Adaptive High-Accuracy Timing Module: Algorithms and Performance Bounds 
Carleton University, Ontario, Canada. November 2009.

In this thesis, new adaptive OCXO frequency drift correction algorithms are proposed for the timing module on the base transceiver stations. The recursive system identification methods are used to replace the previous Batch Least Squares (BLS) method in the algorithm. Two different recursive system identification methods are evaluated and compared, the Recursive Least Squares (RLS) method and the Kalman Filter method.

New system models which include the digital control loop are created. Simulation results show that the new system model has better performance than the previous model.

The Cumulative Time Error (CTE) upperbound of the timing module is analyzed. This upperbound determines the performance bound of the timing module system. First, a simple model structure of the OCXO frequency stability is used to investigate the CTE upperbound. In this simple model, the temperature is linear related to the frequency stability. Then, a refined model structure is used to investigate the CTE upperbound. In this refined model, both temperature effect and ageing effect are considered. The control loop is included in both simple and refined model structures. The simulation results show that the CTE upperbound can be obtained analytically.