一种降低FBMC-OQAM系统PAPR的低复杂度选择性映射算法

摘要

Filter-bank multi-carrier( FBMC) is one of the key objects of the fifth generation cellular net-work(5G) radio access technology. However,there is also a high peak-to-average power ratio(PAPR). Through analyzing the overlapping characteristics and signal power distribution characteristics of FBMC-OQAM signal,the selective mapping( SLM) method of reducing PAPR in OFDM system is improved,and a Low-complexity Dispersion Selective Mapping(LD-SLM) method is proposed,which is better than the Dispersive Selective Mapping( DSLM) method. The LD-SLM method rotates the current data block signal with the alternative rotation vector,and selects the optimal rotation vector by calculating the PAPR of the signal in the current signal period [T,3T],and updates the current data block signal. The data block sig-nals are similarly optimized until all data blocks are optimized. By comparing the algorithm complexity,it is concluded that the LD-SLM algorithm is 50％ lower than the DSLM algorithm. The simulation results show that the LD-SLM method can effectively reduce the PAPR of the FBMC-OQAM system.%滤波器组多载波(FBMC)是第五代蜂窝网络无线接入技术重点考虑的对象之一,然而其存在较高的峰均功率比(PAPR).通过分析FBMC-OQAM信号的重叠特性和信号功率分布特点,将传统选择性映射(SLM)方法加以改进,提出了一种比色散选择性映射(DSLM)方法更优的低复杂度色散选择性映射(LD-SLM)方法.LD-SLM方法用备选旋转矢量将当前数据块信号旋转,通过计算在当前信号周期[T,3T]区间内信号的PAPR来选取最优旋转矢量,并更新当前数据块信号,接着对下一个数据块信号进行同样的优化,直至所有的数据块都被优化.通过比较算法复杂度可知,LD-SLM算法相比DSLM算法降低了50％,仿真实验表明LD-SLM方法能有效降低FBMC-OQAM系统的PAPR.