Method and system for correcting residual deviation of sampling frequency in OFDM systems

Abstract

The invention discloses a method and a system for correcting residual deviation of sampling frequency in OFDM systems, which belongs to the OFDM technical field in the field of wireless communication. The method comprises the following steps: removing modulation information carried by currently received OFDM symbols in each frequency domain at a receiving end; selecting a plurality of frequency points from the OFDM symbols of which the modulation information is removed and calculating phase curves of the selected frequency points and the slope of the phase curves; correcting a channel estimation value according to the slope of the phase curves; and utilizing the corrected channel estimation value to equalize a next received OFDM symbol. The invention has the advantages of avoiding the bit-error performance drop of the systems, which is caused by initial sampling-frequency deviation estimation, corrected error and the own error of sampling clocks, effectively reducing the bit error rate of the systems and improving the performance of the OFDM systems.

Description

technical field [0001] The present invention relates to OFDM (Orthogonal Frequency Division Multiplexing, Orthogonal Frequency Division Multiplexing) technology in the field of wireless communication, in particular to a method and system for correcting the sampling frequency residual deviation in the OFDM system. Background technique [0002] In an actual communication system, the D / A converter at the sending end and the A / D converter at the receiving end use their own clocks, so that there is a sampling frequency deviation between the sending signal and the receiving signal. On the one hand, the sampling frequency deviation causes the phase deviation of the received data, on the other hand, it also destroys the orthogonality between the subcarriers, which has a great impact on the correct decoding, which requires accurate estimation and correction of the sampling frequency deviation. [0003] In OFDM communication systems, the estimation and correction of sampling frequency...

AI Technical Summary

Problems solved by technology

However, if the sampling frequency deviation is only estimated and corrected once in the time domain, if there is a slight deviation in the estimation or correction, as time accumulates, this deviation will become larger and larger, and eventually it will still cause a large bit error , which degrades the system performance; or because the sampling clock is affected by the environment, there is a small deviation, but as time accumulates, the deviation will become larger and larger, which will also cause a large bit error to the system

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