分数间隔快速RLS判决反馈均衡器  

Fractionally spaced fast RLS decision feedback equalizer

作　　者：张峰瑞 江鹏[1] 韩震 ZHANG Fengrui;JIANG Peng;HAN Zhen(GNSS Research Center,Wuhan University,Wuhan 430072,China)

机构地区：[1]武汉大学卫星导航定位技术研究中心,湖北武汉430072

出　　处：《现代电子技术》2022年第19期44-48,共5页Modern Electronics Technique

基　　金：国家重点研发计划(2020YFB050580)。

摘　　要：由于水声信道复杂的特性,如多径效应、多普勒效应和时变性,信号在传输过程中会带有严重的码间串扰,均衡器被广泛应用于水声通信系统中以消除码间串扰。针对水声信道的特点和减少计算量的需求,综合分数间隔结构和快速RLS算法的优点,设计了一种分数间隔快速RLS判决反馈均衡器。使用分数间隔结构取代传统的符号间隔结构,克服符号间隔结构对同步精度要求高的缺点。快速横向滤波算法是一种被广泛应用的快速RLS算法,选择其作为均衡器的自适应算法,以降低均衡器的计算复杂度。分数间隔判决反馈结构的信号不满足算法要求的移不变特性,通过引入置换矩阵,对快速横向滤波算法进行推广,使它适用于分数间隔判决反馈结构的形式。由湖上实验数据的测试表明,提出的均衡器在收敛速度、稳态误差和误码率上都有着更好的表现,并且相较RLS算法,需要的计算量显著减少。Due to the complex characteristics of underwater acoustic channel,such as multipath effect,Doppler effect and time-varying property,the signals are of serious inter symbol interference during transmission. Therefore,equalizers are widely used in underwater acoustic communication system to eliminate inter symbol interference. According to the characteristics of underwater acoustic channel and the need of reducing computational consumption,a fast RLS(recursive least square)decision feedback equalizer(DFE) with fractionally spaced structure is designed by combining the advantages of fractionally spaced structure with fast RLS algorithm. In the design,the fractionally spaced structure is used to replace the traditional symbol spaced structure to overcome the later structure′s shortcoming which requires high synchronization accuracy. The fast transversal filtering(FTF) algorithm,a kind of widely-used fast RLS algorithm,is chosen as the adaptive algorithm to reduce the computational complexity of equalizer. The signal of fractionally spaced decision feedback structure does not meet the shift invariance property of the algorithm. Therefore,by introducing permutation matrix,the FTF algorithm is generalized to adapt to the fractionally spaced decision feedback structure. The result of experimental data test on the lake shows that the proposed equalizer has higher convergence speed,smaller steady-state error and bit error rate,and its computational consumption is significantly reduced in comparison with RLS algorithm.

关 键 词：快速RLS算法 分数间隔结构 判决反馈均衡器 计算复杂度 码间串扰 水声通信 

分 类 号：TN911.5-34[电子电信—通信与信息系统]