5Gb/s单片集成GaAs MSM/PHEMT 850nm光接收机前端

采用0.5μm GaAs PHEMT工艺研制出了一种单片集成850nm光接收机前端,它包括金属-半导体-金属(MSM)光探测器和分布放大器.探测器光敏面积为50μm×50μm,电容为0.17pF,4V偏压下的暗电流小于17nA.分布放大器-3dB带宽接近20GHz,跨阻增益约46dBΩ;在50MHz～16GHz范围内,输入、输出电压驻波比均小于2;噪声系数在3.03～6.5 dB之间.光接收机前端在输入2.5和5Gb/s非归零伪随机二进制序列调制的光信号下,得到较为清晰的输出眼图.     

高灵敏度CMOS光电集成接收机设计

设计了一个由调节型级联跨阻抗放大器(TIA)和双光电二极管(DPD)构成的CMOS光电集成(OEIC)接收机.具体分析了这个光电集成接收机的噪声和灵敏度及其相互关系.接收机中的噪声主要是电路中电阻的热噪声和MOS器件的闪烁噪声.提出了优化接收机灵敏度的方法.通过低成本的CSMC 0.6μm CMOS工艺流片并对芯片进行了测试.从测试眼图可知,该CMOS光电集成接收机可工作在1.25GB/s的传输速率下,灵敏度为-12dBm.     

200 MHz带宽压缩接收技术研究

从傅氏变换基本公式出发,介绍了以色散延迟线（SAW DDL）器件通过“相乘-卷积-相乘（M-C-M）”方式实现傅氏变换的方法。以线性调频（chirp）傅氏变换为基础,研制了测频带宽大于200 MHz、频率分辨小于5 MHz、适应100 ns脉冲的接收机用测频模块,同时给出了样品实验结果和测试波形图,并进一步探讨了改进性能的途径。     

高速超宽带脉冲检测电路的设计

在介绍了一种基于TH-PPM调制方式的并行检测接收机方案的基础上,结合UWB脉冲信号的时域特征提出并实现了一种结构简单、性能稳定的脉冲能量检测电路.实验结果表明该电路可在100Mb/s的高传输速率情况下取得较好的超宽带信号检测效果.     

伽利略系统BOC信号的特性及码跟踪方法研究

为了节省卫星频率资源并提高导航信号的可靠性,新一代的导航定位系统采用了一种更有效的调制方式-BOC调制,它具有与BPSK之间串扰小、抗衰落能力强等诸多优点.但由于BOC调制信号特性比较复杂,因此加大了接收处理的难度.本文主要从理论上介绍了BOC和Alt-BOC的调制方式和信号产生方法、调制后信号的频谱特性以及自相关函数特性,依此分析了BOC信号自相关结果的多峰值特性和由此特性造成的跟踪和锁定难度的增加,以及相应于其频谱特性栽的信号处理方法.并在此基础上提出了一种能提高码跟踪可靠性的基带信号相关处理方法,Matlab仿真结果表明此方法有较好的效果,能提高码跟踪的可靠性.     

低功耗CMOS限幅放大器设计

利用0.18μm CMOS工艺设计了应用于光接收机中的10Gb/s限幅放大器.此限幅放大器由输入缓冲,4级放大单元,一级用于驱动50Ω传输线的输出缓冲和失调电压补偿回路构成.输入动态范围为38dB(10mV～800mV),负载上的输出限幅在400mV,在3.3V电源电压下,功耗仅为99mW.整个芯片面积为0.8×1.3mm2.     

A regression approach to ROC surface, with applications to Alzheimer’s disease

We consider the estimation of three-dimensional ROC surfaces for continuous tests given covariates.Three way ROC analysis is important in our motivating example where patients with Alzheimer’s disease are usually classified into three categories and should receive different category-specific medical treatment.There has been no discussion on how covariates affect the three way ROC analysis.We propose a regression framework induced from the relationship between test results and covariates.We consider several practical cases and the corresponding inference procedures.Simulations are conducted to validate our methodology.The application on the motivating example illustrates clearly the age and sex effects on the accuracy for Mini-Mental State Examination of Alzheimer’s disease.     

Equivalent Model, Error Analysis, and Design Steps of AGC Loop for MM-Wave Receiver

Automatic Gain Controlled (AGC) Loops are used in MM-Wave receiver in wide-ranging. In this paper, the equivalent model and loop equation of AGC Loop are built, the loop errors are analyzed and then the design steps of AGC Loop are given out.     

A Digital TV Content Protection System

To meet the demand of the digital right management for digital TV content, a unified digital content protection framework for various digital interfaces in digital TV, named Digital TV content protection system （DCPS） is proposed, which comprises two parts： the broadcast head-end content protection DCPS-Flag and the digital TV receiver content protection DCPS-CP. The DCPS system aims at achieving three aspects. First, it is to achieve secret transmission of audiovisual content between the interfaces in valid devices. Second, it is to achieve the integrality between the related control information in the valid devices. Third, it is to maintain the integrality of the system by the way of revoking the invalid devices. Analysis shows the security of DCPS system is based on the secrecy of key, which is unrelated to the algorithm itself. And the practical application also shows the good performance of DCPS with low computation and high real time capability, and it can replace the high cost HDCP.     

Adaptive Diagnosis for Fault Tolerant Data Fusion Based on α-Rényi Divergence Strategy for Vehicle Localization

When applying a diagnostic technique to complex systems, whose dynamics, constraints, and environment evolve over time, being able to re-evaluate the residuals that are capable of detecting defaults and proposing the most appropriate ones can quickly prove to make sense. For this purpose, the concept of adaptive diagnosis is introduced. In this work, the contributions of information theory are investigated in order to propose a Fault-Tolerant multi-sensor data fusion framework. This work is part of studies proposing an architecture combining a stochastic filter for state estimation with a diagnostic layer with the aim of proposing a safe and accurate state estimation from potentially inconsistent or erroneous sensors measurements. From the design of the residuals, using α-Rényi Divergence (α-RD), to the optimization of the decision threshold, through the establishment of a function that is dedicated to the choice of α at each moment, we detail each step of the proposed automated decision-support framework. We also dwell on: (1) the consequences of the degree of freedom provided by this α parameter and on (2) the application-dictated policy to design the α tuning function playing on the overall performance of the system (detection rate, false alarms, and missed detection rates). Finally, we present a real application case on which this framework has been tested. The problem of multi-sensor localization, integrating sensors whose operating range is variable according to the environment crossed, is a case study to illustrate the contributions of such an approach and show the performance.