Frequency bias capture method for block signal with relatively large frequency bias

Abstract

The invention discloses a capture method of frequency deviation which is applicable to a block signal with the big frequency deviation. The invention utilizes a lead data structure to factor factors which simultaneously influence the capture range and the estimation precision of the frequency deviation in the prior technology into two factors with relevant intervals and lengths through the lengthof a sliding window and the choosing of the displacement position of the sliding window. Because the relevant interval determines the capture range of the frequency deviation, and the relevant lengthdetermines the estimation precision of the frequency deviation, the function of increasing the capture range of the frequency deviation is achieved through the method of reducing the displacement position L of the sliding window to reduce the relevant interval when the range of frequency deviation is too big; and the reduction of noise and the estimation precision of the frequency deviation can be improved through the method of increasing the length NL of the sliding window to increase the relevant length. Therefore, the inter-constraint conflict of the estimation precision of the frequency deviation and the capture range is resolved. Furthermore, the invention weakens the impact on the estimation precision of the frequency deviation which is caused by the deep weakness of a wireless mobile channel through the method of conducting a weighted summation on the frequency deviation which is got from different positions.

Description

technical field [0001] The invention relates to the field of digital communication, in particular to a frequency offset acquisition method for block signals with large frequency offsets. Background technique [0002] A core issue in the field of digital communication technology is synchronization. Technically, synchronization is divided into carrier synchronization and timing synchronization. There are carrier frequency deviations, phase deviations and timing deviations in the baseband sampling signals obtained by the receiver after passing through the wireless mobile channel. These deviations exist even in indoor environments where the channel is relatively flat in terms of frequency effects and frequency selectivity. [0003] At present, with the rapid increase in demand for new communication services, higher requirements are placed on the transmission rate of wireless communication systems and wireless local area networks, and the increase in transmission rate brings inc...

AI Technical Summary

Problems solved by technology

[0012] The length L of the UW sequence in the above prior art solution determines the frequency offset capture range and estimation accuracy. When the sequence length L is smaller, the frequency offset capture range is larger, but the estimation accuracy is lower.

There is a mutual restrictive relationship between the two. When the frequency offset capture range is large, the estimation accuracy is low, and when the estimation accuracy is guaranteed, a large capture range cannot be guaranteed.

In the actual receiving end, the sampling signal obtained after down-conversion has a relatively large frequency offset. The solution of the prior art needs to reduce the size of L to improve the frequency offset capture range, but the consequence of this is that the estimation accuracy will be greatly reduced. It leads to the failure of the subsequent synchronization algorithm and equalization algorithm; at the same time, due to the influence of deep fading under the wireless mobile channel, even if the sequence length is increased, the frequency offset estimation accuracy may be low.

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