H.264帧内预测和模式判断的并行硬件结构设计

针对H.264视频压缩编码算法中帧内预测和模式判断模块,分析并提出了一种高并行度的FPGA实现方法.完成了硬件结构的设计和验证.用VHDL实现本设计,综合后电路最大延迟为8.34 ns.仿真及综合结果表明.该设计能够完全满足高清数字视频的实时处理要求.     

H.264解码器的帧内预测优化

通过对H.264帧内预测加以优化,以提高其速度。采用4×4块级流水线方式代替串行处理方式,以及自适应的流水线协调不同种类块、不同预测模式下的帧内预测,用四路并行的多功能处理单元在1个周期内计算出1列4个像素点的预测值;以“种子”法取代平面预测模式的直接计算方式。基于FPGA开发平台设计出优化后的预测电路,验证结果表明,优化电路处理一个宏块平均只需196个时钟周期。     

AVS帧内预测算法分析及VLSI实现

文中提出了一种应用于AVS高清实时解码器的VLSI实现.分析了AVS帧内预测算法的特点,提出了一种所有亮度预测模式和前三种色度预测模式通用的运算单元,为第四种色度预测模式设计了独立的运算单元,并充分复用样本寄存器的方法,提高了资源利用率.该VLSI实现每个时钟周期输出8个预测数据,采用0.18 μmCMOS工艺库综合,电路规模为4.4万门,最高工作频率200MHz.     

H.264/AVC帧内4×4预测算法的高效流水线结构

H.264编码器中的帧内4×4预测部分具有严重的数据依赖性,它的硬件化设计很难采用流水线实现,从而导致关键路径很长,硬件利用率很低,成为H.264编码器设计中的一个瓶颈。针对这个问题,在不减少预测模式和不增加系统资源的前提下,提出了一种新的结构,它通过利用原始像素进行模式判决和利用重构像素进行帧内预测的方法,可以使帧内预测与重构循环完全流水线实现,基本上达到了100%的硬件利用率,而且没有明显的PSNR损失。所提出的硬件结构可在215个时钟周期内完成一个宏块的帧内4×4预测。用SMIC 0.13μm工艺库综合,结果显示该结构最高可运行在250 MHz,面积约为116千门,可支持4 096×2 160@30 f/s(帧/秒)视频序列的实时编码。     

H．264／AVC帧间预测关键技术的研究与硬件实现

本文在深入学习理解H．264帧间预测原理的基础上,采用四段流水结构来实现整个帧间预测过程。以Verilog HDL语言完成寄存器级设计,并分析了各个模块,针对参考像素的重复使用性,采用了一种Cache结构来进行缓存。并对分像素预测依据H．264标准设计了一种并行内插运算电路。通过Modelsim的功能仿真和Design Compiler的综合。证明该电路是正确的。能够满足4：2：0制式下16CIF格式图片30fps（帧／秒）的实时解码处理需求。     

一种H.264帧内预测模式判决算法及VLSI实现体系

17种预测模式和率失真优化模式判决极大的增加了H.264帧内编码器硬件设计的复杂度.目前的模式判决快速算法能大量减少模式判决的复杂度,但却不易于硬件实现.本文在Sobel边缘检测模式判决算法的基础上,提出了一种面向VLSI实现的模式判决优化算法.该算法通过修改16×16宏块部分像素的Sobel边缘检测算子来减少存储器读取次数,优化预测模式区域的范围来减少硬件设计复杂度,并采用变换后残差绝对值和(SATD)来简化编码代价判决运算.实验结果表明,采用该算法的帧内硬件编码器可以在确保编码质量的前提下,显著降低硬件实现复杂度和提高编码器效率.     

一种H.264/AVC帧内4x4预测算法的高效流水线结构

H.264编码器中的帧内4x4预测部分具有严重的数据依赖性,它的硬件化设计很难采用流水线实现,从而导致关键路径很长,硬件利用率很低,成为H.264编码器设计中的一个瓶颈。针对这个问题, 在不减少预测模式和不增加系统资源的的前提下,本文提出了一种新的结构,它通过利用原始像素进行模式判决和利用重构像素进行帧内预测的方法,可以使帧内预测与重构循环完全流水线实现,基本上达到了100%的硬件利用率,而且没有明显的PSNR的损失。本文所提出的硬件结构可在215个时钟周期内完成一个宏块的帧内4x4预测。用SMIC 0.13um工艺库综合,结果显示该结构最高可运行在250M,面积约为116K门,可支持4096x2160@30fps视频序列的实时编码。     

基于Node-Cell结构的HEVC帧内编码

随着视频传输和广播的发展,高分辨率视频的应用也越来越广泛,为了更好地适应高清视频内容,JCT-VC(Joint Collaborative Team on Video Coding)工作组制定了具有更高压缩效率的新一代视频压缩标准HEVC(High Efficiency Video Coding)。HEVC中的帧内预测包括Angular预测模式、planar模式等。基于Node-Cell结构的帧内预测方法在Angular预测基础上实现了双向预测,提供了更多的模式选择和更高的预测精度。Node-Cell结构中所有像素在当前块被分成两个子集,node像素点和cell像素点,node像素的重建值被用于内插预测cell像素。新增的帧内模式信息被设计为表示下采样率,它由该编码单元的细节及复杂度决定。为了保证重建质量,node像素和cell像素的残差均被发送到解码器。实验结果表明Node-Cell结构会提高预测精度。     

基于梯度方向算子的H.264帧内模式选择算法

提出梯度方向算子的概念,基于该算子提出了一种H.264帧内模式快速选择算法。本文首先应用梯度方向算子计算编码宏块中各4×4亮度子块的纹理特征和灰度起伏特征,根据这两种特征参量削减4×4帧内候选预测模式。通过统计宏块中各子块的4×4候选预测模式信息,结合梯度方向强度门限判别法削减宏块的16×16候选预测模式,通过率失真优化算法计算得到最优亮度预测模式。进一步根据亮度宏块和色度宏块的对应关系,在亮度候选预测模式的基础上对色度宏块候选预测模式进行削减,最后计算得到最优色度预测模式。该算法削减了50%以上的帧内预测模式,减少了帧内预测模式选择的运算量,实验表明,该算法能够在峰值信噪比和码流比特率变化轻微的前提下减少50%以上的运算量。      

应用模糊隶属度的H.264帧内预测模式快速选择

H.264中采用的率失真优化技术虽然提高了编码效率,但也使计算复杂度增加,影响编码的实时实现。针对这一问题,通过分析H.264中计算复杂度较高的帧内预测模式选择部分,提出一种新的帧内预测模式选择算法。根据模糊隶属度函数预先判断宏块类型,从Intra_4×4和Intra_16×16两种预测模式中选择一种,并通过判断4×4块的纹理方向,减少候选预测模式的数量。实验结果表明,在保持图像性能和码率基本不变的情况下,该算法能有效提高H.264的编码速度,有利于实时应用。     

Resolution Enhancement Technology:Integrated Process Solutions using OPC

DUV lithography, using the 248 nm wavelength, is a viable manufacturing option for devices with features at 130 nm and less. Given the low kl value of the lithography, integrated process development is a necessary method for achieving acceptable process latitude. The application of assist features for rule based OPC requires the simultaneous optimization of the mask, illumination optics and the resist.Described in this paper are the details involved in optimizing each of these aspects for line and space imaging.A reference pitch is first chosen to determine how the optics will be set. The ideal sigma setting is determined by a simple geometrically derived expression. The inner and outer machine settings are determined, in turn,with the simulation of a figure of merit. The maximum value of the response surface of this FOM occurs at the optimal sigma settings. Experimental confirmation of this is shown in the paper.Assist features are used to modify the aerial image of the more isolated images on the mask. The effect that the diffraction of the scattering bars (SBs) has on the image intensity distribution is explained. Rules for determining the size and placement of SBs are also given.Resist is optimized for use with off-axis illumination and assist features. A general explanation of the material' s effect is discussed along with the affect on the through-pitch bias. The paper culminates with the showing of the lithographic results from the fully optimized system.     

Cost-effective test solutions for smart card and other integrated flash applications

From its emergence in the late 1980s as a lower cost alternative to early EEPROM technologies, flash memory has evolved to higher densities and speedsand rapidly growing acceptance in mobile applications.In the process, flash memory devices have placed increased test requirements on manufacturers. Today, as flash device test grows in importance in China, manufacturers face growing pressure for reduced cost-oftest, increased throughput and greater return on investment for test equipment. At the same time, the move to integrated flash packages for contactless smart card applications adds a significant further challenge to manufacturers seeking rapid, low-cost test.     

An improved parallel thinning algorithm with two subiterations

The parallel thinning algorithm with two subiterations is improved in this paper. By analyzing the notions of connected components and passes, a conclusion is drawn that the number of passes and the number of eight-connected components are equal. Then the expression of the number of eight-connected components is obtained which replaces the old one in the algorithm. And a reserving condition is proposed by experiments, which alleviates the excess deletion where a diagonal line and a beeline intersect. The experimental results demonstrate that the thinned curve is almost located in the middle of the original curve connectivelv with single pixel width and the processing speed is high.     

Theoretical analysis of the relationship between the Brillouin gain coefficient and the strain in the optical-fiber sensors

The relation between the power of the Brillouin signal and the strain is one of the bases of the distributed fiber sensors of temperature and strain. The coefficient of the Bfillouin gain can be changed by the temperature and the strain that will affect the power of the Brillouin scattering. The relation between the change of the Brillouin gain coefficient and the strain is thought to be linear by many researchers. However, it is not always linear based on the theoretical analysis and numerical simulation. Therefore, errors will be caused if the relation between the change of the Brillouin gain coefficient and the strain is regarded as to be linear approximately for measuring the temperature and the strain. For this reason, the influence of the parameters on the Brillouin gain coefficient is proposed through theoretical analysis and numerical simulation.     

Novel fiber-optical interferometer with miniaturized probe for in-hole measurements

Today, micro-system technology and the development of new MEMS （Micro-Electro-Mechanical Systems） are emerging rapidly. In order for this development to become a success in the long run, measurement systems have to ensure product quality. Most often, MEMS have to be tested by means of functionality or destructive tests. One reason for this is that there are no suitable systems or sensing probes available which can be used for the measurement of quasi inaccessible features like small holes or cavities. We present a measurement system that could be used for these kinds of measurements. The system combines a fiber optical, miniaturized sensing probe with low-coherence interferometry, so that absolute distance measurements with nanometer accuracy are possible.     

Study of waveguide coupling efficiency in hybrid silicon lasers

This paper presents a new method to increase the waveguide coupling efficiency in hybrid silicon lasers. We find that the propagation constant of the InGaAsP emitting layer can be equal to that of the Si resonant layer through improving the design size of the InP waveguide. The coupling power achieves 42% of the total power in the hybrid lasers when the thickness of the bonding layer is 100 nm. Our result is very close to 50% of the total power reported by Intel when the thickness of the thin bonding layer is less than 5 nm. Therefore, our invariable coupling power technique is simpler than Intel＇s.     

Curved crystal spectrometer for the measurement of X-ray lines from laser-produced plasmas

In order to diagnose the laser-produced plasmas, a focusing curved crystal spectrometer has been developed for measuring the X-ray lines radiated from a laser-produced plasmas. The design is based on the fact that the ray emitted from a source located at one focus of an ellipse will converge on the other focus by the reflection of the elliptical surface. The focal length and the eccentricity of the ellipse are 1350 mm and 0.9586, respectively. The spectrometer can be used to measure the X- ray lines in the wavelength range of 0.2-0.37 nm, and a LiF crystal （200） （2d = 0.4027 nm） is used as dispersive element covering Bragg angle from 30° to 67.5°. The spectrometer was tested on Shengnang- Ⅱ which can deliver laser energy of 60-80 J/pulse and the laser wavelength is 0.35 μm. Photographs of spectra including the 1 s2p ^1P1-1s^2 ^1S0 resonance line（w）, the 1s2p ^3P2-1s^2 1S0 magnetic quadrupole line（x）, the 1s2p ^3P1-1 s^2 ^1S0 intercombination lines（y）, the 1 s2p ^3S~1-1 s^2 ^1S0 forbidden line（z） in helium-like Ti Ⅹ Ⅺ and the 1 s2s2p ^2P3/2-1 s622s ^2S1/2 line（q） in lithium-like Ti Ⅹ Ⅹhave been recorded with a X-ray CCD camera. The experimental result shows that the wavelength resolution（λ/△ 2） is above 1000 and the elliptical crystal spectrometer is suitable for X-ray spectroscopy.     

Preparation and Characterization of TaN ALD Precursors

High purity organic-tantalum precursors for thin film ALD TaN were synthesized and characterized.Vapor pressure and thermal stability of these precursors were studied.From the vapor pressure analysis,it was found that TBTEMT has a higher vapor pressure than any other published liquid TaN precursor,including TBTDET,TAITMATA,and IPTDET.Thermal stability of the alkyl groups on the precursors was investigated using a 1H NMR technique.The results indicated that the tertbutylimino group is the most stable group on TBTDET and TBTEMT as compared to the dialkylamido groups.Thermal stability of TaN precursors decreased in the following order:TBTDET ＞ PDMAT ＞ TBTEMT.In conclusion,precursor vapor pressure and thermal stability were tuned by making slight variations in the ligand sphere around the metal center.     

Electronic Structure of Semiconductor Nanocrystals

This paper reviews our recent development of the use of the large-scale pseudopotential method to calculate the electronic structure of semiconductor nanocrystals, such as quantum dots and wires, which often contain tens of thousands of atoms. The calculated size-dependent exciton energies and absorption spectra of quantum dots and wires are in good agreement with experiments. We show that the electronic structure of a nanocrystal can be tuned not only by its size,but also by its shape. Finally,we show that defect properties in quantum dots can be significantly different from those in bulk semiconductors.     

A rigorous proof of MIMO channel capacity’s increase with antenna number

It is well known that adding more antennas at the transmitter or at the receiver may offer larger channel capacity in the multiple-input multiple-output（MIMO） communication systems. In this letter, a simple proof is presented for the fact that the channel capacity increases with an increase in the number of receiving antennas. The proof is based on the famous capacity formula of Foschini and Gans with matrix theory.