Open AccessCOMPARATIVE ANALYSIS OF MODULATION SCHEMES USING ADAPTIVE EQUALIZATION AS FADING MITIGATION TECHNIQUE
Author(s) -
Sabita Nahata,
Sangeeta Bhattacharya
Publication year - 2012
Publication title -
international journal of electronic signal and systems
Language(s) - English
Resource type - Journals
ISSN - 2231-5969
DOI - 10.47893/ijess.2012.1060
Subject(s) - fading , multipath propagation , computer science , phase shift keying , quadrature amplitude modulation , transmission (telecommunications) , equalization (audio) , electronic engineering , qam , link adaptation , modulation (music) , bit error rate , spectral efficiency , adaptive equalizer , telecommunications , decoding methods , engineering , channel (broadcasting) , philosophy , aesthetics
Inter-symbol interference (ISI) due to multipath fading is a vital problem in high-speed wireless communication which restricts communication quality and capacity. Therefore, in addition to choosing a fading mitigation technique, it is also important to strategically select a modulation scheme for effective data transmission. Recent literature review on wireless standards, such as 3G and 4G indicates that QAM and QPSK are suitable choices for data transmission. In this paper, a comparative analysis on selected modulation schemes is performed in a fading environment. The mitigation of fading is done using adaptive equalization technique. Also, we show that the signal to noise ratio (SNR) is an important parameter to choose. It is observed that, even when an adaptive equalizer is used at the receiver, a very low SNR gives very high symbol error rate (SER). We derive some important conclusions from our simulation result: QPSK shows minimum SER, whereas 256-PSK and 256-PAM perform worse. Given its spectral efficiency and a low SER, the best choice is 256- QAM.