微纳卫星编队的欠采样传输无源定位方法

Passive location method based on sub-sampling transmissions in micro/nano-satellite

基于微纳卫星编队的到达时差(TDOA)/到达频差(FDOA)无源定位系统中,定位精度的提高需大幅度增加链路传输数据量,在星间链路带宽受限情况下将严重制约系统的工作效率。该文提出了一种欠采样传输时频差估计方法,在不增加传输数据量条件下,保持TDOA估计精度不变,且FDOA估计精度随欠采样所形成的时间扩展显著提升。分析了欠采样传输的时差估计精度,以及最大欠采倍数约束条件。仿真表明:对于宽带信号,该方法在传输数据量相同条件下,定位性能相对于压缩感知(CS)方法可提升6倍以上。

In time difference of arrival（TDOA）/frequency difference of arrival（FDOA） passive location systems used in micro/nano-satellite formations,improving the location accuracy usually requires a large increase in data transmissions, which severely reduces the system efficiency due to the narrow data link bandwidth of the satellites.A TDOA/FDOA estimation method is developed based on sub-sampling transmissions without increasing the data transmissions,which significantly improves the FDOA accuracy by a time expansion while maintaining the TDOA estimation accuracy.The TDOA accuracy is analyzed and the maximum sub-sampling rate is derived.Simulations show that for wideband signals,the location accuracy of this method is improved more than 6fold over that of the compressed sensing method for the same data transmission.