Method for estimating frequency deviation in carrier synchronization of wireless communication system

Abstract

The invention relates to a method for estimating the frequency deviation in the carrier synchronization of a wireless communication system, which comprises the following steps: when the frequency deviation is small, estimating and compensating the frequency deviation by using directly decoding information; and when the frequency deviation is large, combining the method with a conventional method,estimating and compensating the initial frequency deviation by the conventional method first, and then further estimating and compensating the residual frequency deviation by using the decoding information. If iterative decoding is performed, the joint iterative frequency deviation estimation and decoding can be performed, and with the increase of iterations, the decoding output information is more and more accurate, and the frequency deviation estimation is also more and more accurate. The method overcomes the defect that the frequency deviation accuracy of a conventional frequency deviationestimation method is limited, effectively inhibits the fluctuation of the residual frequency deviation caused by the conventional frequency deviation estimation method, reduces the influences on the system performance by the residual frequency deviation, improves the error code performance of the system, reduces the demodulation threshold, and improves the utilization ratio of the system power while the system band is not occupied.

Description

technical field [0001] The invention belongs to the field of wireless communication, and in particular relates to a frequency offset estimation method in carrier synchronization of a wireless communication system. Background technique [0002] When communicating, in order to correctly receive the other party's information, the receiving party must generate a carrier signal component identical to that of the received signal in order to achieve coherent demodulation of the received signal. During demodulation, the local carrier and the received signal carrier must be strictly in the same frequency and phase, that is, to achieve synchronization between the received carrier and the local carrier. Carrier synchronization includes frequency synchronization and phase synchronization. In digital communication, in addition to carrier synchronization, bit synchronization, frame synchronization, etc. are also required. Such as figure 1 It is a typical digital communication system. Ca...

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Problems solved by technology

[0007] (2) Performance of traditional frequency correction methods

However, regardless of the DA algorithm or the NDA algorithm, the frequency estimation is independent of the decoding and is located at the front end of the demodulation. The accuracy of the frequency estimation is limited, and some residual frequency offset will always be brought to the demodulation end, resulting in demodulation and decoding. Decline in performance, increase in bit error rate

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