Time synchronization method and device

Abstract

The invention discloses a time synchronization method, which comprises the steps of: carrying out a cross-correlation operation on a received signal and a local sequence, carrying out time weighted average for results of the cross-correlation operation, and determining a symbol timing position based on the results of the weighted average. The method inhibits a peak value of a spurious correlation peak to a certain extent, thereby enlarging a main multipath energy weight, and being capable of obtaining a demanded result, namely the timing position, by operation without searching a maximum value. By adopting the weighted average, the affects of CSD (Cyclic Shift Delay) are further eliminated, and the accuracy of the symbol timing is improved. In addition, because a sequence obtained after displacing and regulating a training sequence is used as a local reference sequence in the embodiment of the invention, the operation can be reduced, the peak value search process is avoided, the synchronous timing position can be rapidly determined, and the system performance can be improved. The time synchronization method is suitable for systems which are different in fluxion and bandwidth.

Description

technical field [0001] The invention relates to the technical field of wireless communication, in particular to a time synchronization method and device. Background technique [0002] Synchronization is an important practical problem in communication systems. Whether the communication system can work effectively and reliably depends largely on whether there is a good synchronization system. Synchronization is the guarantee for reliable reception of transmitted data, and its accuracy is related to the performance of the entire communication system. Orthogonal Frequency Division Multiplexing (OFDM, Orthogonal Frequency Division Multiplexing) is a multi-carrier digital communication modulation technology, which has the characteristics of high spectrum utilization and anti-multipath delay extension, so it is generally considered to be the most important technology in future mobile communication systems. core technology. In an OFDM system, in order to ensure the orthogonality o...

AI Technical Summary

Problems solved by technology

If the receiving end uses the long training sequence symbol to perform cross-correlation operation with the received signal, the correlation result will appear N T At this time, it is difficult for the conventional symbol timing algorithm to judge the starting position of the OFDM symbol according to the position where the maximum value of the cross-correlation occurs

Generally, the correlation peak caused by CSD is called a pseudo-correlation peak in the industry. The appearance of a pseudo-correlation peak makes the result of symbol timing inaccurate; in addition, it is necessary to search the result of cross-correlation (search for the maximum value) to obtain the position of symbol timing

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