Advanced study of video signal processing in low signal to noise environments

摘要: Conventional analytical techniques used to determine and optimize phase-lock loop (PLL) characteristics are most often based on a model which is valid only if the intermediate frequency (IF) filter bandwidth large compared PLL phase error small. An improved (called quasi-linear model) developed takes into account small IF bandwidths nonlinear effects associated with errors. By comparison of theoretical experimental results it demonstrated that accurately predicts characteristics. This true even for errors where conventional invalid. The draw conclusions concerning threshold, multiplier output variance, signal-to-noise ratio, signal distortion. relationship between these bandwidth, modulating spectrum, rms deviation also determined.