Channel equalization method of SC-FDE system under wireless time-varying channel

Abstract

The invention relates to a channel equalization method of an SC-FDE system under a wireless time-varying channel. The method comprises the steps of 1, according to a data frame structure of a short wave unified US Military standard MIL_STD_188_110C based on an SC-FDE system, at a sending end, inserting a certain length of a training sequence (unique word UW) after the unknown data; 2, at a receiving end, properly segmenting an FFT block on a time domain; 3, performing coarse equalization judgment on each data segment by using an MMSE equalization method; and 4, introducing a time domain exhaustive search method with low complexity to perform fine equalization judgment on a coarse equalization judgment result. Compared with traditional methods, the method provided by the invention is greatly improved in equalization performance. When a signal to noise ratio is 24dB, compared with the traditional methods, the error code rate of the method provided by the invention is reduced by about 1.5orders of magnitudes. Therefore, according to the method provided by the invention, the channel equalization performance of the SC-FDE system under the wireless time-varying channel is greatly improved.

Description

Technical field [0001] The present invention relates to the field of communication technology, and more specifically, to a channel equalization method of an SC-FDE system under a wireless time-varying channel. Background technique [0002] The working frequency of shortwave communication is in the range of 3MHz~30MHz. It is widely used in various fields such as military communication and emergency communication by virtue of its advantages of simple equipment, flexibility, and strong survivability. In a wireless communication system, the transmission performance of the system is largely restricted by the wireless channel, and single-carrier frequency domain equalization (SC-FDE) as an anti-multipath interference technology, has the same orthogonal frequency division as the multi-carrier system. Multiplexing (OFDM) is similar to the system block diagram, while avoiding the disadvantages of OFDM such as high peak-to-average ratio and sensitive frequency offset. Generally speaking, S...

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Problems solved by technology

At the same time, rapid changes in the ionosphere will cause Doppler frequency shift and Doppler spread, resulting in channel fading that is not flat in time and frequency. This time-frequency dual-selective channel will reduce the performance of channel equalization. Therefore, how to improve the channel equalization performance of the SC-FDE system under the wireless time-varying channel has further research value

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