AM-AM变换对卫星跟踪和数据中继DOA估计的影响  

Effects of AM-AM Conversion on DOA Estimation in Tracking and Data Relay Satellite System

作　　者：谭晓衡[1] 胡洋[1] 刘煜[1] 

机构地区：[1]重庆大学通信与测控中心,重庆400030

出　　处：《应用科学学报》2010年第5期470-475,共6页Journal of Applied Sciences

基　　金：国家自然科学基金(No.61001089);重庆市自然科学基金(No.2010BB2049)资助

摘　　要：在跟踪和数据中继卫星系统反向链路中,多路频分复用信号通过高功率放大器时存在严重的交调干扰,导致输出的各路阵元信号严重失真.针对这一问题,该文通过幂级数模型分析高功率放大器调幅-调幅(AM-AM)变换对通道间幅度一致性的影响机理,建立幅度不一致性对波达方向(direction of arrival,DOA)估计影响的数学模型,并进行计算机仿真.理论分析和仿真结果表明:高功率放大器的AM-AM变换不会引起估计角度的偏移,但会导致空间角度范围内的谱峰值降低,同时使3 dB谱宽变宽.此外,AM-AM变换还会导致DOA估计性能恶化.In the reverse link of tracking and data relay satellite system（TDRSS）,AM-AM conversion in the high-power amplifier for frequency-division multiplexing（FDM） signals causes severe inter-modulation interference to the signals in different channels.The interference results in distortion of the channel signals.The present work uses power series to analyze the influence of AM-AM conversion on the amplifier＇s magnitude consistency among the channels,and establish a mathematical model of the influence of magnitude inconsistency on DOA estimation.Theoretical analysis and simulation results show that AM-AM conversion in high-power amplifier does not affect the offset of the estimated angle,but reduces the spectral peak within the spatial angle and increases the 3 dB bandwidth.AM-AM conversion also deteriorates the DOA estimation performance.

关 键 词：跟踪和数据中继卫星系统 波达方向 AM-AM变换 高功率放大器 幅度不一致性 

分 类 号：TN911[电子电信—通信与信息系统]