基于分段互相关的5G新空口PSS同步算法  

5G NR PSS synchronization algorithm based on segmented cross-correlation

作　　者：李文星 刘祖深 铁奎 刘龙 贾慧云 LI Wenxing;LIU Zushen;TIE Kui;LIU Long;JIA Huiyun(School of Instrument and Electronics,North University of China,Taiyuan 030051,China;Ceyear Technologies(Anhui)Co.,Ltd.,Bengbu 233010,China;Bengbu Technology Innovation Center on Electronic Measurement Instrumentation Technology,Bengbu 233010,China;School of Mathematical Sciences and Statistics,Baise University,Baise 533000,China)

机构地区：[1]中北大学仪器与电子学院,山西太原030051 [2]中电科思仪科技(安徽)有限公司,安徽蚌埠233010 [3]电子测量仪器技术蚌埠市技术创新中心,安徽蚌埠233010 [4]百色学院数理科学与统计学院,广西百色533000

出　　处：《现代电子技术》2024年第21期7-12,共6页Modern Electronics Technique

基　　金：国家重点研发计划(2022YFF0706700)。

摘　　要：针对5G NR主同步信号(PSS)同步算法不适用于高频偏环境的问题,文中提出利用PSS序列的自相关性,先进行粗同步,在精同步模块考虑了分段互相关算法中叠加噪声项的影响,对分段互相关算法的共轭相乘项进行离散傅里叶变换,通过DFT的负指数项抵抗高频偏,并在时域上进行PSS同步,解决了算法频偏容忍度较低的问题。通过Matlab仿真结果表明,改进算法在AWGN信道环境下,当归一化频偏和信噪比分别设置为2和-5 dB时,检测的峰值位置正确并且相关峰值明显。当归一化频偏为2、信噪比为-6 dB、分段数为4时,PSS检测概率仍有0.6以上。在实际测试环境验证中,通过文中提出的改进算法可将同步流程时间控制在5 ms内,可以满足测试工程需求。通过对分段互相关算法的共轭相乘项进行改进,使改进算法在分段数较少时仍具有较好的频偏容忍度,且具有较强的抗频偏性能,此外,还能有效降低传统分段互相关算法由于分段导致叠加噪声项带来的影响。改进算法应用于国产通信矢量信号分析软件VSA中,并且在6955AC信号收发仪上得到验证,具有一定的实际应用价值。The 5G NR(new radio)primary synchronization signal(PSS)synchronization algorithm is inapplicable to high-frequency bias environment,so the autocorrelation of PSS sequence is used to carry out rough synchronization first,and then,in the fine synchronization module,the influence of the superimposed noise term in the segmented cross-correlation algorithm are taken into account,and the discrete Fourier transform(DFT)on the conjugate multiplication term of the segmented cross-correlation algorithm is carried out.The negative exponential term of DFT is used to resist high frequency bias,and the PSS synchronization is carried out in time domain,which improve the frequency bias tolerance of the algorithm.The results of Matlab simulation show that in AWGN(additive white Gaussian noise)channel environment,when the normalized frequency offset and signal-to-noise ratio(SNR)are set at 2 and-5 dB,respectively,the detected peak position is correct and the correlation peak is obvious.When the normalized frequency offset is 2 and the SNR is-6 dB,the detection probability of PSS is still above 0.6 when the number of segments is 4.It is verified in the actual test environment that the improved algorithm proposed in this paper can keep the synchronous process time within 5 ms,which can meet the demand of test engineering.In this paper,by improving the conjugate multiplicative terms of the segmented cross-correlation algorithm,the improved algorithm still has a good frequency offset tolerance when the number of segments is small;the improved algorithm not only has a strong anti-frequency offset performance,but also can effectively reduce the influence of superimposed noise terms caused by segmentation in the traditional segmented cross-correlation algorithm.The proposed algorithm has been applied to the domestic communication vector signal analysis software VSA and has been verified on the signal transceiver 6955AC.So,it has a certain practical application value.

关 键 词：主同步信号 分段互相关 离散傅里叶变换 自相关 新空口 频偏 

分 类 号：TN911.6-34[电子电信—通信与信息系统]