一种用于快速捕获低轨物联网信号的PMF-FFT改进算法  

Improved PMF-FFT algorithm for fast acquisition of low-orbit internet of things signals

作　　者：戚沪朋 边东明 张更新 QI Hupeng;BIAN Dongming;ZHANG Gengxin(School of Communications and Information Engineering,Nanjing University of Posts and Telecommunications,Nanjing 210003,China)

机构地区：[1]南京邮电大学通信与信息工程学院,南京210003

出　　处：《光通信技术》2023年第6期48-52,共5页Optical Communication Technology

基　　金：国家自然科学基金区域创新发展联合基金重点项目(U21A20450)资助。

摘　　要：为了在高动态、低信噪比的条件下实现对低轨物联网信号的快速捕获,提出了一种用于快速捕获低轨物联网信号的部分匹配滤波-快速傅里叶变换(PMF-FFT)改进算法。首先,利用星历信息预估多普勒频偏,缩小频域搜索范围;然后,通过补零、加窗方法克服PMF-FFT算法的扇贝损失;最后,采用频域差分非相干累积提高低信噪比下的输出增益。仿真分析表明,所提改进算法在信噪比为-25~-15 dB时能提高低轨物联网信号的检测概率,搜索范围由15~35 kHz缩小为24.8~25.2 kHz。In order to achieve rapid capture of low-rail IoT signals under the conditions of high dynamic and low signal-to-noise ratio,a partial matching filter-fast Fourier transform(PMF-FFT)improvement algorithm for rapid capture of low-rail IoT signals is proposed.First of all,the ephemeris information is used to predict the Doppler frequency bias and narrow the frequency domain search range;then,the scallop loss of PMF-FFT algorithm is overcomed by zero padding and windowing.Finally,the frequency domain differential incohere accumulation is used to improve the output gain under low signal-to-noise ratio.The simulation analysis shows that the proposed algorithm can improve the detection probability of low-orbit iot signal when the signal-to-noise ratio is-25~-15 dB,and the search range is reduced from 15~35 kHz to 24.8~25.2 kHz.

关 键 词：低轨卫星物联网 多普勒频移估计 扇贝损失 部分匹配滤波-快速傅里叶变换 

分 类 号：TN91[电子电信—通信与信息系统]