自适应均衡技术的研究与DSP实现
文献类型：学位论文
| 作者 | 吴碧 |
| 学位类别 | 博士 |
| 答辩日期 | 2005 |
| 授予单位 | 中国科学院声学所 |
| 授予地点 | 中国科学院声学所 |
| 关键词 | 码间干扰 自适应均衡 归一化最小均方 |
| 其他题名 | The research and realization of an adaptive equalizer technique based on the high-speed data transmission over cable |
| 中文摘要 | 在电缆高速传输系统中，由于有线信道的传输特性不是理想的，信号的传输受信道带宽的限制，其幅频响应与相频响应会产生畸变，从而引起码间的干扰。并且信道是随着气候、气温等因素而变化的，使得信道的幅频特性和相频特性的失真随时间而变化，从而也引起了码间干扰。自适应均衡技术能补偿由于信道参数变化所引起的畸变、抵消信道信号传输衰减，·同时有效地抗码元经传输引起的码间干扰，减少误码，提高传输速率，因而在通信系统中得到了广泛的应用。本论文在简要介绍了码间干扰（ISI）的产生及其数学模型的基础上，详细介绍了自适应均衡原理，着重研究与本课题关系密切的时域均衡原理，以及应用时域均衡器实现对码间干扰的消除原理。深入地研究了自适应滤波的理论以及其算法，在对常用算法进行了详细的分析、比较后，选择了一种适用于长距离电缆高速数据传输的自适应算法：归一化的最小均方算法（NLMS）。并利用计算机仿真软件SIMUUNK对该算法进行了仿真研究，确定了算法的各个参数，并通过仿真验证了该算法对消除码间干扰的效果。最后，本论文还详细介绍了基于DSP的自适应均衡器的硬件系统、软件系统以及自适应滤波算法的工程实现。 |
| 英文摘要 | In the high-speed data transmission system of long distance over cable, the amplitude-frequency response and phasic-frequency response of the transmitted signal are distorted for the reason that the transmission characteristic of the cable channel is not ideal and the transmission of the signal is limited by the channel's band-width, thus the intersymbol interference(ISI) appears.Besides, the channel may be changed by the weather and the temperature, and it causes that the aberrance of the peculiarity of the channel' amplitude-frequency and phasic-frequency varies time after time, and thus the intersymbol interference(ISI) also appears.The adaptive equalizer technique can compensate the distortion caused by the change of the channel parameter and counteract the attenuation of the channel signal, at the same time it can eliminate the ISI efficiently and then decrease coding errors and enhance the transmitting rate as well, thus the adaptive equalizer technique is utilized extensively in the communication system. This thesis presents the theory of adaptive equalizer in detail based on a brief introduction about the causation and mathematics model of ISI, in which we mainly focus on the theory of time-domain adaptive equalizer related with our subject closed, and the theory to eliminate the ISI by time-domain adaptive equalizer. In addition, the theory of adaptive filter and its algorithm are particularly studied in this paper, and by traversing and comparing the common algorithms employed in the adaptive equalizer technique, an adaptive equalizer named normalized least -mean-squares (NLMS) is chosen, which is suitable for high-speed data transmission of long distance over cable.The computer software SIMULINK is used to simulate the NLMS algorithm, by which each parameter of the algorithm is confirmed and the effect of the NLMS used to eliminate the ISI is proved. Finally, we present the realization of the DSP based adaptive equalizer hardware systems, software systems and algorithm in detail. |
| 语种 | 中文 |
| 公开日期 | 2011-05-07 |
| 页码 | 55 |
| 源URL | [http://159.226.59.140/handle/311008/970]  |
| 专题 | 声学研究所_声学所博硕士学位论文_1981-2009博硕士学位论文 |
| 推荐引用方式 GB/T 7714 | 吴碧. 自适应均衡技术的研究与DSP实现[D]. 中国科学院声学所. 中国科学院声学所. 2005. |
入库方式： OAI收割
来源：声学研究所
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