基于立方Farrow结构的插值细搜频偏估计算法  

Frequency Offset Estimation Algorithm of Interpolation Detail Search Based on Cubic Farrow Structure

作　　者：陆俊宇 李钰[1] LU Junyu;LI Yu(School of Information Science and Engineering,East China University of Science and Technology,Shanghai 200237,China)

机构地区：[1]华东理工大学信息科学与工程学院,上海200237

出　　处：《华东理工大学学报（自然科学版）》2024年第1期121-128,共8页Journal of East China University of Science and Technology

摘　　要：在高动态通信环境中,由相对运动引起的多普勒频移会在接收机下变频所得的基带信号中引入残留频偏,致使基带信号的相位发生偏离。对频偏进行精确估计是提升高动态环境通信质量的重要途径。传统方法通常通过对快速傅里叶变换(Fast Fourier Transform,FFT)后所得频谱进行一维搜索来估计载波频偏值,只能估计整数倍频点。为了进一步提高频偏估计的精度,本文提出了一种基于立方Farrow结构的插值细搜(Interpolation Detail Search, IDS)算法。仿真结果表明,此算法仅在16倍插值条件下就得到了逼近克拉美罗界(Cramer-Rao Bounds,CRB)的频偏估计性能,信噪比精度损失仅为1.2 dB,具有良好的估计性能。In high dynamic communication environment,Doppler frequency shift caused by relative motion will introduce residual frequency offset into the baseband signal obtained by downconversion of the receiver,resulting in phase deviation of the baseband signal.Accurate estimation of frequency offset is an important way to improve the communication quality in high dynamic environment.The traditional method usually estimates the carrier frequency offset value by one-dimensional search of the spectrum obtained by Fast Fourier Transform(FFT),which can only estimate the integral frequency point.In order to further improve the accuracy of frequency offset estimation,this paper proposes an interpolation detail search(IDS)algorithm based on cubic Farrow structure.Based on the rough spectrum obtained by FFT,the proposed approach uses cubic interpolation with Farrow structure to obtain more accurate fractional frequency point.Over the Additive White Gaussian Noise(AWGN)channel,the simulation results show that the algorithm performs quite close to the Cramer-Rao bound(CRB)under the condition of 16 multiples interpolation,and the accuracy loss is only 1.2 dB,which has good estimation performance.

关 键 词：频偏估计 插值细搜 立方Farrow结构 载波同步 前导码 

分 类 号：TP391[自动化与计算机技术—计算机应用技术]