Concurrent Blind Channel Equalization in Impulsive Noise Environments

In some communication systems the trans- mitted signal is contaminated by impulsive noise with a non-Gaussian distribution. Non-Gaussian noise caused significant performance degradation to communication re- ceivers. The new constant modulus blind equalizer based on Fractional lower-order statistics of the equalizer input, which is defined as FLOS_CMA, is able to mitigate impul- sive channel noise while restoring the constant modulus character of the transmitted communication signal. How- ever, like the Constant modulus algorithm （CMA）, the steady-state Mean square error （]VISE） of the FLOS_CMA algorithm may not be sufficient low for the system to ob- tain adequate performance. This paper proposes a con- current equalizer, in which a Decision-directed least mean p norm （DD_LMP） equalizer operates cooperatively with a FLOS_CMA equalizer, controlled through a non-linear link. Simulation results using M-QAM and 8-PSK signal- ing have shown that besides the capability of compensating the phase offset, the proposed concurrent FLOS_CMA and DD_LMP blind equalizer has faster convergence rate and lower steady-state MSE than the FLOS_CMA approach.     

放音磁头的轮廓效应

本文介绍了录音机放音磁头轮廓效应的基本原理及其形成的规律性，轮廓效应影响的定量计算和克服其不良影响的基本方法，及轮廓效应和放音低频响应的关系。     

基于梯度的HEVC自适应码率控制算法研究

针对新一代视频编码标准HEVC中的码率控制问题,提出了一种基于梯度的自适应码率控制算法.算法的主要特点是自适应获取每个LCU的梯度来表示其复杂度,根据复杂度分配LCU层目标比特.同时,在分配帧层目标比特时利用缓冲区的状态信息,以使编码器输出的实际码率更符合给定的目标码率,并使缓冲区滞留的数据尽量少,即传输时延尽量小.实验结果表明,该算法与标准的HEVC码率控制提案K0103相比,缓冲区滞留数据量平均减少约39.31％,峰值信噪比平均提高约0.54 dB,同时实际码率与目标码率之间的码率偏差平均降低约0.39％.     

手机主流数据业务的基准速率测试分析

近年来移动互联网业务的快速发展,手机上网业务已经成为中国移动核心增量业务,不同的移动数据业务也成为了影响业务质量及用户感知度的重要因素,而且业务不同用户的感知需求也不同,所以需要构建新的手机上网业务评估体系评价不同业务的指标,从而辅助网络优化工作。但以往单纯的平均下载速率并不能完全反映业务标准,基准速率之上的相关指标统计更能够反映网络对用户流量业务需求的满足情况,本文就详细介绍了在TD-SCDMA和LTE网络下主流数据业务用户的基准速率的测试分析情况。     

Low complexity encoder optimization for HEVC

High Efficiency Video Coding (HEVC) improved the coding efficiency significantly. Compared to its predecessor H.264/AVC, it can provide equivalent subjective quality with more than 57% bit rate reduction. However, the improvement on coding efficiency is obtained at the expense of much more intensive computation complexity. In this paper, based on an overall analysis of computation complexity at the HEVC encoder, a low complexity encoder optimization scheme is proposed by reducing the number of available candidates for evaluation in terms of the intra prediction mode decision, early termination of coding unit (CU) splitting and adaptive reference frame selection. With the proposed scheme, the rate distortion optimization (RDO) technique of HEVC can be implemented in a low-complexity way for complexity-constrained encoders. Experimental results demonstrate that, compared with the original HEVC reference encoder implementation, the proposed optimization scheme can achieve more than 40% complexity reduction on average with coding performance degradation as only 0.43% which can be ignorable.     

西门子PLC在恒压供水系统中的应用

本文主要介绍一种用西门子PLC200、维纶屏和三垦变频器来控制恒压供水的系统,通过PLC200控制整个系统的运行,三垦变频控制水泵的频率,维纶屏来观察实时数据和修改必要的参数。     

测速定轨中的递推样条滤波算法

针对传统方法在全测速体制下实时处理能力不足,建立了基于递推样条模型的实时滤波算法。算法通过提高测量信息利用率,迭代更新模型参数以快速适应弹道的时变特性。仿真和实测数据的计算结果表明,算法鲁棒性较好,在平稳段落精度优于其它方法。算法就全测速体制的主动段弹道估计问题展开,但其原理具有一定的普适性。      

普及型手机LCD背光趋向使用LDO

文章从技术和市场经济的角度对手机LCD背光LED驱动器的技术演变进行分析,论述了LDO的性价比为普及型手机LCD背光应用赢得新的机遇。     

移动通信中基于智能天线的抗多径干扰技术

本文首先概述了多径信道传输特性,在此基础上,重点讨论了基于智能天线抗多径干扰技术的理论,并对基于ＣＭＡ算法的智能天线抑制多径干扰进行了计算机仿真。