The Research And Implementation Of Papr Reduction Based On OFDM Systems

The basic idea of OFDM (Orthogonal Frequency Division Multiplexing) is to divide the available spectrum into several subchannals and the data is sent by each channal. OFDM could minimize effects of frequency-selective fading and achieve high bandwidth efficiency because the subchannals are overlapping and orthogonal. Because OFDM has the advantages above, it has been widely used in wireless communication and powerline communication.However, a central disadvantage of OFDM is potentially high peak-to-average power ratio (PAPR) values, which can result in significant distortion when transmitted through a nonlinear device, such as a power amplifier transmitter, and increase the complexity of A/D and D/A convertor. Therefore it is highly desirable to reduce PAPR of the OFDM transmitted signals.This paper has particularly researched on methods of PAPR reduction for OFDM, and is arranged as following: the developing process of OFDM technology is introduced in Chapter 1. Chapter 2 mainly discusses the basic concepts of OFDM systems as well as important properties. Chapter 3 discusses the way to reduce PAPR in 3 categories. In Chapter 4, a method of reduce PAPR is choosen by trading off the effect of PAPR reduction and the complexity of hardware realization. How to realize the PAPR reduction method is discussed in detail in Chapter 5. Finally, we sum up all the work and give some prospects of OFDM technology in Chapter 6.