用DDS+PLL实现多普勒频移补偿  

A Method for Compensating Doppler Frequency Shift Based on DDS+PLL

作　　者：钟军涛[1] 陈建民[1] 

机构地区：[1]中国电子科技集团公司第54研究所,河北石家庄050081

出　　处：《无线电通信技术》2007年第2期46-48,共3页Radio Communications Technology

摘　　要：在低轨道卫星(LEO)通信链路中,由于星地之间相对运动速度较快而存在较大的多普勒频移,为了保证通信质量,必须对多普勒频移进行补偿。基于DDS+PLL技术实现对多普勒频移补偿的方法是一种开环控制方式,这种方法结合了DDS的频率分辨率高和频率捷变速率快等优点,以及PLL具有的窄带滤波跟踪特性。分析了DDS频率阶跃对于PLL输出响应的瞬态影响,并且给出了相应的改善方法。该技术已经在工程中得到应用和验证。In LEO satellite communication hnks,there is large range Doppler frequency shift due to rapid relative speed between satellite and earth. To ensure the quality of communication, Doppler frequency shift muse be compensated. The method initroduce in this paper integrates the advantages of DDS such as higher frequency resolution and higher frequency change speed etc. Based on DDS ＋ PLL technology for compensating Doppler frequency shift and including the narrowband filter tracking characteristic of PLL, this method is an open-loop control mode, It analyzes the transient effect of frequency step of DDS on the PLL output response, and puts forward a corresponding improving way. This technology has found application and testification in project.

关 键 词：DDS PLL 多普勒频移 开环控制 最大相位误差 

分 类 号：TN958[电子电信—信号与信息处理]