Fast time-varying channel estimation method based on simplified basis expansion model

Abstract

The invention discloses a fast time-varying channel estimation method based on a simplified basis expansion model and mainly solves the problems of low estimated accuracy and high computation complexity of the existing technology. The method comprises the following implementation steps of 1) computing a matrix of a pilot symbol in a transform domain through a local pilot symbol; 2) obtaining a basis function matrix and a frequency domain matrix of a basis function based on a complex exponential basis expansion model; 3) carrying out fast Fourier transform on a receiving signal to obtain a frequency domain receiving signal and extracting a block-type pilot symbol from the receiving signal; 4) utilizing the received pilot symbol, the matrix of the transform domain in 1) and the frequency domain matrix in 2) to estimate a basis coefficient; 5) utilizing the basis coefficient to fit a time domain channel response matrix; and 6) utilizing a simplified time domain-frequency domain transformation formula to transform the time domain channel response matrix into a frequency domain channel response matrix. The method has the advantages of high estimated accuracy and low computation complexity and is suitable for an SC-FDMA system of the fixed block-type pilot.

Description

technical field [0001] The invention belongs to the field of wireless communication, and relates to a low-complexity fast time-varying channel estimation method, which can be used in a single-carrier frequency division multiple access SC-FDMA system with fixed block pilots. Background technique [0002] In broadband wireless communication, when the two communication terminals move at a relatively fast speed, the Doppler effect occurs, and the wireless channel forms a fast time-varying channel. The inter-subcarrier interference ICI caused by the fast time-varying channel and the inter-symbol interference ISI caused by the multipath effect will cause the rapid deterioration of SC-FDMA system performance. Therefore, it is very necessary to dynamically estimate the channel before demodulating and decoding the signal at the receiving end of the signal. [0003] Most of the existing channel estimation methods are based on pilot-assisted, which periodically inserts known pilot inf...

AI Technical Summary

Problems solved by technology

The disadvantage of this method is: limited by the pilot pattern and quantity, the estimation accuracy of this method will drop sharply in a high-speed mobile environment, and the estimation accuracy of fast time-varying channels cannot be guaranteed

In the article "Fast Time-Varying ChannelEstimation Technique for LTE Uplink in HST Environment" (IEEE Transactions on Vehicular Technology 2012), Yang Lihua et al. proposed a method combining the polynomial base expansion model P-BEM and the autoregressive model AR to improve the fast time-varying Channel estimation accuracy, but this method has high computational complexity and is not easy to implement, and the error of the P-BEM model is larger than that of the complex exponential base extension model CE-BEM, which affects the accuracy of fast time-varying channel estimation

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