Device for dynamically regulating crystal vibration stability of WiMAX base station and implementing method thereof

Abstract

The invention relates to a device for dynamically adjusting crystal oscillation stability of a WiMAX base station and an implementation method thereof. The device consists of a frequency counter, a phase detector, a crystal oscillator, a digital-analog converter and a GPS receiver. The device calibrates the stability of crystal oscillation output signal frequency by applying 1pps signal output bythe GPS receiver, rapidly adjusts error precision of the crystal oscillation within 0.5Hz, and finally keeps the error precision of the crystal oscillation steady within 0.01Hz. The method is characterized in that an adjustment coefficient between the phase detector and the crystal oscillation is calculated in advance and at the time of dynamic calibration, an error figure of the crystal oscillation is calculated out directly after the calculation of the error figure of the phase detector. Adjusting the crystal oscillation error by applying the adjustment coefficient is a new method in the field of crystal oscillation adjustment. The method has the advantages of a fast calibration speed and a simple algorithm, thus adjusting shock frequency of ordinary crystal oscillation to quite high accuracy rapidly with good stability for long-term and short-term.

Description

technical field [0001] The invention relates to a method for adjusting crystal oscillator stability, in particular to a device for dynamically adjusting the crystal oscillator stability of a WiMAX base station and its implementation method. Background technique [0002] The various clocks of the WiMAX base station are provided by the crystal oscillator, so the accuracy of the crystal oscillator determines the accuracy of various clocks of the WiMAX base station. The characteristics of the crystal oscillator determine that it has a high degree of stability in a short period of time, but due to the aging of the crystal itself and the influence of the environment (such as temperature changes, voltage fluctuations, etc.), the natural frequency of the crystal oscillator will drift. The drift parameter will be relatively large, generally a few percent of hertz a day, and a few hertz a year. The drift curve can refer to Figure 4. If a rubidium / cesium crystal oscillator with high s...

AI Technical Summary

Problems solved by technology

If the crystal oscillator is allowed to oscillate freely, the clock accuracy of the WiMAX base station will become worse and worse with time, and the resulting impact will reduce the communication reliability of the WiMAX base station. Therefore, it is necessary to dynamically Adjust the crystal oscillator so that its output frequency is stable within acceptable accuracy

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