Comparative Study on The Performance of Wavelet-Based and DFT-Based MCM

Bekele, Sinshaw (2007) Comparative Study on The Performance of Wavelet-Based and DFT-Based MCM. Masters thesis, Addis Ababa University.

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Abstract

The demand for wireless networks has been growing rapidly over the recent past due to improved reliability, higher supported data rates, seamless connectivity between users and the access point, and low deployment costs relative to wireline infrastructure. This increase in demand started with the popular IEEE 802.11b wireless local area network standard. Many recent wireless network standards are now employing DFT based multicarrier modulation (MCM) popularly termed as OFDM in their design. Multicarrier modulation reduces the system’s susceptibility to the frequency selective fading channel, due to multipath propagation, by transforming it into a collection of approximately flat subchannels. As a result, this makes it easier to compensate for the distortion introduced by the channel. The effects of the Intersymbol Interference (ISI) and Intercarrier Interference (ICI) are reduced by the application of cyclic prefix. On the other hand, related research in wavelets points that due to the high spectral containment of wavelet filters the performance of MCM improves. This thesis work investigates simulation based performance of the DFT-based and Waveletbased MCM. The channel model and system models for both MCM schemes are considered. And using bit error rate (BER) versus signal-to-noise ratio (SNR) as measure of performance, transmission scenarios are implemented in AWGN channel and time varying multipath channel models and studied. Channel coding performances and the effects of carrier frequency offset are investigated. The performance results obtained by the simulation indicate that the wavelet-based implementation outperforms that of DFT-based in some channel scenarios. While in other channel models the DFT-based MCM shows increased performance.

Item Type: Thesis (Masters)
Uncontrolled Keywords: Electrical and Computer Engineering
Subjects: H Social Sciences > HE Transportation and Communications
Q Science > Q Science (General)
Q Science > QA Mathematics > QA75 Electronic computers. Computer science
T Technology > T Technology (General)
T Technology > TK Electrical engineering. Electronics Nuclear engineering
Divisions: Africana
Depositing User: Andriamparany Edilbert RANOARIVONY
Date Deposited: 27 Nov 2018 12:10
Last Modified: 27 Nov 2018 12:10
URI: http://thesisbank.jhia.ac.ke/id/eprint/7778

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