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 the crystal oscillator stability of a WiMAX base station and a realization method thereof. The device includes a frequency counter, a phase detector, a crystal oscillator, a digital-to-analog converter and a GPS receiver. It uses the 1pps signal output by the GPS receiver to calibrate the stability of the crystal oscillator output signal frequency, which can quickly adjust the error accuracy of the crystal oscillator to within 0.5Hz, and finally stabilize the error accuracy of the crystal oscillator within 0.01Hz. The feature of this method is to pre-calculate the adjustment coefficient between the phase detector and the crystal oscillator. During dynamic calibration, the error value of the crystal oscillator can be directly calculated only by calculating the error value of the phase detector. Using the adjustment coefficient to adjust the crystal oscillator error is a novel method in the field of crystal oscillator adjustment. This method has a fast calibration speed and a simple algorithm. It can quickly adjust the oscillation frequency of an ordinary crystal oscillator to high accuracy, and has long-term stability and short-term stability. all good.

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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