【作者】 李柏渝；

【导师】 欧钢；

【作者基本信息】 国防科学技术大学 ， 信息与通信工程， 2011， 博士

【摘要】 高性能卫星导航接收机是卫星导航系统中重要的系统级设备之一,通常要求具有高测量精度与大动态范围。模拟信道是导航接收机中必不可少的组成部分之一,其幅频特性、相频特性成为制约接收机精度向亚纳秒量级推进的瓶颈,其动态范围对接收机抗干扰性能有重要影响。论文以我国北斗卫星导航系统的建设为应用背景,基于导航接收机高精度测距、频率规划和抗干扰大动态范围设计等前沿研究课题,从四个方面对高性能导航接收机的模拟信道展开了研究工作:(1)接收机伪距测量精度和载波相位测量精度的分析方法大多把接收信道的等效低通滤波器hL(t)简化为理想模型或某些特殊模型,难以满足实际高性能接收机的优化设计需求。本文把hL(t)推广为任意复函数,分析得到了相干/非相干早迟码估计器的BPSK/QPSK信号伪距精度表达式和乘法/反正切估计器的BPSK/QPSK信号载波相位精度表达式;给出了反正切估计器下,BPSK/QPSK信号载波相位测量精度的最优滤波器表达式。理论与仿真分析验证了模型的有效性;本文模型明显优于经典分析模型,可作为接收机信道优化设计的参考。(2)测量零值对接收机测距偏差有直接影响,但目前尚没有分析任意信道特性对零值测量影响的通用模型。基于上述的hL(t),本文分别研究了滤波器幅频和群时延波动对BPSK/QPSK信号伪距测量零值和载波相位测量零值的影响;将上述分析方法在时频域抗干扰处理的情况下进行了推广,从理论上解释了干扰带宽、位置变化导致BPSK/QPSK信号伪距零值和载波相位零值发生变化的现象;论文还探讨了时延零值的校正技术,指出校正成立的充分条件及其局限性。理论分析与软件接收机仿真结果最大误差在0.2ns以内,证明了本文分析模型的精确性。(3)随着各导航系统的现代化,宽带导航信号的频率规划受到越来越多的制约。本文针对导航接收机特点,综合考虑接收机性能及软硬件实现复杂度等各方面因素,完善了BPSK/QPSK信号导航接收机的一般性频率规划方法,研究了BOC信号导航接收机的通用频率规划方法,可用于指导导航接收机设计。本文还建立了hL(t)非理想情况下,I/Q幅相误差的分析模型,推导得到了幅相误差影响BPSK/QPSK信号测量精度和测量零值的表达式,理论分析与软件接收机仿真值吻合较好,论证了模拟正交下变频在高性能用户机中应用的可行性。(4)为适应“导航战”的需求,要求抗干扰接收机的模拟信道具有大动态范围。本文建立了模拟信道的简化模型,以给定的噪声系数恶化容限为约束条件,给出了不同信号接收场景下,模拟信道动态范围的优化设计及各级增益划分方法;本文指出了动态范围的优化在实质上就是求曲线交点的过程,揭示了各电路参量与模拟信道动态范围的关系,给出了明确的动态范围优化设计方法。最后,总结了论文的研究成果及其工程应用,并展望了下一步要开展的工作。论文的研究成果已直接应用于我国北斗卫星导航系统的若干工程型号项目中。更多还原

【Abstract】 High performance satellite navigation receiver is one of the important systemicequipments in satellite navigation systems, which usually requires accurate rangingmeasurement and large dynamic range. Analog signal channel is one of the necessaryparts of navigation receivers, its amplitude response and phase response have becomethe bottlenecks which made ranging measurement difficult to reach sub-nanosecondaccuracy, and its dynamic range has great influence on the performance of anti-jammingreceivers. This dissertation takes the construction of the Chinese Compass satellitenavigation system as the application background, and is based on some advanced topicssuch as accuracy ranging measurement of navigation receiver, frequency plan andanti-jamming large dynamic range design, four aspects of the study on analog signalchannel in high performance satellite navigation receivers will be carried out:(1) Most analytical methods of PN ranging measurement and carrier phase rangingmeasurement assume that the hL(t), the channel equivalent lowpass filter, is an idealmodel or some special model, which makes it difficult to meet the design requirementof the actual high performance navigation receivers. This paper extends hL(t) to anycomplex function, and investigates the formula of PN ranging measurement ofBPSK/QPSK signal which is estimated by coherent/non-coherent Early-Late estimatorand the formula of carrier phase ranging measurement of BPSK/QPSK signal which isestimated by multiplier/arctangent estimator; and gives out the expression of the optimalfilter for carrier phase ranging measurement of BPSK/QPSK signal when usedarctangent estimation. The validity of this method has been proved by analytical andsimulation results. The model in the dissertation is obviously better than the classicalanalytical models, which can be used as the reference for the optimal design of thereceiver channel.(2) Zero value has direct impact on the measurement bias in receivers, but there isa lack of general model to analyze the impact of any channel characteristics on the zerovalue measurement. Based on the hL(t) mentioned above, the impact on the PN zerovalue and carrier phase zero value of BPSK/QPSK signal, caused by the filter’samplitude response and group delay, is studied in this dissertation respectively; thisdissertation extends above methods to the occasion with time and frequency domainanti-jamming, explains the phenomena that interfere with different bandwidth andcenter frequency bring on different PN zero value and carrier phase zero value ofBPSK/QPSK signal; the dissertation also discusses the delay calibration technique,presented the sufficient condition which guarantees the validity of the calibration andit’s shortage. The maximal error between the theoretical results and simulation results isless than 0.2 ns, which proves the accuracy of the model. (3) Along with the modernization of various satellite navigation systems, thefrequency plan has been restricted increasingly. According to the characteristic ofnavigation receivers, this dissertation considers the performance of receiver, as well asthe realization complexity of hardware and software, improves the general method offrequency plan for BPSK/QPSK signal navigation receivers, studys the general methodof frequency plan for BOC signal navigation receivers, which can direct the navigationreceiver design. This dissertation also establishes the analysis model for I/Q amplitudeand phase error when hL(t) is non-ideal, works out the formula of ranging measurementand zero value of BPSK/QPSK signal caused by the I/Q amplitude and phase error, thetheoretic result agrees quiet well with the simulation results in the software receiver,which proves the feasibility of analog quadrate down conversion in high performancereceivers.(4) To meet the requirement of the“Navigation Warfare”, a large dynamic range isrequired in the analog channel design of the anti-jamming receivers. This dissertationsets up the ordinary model of analog signal channel, takes the given noise figuretolerance as the restriction, and points out the simple and convenient way to optimizethe dynamic range of analog channel as well as the gain plan for each stage; thisdissertation points out that the essence of the dynamic range optimizing is the process tosolve the point of intersection of a set of curves, reveals the relationship betweendynamic range and each circuit parameters, and presents a clear way to the optimaldesign of dynamic range.At last, the research work in this thesis and its engineering application aresummarized , the further work for next step is also presented. The results of the researchhave been already used in many projects of Chinese Compass satellite navigationsystem.更多还原