Authors : Ali Jawad Ibada and Muntadher Kadhim Abdullah
Abstract: Principles of Orthogonal Frequency Division Multiplexing (OFDM) are widely used in wireless communication. In OFDM system, many digital data are transmitted as sub-carriers. All sub-carriers are orthogonal to each other. High spectral efficiency are obtained due to the spectrum are quite narrow. OFDM also has advantages of saving of bandwidth, easy to implement modulation and demodulation, easy equalization, protection against Inter-Symbol Interference (ISI) and so on. However with all these advantages, there is a major disadvantage that it has large Peak-to-Average Power Ratio (PAPR). Large PAPR value makes system performance quite sensitive to distortion introduced by nonlinear amplifier, caused by nonlinear components. These non-linear components make the Bit Error Rate (BER) performance degraded. In this study, a proposed OFDM system based on BCH channel coding and Discrete Cosine Transform (DCT) technique are used to enhance performance of OFDM system by reducing the PAPR value without serious increasing in computational complexity and this leads to reduce the BER. BER performance also will be improved over Additive White Gaussian Noise (AWGN) and fading channels. All these are obtained with low cost of implementation, simple hardware and no require side information. Finally, results of simulation show the proposed system performance are much better comparing with that of the conventional OFDM system.
Ali Jawad Ibada and Muntadher Kadhim Abdullah, 2019. Performance Analysis and Improvement of OFDM System Based on BCH Channel Coding and DCT Technique. Journal of Engineering and Applied Sciences, 14: 1813-1819.