Calibration method of mobile terminal adopting zero intermediate frequency scheme

Abstract

The invention relates to a calibration method of a mobile terminal by adopting a zero intermediate frequency proposal, essentially adjusting the position of zero intermediate frequency calibration. The zero intermediate frequency calibration is adjusted after the receiving and calibrating operation of all signal channels is completed and before calibration is transmitted. Therefore, the signal ofan apparatus is switched and delayed for one time only; the necessary added work is that the signal channels are switched at the beginning of the zero intermediate frequency calibration, the time forwhich can be neglected, and the efficiency is not influenced. Adoption of the adjustment and improvement does not cause any adverse influence on the results of calibration and eradicates various hidden troubles existing in original method, saves overall calibration time (more obvious particularly when a multi-frequency band requires receiving and zero intermediate frequency calibration for a plurality of times), and achieves good effects on improving production efficiency and can wholly boost calibration efficiency.

Description

technical field [0001] The invention relates to a calibration method of a mobile terminal, in particular to a calibration method of a mobile terminal adopting a zero-IF scheme. Background technique [0002] At present, the zero-IF receiving scheme has been widely adopted in the design of mobile terminals. Depending on the platform, it is sometimes necessary to calibrate the zero-IF part during production testing. At present, most zero-IF calibrations of the Global System for Mobile Communications (GSM) standard no longer need to be calibrated, and the present invention is mainly applicable to zero-IF calibration under the Code Division Multiple Access (CDMA) standard . [0003] Under the CDMA system, in the production test calibration, when the zero-IF receiving scheme is adopted, the corresponding calibration steps are as follows: figure 1 Shown: [0004] Step 1.1, the reference channel is received and calibrated, and the transmitted signal of the instrument is a CDMA si...

AI Technical Summary

Problems solved by technology

[0011] It can be seen that the above scheme requires two signal switching, and due to the signal switching, some delays are required for stability, and in mass production, these delays affect efficiency; in addition, in different Calibration on the instrument may also have inconsistencies in instrument characteristics. At this time, even if the delay is increased in the calibration procedure, it may not be able to achieve very consistent results. The most direct consequence is that the zero-IF calibration value is inaccurate or seriously affects other Channel receive calibration, causing calibration to fail

In mass production, due to different instrument characteristics and different terminal characteristics, this problem may have a serious impact on production test calibration

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