TD-LTE行业专网频偏估计算法优化研究

Research on the Optimization of CFO Estimation Algorithm in TD-LTE Industrial Private Network

为保证时分长期演进(TD-LTE)专网系统在部署覆盖、业务提供过程中正交频分多路复用技术(OFDM)不同子载波之间的正交性,提出TD-LTE行业专网系统频偏估计优化算法,可以正确恢复TD-LTE时域信号,避免信号畸变影响系统性能。首先,对比基于循环前缀(CP)、Moose以及基于主同步信号(PSS)序列相关的三种传统载波频率偏差(CFO)估计算法,证明基于PSS序列相关算法的有效性;然后,基于Moose算法和PSS序列相关算法的思想提出一种基于PSS序列重复协同检测的优化算法,比PSS序列相关算法至少可以提升约2~3 dB。随着PSS序列重复相关的次数增加,CFO估计性能能够不断改善。考虑到所提优化算法的复杂度和CFO估计效果,确定3个PSS序列相关检测性能最佳,比传统效果最好的PSS序列相关算法提升约8~11 dB。

In order to ensure the orthogonality between different subcarriers of OFDM in the process of deployment,coverage and service provision of TD-LTE private network system,a frequency offset estimation optimization algorithm for the TD-LTE industry private network system is proposed,which can correctly recover the TD-LTE time domain signal and avoid the signal distortion affecting system performance.Firstly,the effectiveness of PSS correlation algorithm is proved by comparing three traditional CFO estimation algorithms based on CP,Moose and PSS sequence correlation.Then,based on the idea of Moose algorithm and PSS sequence correlation algorithm,an optimization algorithm based on PSS sequence repeat detection is proposed.Compared with PSS sequence correlation algorithm,it can be improved at least 2-3 dB.As the number of repeated correlations of PSS sequence increases,the CFO estimates performance can continue to improve.Considering the complexity of the proposed optimization algorithm and CFO estimation effect,it is determined the three PSS sequence correlation detection performance is the best,which is about 8-11 d B better than the traditional PSS sequence correlation algorithm with the best effect.