NB-IoT中一种改进的DFT信道估计算法  

An improved DFT channel estimation algorithm in NB-IoT

作　　者：谭钦红[1] 梁泽乾 于敏 TAN Qinhong;LIANG Zeqian;YU Min(College of Telecommunications and Information Engineering,Chongqing University of Posts and Telecommunications,Chongqing 400065,China)

机构地区：[1]重庆邮电大学通信与信息工程学院,重庆400065

出　　处：《南京邮电大学学报（自然科学版）》2020年第6期7-11,共5页Journal of Nanjing University of Posts and Telecommunications：Natural Science Edition

基　　金：国家科技重大专项(2017ZX03001021)资助项目。

摘　　要：在窄带物联网(Narrow Band Internet of Things,NB-IoT)系统中,上行数据链路采用单载波频分多址(Single-Carrier Frequency-Division Multiple Access,SC-FDMA),由于SC-FDMA固有的解码步骤会将估计误差扩展到所有的子载波上,因此对信道估计的误差更加敏感。在传统基于阈值的离散傅里叶变换(Discrete Fourier Transform,DFT)信道估计的基础上,利用NB-IoT的应用场景的低速性、准静态性,提出了一种基于双时隙的DFT信道估计算法。该算法利用两时隙内的导频的线性组合进一步降低噪声的影响,在复杂度增加较小的情况下,提升了系统性能。Matlab仿真结果表明,与基于阈值的DFT信道估计相比,在误比特率(Bit Error Ratio,BER)为1×10^-3时,文中算法相较基于阈值的DFT估计算法约有4 dB的性能增益,具有一定的实用价值。In the narrow band Internet of Things(NB-IoT)system,since the uplink uses single-carrier frequency・division multiple access(SC-FDMA),its decoding step will extend the estimation error to all subcarriers,thus it is more sensitive to the channel estimation error.Based on the traditional thresholdbased discrete Fourier transform(DFT)channel estimation,an improved DFT channel estimation is proposed using the low speed and quasi-static nature of NB-IoT application scenarios.The algorithm uses the linear combination of the pilots in the two slots to further reduce the impact of noise,and improves the sys・tem performance in a lower complexity extent.The Matlab simulation demonstrates that the algorithm can improve the bit error ratio(BER)performance about 4 dB compared with the threshold-based DFT estimation algorithm when BER=10^-3,thus the algorithm has a certain practical value.

关 键 词：窄带物联网 信道估计 离散傅里叶变换 

分 类 号：TN929.5[电子电信—通信与信息系统]