Summary
International Technical Conference on Circuits/Systems, Computers and Communications
2016
Session Number:P3
Session:
Number:P3-8
Non-Multiplier QPSK Modulator Using Simple Trigonometric Function
Lerson Kirasamuthranon, Jeerasuda Koseeyaporn, Pramote Wardkein ,
pp.1021-1024
Publication Date:2016/7/10
Online ISSN:2188-5079
Summary:
The quadrature phase-shift keying (QPSK) is one of the digital modulation techniques using four different phases in order to represent the data bits. Building the QPSK modulating circuit is somewhat complex because of the need of two local frequencies whose phases need to be exactly 90 degree differences. A new technique, which uses just basic Op-Amp circuits in order to create the amplifier circuit and the summing amplifier circuit and also simplifies the QPSK modulation system, is proposed. The designed amplifier circuit is controlled by data bit. Consequently, phase shifting of QPSK signal is regulated by data bit. The data bits are applied so as to control the designed amplifier circuit's gain which also regulated the QPSK signal's phases. From this reason, the proposed QPSK modulating circuit is therefore less complicate than the conventional one. Both theoretical and experimental results thus confirm that the propose technique can be realized in real world application.