【作者】 王玥；

【导师】 汪晋宽；

【作者基本信息】 东北大学 ， 通信与信息系统， 2008， 硕士

【摘要】 随着智能天线理论和阵列信号处理技术的不断发展,基于智能天线定位技术的研究和应用越来越广泛,在雷达测向、导航制导和移动通信等领域中都具有极其重要的意义,受到了国内外学者的广泛关注。智能天线技术能够针对正在变化的信号环境产生空间定向波束,使天线主波束对准用户信号的波达方向,旁瓣或零陷对准干扰信号的波达方向,达到增强期望信号,抑制干扰和噪声的目的。与其他技术相比较,智能天线在定位系统中的应用以其突出的优势具有十分广阔的发展前景。本文详细阐述了智能天线技术的原理、分类及发展趋势,并深入研究了采用智能天线定位的关键技术。分析了目前定位技术的需求领域,深入研究了智能天线中的无线定位算法以及所面临的主要问题。针对单站的情况,采用测向和测距相结合的定位思想,以到达时间(TOA)和波达方向(DOA)估计联合定位为基本方法,设计了基于智能天线技术的无源定位平台,可使单站对多个信源进行定位。一方面,利用DOA估计算法确定了信源方向；另一方面,设计了以到达时间为关键参数的测距方案,给出了信号处理模型,采用自适应波束形成算法用以恢复接收到的信源发送的测距信号。分析了在不同数目信源的情况下,测距方法的性能。对于单目标信源,对不同波束形成算法进行了比较研究,仿真验证了其提取期望信号算法的有效性；对于多目标信源,针对传统算法会出现的重复收敛于某一信号的问题,提出了一种多信源最小二乘恒模算法,不仅能有效分离所有的有用信号,而且可以很好地防止各信源信号间同时接收造成的干扰,收敛速度快、性能稳定,因而能够有效地提高系统性能,具有较强的实用性。仿真实验结果表明,本文提出的基于波束形成的测距算法的优势性和有效性为定位平台的实现提供了理论依据,具有一定的理论价值。本文所提出的基于智能天线技术的定位平台的设计方案,采用智能天线与软件无线电相结合的设计思想,利用中频带通采样数字化结构设计了定位平台硬件系统的各个功能模块。该定位方案能够对远距离目标进行定位,使系统达到较高的定位精度并获得稳定的系统性能,因而对工程实现具有一定的实际意义和参考价值。更多还原

【Abstract】 With the development of smart antenna theory and array signal processing technology,the research and application of location technology based on smart atenna are more and more extensive.There are extremely important meanings in radar direction detection, navigation, guidance and mobile telecommunication area.Digital signal processing technologies were used to produce spatial and directional beam in smart antennas.The main beam aims at the coming direction of reference user and the side lobe points to the coming direction of interference user.Compared with other technologies,smart atenna has a wide development prospect with its outstanding advantage in the application of location system.In this paper it is described that the technology of smart antenna,including its basic theory、basic concept, classification and the development trend of the research on this technology, and the key technology of location based on smart antenna is studied deeply.It introduces the domain requirement,wireless location algorithms and problems faced on present location technology. According to single station, direction finding and ranging as a joint positioning thought and the combination of TOA and DOA as the location method are used to design the location platform based on smart antenna,so that it can locate several targets at the same time.On one hand,the direction of the target is fixed by DOA method;on the other hand,the ranging project with time as the key parameter is designed, and the signal processing model is given.It is analyzed that the performance of ranging in conditions of different number of sources. According to single source, different beamforming algorithms are compared with each other.The computer simulation results indicate the effective performance of extracting desired signal.In the condition of multi-target sources, a novel multi-signals LS-CMA algorithm is proposed to solve the problem that several signals may converge the same signal in some traditional algorithms.This algorithm can not only seprate all these signals effectively,but also prevent these signals interfering each other when they are received at the same time.It has several advantages such as fast convergence and robustness,so it can improve the performance of the system effectively,and also have good practicality. The computer simulations results indicate that the ranging algorithm presented based on beamforming provides theoretical foundation for the location platform and has certain theoretical value.The design scheme of the platform presented by this paper based on smart antenna uses the combination thought of software radio and smart antenna,and IF pass band sampling digital structure to design all the modules of the hardware system of the location platform.This scheme can locate the target in long distance,and has relatively high positioning accuracy and steady performance,so that there are certain practical significance and reference value on engineering realization.更多还原