基于TRIZ的麦克风—摄像机实时定位追踪发言人系统创新设计

TRIZ即发明问题解决理论,是一门可用来解决传统工程领域技术创新问题的方法学,但在新兴信息技术领域问题给出的解决方案较少。目前的麦克风—摄像机发言人实时定位追踪系统存在应用场所有限、实时性和精确度较低的问题。运用TRIZ理论中的三轴分析方法找到系统存在的技术矛盾和物理矛盾,提出了一种采纳了嵌入声纹识别技术和多传感器信息融合技术的优化创新设计方案,有效规避了现有的专利产品,也表明了TRIZ理论应用于新兴信息技术领域进行优化创新的可行性和高效性。     

Analysis and design of distributed ESD protection circuits for high-speed mixed-signal and RF ICs

Electrostatic discharge (ESD) protection devices can have an adverse effect on the performance of high-speed mixed-signal and RF circuits. This paper presents quantitative methodologies to analyze the performance degradation of these circuits due to ESD protection. A detailed S-parameter-based analysis of these high-frequency systems illustrates the utility of the distributed ESD protection scheme and the impact of the parasitics associated with the protection devices. It is shown that a four-stage distributed ESD protection can be beneficial for frequencies up to 10 GHz. In addition, two generalized design optimization methodologies incorporating coplanar waveguides are developed for the distributed structure to achieve a better impedance match over a broad frequency range (0-10 GHz). By using this optimized design, an ESD device with a parasitic capacitance of 200 fF attenuates the RF signal power by only 0.27 dB at 10 GHz. Furthermore, termination schemes are proposed to allow this analysis to be applicable to high-speed digital and mixed-signal systems.     

Introducing a technology index concept and optimum performance design procedure for single-electron-device based circuits

Single electron devices (SEDs) are utilized in designing many logic gates; however, in most cases the examination of the circuits is limited to a DC analysis that only indicates the correct performance of the circuits' logic function. This paper focuses mainly on the issue of optimization. In this regard, comparison of different designs is needed, but it is not possible to compare two different designs unless they both belong to a single technology or can be scaled to a same technology. So, we first introduce a technology index for SEDs, which allows meaningful comparisons between various designs of different technologies. Then, we describe a method for scaling these designs into a single identical technology, and clarifying the relations between the involved concepts. Using two examples, we explain an optimum design method for digital logic gates based on SEDs. Finally, the results of these two examples are presented and compared with the original designs. The comparison showed that all the three major performance features, including lower bit error rate, higher operation frequency, and higher temperature operation are improved in the proposed optimized design.     

Impact of gate-oxide tunneling on mixed-signal design and simulation of a nano-CMOS VCO

Design optimization for performance enhancement in analog and mixed-signal circuits is an active area of research as technology scaling is moving towards the nanometer scale. This paper presents an approach towards the efficient simulation and characterization of mixed-signal circuits, using a 45 nm CMOS voltage controlled oscillator (VCO) with frequency divider as a case study. The performance characteristics of the analog and digital blocks in the circuit are simulated and the accuracy issues arising due to separate analog and digital simulation engines are considered. The tremendous impact of gate tunneling current on device performance is quantitatively analyzed with the help of an “effective tunneling capacitance”, which allows accurate modeling and simulation of digital blocks with almost analog accuracy. To meet the design specifications of the analog VCO using digital CMOS technology, we follow a design of experiments (DOE) approach. The functional specifications of the VCO optimized in this design are the center frequency and minimization of overall power consumption as well as minimization of power due to gate-oxide tunneling current leakage, a component that was not important in previous generations of CMOS technologies but is dominant at 45 nm and below. Due to the large number of available design parameter (gate-oxide thickness and transistor sizes), the concurrent achievement of all optimization goals is difficult. A DOE approach is shown to be very effective and a viable alternative to standard design exploration in the nanometer regime.     

高频高压电源中倍压器的设计

倍压器作为高压电源的重要组成部分对于提高电源的性能具有特殊作用。分析了倍压器相关参数对电源性能的影响规律,用理论分析的方法设计了一种半臂式倍压器,并对其进行了实际测试。仿真与测试结果表明,倍压器参数优化对于电源性能具有显著影响,且实现了倍压器设计的优化。     

Serial concatenation of LDPC codes and differential modulations

In this paper, we consider serially concatenated schemes with outer novel and efficient low-density parity-check (LDPC) codes and inner modulations effective against channel impairments. With a pragmatic approach, we show how to design LDPC codes tailored for simple and robust modulation formats, such as differentially encoded (DE) modulations. The LDPC codes are optimized through the use of a recently proposed analysis technique based on extrinsic information transfer (EXIT) charts. In particular, we optimize, through a "clever" random walk in the parametric space, the degree distributions of the outer LDPC codes, obtaining significant insights on the impact of such distributions on the performance of the proposed concatenated schemes. The optimization is carried out for transmission over both the additive white Gaussian noise channel and a noncoherent channel. The performance predicted by the EXIT chart-based optimization is confirmed by results obtained via computer simulations, considering phase-shift keying and quadrature amplitude modulation at the transmitter side, and iterative demodulation/decoding at the receiver side. The significance of the proposed optimized design of LDPC-coded schemes with DE modulations is validated by the fact that standard nonoptimized LDPC codes perform poorly when used together with inner DE modulations.     

区域覆盖共地面轨迹星座的优化设计

该文讨论了使用中轨共地面轨迹星座建立区域覆盖卫星通信系统的优化设计方法。在深入研究共地面轨迹星座参数特性的基础上,提出了一种能够完整描述该类型星座的编码标识方法,推导了星座与星座的等价关系,讨论了利用该类型星座实现区域覆盖时的优化方法,给出了适用于我国的多个优化星座方案实例。从仿真结果可以看出,该类型星座能够以较少数量的卫星为我国提供良好的覆盖性能,适于我国的区域覆盖卫星通信系统采用。     

PERFORMANCE COMPARISON OF CELL－BASED AND PACKET－BASED SWITCHING SCHEMES FOR SHARED MEMORY SWITCHES

Shared Memory (SM) switches are widely used for its high throughput,low delay and efficient use of memory.This paper compares the performance of two prominent switching schemes of SM packet switches:Cell-Based Switching (CBS) and Packet-Based Switching (PBS).Theoretical analysis is carried out to draw qualitative conclusion on the memory requirement,throughput and packet delay of the two schemes.Furthermore,simulations are carried out to get quantitative results of the performance comparison under various system load,traffic patterns,and memory sizes.Simulation results show that PBS has the advantage of shorter time delay while CBS has lower memory requirement and outperforms in throughput when the memory size is limited.The comparison can be used for tradeoff between performance and complexity in switch design.     

CCD组件参数综合测试系统应用研究

CCD组件参数综合测试系统配备了PCI高速数字图像采集卡获取测试数据,显示测试图像.分析了各参数的综合测试方法与原理,优化的结构设计保证了一台仪器就能够对帧频、饱和输出幅值、均方根噪声等多种性能参量测试.利用统计学的方法对多次测试结果进行了误差分析.试验表明,测试系统具有测试过程自动快速及测试数据准确稳定的优点.     

激光热灼枪准直镜头设计与非球面优化方法

为了满足激光武器对光束质量日益增长的需求,提出了一种光学准直系统的设计思路及非球面镜优化方法,并将该方法成功应用于一款激光热灼枪的镜头设计,使该枪可以在更远范围内获得更高质量的准直光束。首先在战技参数分析和光路计算的基础上得到初始结构,而后对其进行非球面优化,并基于ZEMAX对两次仿真结果做出对比分析,数值结果显示优化结构具有显著优势,其非球系数和曲率半径分别为0.584 mm和115.37 mm,光能利用率在使用GB 1316-88减反射膜的情况下可达99.92%。经过公差分析后加工出镜头并与枪体组合进行了木板烧蚀实验,实验与仿真结果吻合度良好,镜头性能的优越性证明了所提出设计及优化方法的可行性与合理性,也为其他领域的类似问题提供了一定的参考价值。     

A new labeling search algorithm for Bit-Interleaved Coded Modulation with Iterative Decoding

Bit-Interleaved Coded Modulation with Iterative Decoding （BICM-ID） is a bandwidth efficient transmission, where the bit error rate is reduced through the iterative information exchange between the inner demapper and the outer decoder. The choice of the symbol mapping is the crucial design parameter. This paper indicates that the Harmonic Mean of the Minimum Squared Euclidean （HMMSE） distance is the best criterion for the mapping design. Based on the design criterion of the HMMSE distance, a new search algorithm to find the optimized labeling maps for BICM-ID system is proposed. Numerical results and performance comparison show that the new labeling search method has a low complexity and outperforms other labeling schemes using other design criterion in BICM-ID system, therefore it is an optimized labeling method.     

Theory of polarization shift keying modulation

A rigorous analysis of digital coherent optical modulation schemes using the state of polarization as the modulating parameter is presented. The analysis obtains the exact performance of all the polarization-based modulation schemes proposed in the literature so far, including a differential demodulation scheme, named DPOLSK, which does not require either electrooptic or electronic polarization tracking. Preliminary results involving multilevel transmission schemes based on the state of polarization are introduced. A spectral analysis of POLSK signals is also proposed     

Particle-Swarm Optimization in Antenna Design: Optimization of Log-Periodic Dipole Arrays

This paper presents a short tutorial and overview of optimization algorithms based on particle-swarm schemes, and their application to solving electromagnetic problems. As a practical example, a particle-swarm optimization (PSO) tool has been applied in conjunction with the Numerical Electromagnetics Code (NEC) to get the design curves of optimized log-periodic dipole arrays (LPDAs). The graphs show the performance of several radiation parameters (directive gain, front-to-back ratio, bandwidth, SWR, and half-power beamwidth in the E and H planes) as a function of typical design parameters of log-periodic dipole arrays (geometrical parameters and characteristics of the feed). Examples of optimized antennas are given, and their performance is compared to that of standard log-periodic dipole arrays.     

一种结合遗传算法和HFSS 的天线仿真与优化方法

电磁仿真技术在现代天线设计中发挥着重要作用。讨论了一种结合遗传算法和全波电磁仿真软件HFSS 的天线优化设计方法。采用遗传算法进行天线设计,能够直接设计一种新结构天线,并易于对天线的结构进行调整。在介绍了遗传算法基本原理的基础上,阐述了遗传算法在天线仿真和优化设计中的具体应用问题。通过VBS脚本将遗传算法与Ansoft HFSS 连接起来,对一种电磁耦合馈电的双极化毫米波微带天线进行了优化设计,展宽了该天线的阻抗带宽,天线指标满足设计要求,表明了采用遗传算法进行天线仿真的可行性。     

Traveling-wave tube amplifier performance evaluation and design optimization for applications in digital communications with multilevel modulations

In this paper, we demonstrate the use of a power margin as a figure-of-merit for evaluating the performance and optimizing the design of traveling-wave tube amplifiers (TWTAs) used in digital communication applications with multilevel modulations. The power margin is a system-level measure that balances both device efficiency and nonlinear distortion and provides a more direct prediction of the system-level performance of power amplifiers than device-level measures such as device efficiency or error-vector-magnitude. We calculate the power margin for M quadrature amplitude modulation for an existing TWTA to demonstrate the setting of an optimal amplifier operating drive level according to the criterion of the maximum power margin. The power margin can also be used to compare the performance of different traveling-wave tube (TWT) configurations. We compare the calculated power-margin performance for helix TWT circuits optimized with different optimization goal functions using the helix TWT design code CHRISTINE. The goal functions used in the optimization of the TWT circuits include AM/PM optimization, complex gain optimization, efficiency optimization, and a new digital goal function optimization. The digital goal function is shown to provide an enhanced power margin compared to the other three goal functions and demonstrates the potential of TWT device design optimization from a system perspective.     

基于容差分析的电路参数中心值设计研究

论述了电路参数设计的基本原理,提出了在PSpice 9软件上以容差分析为基础的电路参数中心值的设计方案.详细阐述了蒙特卡罗分析法、合格率的估算法及统计重心搜索法,对以蒙特卡罗分析为基础的电路合格率的统计及元件参数中心值的设计进行了研究.考虑到实际元件的容差分布对电路性能的影响,以OTL电路为例分析实现了电路性能指标满足约束条件下以合格率最大为目标的元件参数值的设计,证明了该方案的可行性.同时获得电路性能指标的统计特性及生产合格率的预测数据,对指导实际生产具有理论价值.     

Design of Digital Window Comparators and their Implementation within Mixed-Signal DfT Schemes

An in detail design of digital window comparators is presented. This comparator can be used for the on-chip (and potentially on-line) response evaluation of analogue circuits. The analysis shows that if the design parameter is in the order of 1 ... 0,36 for the NOR and 1 ... 2,8 for the NAND good results for the comparator can be achieved and the variation of the window position is limited to 5%. Parameter and temperature drifts are discussed along with results from characterisation. The results can be extended to deep-submicron technologies if the respective equations are used to derive the logical threshold and beta values. A simplified comparator is described that also allows the localisation of the evaluated signal. The conditions for the implementation of the window comparators into Design-for-Testability schemes are outlined. It is demonstrated that the digital window comparator can be implemented in the digital part of the mixed-signal integrated circuit.     

一种有效的IIR数字滤波器优化设计方法

针对IIR数字滤波器优化设计实质上是一个多参数多目标优化问题,本文提出一种基于量子遗传算法的IIR数字滤波器满意优化设计方法,通过设计满意度函数而构造出满意优化计算模型,将滤波器性能指标的满意设计与参数优化统一考虑,并用本文提出的收敛速度快和全局寻优能力强的新量子遗传算法(NQGA)搜索满意解。通过低通和带通IIR数字滤波器的设计结果表明,该方法是有效、实用的。     

光学系统主镜组件的轻量化设计及结构-热分析

根据某型卡塞格林系统主反射镜组件的设计要求,在遵循主镜支撑结构材料的线膨胀系数与主镜材料相匹配原则的基础上,采用有限元分析和参数优化设计相结合的方法,设计和分析了3套主镜组件方案.结果表明,在结构参数相同情况下,SiC主镜的静态、动态性能优于熔石英和K9主镜.对SiC主镜进行轻量化参数优化后,得到了直径为256 mm、质量仅为1.22 kg的镜体.通过对3种方案主镜组件的结构-热分析表明,主镜及其支撑结构均采用SiC材料的第3种主镜组件方案,消除了材料间的热膨胀错配,主镜面的变形误差完全满足设计要求,综合性能优于其它两种方案.     

圆极化微带贴片天线的设计与优化

圆极化微带贴片天线的贴片形状是影响天线性能的重要因素,圆极化天线的设计与优化有助于其应用.通过HFSS软件,设计并优化了一副圆极化微带贴片天线,采取S11参数分析,电压驻波比分析,阻抗导纳分析等,确认数据的正确性,优化后的天线达到匹配要求.