国防科技大学学报
國防科技大學學報
국방과기대학학보
JOURNAL OF NATIONAL UNIVERSITY OF DEFENSE TECHNOLOGY
2015年
4期
82-86
,共5页
关刚强%庞晶%刘文祥%王飞雪
關剛彊%龐晶%劉文祥%王飛雪
관강강%방정%류문상%왕비설
载噪比估计%信号畸变%异常监测%二阶阶跃
載譟比估計%信號畸變%異常鑑測%二階階躍
재조비고계%신호기변%이상감측%이계계약
carrier-to-noise ratio estimation%signal distortion%anomaly monitor%2nd order step
载噪比作为评估导航信号质量的重要指标,直接影响着接收机的捕获、跟踪和电文解调性能。推导了基于国际民航组织二阶阶跃信号畸变模型下导航接收机采用相关、非相关处理时载噪比估计与畸变模型参数之间的解析表达式,并分析了畸变参数对导航接收机载噪比估计误差的影响。理论分析及仿真结果表明:数字畸变参数变化范围下导航信号载噪比变化在10-2量级,增大模拟畸变的振荡频率或者减小衰减频率将会提高载噪比估计值,模拟畸变参数变化引起的载噪比损耗可达0.1 dBHz,畸变参数对载噪比估计的影响整体上都较小,因此导航接收机的载噪比输出不能作为监测导航信号是否异常的完备检测量。
載譟比作為評估導航信號質量的重要指標,直接影響著接收機的捕穫、跟蹤和電文解調性能。推導瞭基于國際民航組織二階階躍信號畸變模型下導航接收機採用相關、非相關處理時載譟比估計與畸變模型參數之間的解析錶達式,併分析瞭畸變參數對導航接收機載譟比估計誤差的影響。理論分析及倣真結果錶明:數字畸變參數變化範圍下導航信號載譟比變化在10-2量級,增大模擬畸變的振盪頻率或者減小衰減頻率將會提高載譟比估計值,模擬畸變參數變化引起的載譟比損耗可達0.1 dBHz,畸變參數對載譟比估計的影響整體上都較小,因此導航接收機的載譟比輸齣不能作為鑑測導航信號是否異常的完備檢測量。
재조비작위평고도항신호질량적중요지표,직접영향착접수궤적포획、근종화전문해조성능。추도료기우국제민항조직이계계약신호기변모형하도항접수궤채용상관、비상관처리시재조비고계여기변모형삼수지간적해석표체식,병분석료기변삼수대도항접수궤재조비고계오차적영향。이론분석급방진결과표명:수자기변삼수변화범위하도항신호재조비변화재10-2량급,증대모의기변적진탕빈솔혹자감소쇠감빈솔장회제고재조비고계치,모의기변삼수변화인기적재조비손모가체0.1 dBHz,기변삼수대재조비고계적영향정체상도교소,인차도항접수궤적재조비수출불능작위감측도항신호시부이상적완비검측량。
CNR(Carrier-to-Noise Ratio),an important indicator to evaluate the navigation signal quality,which directly affected the global navigation satellite system receiver performances of signal acquisition,carrier tracking,and data demodulation.Based on the distortion model of ICAO 2OS (International Civil Aviation Organization 2nd Order Step),the analytical expressions between CNR estimation and the distortion parameters of ICAO 2OS threat model were induced by using both coherent early-late processing and non-coherent early-late processing.And the influence of distortion parameters on CNR estimation error was analyzed.Theoretical analysis and simulation results show that carrier-to-noise ratio only changes in the 10 -2 order of magnitude when the TMA(Threat Model A)parameter changes within the set range,and can reach about 0. 1 dBHz caused by the TMB(Threat Model B)parameters.When increasing the TMB oscillation frequency and decreasing the attenuation factor can increase the estimated CNR.Consequently the distortion parameters of ICAO 2OS threat model have a small influence on the CNR estimation loss.Therefore,using the output CNR of the global navigation satellite system receiver to monitor the navigation signal abnormality is not reliable.