公开(公告)号：US20140049331A1

公开(公告)日：2014-02-20

申请号：US13784761

申请日：2013-03-04

Applicant: MaxLinear, Inc.

Inventor： Anand K. Anandakumar ,  Hyungjin Kim ,  Curtis Ling

IPC: H03L1/02

CPC classification number: H03L1/026 ,  G01S19/235 ,  H03L1/022 ,  H03L7/1976

Abstract: To determine the level of frequency drift of a crystal oscillator as a result of a change in the its temperature, the temperature of the crystal oscillator is sensed and used together with previously stored data that includes a multitude of drift values of the frequency of the crystal oscillator each associated with a temperature of the crystal oscillator. Optionally, upon initialization of a GPS receiver in which the crystal oscillator is disposed, an initial temperature of the crystal oscillator is measured and a PLL is set to an initial frequency in association with the initial temperature. When acquisition fails in a region, the ppm region is changed. The temperature of the crystal oscillator is periodically measured and compared with the initial temperature, and the acquisition process is reset if there is a significant change in temperature. The GPS processor enters the tracking phase when acquisition is successful.

Abstract translation: 为了确定晶体振荡器的温度变化导致的晶体振荡器的频率漂移，晶体振荡器的温度与先前存储的包含晶体频率漂移值的数据一起被检测并使用 每个振荡器都与晶体振荡器的温度相关联。 可选地，在其中设置晶体振荡器的GPS接收机初始化时，测量晶体振荡器的初始温度，并将PLL设置为与初始温度相关联的初始频率。 当区域中的采集失败时，ppm区域发生变化。 周期性地测量晶体振荡器的温度并将其与初始温度进行比较，如果温度有明显变化，则采集过程将被重置。 采集成功后，GPS处理器进入跟踪阶段。