基于FPGA的级联码译码器的设计与实现

介绍了一种基于FPGA的级联码译码器的设计及其实现,给出了其系统结构,该级联码由RS码、卷积码以及交织器构成。其中内码卷积码采用viterbi译码,由分支路径度量,加比选和幸存路径度量等几部分组成,交织器采用块交织,交织宽度为204,交织深度为4;外码RS码采用BM迭代算法,由伴随式的计算、关键方程的求解、钱控索和Forney算法等几部分组成。     

基于m序列的Turbo码交织器

Turbo码是近年来提出的一种高性能的信道编码.Turbo码交织器的设计是Turbo编解码器设计中的关键.分析了Turbo码对交织器的设计要求,根据m序列的伪随机特性,提出了一种利用m序列生成器的交织器设计.这种交织器可以大幅降低对寄存器资源的占用,而且结构简单易于实现.仿真实验表明,该交织器的性能介于查表法伪随机交织器和行列交织器之间.     

一种非对称IDMA交织器的设计及分析

交织分多址(IDMA)通信系统采用不同的交织器来区分不同的用户,各用户使用相同的扩频序列进行扩频,所以交织器在IDMA保密通信性能上有关键的作用.目前还没有关于具保密通信功能的IDMA交织器设计的研究.为此,文中提出了一种非对称IDMA交织器设计方案,该方案基于离散Arnold映射,通过类似非对称密钥加密的方法实现保密通信.仿真结果表明,文中提出的交织器不但在通信性能上等同于伪随机交织器,而且能提供保密通信的功能.     

TETRA数字集群通信系统中交织器的仿真与实现

采用交织技术使连续的突发错误分散，并转换为随机错误，可以纠正数据在信道传输过程中的成群突发错误。在分析TETRA数字集群通信系统语音信道编码结构和流程的基础上，基于FPGA技术的采用块内交织方法的交织器，提高了整个通信系统的可靠性。利用QuartusⅡ对其进行时序仿真分析，结果表明了该实现方案的正确性和可行性。     

一种低资源消耗的物理不可克隆函数FPGA设计

针对传统仲裁器物理不可克隆函数(PUF)在FPGA上实现后唯一性很差,而且资源消耗代价大的问题,在分析FPGA Slice的结构基础上,设计了一种新型结构的仲裁器PUF电路,该电路大幅度地提高了唯一性,大大减少了FPGA的资源消耗,使得仲裁器PUF可应用于FPGA.基于此提出了一种对传统仲裁器PUF结构改进的方案,利用Slice之间的对称性来提升PUF的唯一性,并充分利用Slice内部的组合逻辑资源以降低资源消耗.实验测量了片间海明距离和片内海明距离,评估了64bit的仲裁器PUF电路的唯一性和稳定性,结果表明:改进后的仲裁器PUF非常适合在FPGA上实现,能够降低62.5%的资源消耗,并且唯一性比较接近理想值.     

LTE中Turbo码内部交织器的研究

为了实现高速并行译码,LTE Turbo码采用QPP交织器.研究了QPP交织器的最大无争用特性,该特性使得LTE Turbo码译码器设计灵活,运算复杂度较低.仿真表明,与串行译码相比,并行译码损失了少量译码性能,显著提高了译码效率;在相同条件下,由于采用QPP交织器,LTE的译码性能优于HSPA.     

利用循环计数器优化设计实现卷积交织器

卷积交织器和去卷积交织器的实现方法有多种,本文基于Altera公司开发的Max PlusII软件平台和仿真环境,以DVB-C系统中深度I=12的卷积交织为例,利用循环计数器设计实现先进先出(FIFO)移位存储器,提出了一种使用理论最小资源的方法来实现卷积交织器,最高工作频率可以达到80MHz,而不使用片外RAM,仅使用Altera的FLEX10KE系列器件中的EAB.     

Turbo码中交织器的设计及其性能

在Ｔｕｒｂｏ码理论中,交织器的选择具有重要的地位。讨论了各种交织器的性能,给出了提高线笥同余交织器有效自由距离的公式,提出了一种对称交织器的选取方法,并用ＳＯＶＡ算法对行列交织器,随机交织器的所选定的交织器的性能进行了比较,给出了基于距离谱的一些解释。仿真有效用提出的方法所设计的交织器具有较好的性能,且具有实现上的优点。     

基于FPGA的Turbo码译码器设计与实现

对Turbo码的Log-MAP译码算法进行了研究,引入滑动窗技术对Log-MAP译码算法进行了优化,并设计了适合硬件实现的流水线结构的译码器。结合3G标准规定的数据速率,对译码器和交织器进行硬件电路的设计和FPGA实现。仿真结果表明所设计的电路在译码性能和延迟方面满足实际要求,具有一定的实用价值。     

基于FPGA实现的交织编码器

提出了一种用FPGA实现交织编码器的设计,详细阐述了交织编码原理,并给出了交织编码器的电路设计及仿真结果,并通过实例验证了硬件的可靠性、通用性以及设计升级的方便性。     

Markedness and its Interpretation in Language Use

Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.     

Features of Women's language

Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women＇s language from these perspectives： pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women＇s language, more attention should be paid to language use in social context. What＇s more, the linguistic phenomena in a speaking community can be understood more thoroughly.     

低渗透非均质砂岩油藏启动压力梯度研究

理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。     

On Tragic Consciousness In The Works By Ernest Hemingway

As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.     

Achieving Unusual States of Matter Under High Pressure

正The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry,rooted in the atomic shell structure.Within compounds,Group I elements,for example,invariably assume the+1 oxidation state,and their chemical properties differ completely from those of the p-block elements.These general rules govern our understanding of chemical structures and reactions.Using first principles calcula-     

Exchange-Correlation and Electronic Excitation Energies from Pairing Matrix Fluctuations

We have developed an adiabatic connection to formulate the ground-state exchange-correlation energy in terms of pairing matrix linear fluctuations.This formulation of the exchange-correlation energy opens a new channel for density functional approximations based on the many-body perturbation theory.We illustrate the potential of such approaches with an approximation based on the particle-particle Random Phase Approximation(pp-RPA).This re-     

Density Functional Theory for the Response of Periodic Systems to Electric Fields Based on the Vector Potential Approach

正The electronic and nuclear(structural/vibrational)response of 1D-3D nanoscale systems to electric fields gives rise to a host of optical,mechanical,spectral,etc.properties that are of high theoretical and applied interest.Due to the computational difficulty of treating such large systems it is convenient to model them as infinite and periodic(at least,in first approximation).The fundamental theoretical/computational problem in doing so is that     

On the Thermodynamic Limit for Responses to Static Electromagnetic Fields

For molecular systems,the quantum-mechanical treatment of their responses to static electromagnetic fields usually employs a scalar-potential treatment of the electric field and a vector-potential treatment of the magnetic field.Although the potential for each field separately is associated with the choice of an(unphysical)origin,the precise choice of the origin for the electrostatic field has little consequences for the results.This is different for the     

An affordable accurate evaluation of the binding conformations predicted by molecular docking studies in bio-system

Franck-Condon factors bridge the gap between theoretical modeling and experimental observations for molecular electronic spectroscopy and electron transfer.Under the displaced harmonic oscillator approximation,multidimensional Franck-Condon factors are decomposed into a product of many one-dimensional(1D)Franck-Condon(FC)factors,and each 1D-FC factor is associated with one Huang-Rhys factor that determines the leading contribution of     

Call for Papers

<正>"The Journal of Shanghai Normal University:Mathematics"is published by Shanghai Normal University as regular issues of The Journal of Shanghai Normal University each year from 2014 in English.The editors-in-chief of the issues are professors Yuhao Cong and Maoan Han.The Journal of Shanghai Normal University was started in 1958 with