【作者】 赵海全；

【导师】 张家树；

【作者基本信息】 西南交通大学 ， 信号与信息处理， 2005， 硕士

【摘要】 在日益高速发展的现代通信环境下,传输信道的非线性已成为影响信道误码性能的主要因素,只有采用基于非线性滤波器理论的非线性均衡技术才能有效抑制高速传输信道的码间干扰。因此,非线性信道的均衡技术就成为高速无线通信领域的一个研究热点。 借助多项式自适应滤波器以及神经网络滤波器两种非线性模型,从减少多项式中耦合项的数量和使用另外一种形式的非线性系统来逼近Volterra非线性系统两个方面入手,研究和探讨了新型结构的非线性自适应均衡器,主要在对多项式滤波器、神经自适应滤波器、一般非线性多项式及正交多项式神经网络等结构研究基础之上,并适当地把判决反馈结构、双线性结构融合其中,提出了一系列新型结构的非线性信道均衡器,并且对各种结构非线性均衡器作了性能分析,计算机仿真证明了它们的正确及有效性。 论文的主要研究成果包括: 1.研究了一种基于DCT域二阶多项式自适应均衡器,解决了输入信号的自相关矩阵的特征条件过大以及二阶Volterra展式的耦合项数量过大的问题。该均衡器具有优点是结构简单、参数个数少以及计算复杂性较低。 2.在分析非线性系统级联结构的基础上,先后研究了线性滤波器与多项式级联结构、神经网络与多项式级联结构、神经Legendre正交多项式以及神经Chebyshev正交多项式判决反馈均衡器。研究结果为构造新型非线性滤波器提供了新的思路。 3.研究了线性滤波器与多项式级联结构的复值自适应均衡器、神经网络与多项式级联结构的复值自适应均衡器,并推导出了相应复数自适应算法。仿真结果为实际工程的复值信道实时应用提供了新的依据。 4.研究了神经网络与多项式级联结构的自适应均衡器在卫星通信非线性信道中的应用,仿真结果证实了该自适应均衡器有效性。更多还原

【Abstract】 In the increasingly developing circumstance with high data rate, the communication channel’s nonlinearity has become the main factor affecting the bit error rate, when only the nonlinear equalization technology with based on nonlinear filter theory can remove the ISI effectively. So, the research on the nonlinear channel equalization is now a hot spot in the high-rated wireless communication area.This paper is performed mainly on the adaptive equalization technology in the nonlinear channel, based on summarizing the present study on nonlinear adaptive signal processing and nonlinear channel equalization domestically and abroad. By using polynomial adaptive filtering and neural network technology, novel ways on how nonlinear adaptive filter (or neural network) can be applied into the nonlinear equalization are discussed and several novel nonlinear equalizers are proposed, which have shown better equalization performance than the general ones.The main results of this paper are as follows:1. Based on DCT polynomial adaptive equalizer is proposed for autocorrect matrix’s characteristic condition of input’s signals and product coupling items, which has a very simple structure and few parameter but with good nonlinear equalization performance.2. Linear Filer linked Nonlinear polynomial adaptive equalizer、 Neural Network linked Nolinear polynomial adaptive equalizer 、 Neural Network Legendre polynomial adaptive equalizer and Neural Network Chebyshev polynomial decision feedback equalizer for nonlinear polynomial adaptive filers are proposed, the equalizer’s anti-nonlinear performance can be improved effectively.3. Linear Filters linked Nonlinear and Neural Network linked Nonlinear polynomial complex adaptive equalizers are proposed for complex nonlinear channel, the complex algorithm is given,. Simulation’s results show that they can effectively compensate the phase and amplitude loss in the complex channel.更多还原