A Review of Various Digital Modulation Schemes Used in Wireless Communications

Abstract

A variety of modulation schemes is used to fulfill the requirement of digital communication. There has been a mammoth work done on the study of various modulation techniques under different channel and environmental conditions. This paper gives a succinct review of the various digital modulation schemes used in wireless communication. If we want to go for extra information capacity, enhanced quality communication, faster system availability, and higher data security, then digital modulation plays a vital role in the field of communication and its application, although there are some constraints like available bandwidth, power level, inherent noise level of the communication system. As for the designers of digital wireless communication system, the highest priority is large bandwidth efficiency with low bit error rate (BER) while for the designers of hand-held cellular phones, the highest priority is power efficiency. From today’s point of view, digital modulation techniques such as ASK, PSK, FSK, DPSK,QPSK, MSK, QAM, digital optical modulation, and multicarrier modulation play an important role in various wireless application. In this paper, we will discuss the various digital modulation schemes, its comparison and identifies the best possible modulation schemes for various application purposes.