一个简单有效的LTE随机接入前导检测系统  

Simple and Efficient Approach to Detect Random Access Preamble in LTE Systems

作　　者：李平安[1] 王江海[1] 管鲍 王俊 

机构地区：[1]武汉理工大学信息工程学院宽带无线通信与传感器网络湖北省重点实验室,武汉430070 [2]武汉虹信通信技术有限责任公司,武汉430074

出　　处：《系统仿真学报》2013年第6期1303-1308,共6页Journal of System Simulation

基　　金：国家科技重大专项(2009ZX03002-009)

摘　　要：简要介绍了LTE中PRACH的基带发射与接收系统,提出了一种简单有效的LTE随机接入前导检测系统,使用降采样技术和频域计算相关的方法来降低计算复杂性,便于系统的硬件实现。采用信号预处理和噪声平滑操作使检测系统适合低信噪比背景下的前导测量,明显改善了接收机的漏检概率。分析了多天线非相干合并后AWGN功率级随机变量的概率密度函数和累积分布函数的特征,分别针对2个和4个接收天线提出了线性近似虚警概率的阈值设定方法,使得阈值设定简单有效,并通过MATLAB对虚警概率和不同SNR下的漏检概率进行仿真,验证了提出系统的有效性。The launch and receiving system of PRACH were briefly introduced.A simple and efficient approach to detect random access preamble was proposed.Down sampling technique and correlation calculation in the frequency domain were used to lower the computational complexity,which could facilitate the hardware implementation.An effective signal pre-processing approach and a noise smoothing process were proposed to improve performance of detection in low SNR scenarios.Non-coherent combination in the power-level was applied to the multiple receive antennas after the correlation calculation.The characteristics of the probability density function and the cumulative distribution function of an AWGN power-level random variable after non-coherent combining were analyzed.A decision threshold approach based on the linear approximation of false alarm probability was proposed for both 2 receive antenna systems and 4 receive antenna systems,which made the threshold setting simple and effective.The false-alarm probability and miss probability under different SNR were simulated by MATLAB,and the results demonstrate the effectiveness of the proposed scheme.

关 键 词：LTE随机接入 前导信号检测 低SNR 阈值设定 

分 类 号：TN911.23[电子电信—通信与信息系统]