Abstract-The effect of the companding process on QAM signals has been under investigation for the past several years. The compander, included in the PCM telephone network to improve voice performance, has an unusual affect on digital QAM data signals which are transmitted over the same channel. The quantization noise, generated by the companding process which is multiplicative (and asymmetric), degrades the detectability performance of the outermost points of the QAM constellation more than that of the inner points. The combined effect of the companding noise and the inherent white gaussian noise of the system, leads us to a re-examination of signal constellation design. In this paper we investigate the detectability performance of a number of candidates for signal constellations including, a typical rectangular QAM constellation, the same constellation with the addition of a smear-desmear operation, and two new improved QAM constellation designs with two-dimensional warpi
标签： investigation Abstract-The companding the
上传时间： 2013-12-20
上传用户：英雄
一个iscsi实现源码，值得参考。It is a high-performance, transport independent, multi-platform implementation of RFC3720 iSCSI.
上传时间： 2016-06-30
上传用户：it男一枚
Zigbee 精简版技术协议，英文原版的，很好，值得参考！ A Zigbee-subset/IEEE 802.15.4 Multi-platform Protocol Stack
上传时间： 2013-12-09
上传用户：sqq
彈跳球遊戲，multi-threads控制每個球，碰到牆壁就會反彈
标签：
上传时间： 2013-12-24
上传用户：onewq
Host Identity Protocol on Linux is an implemetation of the Host Identity Protocol (HIP) and the related architecture. HIP is a proposal to change the TCP/IP stack to securely support mobility and multi-homing. Additionally, it provides for enhanced security and privacy and advanced network concepts, such as moving networks and mobile ad hoc networks. HIP is "cool", which means that as a mobile VPN solution, when your network interfaces go up or down, there is no need to re-establish a secure tunnel.
标签： Identity Protocol Host implemetation
上传时间： 2016-09-01
上传用户：皇族传媒
The OpenGL graphics system is a software interface to graphics hardware. (The GL stands for Graphics Library.) It allows you to create interactive programs that produce color images of moving three-dimensional objects.
标签： graphics The interface Graphics
上传时间： 2013-11-27
上传用户：Altman
外国人开发的电磁时域有限差分方法工具包 Electromagnetic Finite-Difference Time-Domain (EmFDTD) is a basic two-dimensional FDTD code developed at the School of Electrical Engineering, Sharif University of Technology. This code has been written based on the standard Yee s FDTD algorithm. Applications include propagation, scattering, and diffraction of electromagnetic waves in homogeneous and non-homogeneous isotropic media for in-plane propagating waves. Negative permittivites or permeabilities as well as dispersion is not included. Zero, Periodic, and Perfectly Matched Layer boundary conditions may be selectively applied to the solution domain. The program is best suited for study of propagation and diffraction of electromagnetic waves in Photonic Crystal structures. EmFDTD is written in MATLAB language and has been tested under MATLAB 5.0 and higher versions.
标签： Finite-Difference Electromagnetic two-dimensio Time-Domain
上传时间： 2014-11-24
上传用户：watch100
The Inter IC bus or I2C bus is a simple bidirectional two wire bus designed primarily for general control and data transfer communication between ICs. Some of the features of the I2C bus are: • Two signal lines, a serial data line (SDA) and a serial clock line (SCL), and ground are required. A 12V supply line (500mA max.) for powering the peripherals often may be present. • Each device connected to the bus is software addressable by a unique address and simple master/ slave relationships exist at all times masters can operate as master-transmitters or as master-receivers. • The I2C bus is a true multi-master bus including collision detection and arbitration to prevent data corruption if two or more masters simultaneously initiate data transfer systems. • Serial, 8-bit oriented, bidirectional data transfers can be made at up to 100 KBit/s in the standard mode or up to 400 KBit/s in the fast mode.
标签： bus bidirectional primarily designed
上传时间： 2013-12-11
上传用户：jeffery
最受欢迎的Joomla社区用户管理收费插件 - Commnity Builder 1.2 RC2。 Community Builder suite (CB) extends the Joomla! user management system. Key features: extra fields in profile, enhanced registration workflows, user lists, connection paths between users, admin defined tabs and user profiles, image upload, front-end workflow management, integration with other components, like PMS, Newsletter, Forum, Galleries. Release 1.1 is compatible with all Joomla! 1.0.x (including 1.0.15) and Mambo 4.5.2-4.6.4. New CB version 1.2 RC brings Joomla 1.5 native compatibility (and keeping Joomla 1.0.x and Mambo 4.5.2-4.6.4 native compatibility), multi-criteria user searches, full field controls of core fields, ajax email and username checkers, new lost username/password form and many more features and fixes. Please see announcement on our homepage.
标签： Builder Joomla Community Commnity
上传时间： 2016-10-20
上传用户：daoxiang126
最受欢迎的Joomla 社区用户管理收费插件 Community Builder 1.2 RC2 的电子书，仅提供给付费会员 Community Builder suite (CB) extends the Joomla! user management system. Key features: extra fields in profile, enhanced registration workflows, user lists, connection paths between users, admin defined tabs and user profiles, image upload, front-end workflow management, integration with other components, like PMS, Newsletter, Forum, Galleries. Release 1.1 is compatible with all Joomla! 1.0.x (including 1.0.15) and Mambo 4.5.2-4.6.4. New CB version 1.2 RC brings Joomla 1.5 native compatibility (and keeping Joomla 1.0.x and Mambo 4.5.2-4.6.4 native compatibility), multi-criteria user searches, full field controls of core fields, ajax email and username checkers, new lost username/password form and many more features and fixes. Please see announcement on our homepage.
标签： Community Builder Joomla 1.2
上传时间： 2016-10-20
上传用户：王者A
