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TD-SCDMA terminal initial downlink synchronization method

A TD-SCDMA and terminal technology, which is applied in the field of user terminal cell initial search and downlink synchronization, and can solve problems affecting detection effectiveness and autocorrelation deterioration

Inactive Publication Date: 2013-01-23
MSTAR SEMICON INC
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

Therefore, when the initial frequency offset is large, the autocorrelation of the SYNC_DL code deteriorates severely, which seriously affects the effectiveness of detection

Method used

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  • TD-SCDMA terminal initial downlink synchronization method
  • TD-SCDMA terminal initial downlink synchronization method
  • TD-SCDMA terminal initial downlink synchronization method

Examples

Experimental program
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Embodiment Construction

[0053] In order to fully illustrate the technical solution of the method of the present invention, a practical example will be described below in conjunction with the accompanying drawings. First calculate the correlation power peak value and position of N subframes, the process is as follows:

[0054] In the first step, if the frequency offset is artificially increased by the AFC method, then for the nth subframe to be received, adjust the additional frequency offset corresponding to the subframe -K+n*(2K+1) / N; otherwise, go directly to the nth subframe two steps.

[0055] The second step is to continuously receive the data of the nth subframe with a length of N frame , take N frame =6400. Considering that during the initial search of the cell, the position of the DwPTS synchronization signal is not determined, and it may appear at the end of the receiving sequence, resulting in detection omissions, so an additional downlink synchronization code length N is received syncd...

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Abstract

In a TD-SCDMA system, a direct correlation method of the downlink synchronization of an area initial searching stage can be affected by large frequency swing after a terminal is started up, in order to overcome the affection of the large frequency swing, the invention provides a TD-SCDMA terminal initial downlink synchronization method on the basis of the direct correlation method. Certain initialfrequency swings are added into the initial stage, thus not only the affection of the large frequency swing on data can be effectively eliminated, an accurate SYNC_DL number and a synchronous position are detected, but also the large frequency swing is accurately estimated relatively, and the large frequency swing is reduced into a proper range so that a subsequent frequency regulation operationcan be effectively carried out. The invention provides an effective solving scheme for accurately carrying out the downlink synchronization in the area initial searching process.

Description

technical field [0001] The invention relates to the technical field of wireless communication, in particular to a downlink synchronization method for initial cell search of a user terminal in a Time Division Synchronous Code Division Multiple Access (TD-SCDMA) mobile communication system. Background technique [0002] In a digital cellular mobile communication system, when a terminal equipment (UE, User Equipment) is powered on in a wireless network system, the initial cell search stage must be performed first. The UE needs to obtain the timing position of the downlink signal of the base station in the initial cell search stage, so that the terminal device can access the network as soon as possible, monitor the broadcast channel, receive cell information, and then perform subsequent communication processes. [0003] Therefore, downlink synchronization is an important step in the initial cell search process. In the TD-SCDMA system, this process is completed by searching the d...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): H04W48/16H04W56/00H04L27/26H04B1/7083
Inventor 孙飞雪戎波
Owner MSTAR SEMICON INC