扩频通信多天线干扰检测技术研究

It is no doubt that spread spectrum communications has been extensively applied into wireless communications. Since there exist different interference in a wireless environment, techniques of interference migration have to be used to improve performance of the system. Hence, interference detections becomes one of most important techniques. The most existing methods of the interference detection are established on the local parameter hypothesis test, which almost can not be implemented quickly and efficiently, especially under of low SNR and small number of samples. This application proposes several methods of the detections based on fit test of goodness for the spread spectrum system with multiple antennas. The basic idea of these methods is to measure a distance between the distribution of received signals and some default distribution, and conduct the detection based on this distance. Because a distribution can completely determine a random variable, the proposed methods should outperform the existing mehods. Moreover, to combine fit test of goodness with various diversities provided by multiple antennas, this application will build different methods of the detection based on time dimension, space dimension, and order statistics of time-space dimension, respectively. ..

扩频通信在无线通信中得到了广泛的应用。由于无线环境中存在着各种复杂的干扰，为了提高扩频通信在干扰下的性能，必须采取一定的抗干扰措施。这样，干扰检测是扩频通信系统抗干扰的关键步骤之一。目前的干扰检测方法主要是基于局部参数假设检验，无法满足扩频通信系统在低信噪比、小样本条件下对干扰进行快速检测。本申请针多天线扩频通信系统，研究基于多元拟合优度检验的快速干扰检测技术。基本原理是通过度量接收信号的整体特征与某个假设条件下信号整体特征之间的差异进行干扰检测。这种以多天线接收信号整体特征为目标的干扰检测方法，突破了传统干扰检测方法原理上的限制，具有更好的检测性能。为了把拟合优度检验原理和多天线增益进行融合，本申请从多天线信号的时域分布函数整体特性、空域特征函数整体特性、空时域顺序统计量整体特性提出基于多元拟合优度检验的快速干扰检测方法。

本课题主要研究内容是通信系统中干扰检测和抵消技术。在通信系统中存在各种干扰，比如：扩频通信、OFDMA中的窄带干扰、OFDMA系统中相邻载频干扰，5G中的同频干扰等。为了提高通信系统的性能，这里就面临着两个问题。第一如何检测干扰信号的存在；第二如果有干扰信号存在如何对干扰信号进行抵消，或者说在干扰信号存在的情况下，如何更好的解码。. 本课题分别对扩频通信系统，OFDMA系统，大规模天线系统进行了干扰检测和抵消技术研究。从信号的结构特性出发，我们可以认为，扩频系统是信号在扩频序列上的投影、OFDMA系统是信号子载波上的投影、大规模天线系统是信号在大规模天线矩阵上的投影出发. .分析这些信号基于投影结构的时域、空域和空时域整体特征。并利用这些信号整体特征对接收到的信号进行干扰检测和干扰抵消，提高通信系统的解码性能。项目给出了所提干扰检测算法的检测概率理论表达式和所提干扰抵消算法的均方误差理论下界和误比特率的闭式表达式。. 本项目在分析通信系统信号结构特性的基础上，提出了基于时域、空域、空时域整体特征的干扰检测和抵消算法。所提方法利用信号的统计特性来对干扰和信号分离完成抗干扰检测和抗干扰。比传统的基于局部特征的干扰检测和抵消算法具有更好的性能。我们的研究成果表明（19篇论文，其中SCI 二区3篇， 三区1篇， 4区两篇），项目的研究成果在扩频通信、OFDMA通信、5G通信系统中有广泛的应用前景。