Simulation of models and BER performances of DWT-OFDM versus FFT-OFDM

Abdullah, Khaizuran and Hussain, Zahir M. (2011) Simulation of models and BER performances of DWT-OFDM versus FFT-OFDM. In: Discrete wavelet transforms: algorithms and applications. InTech, Rijeka, Croatia, pp. 57-66. ISBN 9789533074825

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Abstract

Simulation approaches using MATLAB for wavelet based OFDM, particularly in DWT-OFDM as alternative substitutions for Fourier based OFDM are demonstrated. Conventional OFDM systems use IFFT and FFT algorithms at the transmitter and receiver respectively to multiplex the signals and transmit them simultaneously over a number of subcarriers. The system employs guard intervals or cyclic prefixes (CP) so that the delay spread of the channel becomes longer than the channel impulse response. The system must make sure that the cyclic prefix is a small fraction of the per carrier symbol duration. The purpose of employing the CP is to minimize inter-symbol interference (ISI). However a CP reduces the power efficiency and data throughput. The CP also has the disadvantage of reducing the spectral containment of the channels. Due to these issues, an alternative method is to use the wavelet transform to replace the IFFT and FFT blocks. The wavelet transform is referred as Discrete Wavelet Transform OFDM (DWT-OFDM). By using the transform, the spectral containment of the channels is better since they are not using CP. The wavelet based OFDM (DWT-OFDM) is assumed to have ortho-normal bases properties and satisfy the perfect reconstruction property. We use different wavelet families and compare with conventional FFT-OFDM system. BER performances of both OFDM systems are also obtained. It is found that the DWT-OFDM platform is superior as compared to others as it has less error rate, especially using bior5.5 or rbior3.3 wavelet family.

Item Type:	Book Chapter
Additional Information:	3407/35320
Uncontrolled Keywords:	DWT-OFDM, FFT-OFDM
Subjects:	T Technology > TK Electrical engineering. Electronics Nuclear engineering > TK5101 Telecommunication. Including telegraphy, radio, radar, television
Kulliyyahs/Centres/Divisions/Institutes (Can select more than one option. Press CONTROL button):	Kulliyyah of Engineering > Department of Electrical and Computer Engineering
Depositing User:	Dr Khaizuran Abdullah
Date Deposited:	04 Mar 2014 15:34
Last Modified:	09 Mar 2014 05:45
URI:	http://irep.iium.edu.my/id/eprint/35320

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