Determining the optimal decision delay parameter for a linear equalizer

1 Introduction Equalization techniques play an ever-increasing role in combating distortion and interference in mod- ern communication links[1,2]. It is well-known that the choice of equalizer decision delay parameter crit- ically determines achievable bit error rate (BER) performance[3,4]. We present a simple and e?ective method for determining an optimal decision delay pa- rameter that results in the best bit error rate perfor- mance for a linear equalizer. The proposed technique computes …     

合成绝缘子均压环安装方式的研究

介绍了合成绝缘子均压环的作用及正确安装使用方法,重点说明开口均压环环的特点及使用方法。     

整流柜均流系数测算方法的改进

传统的整流柜均流系数测算需要工作人员在正常运行或电流升高的整流柜上测量快熔两端的毫伏压降,这对测试人员和整流柜来说都存在较高的危险。使用红外线测温仪可以随时检查每条桥臂上整流元件和快熔的运行情况,套用计算均流系数的公式可以计算桥臂的温度系数,跟踪桥臂的均流变化情况,比传统的方法更安全、简便。     

基于分频带传输的单载波水声通信技术研究

针对正交频分复用技术的峰均功率比较高且对多普勒频偏敏感等问题,提出基于分频带传输的单载波水声通信技术,为水下高速通信领域提供了一种可行性方案。该方案将相对较宽的通信频带划分为若干子带,在每个子带间插入保护频带,以消除载波间干扰。开展了水声通信试验,发射换能器频带被划分为两个子频带,每个子带带宽为2.25 kHz,子频带保护间隔为0.75 kHz,载波频率分别为3 kHz和6 kHz. 采用被动时间反转镜联合判决反馈均衡器的接收机结构抑制码间干扰,当映射方式为8相移键控时,3 km、5 km和7 km距离上的试验数据均实现了通信速率为9 kbit/s的 低误码率数据传输,验证了该系统的稳健性。     

Using self‐constructing recurrent fuzzy neural network as a digital channel equalizer

Abstract

In this paper the design of a self‐constructing recurrent fuzzy neural network (SCRFNN)‐based digital channel equalizer is proposed. It is found that a digital channel equalizer based on SCRFNN can recover channel distortions effectively. We compare the performance of SCRFNN with adaptive‐based‐network fuzzy inference system (ANFIS) and the Bayesian equalizers in complex‐valued linear channels. Our simulations show that the performance of SCRFNN is close to the Bayesian optimal solution. Furthermore, the hardware requirement of the trained SCRFNN equalizer is relatively lower than the other two structures.     

基于NOLM的二元信号功率均衡器研究

为了全光处理具有固定功率差异光信号,本文在详细分析非线性光纤环形镜(NOLM)受不同泵浦作用时输出特点的基础上,设计了将二元功率光信号进行幅度直接均衡的方案.利用光子学仿真软件进行了数值实验,结果显示二元信号经幅度均衡后的输出功率由均衡器输出级探测波功率直接确定,输出脉冲无波长改变,且幅度抖动小.输出脉冲无基座表明该方...     

基于超级电容器的动力锂离子电池均衡电路

这里对电动汽车等使用的串联锂电池组存在的多次充放电后不均衡问题,提出一种基于超级电容器和模糊控制的能量转移型均衡电路。该均衡电路从串联电池组中电压高的电池汲取能量,并转移给电压低的电池,从而维护了电池组电压一致性,具有结构简单,控制方便,快速有效的优点。这里对电路工作原理进行分析,介绍了基于模糊逻辑的控制策略,最后用实验结果证明了该均衡电路优良的稳态和动态特性。     

一种适用于高速接口电路的新型均衡电路

本文提出了一种新型高速均衡电路.在传统源极负反馈均衡滤波结构的基础上改进电路结构,使用有源电感及对称负载结构改善了电路性能,避免了使用片上电感,优化了电路结构,节省了芯片面积,同时缓解了传统均衡电路的速度瓶颈.经仿真验证,该均衡器电路高频补偿增益达到17.2dB ,高低频增益比达到5.24,信号速率达到5Gb/s 时能完整接收信号,实现均衡效果.该电路结构简单,适用于各种高速信号接口电路.该电路采用0.13μm CMOS 工艺实现.     

一种在多径信道下LDPC码的解码设计

本文首先简单介绍了基带编码调制的LDPC系统与信道模型,接着设计了一种适合应用在多径信道下的自适应均衡器;然后,对LDPC码以及编译码模块进行了构造;最后,本文对所提出的由自适应均衡滤波器和LDPC解码器组成的自适应LDPC译码系统的误比特率（BER）性能进行了仿真,仿真结果表明新的译码系统可以解决在多径信道下BER性能较差的问题。     

Adaptive MMSE decision feedback equalizer for asynchronous CDMA with erasure algorithm

Adaptive decision feedback equalizer with erasure algorithm (E-DFE) is proposed for asynchronous code division multiple access (CDMA) transmission, which not only combats intersymbol interference (ISI) and multiple access interference (MAI) but also reduces the effects of error propagation in the presence of Gaussian background noise. To reduce the possibility of feeding back the wrong decisions, the output of the feedforward filter of the E-DFE is processed before it is fed back to the feedback filter. Specifically, the focus is on the performance of E-DFE using soft-slicer based on a novel erasure algorithm. In addition, the fully connected feedback filter of E-DFE has been used to eliminate ISI due to other active users. Comparison of the performance of conventional decision feedback equalizer (C-DFE) and E-DFE over slowly varying frequency selective fading channel is presented to show the advantages of E-DFE in terms of reduced average bit error rate performance. Simulation results are also presented to show the substantial improvement in its performance under near-far situations and the sudden change in the signal power of the desired user.