宽线性波束形成技术综述

在圆信号的假设条件下，传统的线性波束形成技术仅仅利用了天线阵列观测矢量的协方差矩阵。然而，现代通信领域中的很多人工调制信号具有非圆特性，观测矢量不仅存在协方差矩阵，还存在伪协方差矩阵。宽线性波束形成技术是针对非圆信号环境提出的一类新技术，该类技术通过构造一个包含天线阵列观测矢量及其共轭的扩展观测矢量，建立有利于特定方向信号接收的目标函数及约束，推导出相应的扩展权重矢量。同传统线性波束形成技术相比，宽线性波束形成技术对非圆信号的接收性能有了明显提升，近年来，该类技术成为国内外研究热点之一。本文介绍了圆信号和非圆信号定义，给出了阵列模型并介绍了最小方差无畸变响应波束形成，对各种宽线性波束形成算法进行了综述，并对宽线性波束形成技术的下一步研究方向进行了展望。

Review for widely linear beamforming technique

Under the assumption of noncircular signals, the conventional linear beamforming technique only utilizes the covariance matrix of the observation vector from the antenna array. However, in the area of modern communication, many artificial modulation signals have noncircularity property, i.e., the observation vector not only has the covariance matrix but also has the conjugated covariance matrix. The WL beamforming technique is proposed as a new technique under the scenario of noncircular signals, which is achieved by defining an extended observation vector consisted by the observation vector and its conjugated version, and obtaining a extend weight vector after constructing an objective function and constraints. In contrast with the conventional beamforming technique, the WL beamforming technique for the reception of noncircular signal has an obvious improvement. In recent years, the WL beamforming technique has been the focus of research at home and abroad. In this paper the definitions of circular and noncircular are introduced, the array model, the minimum variance distortionless response beamformer and various WL beamforming algorithms are presented. Finally, the future research directions are prospected.