低信噪比高动态信号的大载波频偏捕获算法  

Large Carrier Frequency Offset Acquisition Algorithm for High Dynamic Signal with Low SNR

作　　者：崔艳[1] 秦勇[2] 

机构地区：[1]西安财经学院统计学院 [2]中国人民解放军92497部队70分队

出　　处：《科学技术与工程》2014年第27期237-241,共5页Science Technology and Engineering

基　　金：陕西省教育厅自然科学基金项目(12JK0877)资助

摘　　要：针对低信噪比高动态信号的载波频偏捕获提出了一种新的算法即谱线平移算法。首先,介绍了现有的大载波频偏捕获技术,分析了其不能适应高动态信号捕获的原因;其次,分析了载波频偏及其变化率对载波频偏捕获的影响,主要考虑多普勒频移变化率对信号捕获的影响,它将严重限制低信噪比情况下对载波频偏估计时非相干累加的次数,在此基础上,提出并研究了适应低信噪比高动态信号大载波频偏捕获的谱线平移算法,并对算法进行了性能仿真,表明其具有2-3 dB的改善增益,与最大似然算法相比具有一定优势。A new algorithm is provided for carrier frequency offset acquisition for high dynamic signal with low SNR,and it is spectrum line shift algorithm. Firstly,current large carrier frequency offset acquisition technology is introduced,and the reason why this technology can＇t adapt to high dynamic signal acquisition is analyzed. Secondly,carrier frequency offset acquisition affected by carrier frequency offset and its rate of change is analyzed. It＇s mainly considered that Doppler frequency shift change rate affects signal＇s acquisition. Doppler frequency shift change rate seriously reduces non-coherent accumulation number during carrier frequency offset estimation at low SNR. On this base,spectrum line shift algorithm is provided and researched,and it can adapt to large carrier frequency offset acquisition for high dynamic signal with low SNR. It＇s shown that the algorithm has improvement of gain of 2 - 3 dB,and compared with ML,the algorithm has absolute advantage by MATLAB simulation.

关 键 词：多普勒频偏 卫星移动通信 载波频偏捕获 低地球轨道 

分 类 号：TN97[电子电信—信号与信息处理]