| 摘要: |
| 针对基于非正交多址接入的通用滤波多载波（Non-orthogonal Multiple Access Combined with a Universal Filtered Multi-carrier，NOMA-UFMC）系统应用传统离散傅里叶变换(Discrete Fourier Transform，DFT)信道估计算法的局限性展开研究，系统分析了其在噪声抑制方面存在的两个关键问题：噪声区间不连续性和信道长度内噪声残留现象。基于最小二乘(Least Square，LS)估计方法，提出一种改进型DFT信道估计算法。该算法通过时域阈值门限设计实现样本内噪声抑制，同时采用矩形窗与汉明窗的时域不对称复合加窗方法，构建了具有双重降噪机制的优化方案。仿真结果表明，改进算法显著增强了系统噪声抑制能力，相较于传统DFT算法，远端用户1与近端用户2可分别获得约5 dB和6 dB的误码性能增益。 |
| 关键词: NOMA-UFMC 信道估计 离散傅里叶变换 不对称加窗 |
| DOI：10.20079/j.issn.1001-893x.240912002 |
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| 基金项目:河北省自然科学基金资助项目（F2024201053）;保定市科技局创新能力提升专项（2394G026） |
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| An Improved Algorithm Based on DFT ChannelEstimation in NOMA-UFMC |
| TIAN Xiaoyan,JIA Miaoyi,JIANG Yumai,CHEN Lei |
| (College of Electronic Information Engineering,Hebei University,Baoding 071000,China) |
| Abstract: |
| The limitations of applying the traditional discrete Fourier transform(DFT) channel estimation algorithm to the non-orthogonal multiple access combined with a universal filtered multi-carrier（NOMA-UFMC）system is investigated and two key problems in noise suppression,the discontinuity of the noise interval and the residual noise within the channel length,are systematically analyzed.Based on the least square(LS) estimation method,an improved DFT channel estimation algorithm is proposed.This algorithm achieves noise suppression within the sample through the design of a time-domain threshold gate and simultaneously adopts an asymmetric composite windowing method of rectangular and Hamming windows in the time domain to construct an optimized scheme with a dual noise reduction mechanism.Simulation results show that the improved algorithm significantly enhances the system’s noise suppression capability,and compared with that of the traditional DFT algorithm,the far-end user1 and the near-end user2 can respectively obtain about 5 dB and 6 dB of bit error performance gains. |
| Key words: NOMA-UFMC channel estimation discrete Fourier transform asymmetrical windowing |
《电讯技术》编辑部 