The Research and Implementation of the Adaptive Interference Cancellation in WCDMA Repeater

直放站是一种中继设备，在已经到来的3G时代依旧需要其协助基站来扩大信号的覆盖范围。无线直放站在应用中常会因为收发天线间隔离度不高而引发严重的干扰问题，本论文应用自适应干扰抵消技术对WCDMA无线直放站的同频干扰进行抵消，进而提高WCDMA直放站的性能，方便其使用。 本文首先对WCDMA直放站中存在的干扰进行分析，说明了使用自适应滤波进行干扰抵消的必要性。根据自适应干扰抵消应用的原理，结合直放站干扰环境，确定了WCDMA直放站下的自适应干扰抵消方案。 本文在自适应干扰抵消算法的性能以及成本比较后，选择了适合硬件实现的DLMS算法来实现关键的自适应滤波模块。为了提高FPGA上实现的自适应干扰抵...Repeater is a type of relaying equipment and can be used to provide wider coverage. In the age of 3G, repeater is still widely used. Repeater always be disturbed by a serious feedback interference that comes into the receive antenna from the transmit antenna of the repeater. In this paper, adaptive interference cancellation technology is implemented in WCDMA repeater to cancel the inherent co-chan...学位：工学硕士院系专业：信息科学与技术学院通信工程系_通信与信息系统学号：2332008115329

The Research and FPGA Implementation of WCDMA Interference Cancellation Repeater

随着无线通信技术的快速发展，直放站由于其低投入、低成本、较短的建设周期和较好的网络质量等优点，已经被广泛用于无线网络中的扩展覆盖区和填补信号弱区盲区。但直放站应用的一大缺陷是严重的同频干扰，本文将自适应干扰抵消技术应用到WCDMA无线直放站，正是为了减小同频干扰造成的自激。 本文首先简单概述了几种常用的自适应干扰抵消算法，并对算法性能进行了Matlab仿真，结合算法收敛速率和算法计算复杂度，以及信号实时高速处理的需要，本文选择了DLMS算法作为AIC直放站的干扰抵消算法。其次详细介绍和仿真了基于CAZAC序列的AIC直放站，且将重定时技术引入到DLMS滤波器结构变换中，对插入的延时进行重分配...As wireless communication technology developing, for the good characteristics of low-input, low operating cost, relatively short construction period and good network quality, the repeater, as an effective radio signal transmission and amplification device, has been widely used to expand the networks and fill the blind area. However, the feedback oscillation is always a weakness in engineering appl...学位：工学硕士院系专业：信息科学与技术学院通信工程系_通信与信息系统学号：2332009115280

Complex ICA based adaptive feedback interference cancelling algorithm for wireless repeaters

为了利用自适应滤波器抵消转发与接收天线间的反馈干扰,根据卷积型混合与独立分量分析ICA解混的原理,将反馈干扰抵消问题纳入了ICA方法的框架中。针对亚高斯复值信号的特点,依据极小化互信息的准则,提出了一种基于复数ICA的自适应算法,简要分析了算法收敛的平衡点并据此给出了新的干扰抵消器的结构。计算机仿真结果表明,相比于lMS算法,所提的算法在反馈信道辨识误差以及输出信号的误差矢量幅度方面有明显的改善。Feedback interference cancelling by using adaptive filters is one of the core technologies of wireless repeaters.The problem was summed up into the framework of ICA in terms of the ICA demixing principle of convolutive mixtures.Aiming at complex signals' subgaussian feature,an adaptive algorithm based on complex ICA was proposed according to minimization of mutual information criterion.The convergence equilibrium point of the proposed algorithm was briefly analyzed and a new structure of interference canceller presented accordingly.Computer simulation demonstrated that the proposed algorithm had obvious performance improvement over conventional LMS in the identification error of feedback path and of the error vector magnitude the output signals'.国家863计划资助项目(2007AA01Z267);福建省重大专项基金资助项目(2009HZ0003-1);福建省教育厅科技项目(JA10251

认知型水声通信时空自适应处理算法研究

针对浅海水声通信面临的复杂干扰环境,提出了一种适用于水声通信系统的认知型时空自适应处理算法。该算法在传统时空自适应阵列处理算法的基础上引入了干扰认知的功能,通过干扰认知处理降低计算量,并且实现干扰样本的选取,确保自适应算法的可靠收敛。利用了协方差矩阵特征分解和多重信号分类(Multiple Signal Classification, MUSIC)估计干扰的个数,辅助选取盲源分离算法中的维度和时空自适应算法中的空域维度,进行算法降维处理。针对采用盲源分离后的各干扰,采用包络检测法提取时域特征,采用短时傅里叶变换(Short-time Fourier Transform, STFT)方法提取时频谱特征,分析干扰特征,实现干扰分类,从而实现干扰样本的选取。通过计算机仿真验证了该认知处理算法的性能。水声通信与海洋信息技术教育部重点实验室开放基金资助(厦门大学)(201703);;江苏省自然科学基金资助项目(BK20151501);;中央高校基本科研业务费专项资助项目(2015B03014