摘要
为降低正交频分复用系统(OFDM)中高旁瓣对主用户的影响,使用基因算法探讨了OFDM系统中的旁瓣抑制问题。该方法是基于基因算法的搜索技术,在OFDM传输频带两侧插入取消子载波(CC),通过改变取消子载波的数目和载波频率间隔,确定以取消子载波权重为变量的旁瓣抑制适应度函数,再经过基因算法计算,使适应度函数达到最小值,确定最佳载波权重和数目。综合功率峰均比与占用频谱资源这两个条件考虑,仿真结果表明:在OFDM主频带两侧分别插入2个频率间隔与数据子载波相同的取消子载波,可抑制旁瓣达到49.86 d B,较之经典的CC算法旁瓣抑制效果更佳。
In this paper,side-lobe suppression in orthogonal frequency division multiplexing(OFDM)systems is investigated by using genetic algorithm,in order to reduce the influence of high sidelobe on primary user.The method is based on the search technique of genetic algorithm.By inserting cancellation sub-carriers(CC)on both sides of the OFDM transmission band and changing the number of sub-carriers as well as the carrier frequency interval,the fitness function of side-lobe suppression is determined whose variations are the weights of cancellation sub-carriers.Then the best carrier weights and number were determined as gene algorithm calculates the fitness function to a minimum.The simulation results show that when two sub-carriers with the same frequency offset of data sub-carriers are inserted on both sides of the OFDM transmission band,it can suppress the side-lobe to 49.86 dB,which achieves better results compared to the classic CC algorithm.
作者
薛梅
周杰
刘娜
XUE Mei;ZHOU Jie;LIU Na(School of Electronic and Information Engineering,Nanjing University of Information Science and Technology,Nanjing 210044,China)
出处
《广西大学学报（自然科学版）》
CAS
北大核心
2018年第2期596-603,共8页
Journal of Guangxi University（Natural Science Edition）
基金
国家自然科学基金面上项目(61471153)
江苏省高校自然科学基金重大项目(14KJA510001)
关键词
正交频分复用(OFDM)
旁瓣抑制
基因算法
取消子载波
适应度函数
orthogonal frequency division multiplexing(DFDM)
side-lobe suppression
gene algorithm
cancellation carrier
fitness function
