Summary: | 碩士 === 國立中正大學 === 通訊工程研究所 === 95 === The technology brought by wireless communication has been one of the most important benefits to mankind in recent years. Since everything has become digitalized, and video and audio processing being more advanced than ever, multimedia has become more and more necessitated. Thus, to find out ways that can employ limited bandwidth efficiently and increase data transmitting rate is a very important subject. One of the ways is by using the OFDM system. Not only does it use the orthogonality among different sub-carriers to employ limited bandwidth efficiently, the OFDM system also has its own unique guard interval and cyclic prefix to solve the inter-symbol interference effectively while maintaining the same orthogonality between each sub-carrier.
In this thesis, we had suggested a way to reduce PAPR under the OFDM system by using data position permutation method (DPP). In addition to that, we had further modified DPP to lower BER. Through simulation results and comparison tables of complexity, spectrum efficiency and BER, we were able to prove that our proposed method is indeed better. Although the modified method shows a decrease of spectrum efficiency, but in return, it gets lower BER, and still manages to keep the performance of PAPR reduction the same as the original DPP method. To conclude, the original method has higher BER with higher spectrum efficiency; the modified method has lower BER but lower spectrum efficiency. Both methods can be used interchangeably depending on the need of the system.
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