Mobile terminal and method with automatically calibrated clock source

A mobile terminal, automatic calibration technology, applied in the direction of automatic power control, electrical components, transmission systems, etc., can solve problems such as failure to work normally, frequency tracking algorithm failure, and mobile terminal performance degradation, and achieve the effect of improving performance.

Inactive Publication Date: 2008-12-10
ST ERICSSON SEMICON BEIJING
View PDF4 Cites 0 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, if the initial value of the AFC control voltage read at startup deviates too far from the accurate value, the frequency tracking algorithm will fail, and the performance of the mobile terminal will be severely degraded, which will seriously cause it to fail to work normally.
[0006] The problem with this method is: for VC-TCXO with high temperature stability, the aging of the crystal is a very important factor affecting the frequency
At present, the long-term stability of most crystals exceeds 1-1.5ppm / year. Therefore, after the mobile terminal has been used for a period of time, the initial value of the AFC control voltage calibrated at the factory will deviate from the actual VC-TCXO output accuracy due to the aging of the crystal. Voltage control voltage value
At present, the frequency tracking algorithm adopted by the mobile terminal has strict requirements on the initial frequency offset. If the initial frequency offset is large, the performance of the mobile terminal will be severely degraded.

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Image

Smart Image Click on the blue labels to locate them in the text.
Viewing Examples
Smart Image
  • Mobile terminal and method with automatically calibrated clock source
  • Mobile terminal and method with automatically calibrated clock source

Examples

Experimental program
Comparison scheme
Effect test

Embodiment Construction

[0023] In mobile communications, the frequency deviation of mobile devices has a significant impact on the block error rate of data received by the device. For example, for TDSCDMA mobile phones, when the frequency deviation exceeds 1ppm, it will cause errors in receiving data, making the mobile phone unable to access. In other words, only when the frequency deviation of the mobile device is within a certain range, the block error rate of the received data may be less than a certain threshold. Since the voltage-controlled crystal oscillator VCXO is generally used in mobile communication equipment terminals, its output frequency is controlled by the AFC control voltage, so for mobile communication equipment terminals, when the block error rate of the received data meets its normal communication requirements , its AFC control voltage is also in a correct range.

[0024] Therefore, according to this characteristic, the AFC control voltage value whose block error rate is within an...

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

PUM

No PUM Login to View More

Abstract

This invention relates to mobile terminal with pressure clock unit and correction device, wherein, the correction device records the mobile terminal to receive data with error rate less than set gate limit pressure clock unit control voltage as pressure time unit control voltage initial value to Make the mobile terminal pressure time unit AFC to avoid transistor aging problem to improve mobile terminal property.

Description

technical field [0001] The invention relates to a mobile terminal for automatically calibrating a clock source and a method for automatically calibrating the clock source. Background technique [0002] The clock unit (clock source) is an important part of the communication system, and it is equivalent to the heart of the mobile communication terminal (UE) device. It not only provides the clock of the processor, but also provides the clock of analog-to-digital sampling and the clock of the frequency synthesizer of the radio frequency device. The stability and accuracy of the clock unit affect the performance of the mobile communication terminal to a great extent. [0003] Currently, VC-TCXO is commonly used in mobile terminals (including mobile phones), which is a crystal oscillator whose output frequency is controlled by voltage, and has been temperature compensated. [0004] Before the mobile terminal (including mobile phone) leaves the factory, its VC-TCXO must be calibr...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

Application Information

Patent Timeline
no application Login to View More
Patent Type & AuthorityPatents(China)
IPC IPC(8): H03L1/00H03L5/00H03L7/00H04B1/40H04Q7/32H04B1/3827
Inventor何明星朱泽睿
OwnerST ERICSSON SEMICON BEIJING