The Study Of PAPR Reduction In OFDM System

It will become the aim of the mobile communication systems of next generation to realize multimedia transmission with high quality and speed. Orthogonal Frequency Division Multiplexing (OFDM) is regarded as the key technology of physical layer in the wireless communication systems of the next generation because of its robustness against multi-path channel. Up to now it has been applied to many wireless communication systems. As one of multi-carrier communication systems, OFDM also suffers from the problem of high Peak to Average Power Ratio (PAPR). Higher PAPR is the major problem that needs to be resolved in OFDM system, because it would directly affect the cost and efficiency of the whole system.The way to reduce PAPR is generally to be divided into three kinds: pre-distortion, coding, and phase-controlling. Simple theoretical analysis and research are given to all the above kinds in this article, and we focus the main emphasis on clipping and filtering, which is one kind of pre-distortion, and also selected mapping, which is one kind of phase-controlling. Beside theoretical analysis and computer simulation of the two kinds of technique, we also do some deeply research and make some improvement and extension of these two algorithms, and at the same time, compare the difference of the performance of them. In the end of this article, we give our analysis and prediction about the probability of application of these techniques.