基于TMS320VC5509A的自适应均衡器的算法设计

发布时间：2018-05-06 09:10

本文选题：多径衰落 + 自适应均衡　；参考：《中北大学》2017年硕士论文

【摘要】：有效性和可靠性是设计通信系统时不得不考虑的两个问题,在无线通信系统中,多径效应和多普勒频移是造成码间干扰,导致频率和时间选择性衰落的主要原因。自适应均衡技术应运而生,由于自适应均衡器可以产生与信道特性相反的特性,用来消除信道的的时变多径传播特性带来的干扰,在现代数字微波通信系统中得到了广泛的应用。本文主要针对数字微波通信系统中信道的时变多径衰落的特性,对自适应均衡器及其算法进行了研究,并在TI公司生产TMS320VC5509A定点DSP开发板上进行了实现。首先本文介绍了无线通信中的信道以及所用的模型,并给出了信道的等效离散时间模型。紧接着对自适应均衡器的结构分类以及工作原理做了阐述,对自适应均衡算法及其调节准则做了理论性的介绍分析,并在MATLAB软件环境下模拟实际环境,对使用LMS和RLS算法实现自适应均衡器的性能进行了验证分析。随后在VC6.0环境下对自适应均衡器进行了模拟仿真,用C++语言编写了矩阵类,实现了矩阵的基本操作,产生了高斯白噪声和数据输入矩阵,在此基础上实现了RLS和LMS两种算法的自适应均衡器,为利用DSP实现自适应均衡器打下基础。最后,先通过建立自适应噪声消除模型,在TMS320VC5509A定点DSP开发板上对使用LMS和RLS两种算法自适应均衡器中滤波部分的功能进行了仿真验证,达到了理想要求,最终,在上述开发板上实现了采用LMS算法的自适应均衡器,并对不同信道不同信噪比不同步长以及信道发生变化的时变信道的实验结果进行了比较和分析。本系统主要采用C语言编写完成,具有很好的可读性和可移植性,维护方便,参数设置灵活,具有很好的应用前景。
[Abstract]:Effectiveness and reliability are two problems that must be considered when designing communication systems. In wireless communication systems, multipath effect and Doppler frequency shift are the main causes of inter-symbol interference and frequency and time selective fading. The adaptive equalization technique emerges as the times require. Because the adaptive equalizer can produce the opposite characteristics of the channel, it is used to eliminate the interference caused by the time-varying multipath propagation of the channel. It is widely used in modern digital microwave communication system. In this paper, the adaptive equalizer and its algorithm are studied in view of the time-varying multipath fading characteristics of the channel in digital microwave communication system, and implemented on the TMS320VC5509A fixed-point DSP development board produced by TI Company. Firstly, this paper introduces the channel and the model used in wireless communication, and gives the equivalent discrete time model of the channel. Then the structure classification and working principle of the adaptive equalizer are expounded, and the adaptive equalization algorithm and its adjustment criterion are introduced and analyzed theoretically, and the actual environment is simulated in the environment of MATLAB software. The performance of adaptive equalizer using LMS and RLS algorithms is verified and analyzed. Then the adaptive equalizer is simulated under the VC6.0 environment, and the matrix class is written in C language, which realizes the basic operation of the matrix and produces Gao Si white noise and data input matrix. On this basis, the adaptive equalizer of RLS and LMS algorithms is implemented, which lays the foundation for the realization of adaptive equalizer using DSP. Finally, by establishing an adaptive noise cancellation model, the functions of filtering part of adaptive equalizer using LMS and RLS algorithms are simulated on the TMS320VC5509A fixed-point DSP development board. An adaptive equalizer using LMS algorithm is implemented on the above development board, and the experimental results of time-varying channels with different signal-to-noise ratio (SNR) nonsynchronous length and channel variation are compared and analyzed. The system is mainly written in C language, which has good readability and portability, convenient maintenance, flexible parameter setting, and has a good application prospect.
【学位授予单位】：中北大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TN715

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