Reliability Estimation of Blu‐Ray Recordable Media with Effect of Initial Recording Performance

The lifetime and the reliability of Blu‐Ray Recordable media were estimated with an acceleration test varying the temperature and the relative humidity. Some brand of the media showed relatively long lifetime over 80 years, but another brand was immeasurable because the media was broken during the acceleration procedure. A strong dependence of the lifetime of the media on the brand was observed. Effect of the initial recording performance in terms of the random symbol error rate and the jitter on the reliability was analyzed. The random symbol error rate showed a strong correlation with the reliability of the Blu‐Ray Recordable media. Copyright © 2014 John Wiley & Sons, Ltd.     

A low-jitter low-power monolithically integrated optical receiver for SDH STM-16

A high-scale integrated optical receiver including a preamplifier, a limiting amplifier, a clock and data recovery (CDR) block, and a 1:4 demultiplexer (DEMUX) has been realized in a 0.25 μm CMOS technology. Using the loop parameter optimization method and the low-jitter circuit design technique, the rms and peak-to-peak jitter of the recovered 625 MHz clock are 9.4 and 46.3 ps, respectively, which meet the jitter specifications stipulated in ITU-T recommendation G.958. In response to 2.5 Gb/s PRBS input da...     

Fractional Fourier transform based transmitted reference scheme for UWB communications

In this paper,we propose a receiving system for impulse radio ultra-wideband (IR-UWB) communications,in which the data and reference pulses are combined as one signal to transmit,and the received signal can be divided into the data and reference pulses in the receiver end using the energy concentration property of Chirp pulses in fractional Fourier transform (FrFT) domain.A detailed theoretical analysis of the proposed system is given,and the formulation of bit error rate (BER) is obtained.Then according to...     

基于E-Model的VoIP语音质量研究

针对目前网络电话语音质量难以准确评价及预测的情况,基于E-Model对VoIP的语音质量进行预测。分析几个主要影响因素,如延时、丢包等对话音质量的影响,构建VoIP语音质量预测模型,将E-Model中未考虑到的抖动因素引入模型公式,着重考虑抖动缓冲区的大小对语音质量的影响。通过设计相关验证实验,证明该模型对VoIP语音质量的预测具有较高的准确度。     

数控机床工作台抖动的原因及分析

针对目前维修过程中经常遇到的有关机床工作台抖动的现象,进一步分析阐述了引起数控机床工作台抖动的原因及处理方法,有效避免在加工过程中由于工作台抖动而引起零件质量问题。     

基于延迟敏感的组播路由遗传算法的研究

1 引言为了保证多媒体实时业务流的QoS传输,所采用的路由技术之一是通过组播路由(multicast routing)为实时应用寻找最佳路径。以往,人们对非受限组播路由问题研究较多,但由于它们都未考虑QoS的延迟标准,因此,对多媒体实时传输的要求显得束手无策。Widyono阐述了受限Bellman-Ford(CBF)算法,它的性能较优,但其计算时间随着网络规模的增大而呈指     

Dejittering in the transport of MPEG-2 and MPEG-4 video

When multimedia information is transported over a packet-switched network, the quality of presentation can be degraded due to network delay variation or jitter. This paper presents a dejittering scheme that can be used in the transport of MPEG-4 and MPEG-2 video to absorb any introduced network jitter, thus preserving the presentation quality of transported media streams. The dejittering scheme is based on the statistical approximation of delay variation in the arrival times of video packets carrying encoded clock reference values and a filtering and re-stamping mechanism. In addition, a brief overview of the MPEG-4 system is presented.     

正交调幅数字系统

文章分析了存在载波相位起伏、正弦干扰、高斯白噪声时正交调幅数字系统的抗扰性。结果表明,当接收载波相位起伏低于0.5度时,16QAM达最佳。     

The “Median” Method for the Reduction of Noise and Trigger Jitter on Waveform Data

The “median” method for the reduction of the effect of noise and trigger jitter on waveform data is described. The effectiveness of this method was examined using simulations and experiments and, for typical jitter and noise observed in electrical pulse metrology, is shown to provide reconstructed waveforms with transition durations that accurately match those of the input signal. Also, for aberrations, an upper bound on the error in the amplitude of the aberration is provided.     

开关电源的新技术及其应用

开关电源被誉为高效节能电源，它代表着稳压电源的发展方向。重点阐述开关电源研发领域的几项具有代表性的新技术及其典型应用。