agreement between them.

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.

Wireless communications has become an emerging and fastly growing field in our modern life and creates enormous impact on nearly every feature of our daily life. A tremendous technological transformation during the previous two decades has provided a potential growth in the field of digital communication and lot of latest applications and technologies are coming up every day due to these valid reasons. Digital modulation schemes contribute to the evolution of mobile communications by increasing the capacity, speed as well as the quality of the wireless network. In communication, the concept of modulation is a prime factor because without an appropriate modulation scheme, it would be impossible to achieve an expected throughput. Available bandwidth, permissible power and inherent noise level of the system are the constraints which should be considered while developing the communication systems. Due to error-free capability in digital modulation, it is preferred over the analogue modulation techniques. The Worldwide interoperability for Microwave Access (Wi-max) uses combinations of different modulation schemes which are BPSK, QPSK , 4-QAM AND 16-QAM and it is a promising technology which offers high speed voice, video and data services. In this paper the literature review on the different digital modulation techniques which are generally used for the wireless communication is presented.