一种结合DWT与DCT插值的OFDM信道估计新方法

发布时间：2018-05-08 13:31

本文选题：信道估计 + 正交频分复用　；参考：《江苏大学学报(自然科学版)》2017年03期

【摘要】：针对传统的基于离散余弦变换(DCT)的正交频分复用(OFDM)信道估计算法去除噪声不够理想的问题,提出了一种结合离散小波变换(DWT)与DCT插值的OFDM信道估计新方法.在对信号进行最小二乘(LS)估计后,利用DWT对信号进行阈值量化消噪处理,然后将循环前缀(CP)内各采样点上的能量均值作为DCT线性插值过程中的阈值,对循环前缀内的噪声进行再次处理,从而进一步降低噪声的影响.对算法的误码率(BER)和均方误差(MSE)等进行了试验仿真.仿真结果表明:文中算法的性能明显优于经典的LS算法、传统的DFT算法、基于改进阈值的DCT信道估计算法.新算法使循环前缀内的噪声得到了有效的抑制,与基于改进阈值的DCT信道估计算法相比,在相同BER下,文中算法的SNR提升了约1 dB;当MSE相同时,文中算法SNR约有2 dB提高.
[Abstract]:Aiming at the problem that the traditional channel estimation algorithm of orthogonal frequency division multiplexing (OFDM) based on discrete cosine transform (DCT) is not ideal enough to remove noise, a new method of OFDM channel estimation based on discrete wavelet transform (DWT) and DCT interpolation is proposed. After the least squares (LS) estimation of the signal, the signal is de-noised by threshold quantization using DWT, and the energy mean of each sampling point in the cyclic prefix is used as the threshold in the process of DCT linear interpolation. The noise in cyclic prefix is reprocessed to further reduce the effect of noise. The error rate (BER) and mean square error (MSE) of the algorithm are simulated. The simulation results show that the performance of the proposed algorithm is better than that of the classical LS algorithm. The traditional DFT algorithm and the DCT channel estimation algorithm based on the improved threshold are presented. Compared with the DCT channel estimation algorithm based on the improved threshold, the proposed algorithm improves the SNR of the proposed algorithm by about 1 dB under the same BER, and improves the SNR by about 2 dB when the MSE is the same.
【作者单位】：江西理工大学信息工程学院;
【基金】：国家自然科学基金资助项目(61363076) 江西省自然科学基金资助项目(20142BAB207020)
【分类号】：TN911.23

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