Orthogonal Frequency Division Multiplexing System Peak To Average Power Ratio Study

OFDM is a representative one in the technologies of 4^th generation mobile communication, for the reason that it has very high bit rate and can also resist frequency-selective fading effectively. However, high PAPR (peak-to-average power ratio) is always an important factor which degrades the performance of OFDM system seriously. First, this paper introduces the essential principle of OFDM technology, then discusses the methods to determine the parameters of it. After that, the simulation results of OFDM system are given using different coding rate and modulation over different transmission environment. Subsequently, the paper describes the reasons for the PAPR. Meanwhile, with the simulation performance of them shown, several basic means to reduce PAPR are introduced. Besides, this paper also modifies one of the traditional schemes and proposes a simpler one, and the simulation results indicate its good performance. Especially, we propose a new method for the UWB-OFDM to reduce PAPR. Simulation on the computer tells us that it results in a great decrease on PAPR, so it has significant application value to the future communication systems with high speed and wide band.