摘要
数模转换器的时钟抖动引起输出信号的误差,该误差会影响后继的信号处理。本文分析了数模转换器中输入为线性调频信号时,由时钟抖动引起的误差。首先给出了该误差平均功率表达式,然后根据该表达式推导出输出信噪比的近似计算公式,最后对影响信噪比的各种因素进行讨论,其中信号的带宽及时钟抖动参数的增大均会降低输出信噪比,而调频斜率的变化对输出信噪比影响较小,采样频率的增大可以在一定程度上提高信噪比。仿真结果验证了信噪比计算公式的正确性,并给出了信噪比随各种因素变化的趋势。
The error of output signal is caused by clock jitter in the digital-to-analog converter,which can affect the succeeding signal processing. This paper analyzes error caused by clock jitter, when a linear frequency modulated signal inputs to digital-to-analog converter. Firstly an expression for the average error power is given, then according to the expression, approximate calculated formula for output signal-to-noise ratio is derived,lastly various factors effecting signal-to-noise ratio are discussed. The signal-to-noise ratio in output signals is reduced with the increase of signal bandwidth and the parameter of clock jitter, and the change of slope makes little effect for it, sampling frequency can improve it in a certain extent. The calculated formula for signal-to-noise ratio is verified by simulation results, and the change tendency of signal-to-noise ratio following various factors is given.
出处
《信号处理》
CSCD
北大核心
2009年第11期1781-1784,共4页
Journal of Signal Processing
关键词
数模转换器
时钟抖动
线性调频信号
信噪比
Digital-to-analog converter
Timing jitter
Linear frequency modulated signal
Signal-to-noise ratio
