基于FPGA乘法器架构的RNS与有符号二进制量转换

RNS(余数数制系统)是一种整数运算系统,在粒度精确性,能源损耗和响应速度上有很大的优势.从RNS到二进制数的输入输出转换是基于余数算法的专用架构实现的关键.本文提出了一个基于N类模的RNS与有符号二进制量的通用转换算法在FPGAs的乘法器上的实现过程.该算法能更有效地进行有符号数与RNS的转换.基于该算法类型乘法器在同类型乘法器中显示出了速度优势.文章中该架构被映射到Altera的10K系列的FPGA上.     

RNS与Delta-Sigma编码的位数据流的数值转换算法及硬件实现

利用RNS(余数数制系统)可以执行并行的数据处理以及实现快速无进位算法,在VLSI(超大规模集成电路)设计中表现出低功耗、占用面积小和时延少等优良特性.根据中国剩余定理,基于(2n-1)2n(2n+1)模组,利用Verilog语言设计了RNS到位数据流的数值转换接口电路.以使传统的多位数(Bit)的复杂运算转化为多个并行的较少位数的简单运算,从而降低单次运算的复杂度、时延和功耗.该转换电路面向"Σ-Δ"编码的数据流,不同于传统的二进制数据转换,可以方便地与基于DSD(Direct Stream Digital)的Delta-Sigma系统进行无缝连接.     

Design and Implementation of High-Performance RNS Wavelet Processors Using Custom IC Technologies

The design of high performance, high precision, real-time digital signal processing (DSP) systems, such as those associated with wavelet signal processing, is a challenging problem. This paper reports on the innovative use of the residue number system (RNS) for implementing high-end wavelet filter banks. The disclosed system uses an enhanced index-transformation defined over Galois fields to efficiently support different wavelet filter instantiations without adding any extra cost or additional look-up tables (LUT). A selection of a small wordwidth modulus set are the keys for attaining low-complexity and high-throughput. An exhaustive comparison against existing two's complement (2C) designs for different custom IC technologies was carried out. Results reveal a performance improvement of up to 100% for high-precision RNS-based systems. These structures demonstrated to be well suited for field programmable logic (FPL) assimilation as well as for CBIC (cell-based integrated circuit) technologies.     

A Reconfigurable Channel Filter for Software Defined Radio Using RNS

This paper presents a high-speed FIR channel filter using residue number system (RNS) whose frequency response can be reconfigured to adapt to a multitude of channel filtering specifications of a multi-standard software defined radio (SDR) receiver. The channel filters in the channelizer of an SDR extract multiple narrowband channels corresponding to different communication standards from the wideband input signal. The proposed architecture has been synthesized on TSMC 0.18 μm CMOS standard cell technology. Synthesis result shows that the proposed reconfigurable FIR channel filter, for a Digital Advanced Mobile Phone Systems (D-AMPS) example, offers speed improvement of 42% and AT complexity reduction of 26% over existing reconfigurable FIR method.     

Using linear programming to Decode Binary linear codes

A new method is given for performing approximate maximum-likelihood (ML) decoding of an arbitrary binary linear code based on observations received from any discrete memoryless symmetric channel. The decoding algorithm is based on a linear programming (LP) relaxation that is defined by a factor graph or parity-check representation of the code. The resulting "LP decoder" generalizes our previous work on turbo-like codes. A precise combinatorial characterization of when the LP decoder succeeds is provided, based on pseudocodewords associated with the factor graph. Our definition of a pseudocodeword unifies other such notions known for iterative algorithms, including "stopping sets," "irreducible closed walks," "trellis cycles," "deviation sets," and "graph covers." The fractional distance d/sub frac/ of a code is introduced, which is a lower bound on the classical distance. It is shown that the efficient LP decoder will correct up to /spl lceil/d/sub frac//2/spl rceil/-1 errors and that there are codes with d/sub frac/=/spl Omega/(n/sup 1-/spl epsi//). An efficient algorithm to compute the fractional distance is presented. Experimental evidence shows a similar performance on low-density parity-check (LDPC) codes between LP decoding and the min-sum and sum-product algorithms. Methods for tightening the LP relaxation to improve performance are also provided.     

Texture Image Classification Using Deep Neural Network and Binary Dragon Fly Optimization with a Novel Fitness Function

Wireless Personal Communications - Texture is one of the most significant characteristics of an image for retrieving visually similar patterns. So far, researchers utilize large number of gray...     

利用奇异值分解快速计算单站RCS的算法

在特征基函数方法中,应用多层奇异值分解技术,由空间各个角度入射的一系列平面波谱生成的初次特征基函数构造出与入射角度、极化方式无关的正交特征基函数组,通过该组基函数的不同线性组合,求出平面波以任意角度照射下金属目标的表面电流分布,进而实现金属目标单站RCS曲线的快速计算。文中结合物理光学法和二叉树动态存储技术,进一步降低存储需求和初次基函数的计算时间。数值算例表明本文方法的正确性和高效性。     

All-Optical Conversion From RZ to NRZ Using Gain-Clamped SOA

An all-optical converter from return-to-zero (RZ) pulses to the nonreturn-to-zero (NRZ) format is presented. The converter operates in two stages: the laser generated in a gain-clamped semiconductor optical amplifier (SOA) is modulated with the data signal; afterwards this signal is wavelength-converted by cross-gain modulation in a common SOA. The setup is noninverting and can feature wavelength conversion. Experimental error-free conversion from 5- and 40-ps RZ pulses to NRZ format is presented at 10 Gb/s using a 2¹¹-1 bit sequence     

用MSP430实现斜率A/D转换

本文结合斜率A/D转换的原理详细说明了MSP430F1121单片机在A/D转换中的应用,给出了典型应用电路和A/D转换的源程序.     

一种改进的二进制自适应算术编码数据转换方法

本文提出了一种用于二进制自适应算术编码的数据转换方法，并通过实验和理论分析，与直接数据转换法、适于灰度图像的数据转换法进行了比较，证明改进的转换方法效率更高     

车牌识别中的二值化及快速倾斜校正算法

根据车牌几何形状和纹理的特点,提出了基于图像的特征线确定二值化阈值的方法.为了解决车牌图像倾斜对字符分割与识别带来的不良影响,对一种基于字符间投影距离的倾斜校正方法做了研究.在该方法中,根据倾斜车牌与非倾斜车牌字符的投影距离大小比较来确定车牌图像的倾斜角度,再用基于双线性插值的旋转方法进行矫正.针对该方法的不足之处,提出了该算法的改进算法.试验结果表明,该算法是快速而有效的.     

二元光学位相板修正干涉仪误差

本文提出了采用Ｚｅｒｎｉｋｅ多项式拟合干涉条纹的一种新的算法，详细讨论了采用二元光学位相板修正球面干涉仪误差的原理和方法，并根据计算出的球面干涉仪的误差制作了蚀刻二元光学位相板所需的掩膜片。     

用声表面波器件实现小波变换的研究

当声表面波叉指换能器的指条重叠包络按照小波函数的包络设计时,得到的声表面波叉指换能器脉冲响应函数等于小波函数,从而制造出了声表面波式小波变换器件。本文提出了利用两只声表面波式小波变换器件构造小波变换重构器件的新方法。对器件误差的来源作了分析,提出减小误差的方法。     

一种二元域上的快速计算哈希函数

论文从映射的角度,将哈希函数分为三类:严格哈希函数、计算哈希函数和实用哈希函数。在此基础上,根据二元域上二次方程x2 x c=0的部分不可解的性质,构造了一种计算哈希函数,它满足单向性和一一对应性,同时具有运算速度快的优点。     

二元光学在红外成像仪中的作用

讨论了二元光学元件的特点和光学功能,以及它在微透镜列阵、折射／衍射混合设计了不可替代的作用,指出二元光学元件给红外成像系统带来的好处是常规光学无法比拟的。介绍地元光学元件用于红外成像仪的典型便子,展望其在该领域中的应用前景。     

Fault-Tree Analysis Using a Binary Decision Tree

A new algorithm for the production of a short disjoint-products form of a fault-tree output function is presented and discussed. This algorithm consists of a sequential binary decision process to find first big, then smaller sets of elementary system-failure states which correspond to disjoint-product terms. The identification of bad and good system states can be eased by a simple ternary (3-state) decision for which an auxiliary procedure is presented. The main advantages of this algorithm appear to be its efficiency, simplicity, and usefulness as an alternative (in the sense of multiversion programming for software fault tolerance) for the Shannon decomposition algorithm.     

Optical CDMA Code Wavelength Conversion Using PPLN to Improve Transmission Security

We demonstrate optical code-division multiple access (OCDMA) code conversion in the wavelength domain using periodically poled LiNbO $_{3}$ for enhanced transmission security. The number of possible OCDMA codes in the channel is greatly increased and randomized dynamic code conversion is feasible, thus making it more difficult for an eavesdropper to intercept and decode the code. A 2.5-dB power penalty is reported at a bit-error rate of $10^{-9}$ after two back-to-back wavelength conversions.      

All-Optical Analog-to-Digital Conversion Using Split-and-Delay Technique

We propose a simplified configuration of all-optical analog-to-digital (A/D) conversion using nonlinear optical loop mirrors (NOLMs). While the conventional scheme of such all-optical A/D conversion requires encoders and threshold, for -bit resolution, the proposed configuration realizes an -bit resolution only using a single encoder and threshold, based on a split-and-delay technique, in which the encoder and the threshold operate more than times as fast as the sampling speed. After discussing detailed design issues of the NOLM-based encoder with particular emphasis on the so-called counterpropagating effects, all-optical 3-bit A/D conversion at 10 GS/s is experimentally demonstrated using the proposed configuration.     

用汇编语言实现GPS时间、日期转换

GPS接收机收到的时间、日期信息基于格林威治时间、日期.本文描述了用汇编语言将GPS收到的时间、日期转换为当地时间、日期的一种有效方法.