一种基于多无线收发器的无线自组网服务质量保障机制

为了提高无线自组网的容量,满足多媒体任务的服务质量(QoS)要求,该文引入多无线收发器技术,扩展单接口单信道下的无状态QoS模型SWAN为多接口多信道下的无状态QoS模型MMSWAN。同时,提出一种多接口多信道下的QoS路由协议MMQAODV,通过与MMSWAN的结合,实现了一种跨层的QoS保障机制。模拟试验表明,这种机制有效地提高了多媒体任务的QoS和尽力而为任务的性能,与SWAN相比延迟减少为它的2%~27%左右,提交的尽力而为数据量为它的1.29~3.55倍。     

基于FPGA的固态硬盘控制器的研究与设计

随着Flash存储芯片性价比越来越高,基于Flash存储芯片的固态硬盘已成为手持电子终端设备中的主流存储设备,并已开始大举进入笔记本计算机等领域.固态硬盘控制器是固态硬盘的核心部件,固态硬盘控制器性能的好坏直接决定固态硬盘的好坏,由于FPGA具备可编程、设计灵活性、设计周期短、可在线升级等优点,本文研究基于FPGA的16通道、双核固态硬盘控制器.     

大动态范围多通道电荷测量系统的研制

基于新型探测系统的特点,利用挪威IDEAS公司的电荷测量芯片Viking Chip构建一个大动态范围(0-13pC)、多通道(每个模块32通道以上)、高精度(所有通道的噪声均方差在1.2-1.4fC)的电荷测量系统,最大可测信号和噪声的比值达104。     

A versatile 16-channel front-end integrated circuit for semiconductor radiation detectors

A CMOS front-end integrated circuit consisting of 16 identical analog channels is proposed for semiconductor radiation detectors. Each of the 16 channels has a low noise charge sensitive amplifier, a pulse shaper, a peak detect and hold circuit and a discriminator, while analog voltage and channel address are routed off the chip. It can accommodate both electron and hole collection with selectable gain and peaking time. Sequential and sparse readout, combining with self-trigger and external trigger, makes four readout modes. The circuit is implemented in a 0.35 μm DP4M (double-poly-quad-metal) CMOS technology with an area of 2.5×1.54 mm2 and power dissipation of 60 mW. A single channel chip is tested with Verigy 93000. The gain is adjustable from 13 to 130 mV·fC–1 while the peaking time varies between 0.7 and 1.6 μs. The linearity is more than 99% and the equivalent noise charge is about 600e.     

基于FPGA的ZigBee阵列协议分析仪设计

针对现有部分ZigBee嗅探器只能监听单路信道与实时性差的特点,提出了一种基于FPGA技术的ZigBee阵列协议分析仪设计方案。该ZigBee阵列协议分析仪通过基于CC2530芯片设计的无线嗅探器嗅探ZigBee网络的数据包,通过FPGA技术实现了多路信道数据的实时采集、缓存与转发,使用CY7C68013A芯片实现了分析仪与PC机之间的高速数据传输。经测试USB传输速度最高可达32Mb/s,并且能同时嗅探最多16个信道的无线数据包。最终为多信道实时嗅探提供了一种良好的解决方案。     

基于STM32和USB的多通道数据采集系统设计与实现

意法半导体32位系列微控制器芯片作为高性能、低成本、低功耗的微控制器,在工业生产和自动化控制领域的应用十分广泛。但是随着技术的发展,其通用串行总线的传输速度已经相对较慢。为了使STM32的USB传输速率和性能有更进一步的提升,设计了一种由STM32控制USB通信接口的多通道数据采集系统。首先,该系统采用以STM32的增强型STM32F103为核心的控制电路,实现了10路通道的模拟/数字信号(A/D)数据的采集和转换。然后,利用STM32系统资源对EZ系列通用串行总线(EZ-USB)CY7C68013A的内部从属先进先出(FIFO)缓存器进行读写控制及数据传输处理。最后,数据的处理和显示通过由虚拟仪器(LabVIEW)设计的上位机程序实现。系统测试表明,STM32和EZ-USB组成的系统可以将STM32原有的USB传输速度提升两倍以上,并且采集的数据能在虚拟仪器上位机上实时显示。它可以使STM32更加快速、稳定地采集和处理数据,是一个适用性很强的数据采集系统。     

A combined multi-channel Wiener filter-based noise reduction and dynamic range compression in hearing aids

Noise reduction (NR) and dynamic range compression (DRC) are basic components in hearing aids, but generally these components are developed and evaluated independently of each other. Hearing aids typically use a serial concatenation of NR and DRC. However, the DRC in such a concatenation negatively affects the performance of the NR stage: the residual noise after NR receives more amplification compared to the speech, resulting in a signal-to-noise-ratio (SNR) degradation. The integration of NR and DRC has not received a lot of attention so far. In this paper, a multi-channel Wiener filter (MWF)-based approach is presented for speech and noise scenarios, where an MWF-based NR algorithm is combined with DRC. The proposed solution is based on modifying the MWF and the DRC to incorporate the conditional speech presence probability in order to avoid residual noise amplification. The goal is then to analyse any undesired interaction effects by means of objective measures. Experimental results indeed confirm that a serial concatenation of NR and DRC degrades the SNR improvement provided by the NR, whereas the combined approach proposed here shows less degradation of the SNR improvement at a low increase in distortion compared to a serial concatenation.     

基于MPC5554的飞机二次配电设备多路采样的设计

分析了以32位PowerPC微控制器MPC5554为核心的飞机二次配电设备的结构和功能，介绍了MPC5554中eQADC（增强型序列模数转换）模块的工作机制。针对MPC5554进行多路模拟信号采样数据存取量大的问题，提出了一种由eDMA辅助完成多路采样的方法，并以嵌入式操作系统μC／OS-Ⅱ为平台对多路采样实时任务进行了设计。飞机地面电网试验表明，该系统运行稳定可靠，能够实时准确采集多路信号，并显著提高了主CPU的效率。     

Multi-channel monolith reactors as dynamical systems

A model for an array of channels in a catalytic monolith reactor is presented and its qualitative behavior is examined, using a dynamical systems approach. The model uses a “coupled map lattice” system to represent a row of channels across the monolith. The aim is to provide a simple model that can give qualitative solutions for a wide range of parameter values. The model exhibits multiple stable solutions and periodic solutions which have been seen experimentally in monoliths [1] and [2] and single-channel models [3] but have not been explored theoretically in multi-channel models. This multi-channel model displays richer behavior than is possible in a single channel model; path-following techniques are used to explore the distribution in parameter space of the varying phenomenology.     

The development of a multi-channel GPR system for roadbed damage detection

This paper describes the development of a novel six-channel ground penetrating radar (GPR) for roadbed damage inspections, which can be operated in the customized cart-loading units and driven by vehicles at regular speed(60 km/h). In comparison with an existing GPR system, this novel GPR system is improved with the following design features: six channels operation which effectively improves the survey efficiency; positioning capability by implementing joint positioning and video system; FPGA control module coordinates the multi-channel microwave circuit synchronization; customized designed cart-loading units which can be operated in series mode or parallel mode, guarantees the operating capability at regular driving speed. Moreover, the pavement damage detection experiments are conducted for design validations, and the measurement results show the high inspection performance of the novel GPR system