F-OFDM系统中的自适应EM相位噪声抑制算法

Self-adaptive EM Phase Noise Suppression Algorithm in F-OFDM System

滤波正交频分复用技术(Filtered Orthogonal Frequency-Division Multiplexing,F-OFDM)是针对下一代移动通信的新技术,它在保持4GOFDM技术强抗干扰能力等诸多优点的基础上,能够适应未来各种灵活的业务配置;但其对相位噪声更加敏感,相噪会导致其出现子带共同相位误差(Sub-Band Common Phase Error,SCPE)和子带载波间干扰(Sub-Band Inter-Carrier Interference,SICI),严重降低系统性能。基于最大期望准则(EM),提出一种自适应EM相噪抑制算法(AEM-PNS),其中包含EM-SCPE和EM-SICI两个子算法,算法通过在符号帧中插入的相噪指示符(Phase Noise Instruction Symbol,PNIS)和导频指示符(Pilot Instruction Symbol,PIS)自动选择子算法。仿真结果表明,新提出的算法能自适应跟踪相噪的变化,有效降低相位噪声的影响,同时具有较低的计算复杂度和较高的频谱效率。

Filtered orthogonal frequency-division multiplexing(F-OFDM)is a new technology for next generation mobile communication system.F-OFDM can maintain the advantages such as strong anti-interference ability in OFDM system,and is adaptive for different flexible service configuration in the future.However,it’s more sensitive to phase noise than OFDM,which will cause sub-band common phase error(SCPE)and sub-band inter-carrier interference(SICI),thus seriously decreasing the performance of the system.This paper proposed a self-adaptive EM phase noise suppression algorithm(AEM-PNS)to reduce the phase noise in F-OFDM.It includes two sub-algorithms:EM-SCPE and EM-SICI.AEM-PNS can choose suitable phase noise suppression sub-algorithm automatically according to the inserted phase noise instruction symbol(PNIS)and pilot instruction symbol(PIS)in symbol frame.Simulation results show that the proposed algorithm can track phase noise adaptively,reduce the influence caused by phase noise effectively,and keep low complexity and high spectral efficiency simultaneously.