共查询到19条相似文献,搜索用时 140 毫秒
1.
超宽带通信系统(UWB)所占用的带宽非常宽,研究超宽带通信系统和其它通信系统间的电磁兼容问题对多通信系统的共存应用具有十分重要的实际意义。本文通过有针对性地选取无线信道传输模型,研究了超宽带通信设备与现存小灵通通信系统间的电磁干扰问题;并根据FCC 和ETSI 所给出的系统参数,给出了此二系统之间的电磁干扰仿真实验结果。 相似文献
2.
现代通信系统中多种信息速率并存,多速率兼容成为一个突出的问题.基于直接序列扩频(DS-SS)和卷积编码技术,提出了一种可以满足多速率兼容的调制解调器实现方法,通过选择不同长度的伪随机序列或者卷积编码,不同的信息速率占用相同的传输带宽.对扩频、解扩以及卷积码的编码和解码部分进行了较为详细的论述,给出了关键模块的原理和实现方法,对使用此调制解调器的通信系统进行了测试,并给出了测试数据. 相似文献
3.
针对GSM终端设备在FCC和IC认证中输出功率、占用带宽、杂散发射、频率稳定度等射频测试项目,详细介绍测试目的及方法、测试设置与步骤,并总结了测试的要点和技巧. 相似文献
4.
阐述了2.4 GHz终端设备在FCC认证中最大发射功率、占用带宽测试项目的重要性,介绍了这两项测试的目的,详细说明了测试的设置方法与步骤,总结了测试过程中的注意事项. 相似文献
5.
6.
7.
8.
9.
扩展频谱通信技术是一种信息传输方式。其系统占用的频带宽度远远大于要传输的原始信号带宽(或信息比特率)。本论文工作的重点是在Max plus2开发平台上具体实现这个扩频系统,并对系统中的每个模块进行相应的功能仿真。 相似文献
10.
Richard Comerford 《今日电子》2005,(10):36-36
近期由PXI系统联盟工业集团(PXI Systems AUiance industry group)提出的PXI Express(PXIe)将为测试系统提供高达6Gb/s的底板带宽,是传统的132Mb/s PXI系统的45倍多.这使得测试系统可以建在PXIe板上--它比独立仪器配置价格低--实现高带宽的通信、视频以及大量、多通道的数据采集应用,这些都是以往PXI系统不能处理的. 相似文献
11.
半球谐振陀螺是一种高精度的惯性器件,在航空航天等领域有着重要的应用,但其本征带宽较低,对其力平衡控制回路及带宽测试方法要求较高。该文提出一种新型的基于虚拟科里奥利力的半球陀螺带宽电学快速测试方法,可代替角振动台等昂贵仪器对半球陀螺进行迅速自标定,从而为半球陀螺的高性能控制回路设计方法和批量化测试提供一种新的技术解决方案。首先在基础理论层面分析半球谐振陀螺动力学方程,建立起本征带宽系统模型,为虚拟电旋转的引入和自标定方法提供了理论基础。随后设计了基于虚拟科氏力的电旋转激励信号,并将其集成到陀螺接口电路系统中。最后设计了力平衡控制回路,并对该电学自标定方法进行了实验验证。实验结果表明,虚拟电旋转法能在不借助外部设备的情况下,有效准确地对半球陀螺带宽进行测试和标定,从而有效地促进高性能力平衡控制方法的开发和提高半球陀螺带宽测试效率。 相似文献
12.
13.
EPON系统动态带宽管理技术及测试方法 总被引:1,自引:0,他引:1
光接入网方兴未艾,作为现阶段我国采用的主要光接入技术手段——基于以太网的无源光网络(EPON)正处于大规模商用阶段。在多用户和多业务的环境中,系统的带宽有效管理技术变得至关重要。目前EPON中所使用的动态带宽分配基本上都是基于请求一授权的分配方式,如何评测某种动态带宽分配(DBA)算法的效率成为测试领域的新课题。一个完整的测试方案需包括:测试参考点的选取,测试参考模型的搭建,测试步骤的确立以及结果分析等。 相似文献
14.
为了消除传统电模拟法引入的激励信号对力矩器驱动模块造成的影响,提出了一种在数字闭环加速度计系统反馈回路数模转换器输入端叠加一个激励信号来测试系统带宽的方法.通过对该方法的电激励模型进行分析,表明在带宽测试时系统反馈回路D/A输入端叠加激励信号可以等效为外界输入的加速度.搭建测试平台测试系统带宽,实验表明,用该方法测得的数字闭环加速度计系统带宽与传统机械振动法的测试结果相接近.该方法未增加其它电路,降低了系统的复杂度,消除了电模拟法外加激励信号源对力矩器驱动模块的影响.此外,该方法操作快速简单、便于在线测试,可满足大多数数字闭环加速度计的带宽测试要求. 相似文献
15.
16.
17.
《Broadcasting, IEEE Transactions on》1997,43(1):96-103
Bandwidth efficiencies that have not been possible in the past are now being achieved using variable PSK (VPSK) and variable MSK (VMSK) modulation without the loss of signal power that normally accompanies high bandwidth efficiency methods. Theoretically, these two methods do not lose any signal energy with increasing bandwidth compression. Efficiencies up to 15 bits/sec/Hz are now being achieved in usable hardware with C/N ratios better than that obtainable using FM, BPSK or QPSK. This paper explains how this is accomplished and gives a full mathematical analysis of the method. FM-SCA, VSAT, STL and RPU equipment are now undergoing beta testing prior to FCC Type Acceptance submission. Installation is expected on a large network during 1997 相似文献
18.
Ayers S. Gillis K.D. Lindau M. Minch B.A. 《IEEE transactions on circuits and systems. I, Regular papers》2007,54(4):736-744
High-throughput electrode arrays are required for advancing devices for testing the effect of drugs on cellular function. In this paper, we present design criteria for a potentiostat circuit that is capable of measuring transient amperometric oxidation currents at the surface of an electrode with submillisecond time resolution and picoampere current resolution. The potentiostat is a regulated cascode stage in which a high-gain amplifier maintains the electrode voltage through a negative feedback loop. The potentiostat uses a new shared amplifier structure in which all of the amplifiers in a given row of detectors share a common half circuit permitting us to use fewer transistors per detector. We also present measurements from a test chip that was fabricated in a 0.5-mum, 5-V CMOS process through MOSIS. Each detector occupied a layout area of 35 mumtimes15 mum and contained eight transistors and a 50-fF integrating capacitor. The rms current noise at 2-kHz bandwidth is ap110 fA. The maximum charge storage capacity at 2 kHz is 1.26times106 electrons 相似文献
19.
Smart wireless sensor systems that incorporate multiple sensors often cannot be implemented on a single chip. Advanced integration
and assembly allows for a more complex conjugation and configuration of multiple system modules implemented under different
technologies together in a small tiny package. In tiny sensor systems such as these, three common challenges seen across most
platforms are: the difficult test access due to non-standard assembly and packaging, the testing of multiple heterogeneous
sensor species, and the strict dimensional requirements limiting availability of any built-in hardware for testing. We discuss
the method of testing by modules for testing a multilayer mechanically flexible wireless multisensor platform. A hierarchical
test flow is presented for verifying the functionalities and assessing the performance of the various modules of the system.
We also present an example of a design for testing feature, a built-in test point access bus that improves reliability for
test point access, reduces the cost of testing and overall system bill-of-material, as well, increases test channel bandwidth
allowing for full access to all critical subsystem nodes. Lastly, we provide examples of subsystem performance assessment
and verification testing of selected sensor species on the multisensor platform as well as the system power consumption versus
transmission range, to illustrate the usefulness of the test concepts, flow, and features introduced. 相似文献