OFDM symbol timing synchronization method in complex multipath environment and receiving device

Abstract

The invention discloses an OFDM symbol timing synchronization method under a complex multipath channel and a receiving device. The method comprises the following steps: S1, acquiring a frequency domain signal of an OFDM symbol containing pilot frequency from a time domain receiving signal, and recording a first frequency domain signal; obtaining a pilot channel estimation value of the first frequency domain signal; S2, combining the pilot channel estimation values of all the first frequency domain signals to obtain an overall pilot channel estimation value; S3, obtaining a pilot channel time domain impulse response; S4, searching a first path position of the signal; S5, obtaining an OFDM symbol timing synchronization deviation adjustment value under the current bandwidth; and S6, performing timing synchronization deviation correction on the time domain receiving signal. The number of pilot frequency reference signals participating in calculation is increased, and the influence of noiseis smoothed, so that the method still has very high timing synchronization precision in a ubiquitous complex multi-path environment; and the influence of noise and multipath interference is small, extra frequency band resources are not occupied, and the practical value is very high.

Description

technical field [0001] The invention belongs to the field of wireless or wired communication, and relates to an OFDM symbol timing synchronization method, in particular to an OFDM symbol timing synchronization method and a receiving device under complex multipath channels. Background technique [0002] OFDM (Orthogonal Frequency Division Multiplexing, Orthogonal Frequency Division Multiplexing), as one of the technical solutions with the most research value and application prospects in wireless communication, has the advantages of high utilization of spectrum resources, strong bandwidth expansion, anti-multipath fading, spectrum Technical advantages such as flexible resource allocation. But its shortcomings are also obvious, that is, there are strict requirements on the orthogonality between subcarriers. In order to ensure the orthogonality between sub-carriers, the synchronization needs to be precise enough, otherwise, it will directly affect the orthogonality between sub-...

AI Technical Summary

Problems solved by technology

However, in a complex multipath fading channel, the location with the largest energy value is not necessarily the first path of the signal, and the timing synchronization point is on the path with the largest energy, which may cause the FFT window to fall in the data domain, seriously affecting the accuracy of signal demodulation sex

[0005] The number of samples in the existing OFDM symbol timing synchronization algorithm based on CRS (Cell-specific reference signal, cell-specific reference signal) is small. The first path of the signal is detected by a fixed threshold, so the accuracy of timing synchronization is not high

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