Adaptive correction method for an OCXO

Traditional oscillators used in timing modules of CDMA and WiMAX base stations are large and expensive. Applying cheaper and smaller oscillators in timing modules is an interesting research challenge. An adaptive control algorithm is presented to enhance these cheap but more inaccurate oscillators to meet the requirements of base stations during holdover mode. An oscillator frequency stability model is developed for the adaptive control algorithm. This model takes into account the control loop which creates the correction signal when the timing module is in locked mode. Simulation results show that an oscillator enhanced by our adaptive control algorithm improves the oscillator performance significantly, compared to uncorrected oscillators or alternate control algorithms. We also analyze the cumulative time error upperbounds of the resulting timing module.