Method and equipment for detecting middle guiding code sequence in TD-SCDMA system

Abstract

A Midamble code word sequence detection method and device applied to a Time Division Synchronous Code Division Multiple Access (TD-SCDMA) mobile communication system, which can be used under low signal-to-noise ratio conditions and in mobile communication environments with frequency and time diffusion, It achieves a high probability of correct detection and a very low probability of false detection, and can generate a rejection flag to eliminate a batch of wrong input events, such as wrong code group number input, wrong synchronization information input and excessive local oscillator frequency deviation, etc. situation, so as to achieve the purpose of effectively shortening the initial cell search time in the TD-SCDMA system, and it is easy to realize. The invention includes Midamble receiving signal sampling extraction, Midamble code word sequence generation, sliding correlation, delay envelope calculation, multi-frame merging, path selection, likelihood value calculation, maximum value detection, credibility calculation and comparison, and detection rejection flag Steps and modules such as generation and detection of Midamble code word sequence number generation.

Description

technical field [0001] The present invention relates to a method applied to a wireless communication system, in particular to a method applied to a Time Division Synchronous Code-Division Multiple Access (TD-SCDMA) mobile communication system. A method and device for detecting a midamble (Midamble) sequence of a user terminal device in a Cell Search process. Background technique [0002] In 1946, Bell Laboratories in the United States proposed to divide the service area of ​​mobile phones into several cells, and set up a base station in each cell to form a new concept of cellular (Cellular) mobile communication in a cellular system. In 1978, this system was successfully tested in Chicago, USA, and it was officially put into commercial use in 1983. The adoption of the cellular system enables the same frequency to be used repeatedly, thereby greatly increasing the capacity of the mobile communication system and meeting the objective needs of the sudden increase of mobile comm...

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Problems solved by technology

[0019] (5) Since the work is in the initial cell search stage, many synchronization processes, such as time synchronization and frequency synchronization, are often not completed accurately, so the Midamble codeword sequence detection method should have a certain degree of robustness (Robustness), to overcome the above-mentioned disadvantages Detection performance degradation issues that may be caused by accurate synchronization issues

But wherein in the device of the second step of the relevant cell search, only the Midamble codeword sequence output with the maximum correlation value, so the aforementioned design requirements (2) and (3) cannot be well satisfied; meanwhile, due to receiving the Midamble signal part position is According to the DwPTS position detected in the first step of the cell search, the inaccuracy and fast multipath fading that may exist due to time synchronization are not considered, so the device also fails to meet the aforementioned design requirements. (4) and (5)

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