基于联合算法降低OFDM峰均比技术的仿真研究

OFDM PAPR Reduction Technology Based on Union Algorithm Scheme

高峰均功率比(PAPR)是正交频分复用(OFDM)技术中存在的主要缺点,高的峰均功率比会导致功放处于非线性区造成信号失真,而传统部分选择映射(SLM)虽然能够有效的降低峰均功率比,但是由于采用多路IFFT变换,复杂度非常高。为解决以上问题,提出了一种改进的部分选择映射和限幅的联合算法。改进算法利用这两种方法在性能上互补的特性来降低峰均功率比,并且改进的SLM算法在发送端采用数据分组以及选择合适的矩阵代替IFFT模块,使得IFFT模块运算大大减少,从而降低了系统的复杂度。通过理论分析以及在MATLAB软件上仿真的结果表明,改进方法不仅能更有效地抑制峰均功率比,同时可减小计算的复杂度与系统实现的复杂度。

High Peak-to-Average Power Ratio（PAPR） is the main shortcoming in Orthogonal Division Multiple- xing（OFDM） systems. Larger peak power will lead the amplifier to non-linear area, causing signal distortion. Al- though the traditional part mapping （SLM） choice can effectively reduce peak power, because of the IFFT transform, the complexity is very high. To solve the above problems, a union algorithm of improved SLM and clipping was pro- posed for PAPR reduction. The union algorithm uses SLM and clipping in performance characteristics of complemen- tary to reduce PAPR. The improved SLM algorithm, which uses the data packet after the sender and chooses appro- priate matrix instead of IFFT module, makes the IFFF module operation decrease greatly and reduces the complexity of the system. At the same time, the PAPR performance can be further improved. Through the theoretical analysis and the simulation of MATLAB software, the results show that the method can not only restrain the peak power more effectively, but also reduce the complexity of the algorithm and the complexity of the system.