An Enhanced Oscillator Model for Clock Synchronization Protocols

Abstract

This paper describes an enhanced oscillator model that is able to handle several disturbing noise sources influencing its instantaneous frequency and/or phase. Besides the well-known white and random walk frequency noises, also flicker noise is generated. It is highlighted that flicker noise can only be applied with limitations. Furthermore, the model is able to accept the temperature dependence of the oscillator as input. Although this is an important influencing parameter, especially for low-cost oscillators, this effect is often neglected. Therefore, with this supplement, a more realistic oscillator model can be achieved. The functionality of the model is demonstrated through simulations. During the tests, three temperature patterns along with generally assumed Gaussian type noise sources are investigated in order to simulate real circumstances. The effects are analyzed by help of Allan variance plots. It is highlighted that for long time intervals, temperature dependence affects the Allan variance of low-cost and temperature compensated crystal oscillators (TCXOs) considerably.