PAPR Suppression Algorithm For OFDM Systems Research

With the development of communication technology to human growth in demand for information provides an objective condition. People are becoming increasingly dependent on information and information technology permeate into the society, live, learn and work in all aspects. In particular, the demand for high speed data services is growing, however, due to limited bandwidth resources, and environmental interference and other factors of uncertainty inhibits the information needs of people on a huge expansion. It is this contradiction between supply and demand, stimulated people launched a series of studies in communication technology.OFDM technology because of its high frequency band utilization, anti-multipath interference, etc. characteristics, has been widespread concern in the industry, but also these advantages, making it a key technology of next generation wireless communication, and very likely to be the core of the fourth generation mobile communication technology. However, OFDM system, has fatal flaws: Fist,high peak average power ratio; Second, the sensitivity of frequency offset and phase error. These hindered the widespread use of OFDM system more prospects. The thesis focused on inhibition of OFDM systems with high PAPR.First of all, the value of academic research on the topic and research status were analyzed, Then theoretical analyzed and simulated the basic principles of OFDM systems, and PAPR suppression technology.Focuses on the program of sub-scrambling code insertion and the traditional SLM technology, then respectively according to different characteristics and advantages, disadvantages of two technology, optimized the existing technology solutions, formed two excellent PAPR reduction algorithm,one is the program of optimized sub-scrambling code insertion, another program is the improved SLM, discussed and simulation analyed the parameters of two technical programs, obtained some research results, but both technology have defects,which that category has.Therefore, introduced the idea of sub-scrambling codes insertion to the improved SLM program,formated a new integrated technology solutions. Strengthened its technical advantages,but also restrained the technical defects in this method, so, not only the performance of PAPR reduction has been remarkable increased, but also the system complexity, the computational complexity, system cost, have made considerable progress in both.The program of optimized sbu-scrambling code insertion and the integration of technology solutions,seried into a new OFDM system framework. As a result of those features , made this new OFDM framework has great value in the practical application.