The frequency band between 5 010 MHz and 5 030 MHz allocated as C band has been used as a candidate in the global navigation satellite systems （GNSS） along with more and more naviga- tion services in L band. The pot...The frequency band between 5 010 MHz and 5 030 MHz allocated as C band has been used as a candidate in the global navigation satellite systems （GNSS） along with more and more naviga- tion services in L band. The potential benefits and technical requirements of C band for satellite navi- gation have been analyzed before. However the degradation of effective carrier-power-to-noise densi- ty ratio（ A （C/No ）eu） based on code tracking spectral sensitivity coefficient（ CT_SSC ） as a compati- bility assessment methodology for potential GNSS radio frequency compatibility in C-Band has not been discussed clearly. So the compatibility of the signals in the C band between BeiDou （BD） B1 C and GPS L1C, L1C/A, Galileo E1Os as the interoperability or classical signals in L band is analyzed. Simulation results reveal the interference degree between BD III B1C and GPS L1C/A, L1C, Galileo E1OS. The results can also reveal that the multiplexed binary offset carrier （MBOC） and binary phase shift keying （BPSK） modulation is not appropriate for C band.展开更多
针对基于载噪比(carrier to noise ratio,CNR)的GNSS干扰源定位,在存在多个干扰源、多径传输且接收机间距较远时定位难度大、精度低的问题,提出了一种加权K均值(K-Means)聚类算法与基于差分接收信号强度(differential received signal s...针对基于载噪比(carrier to noise ratio,CNR)的GNSS干扰源定位,在存在多个干扰源、多径传输且接收机间距较远时定位难度大、精度低的问题,提出了一种加权K均值(K-Means)聚类算法与基于差分接收信号强度(differential received signal strength,DRSS)的方程解算定位相结合的多干扰源定位方法.在假设干扰源个数确定以及单个接收机只受到一个干扰源影响的前提下,设计了改进的加权K-Means聚类算法实现对多个干扰源位置的初步估计.为了进一步降低在观测接收机相距较远时加权K-Means方法的定位误差,在聚类后选取各簇内受干扰影响显著的接收CNR构建基于DRSS的定位方程组,通过方程解算得到更加精细的定位结果.仿真结果表明,所提出的定位方案可以实现对多干扰源的定位,结合DRSS参数定位后,单干扰源场景下定位误差可降低19%以上,存在两个单音干扰源的场景下定位误差可降低38%以上.展开更多
A dual transponder carrier ranging method can be used to measure inter-satellite distance with high precision by combining the reference and the to-and-fro measurements. Based on the differential techniques, the oscil...A dual transponder carrier ranging method can be used to measure inter-satellite distance with high precision by combining the reference and the to-and-fro measurements. Based on the differential techniques, the oscillator phase noise, which is the main error source for microwave ranging systems, can be significantly attenuated. Further, since the range measurements are derived on the same satellite, the dual transponder ranging system does not need a time tagging system to synchronize the two satellites. In view of the lack of oscillator noise analysis on the dual transponder ranging model, a comprehensive analysis of oscillator noise effects on ranging accuracy is provided. First, the dual transponder ranging system is described with emphasis on the detailed analysis of oscillator noise on measurement precision. Then, a high-fidelity numerical simulation approach based on the power spectrum density of an actual ultra-stable oscillator is carried out in both frequency domain and time domain to support the presented theoretical analysis. The simulation results under different conditions are consistent with the proposed concepts, which makes the results reliable. Besides, the results demonstrate that a high level of accuracy can be achieved by using this oscillator noise cancelation-oriented ranging method.展开更多
基金Supported by the National High Technology Research and Development Program of China(863Program)(2011AA120502)
文摘The frequency band between 5 010 MHz and 5 030 MHz allocated as C band has been used as a candidate in the global navigation satellite systems （GNSS） along with more and more naviga- tion services in L band. The potential benefits and technical requirements of C band for satellite navi- gation have been analyzed before. However the degradation of effective carrier-power-to-noise densi- ty ratio（ A （C/No ）eu） based on code tracking spectral sensitivity coefficient（ CT_SSC ） as a compati- bility assessment methodology for potential GNSS radio frequency compatibility in C-Band has not been discussed clearly. So the compatibility of the signals in the C band between BeiDou （BD） B1 C and GPS L1C, L1C/A, Galileo E1Os as the interoperability or classical signals in L band is analyzed. Simulation results reveal the interference degree between BD III B1C and GPS L1C/A, L1C, Galileo E1OS. The results can also reveal that the multiplexed binary offset carrier （MBOC） and binary phase shift keying （BPSK） modulation is not appropriate for C band.
文摘针对基于载噪比(carrier to noise ratio,CNR)的GNSS干扰源定位,在存在多个干扰源、多径传输且接收机间距较远时定位难度大、精度低的问题,提出了一种加权K均值(K-Means)聚类算法与基于差分接收信号强度(differential received signal strength,DRSS)的方程解算定位相结合的多干扰源定位方法.在假设干扰源个数确定以及单个接收机只受到一个干扰源影响的前提下,设计了改进的加权K-Means聚类算法实现对多个干扰源位置的初步估计.为了进一步降低在观测接收机相距较远时加权K-Means方法的定位误差,在聚类后选取各簇内受干扰影响显著的接收CNR构建基于DRSS的定位方程组,通过方程解算得到更加精细的定位结果.仿真结果表明,所提出的定位方案可以实现对多干扰源的定位,结合DRSS参数定位后,单干扰源场景下定位误差可降低19%以上,存在两个单音干扰源的场景下定位误差可降低38%以上.
基金Project(61106113)supported by the National Natural Science Foundation of China
文摘A dual transponder carrier ranging method can be used to measure inter-satellite distance with high precision by combining the reference and the to-and-fro measurements. Based on the differential techniques, the oscillator phase noise, which is the main error source for microwave ranging systems, can be significantly attenuated. Further, since the range measurements are derived on the same satellite, the dual transponder ranging system does not need a time tagging system to synchronize the two satellites. In view of the lack of oscillator noise analysis on the dual transponder ranging model, a comprehensive analysis of oscillator noise effects on ranging accuracy is provided. First, the dual transponder ranging system is described with emphasis on the detailed analysis of oscillator noise on measurement precision. Then, a high-fidelity numerical simulation approach based on the power spectrum density of an actual ultra-stable oscillator is carried out in both frequency domain and time domain to support the presented theoretical analysis. The simulation results under different conditions are consistent with the proposed concepts, which makes the results reliable. Besides, the results demonstrate that a high level of accuracy can be achieved by using this oscillator noise cancelation-oriented ranging method.
