The Ofdm System Based On Intelligent Algorithm Papr Suppression Technology Research

In recent years, one of the fastest growing and most widely used technologies inthe field of communication is wireless communication technology. Moreover, thedemand of the volume of business and communication quality of wirelesscommunications continues to increase. However, the available spectrum in nature islimited. As a result, the requirements for the data transfer rate and spectral efficiency inwireless communication technology is more rigorous than before.The technology of orthogonal frequency division multiplexing (OFDM), which isa high-speed transmission technology, appropriates for the wireless communicationenvironment very much. The OFDM technology has quite a lot of advantages, such asthe strong ability of againsting multipath fading, the high spectral efficiency, and thefast data transfer rates. Therefore, it has been widely used in various fields of wirelesscommunications. But the OFDM system has its inherent drawbacks: the high peak toaverage ratio (PAPR). This will affect the transmission performance of the OFDMsystem, increase the equipment complexity and improve the cost. So the high PAPR isa key factor of limiting the use of OFDM technology.In response to the above-mentioned issue, the methods reducing the PAPR of theOFDM system are put forward in this thesis. By analyzing the causes of the high PAPRof the OFDM system and studying the existing PAPR reduction techniques, threemethods of PAPR suppression are proposed in this thesis:1. The PAPR suppression method based on improved genetic algorithm. Thismethod, which combines the advantages of Newman phase sequence, SNTN phasesequence and GA, performances a better inhibitory effect;2. The PAPR suppression method based on bacterial foraging optimizationalgorithm. The main idea of this method is through optimizating the phases of thesub-carriers of OFDM signal by BFOA to avoid the generation of signals with highPAPR. The results of MATLAB simulation show that the bacterial foragingoptimization algorithm can effectively reduce the PAPR of OFDM system;3. The PAPR suppression method based on improved BFOA. Using the strong local search ability of BFOA and the Rapid positioning capability of phase sequence,this method obtains a better inhibitory effect than the above two methods;The study in this thesis shows that, it’s a new way for inhibiting the PAPR of theOFDM system to combine the intelligent optimization algorithms and mathematicaloptimization methods.