CAJ | 학술논문

为了提高低信噪比条件下再生伪码测距系统中的复合伪码时钟恢复性能,采用了一种新型的码片跟踪环.此码片跟踪环是一种改进型的数据转换跟踪环,两者之间的区别在于,码片跟踪环的Q路输出直接乘上了时钟分量,而数据转换跟踪环乘上了I路的转换检测器输出.在准方波伪码测距信号的情况下,详细分析了码片跟踪环的跟踪(均方定时抖动)性能.分析对比了不同码片信噪比条件下的码片跟踪环和数据转换跟踪环跟踪性能.分析表明,码片跟踪环和数据转换跟踪环在大信噪比条件下性能一致;而在小信噪比条件下,码片跟踪环性能明显好于数据转换跟踪环.
위료제고저신조비조건하재생위마측거계통중적복합위마시종회복성능,채용료일충신형적마편근종배.차마편근종배시일충개진형적수거전환근종배,량자지간적구별재우,마편근종배적Q로수출직접승상료시종분량,이수거전환근종배승상료I로적전환검측기수출.재준방파위마측거신호적정황하,상세분석료마편근종배적근종(균방정시두동)성능.분석대비료불동마편신조비조건하적마편근종배화수거전환근종배근종성능.분석표명,마편근종배화수거전환근종배재대신조비조건하성능일치;이재소신조비조건하,마편근종배성능명현호우수거전환근종배.
To improve the performance of composite pseudo-noise (PN) code clock recovery in a regenerative PN ranging system at a low symbol signal-to-noise ratio (SNR), a novel chip tracking loop (CTL) used for regenerative PN ranging clock recovery is adopted. The CTL is a modified data transition tracking loop (DTTL). The difference between them is that the Q channel output of the CTL is directly multiplied by a clock component, while that of the DTTL is multiplied by the I channel transition detector output. Under the condition of a quasi-squareware PN ranging code, the tracking (mean square timing jitter) performance of the CTL is analyzed. The tracking performances of the CTL and the DTTL are compared over a wide range of symbol SNRs. The result shows that the CTL and the DTTL have the same performance at a large symbol SNR, while at a low symbol SNR, the former offers a noticeable enhancement.