Calculation method in time-frequency synchronization process

A technology of synchronization process and calculation method, which is applied in the direction of multi-frequency code system, digital transmission system, electrical components, etc., can solve the problems of large amount of calculation and reduce the amount of calculation, so as to reduce the synchronization time, reduce the amount of calculation, and reduce the amount of calculation Effect

CN112039811AActive Publication Date: 2020-12-04WUHAN MENGXIN TECH CO LTD
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Patent Information

Authority / Receiving Office
CN · China
Patent Type
Applications(China)
Current Assignee / Owner
Publication Date
2020-12-04

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Abstract

The invention discloses a calculation method in a time-frequency synchronization process. The method comprises the following steps of: performing down-sampling processing on received sampling data, performing autocorrelation operation at different orthogonal frequency division multiple access symbol intervals in a time domain, performing wireless inter-frame combination and combination of different symbol intervals on an obtained autocorrelation value, judging whether an NPSS exists or not according to the signal-to-noise ratio and the autocorrelation value after merging processing, preliminarily calculating time offset and fractional frequency offset according to the autocorrelation value after merging processing, and judging whether coarse cross-correlation calculation and fine cross-correlation calculation are carried out or not according to a judgment result. Through the method, the operand of calculating the time offset and the frequency offset in the synchronization process can be reduced, and meanwhile, the correct judgment rate for judging whether the NPSS exists or not is improved.
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Description

technical field

[0001] The invention relates to the field of synchronous signal processing, in particular to a calculation method in the process of time-frequency synchronization. Background technique

[0002] The first step for starting up the UE of the narrowband Internet of Things NB-IoT (Narrow Band Internet of Things) system is to perform frequency point synchronization on the frequency band it supports, find the center frequency point where NB-IoT cells may reside, and then pass a large number of The autocorrelation and cross-correlation operation of the cell is used to obtain the time and frequency synchronization of the cell. In this synchronization process, a large number of blind correlation operations are performed in the time domain and frequency domain based on the NB-IoT primary / secondary synchronization signal. Since the primary synchronization signal NPSS The 11 Orthogonal Frequency Division Multiplexing OFDMA symbols have correlation, so it is necessary to p...

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Embodiment Construction

[0049] The principles and features of the present invention are described below in conjunction with the accompanying drawings, and the given embodiments are only used to explain the present invention, and are not intended to limit the scope of the present invention.

[0050] Such as figure 1 As shown, a schematic flow chart provided by an embodiment of a calculation method in a time-frequency synchronization process of the present invention includes:

[0051] Step 1. Perform down-sampling processing on the received sampling data, perform autocorrelation calculations in the time domain with different OFDMA symbol intervals, and combine the obtained autocorrelation values ​​between wireless frames and different symbol intervals merging, according to the signal-to-noise ratio and the combined autocorrelation value to judge whether there is NPSS, and preliminarily calculate the time offset and fractional frequency offset according to the combined autocorrelation value;

[0052] S...