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BER performance evaluation in OFDM system using channel coding techniques

BER performance evaluation in OFDM system using channel coding techniques / Celine Lim Chai Lin
Pada zaman ini, sistem perhubungan tanpa wayar berkembang dengan pesat disebabkan oleh permintaan yang tinggi dalam perkhidmatan data dan penggunaan lebar jauh juga bertambah. Sejak kebelakangan ini, Pemultipleksan Pembahagian Frekuensi Orthogon (OFDM) telah berjaya diaplikasikan dalam penyiaran video digital dan menunjukkan bahawa ia mampu menguasai dunia sistem teknik modulasi tanpa wayar pada masa depan. Sistem perhubungan tanpa wayar yang bergenerasi baru menuntut penggunaan kuasa yang lebih rendah, pemprosesan data yang lebih cepat dan mempunyai kebolehpercayaan yang lebih tinggi. Ini boleh dicapai melalui sistem OFDM berkod (COFDM). Teknik-teknik saluran pengekodan seperti kod Konvolusi, kod Turbo, Reed-Solomon (RS) dan kod gabungan Reed-Solomon dengan kod Konvolusi (RS-CC) telah digunakan dalam projek ini. Selain itu, saluran frekuensi Rayleigh dipilih sebagai saluran hingar dalam projek ini. Tiga kadar kod yang berbeza iaitu 1⁄3, 1/2 dan 2/3 telah digunakan untuk menguji prestasi BER. Hasil simulasi menunjukkan bahawa apabila kadar kod semakin berkurang, sistem OFDM akan menunjukkan peningkatan dalam prestasi BER. Pada BER 10−3 dengan kadar kod 1/3, RS-CC memberi prestasi BER 8 dB, manakala kod Turbo, kod Konvolusi, dan kod Reed-Solomon masing-masing menjanakan prestasi BER 7.6 dB, 6.5 dB dan 6 dB berbanding dengan sistem OFDM tanpa kod. Pada BER 10−3 dengan kadar kod 1/2, keuntungan sebanyak 6 dB, 4.6 dB, 4.5 dB dan 4 dB dicatatkan bagi RS-CC, kod Turbo, kod konvolusi dan RS kod. Keputusan membuat kesimpulan bahawa RS-CC adalah kod pilihan pada kadar kod 1/3. _______________________________________________________________________________________________________ Wireless communication systems are rapidly evolving with the demand for an enhanced data services and greater use of bandwidth. In recent years, Orthogonal Frequency Division Multiplexing (OFDM) has been successfully used in terrestrial digital video broadcasting and shown that it is a strong candidate for the modulation technique of future wireless systems. New generation wireless communication systems demand low power consumption, high data throughput, and high reliability. These requirements are often achieved through Coded OFDM (COFDM) systems. Convolutional code, Turbo code, Reed Solomon (RS) code and the concatenation of Reed-Solomon and Convolutional code (RS-CC) are implemented in this work for channel coding purposes. A Rayleigh frequency selective fading channel is being considered as the fading channel. BER performance evaluation of the considered codes was implemented using three different code rates which are 1⁄3, 1/2 and 2/3 code rates. Results from simulation reveals that lower code rate directly corresponds to an increase in OFDM system BER performance. At a BER of 10−3 with a 13⁄3 code rate, the RS-CC gave an 8dB performance gain in BER while Turbo code, Convolutional code, and Reed-Solomon code generated 7.6 dB, 6.5 dB and 6 dB BER performances respectively in comparison to the uncoded OFDM system. Results show that for the three different code rates considered, RS-CC demonstrated a better performance in improving the BER. In contrary when a code rate of 1/2 was considered at a BER of 10−3 , gain of 6dB, 4.6dB, 4.5 dB and 4dB were recorded for RS-CC, Turbo code, Convolutional code and RS code. It is concluded that RS-CC is the preferred code at the code rate of 13⁄.
Contributor(s):
Celine Lim Chai Lin - Author
Primary Item Type:
Final Year Project
Identifiers:
Accession Number : 875006084
Language:
English
Subject Keywords:
Wireless; communication; bandwidth
First presented to the public:
6/1/2016
Original Publication Date:
7/3/2018
Previously Published By:
Universiti Sains Malaysia
Place Of Publication:
School of Electrical & Electronic Engineering
Citation:
Extents:
Number of Pages - 119
License Grantor / Date Granted:
  / ( View License )
Date Deposited
2018-07-03 16:39:42.749
Date Last Updated
2019-01-07 11:24:32.9118
Submitter:
Mohd Jasnizam Mohd Salleh

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