ADSL-DMT系统的子信道均衡算法仿真  

Simulation of Per Tone Equalization for ADSL-DMT

作　　者：张静飞[1] 印晓芬[1] 陈建亚[1] 王振凯[1] 

机构地区：[1]北京邮电大学电信工程学院,北京100876

出　　处：《计算机仿真》2006年第6期109-112,共4页Computer Simulation

摘　　要：在采用离散多载波调制(DMT)的ADSL中,需要使用均衡技术来缩短信道的响应时间,从而使系统发端可以采用长度较短的循环前缀来消除码间干扰。但传统的均衡算法复杂度高且对所有子信道做统一处理,限制了系统性能。针对这一问题,该文介绍了一种改进的结构———每个子音频信道上使用一个多抽头的频域均衡器,并通过仿真分析得到,该均衡器能够实现各个子信道的信噪比最大化,从而在相同传输条件下提高了系统容量,降低了系统对同步时延的敏感度,最后分析总结了该均衡器的简单初始化方法。Time - domain equalizer is used in the discrete muhitone - based ADSL system in order to reduce the duration of overall response of the transmission system, so that a shorter - length cyclic prefix could be used to eliminate intersymbol interference. However, traditional equalization technology is optimized over all subehannels with complicated computation, which limits the performance of ADSL. This paper introduces a new equalizer structure with a muhitap FEQ per tone. With the simulation and analysis based on the new structure, the signal - to - noise ratio is maximized for each individual tone separately, and a larger bit rate is achieved while complexity during data transmission is kept at the same level. Moreover, the per tone equalization is shown to have a reduced sensitivity to the synchronization delay. At last, some cheap initialization schemes for PTEQ are also mentioned.

关 键 词：均衡器 子信道均衡 最小均方误差 最小二乘 离散多载波调制 

分 类 号：TN911.5[电子电信—通信与信息系统]