This project aim was to build wireless software modem for data communication between two computers using an acoustic interface in the voice frequency range (20Hz– 20,000Hz). The transmitting antenna is a speaker (frequency response of: 90Hz – 20,000Hz) and the receiving antenna is a microphone (frequency response of: 100Hz – 16,000Hz). The test files used as information files were text files. This goal was attained both in an incoherent scheme and in a coherent scheme. Build under Matlab code, our modem uses OFDM (orthogonal frequency division multiplexing) modulation, synchronization by LMS sequence, channel estimation (no equalizer) via pilot tones. The symbols are either PSK or ASK for a constellation size of 2 or 4. To optimize the probability of error, these symbols were mapped using Gray mapping. Report
标签： communication computers software wireless
上传时间： 2014-05-29
上传用户：wangdean1101
In this letter, the error performance of an ultra-wideband (UWB) system with a hybrid pulse amplitude and position modulation (PAPM) scheme over indoor lognormal fading channels is analyzed. In the PAPM UWB system, input data is modulated onto both the pulse amplitudes and pulse positions.
标签： ultra-wideband performance amplitud letter
上传时间： 2014-01-08
上传用户：yulg
1984年出版，成型于美国麻省理工学院(MIT)多年使用的一本教材，1996年修订为第2版。在过去的二十多年里，本书对于计算机科学的教育计划产生了深刻的影响。 本版中大部分重要程序设计系统都重新修改并做过测试，包括各种解释器和编译器。 目录 出版者的话 专家指导委员会 序 第2版前言 第1版前言 致谢 第1章 构造过程抽象 1.1 程序设计的基本元素 1.2 过程与它们所产生的计算 1.3 用高阶函数做抽象 第2章 构造数据现象 2.1 数据抽象导引 2.2 层次性数据和闭包性质 2.3 符号数据 2.4 抽象数据的多重表示 2.5 带有通用型操作的系统 第3章 模块化、对象和状态 3.1 赋值和局部状态 3.2 求值的环境模型 3.3 用变动数据做模拟 3.4 并发：时间是一个本质问题 3.5 流 第4章 元语言抽象 4.1 元循环求值器 4.2 scheme的变形——惰性求值 4.3 scheme的变形——非确定性计算 4.4 逻辑程序设计 第5章 寄存器机器里的计算 5.1 寄存器机器的设计 5.2 一个寄存器机器模拟器 5.3 存储分配和废料收集 5.4 显式控制的求值器 5.5 编译 参考文献 练习表 索引
标签： 1984
上传时间： 2013-11-29
上传用户：咔乐坞
无线传感器网络的主要功能是实现数据发布,在接收到信息查询时能够以有效的方式传输给查询者.目前的数据发布方式通常基于洪泛机制查询信息,浪费了有限的能源.虽然一些最近的数据发布协议从不同程度上解决了这一问题,但不能保证查询成功率.基于圆形节点分布网络模型提出了一种既能减少能源消耗,又能提高成功率的数据发布模式——直径-弦模式DCS(diameter-chord scheme).该模式利用了每个圆的弦都存在一个直径与之垂直相交的性质.在此基础上提出了Two-Phase协议.它在信息查询时分成两个工作方式不同的阶段进行,在第1段查询不中时触发第2段查找.为了减少Two-Phase的延迟,提出了基于优先级和概率转发两种解决方法.理论分析和实验结果都表明,所提出的数据发布协议具有较好的性能.
上传时间： 2016-04-29
上传用户：李梦晗
JAVA 语言的函数式编程扩展，支持Erlang的Actor通信编程，支持类似Lisp或scheme语言的高阶函数，支持Continiuation！
上传时间： 2016-06-07
上传用户：thuyenvinh
A framework written in Java for implementing high-level and dynamic languages, compiling them into Java bytecodes. An implementation of scheme, which is in the Lisp family of programming languages. Kawa is a featureful dialect in its own right, and additionally provides very useful integration with Java. It can be used as a “scripting language”, but includes a compiler and all the benefits of a “real” programming language, including optional static typing.
标签： implementing high-level framework compiling
上传时间： 2014-01-05
上传用户：libinxny
Versatile visual servoing without knowledge of true jacobian.pdf cobian matrix estimator. The Jacobian matrix estimator does not need a priori knowledge of the kinematic structure and parameters of the robot system, such as camera and link parameters. The proposed visual servoing control scheme ensures the convergence of the image-features to desired trajectories, by using the estimated Jacobian matrix, which is proved by the Lyapunov stability theory. To show the effectiveness of the proposed scheme, simulation and experimental results are presented.
标签： Versatile knowledge estimator servoing
上传时间： 2016-08-26
上传用户：大三三
In an electromagnetic cloak based on a transformation approach, reduced sets of material properties are generally favored due to their easier implementation in reality, although a seemingly inevitable drawback of undesired reflection exists in such cloaks. Here we suggest using high-order transformations to create smooth moduli at the outer boundary of the cloak, therefore completely eliminating the detrimental scattering within the limit of geometric optics. We apply this scheme to a non-magnetic cylindrical cloak and demonstrate that the scattered field is reduced substantially in a cloak with optimal quadratic transformation as compared to its linear counterpart.
标签： electromagnetic transformation properties approach
上传时间： 2017-03-30
上传用户：pkkkkp
The application note covers the various domains of the FIFO architecture, improving data rate using the multiple buffering scheme, using the part in port I/O, slave FIFO or the GPIF
标签： architecture application improving the
上传时间： 2017-04-03
上传用户：变形金刚
This gorgeous, full-color book will guide you through the complete design process, from getting inspiration and sketching ideas out, through to choosing a color scheme, designing the layout, and selecting effective imagery. Throughout, the focus is on simple and practical techniques that anyone can use 鈥?you don鈥檛 need to have gone to art school or have artistic flair to create stunning designs using the methods outlined in this book. You鈥檒l follow along as author and design guru Jason Beaird creates a complete web site layout using the techniques that you鈥檝e learned. The book鈥檚 full-color layout and large format (8鈥?x 10鈥? make The Principles Of Beautiful Wed Design a pleasure to read.
标签： full-color gorgeous complete getting
上传时间： 2017-05-08
上传用户：2404
