OFDM系统中基于SNR估计的改进DFT信道估计算法

为提高目前无线通信系统中正交频分复用(Orthogonal Frequency Division Multiplexing,OFDM)技术下的信道估计性能,分析了基于离散傅里叶变换(Discrete Fourier Transform,DFT)的信道估计算法存在的缺陷.针对传统DFT信道估计算法没有考虑循环前缀内噪声的...

An improved DFT channel estimation algorithm based on SNR estimation in OFDM system

In order to improve the channel estimation performance under the orthogonal frequency division multiplexing(OFDM) technology in current wireless communication systems,the defects of the channel estimation algorithm based on discrete Fourier transform(DFT) are studied.In view of the problem that the traditional DFT channel estimation algorithm does not consider the influence of noise in the cyclic prefix and there exists energy leakage in non-integer delay channels,an improved DFT channel estimation algorithm based on signal-to-noise ratio(SNR) estimation is proposed.Based on the Least Square(LS) algorithm,the SNR of the system is estimated by the pilot sequence after windowing in the frequency domain,which is transformed into the denoising threshold in the cyclic prefix,and the denoising operation is carried out twice.Simulation results show that the improved algorithm can not only effectively eliminate the noise in the loop prefix,but also suppress the influence of energy leakage in the non-integer multiple delay channels,and has better performance than the traditional DFT channel estimation algorithm.