Device and method for realizing frequency switch and automatic control of multiple-module mobile communication terminal

Abstract

The invention relates to a device for realizing multi-mode mobile communication terminal frequency switch and automatic control, and a relative method, wherein each mode sending / receiving module of multi-mode mobile terminal shares one crystal vibrator to save cost and energy consumption, to allow the terminal to use automatic frequency lock ring at each mode, to effectively keep the carrier wave synchronous of communication chain. And the invention comprises: a multi-mode automatic frequency control word refresher, a voltage-control crystal vibrator and a digit / analogue converter; the refresher is used to select and calculate the frequency control word of target mode; the digit / analogue converter based on said control word generates control voltage via digit signal; said vibrator based on the control voltage generates reference frequency signal; and the invention also provides a multi-mode automatic frequency control word refreshing module to replace the multi-mode automatic frequency control word refreshing device.

Description

Technical field [0001] The invention relates to a method and device for frequency switching and frequency control of a mobile terminal device supporting a multi-mode communication system to a multi-mode base station. Background technique [0002] In the field of mobile communication, the third-generation mobile communication technology will surely replace the second-generation mobile communication technology due to its technological advancement. GSM is a global digital mobile communication system, which belongs to the second-generation mobile communication system specification. WCDMA is a wideband code division multiple access technology and one of the three major standards for the third-generation mobile communication system specifications. [0003] In the technology update stage, in order to avoid risks and take into account the higher penetration and coverage of second-generation communication devices, mobile communication terminal devices supporting two or more modes have eme...

AI Technical Summary

Problems solved by technology

like figure 2 As shown, it is a block diagram of the automatic frequency locking loop structure of the current dual-mode terminal. This dual-mode terminal uses a completely independent carrier synchronization loop, which is not conducive to reducing the cost of terminal equipment. In the active state of the first mode, the second It is difficult to determine the initial setting value of the frequency control loop of the second mode when the base station of the second mode performs measurements

In the case of a large frequency offset, the signal measurement results of the base station in the second mode are inaccurate, and it is more likely that the frequency control loop cannot be locked for a long time when the terminal switches from the first mode to the second mode, causing service interruption

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