部分频带干扰下伪码跟踪误差分析

为精确分析部分频带干扰下伪码跟踪误差,需要考虑伪码的非理想随机特性。引入伪码的精细功率谱模型,对比分析了不同带宽干扰下基于简化谱和精细谱的码跟踪误差。定义了相对误差系数,用以定量描述伪码非理想随机特性对码跟踪误差的影响。当干扰带宽增大时,相对误差系数逐渐减小,伪码非理想随机特性对码跟踪误差的影响逐渐减小,基于简化谱的分析趋近于基于精细谱的分析。结合GPS L1 C/A码,给出了相对误差小于0.2的最小干扰带宽,并将其作为基于简化谱分析的适用条件。研究表明当干扰带宽大于伪码周期的频率的300倍时,伪码非理想随机特性导致的码跟踪精度变化可忽略,反之,则需要基于精细的功率谱模型进行码跟踪精度分析。

Analysis of code tracking error in the presence of partial-band interference

The nonideal random property of the pseudorandom code should be taken into account to analyze the code tracking error accurately in the present of partial-band interference. A precise power spectrum of the code is introduced, and the tracking errors obtained by simplified spectrum and precise spectrum are compared for different interference bandwidths. The relative error coefficient (REC) is defined to quantitatively describe the effect of nonideal random property on the tracking error. If the interference bandwidth is larger, the REC is smaller, and then the analysis results based on simplified spectrum and precise spectrum tend to agree. When the REC is smaller than 0.2, the minimum interference bandwidths are presented for GPS L1 C/A codes. The bandwidths are the bounds of the application scope of the analysis based on simplified spectrum. Research results indicate that if the interference bandwidth is larger than three hundred times of the frequency of the code period, the change of the code tracking error induced by the nonideal random property can be neglected. Conversely, the analysis based on precise spectrum is needed in the study of code tracking precision.