欧洲W-CDMA开发进展及其技术指标

本文简要介绍了欧洲Ｗ－ＣＤＭＡ的发展状况、系统参数配置和系统功能。     

数字电视的数字调制技术

主要介绍数字有线电视网下行、上行信道频谱的划分,各种数字调制方法、性能特点和优缺点比较.     

Architectures for Heterogeneous Multi-Tier Networks

Next-generation wireless computing platforms will contain flexiblecommunications capabilites. At Rice University,the Rice Everywhere NEtwork (RENÉ) project is investigating a multi-standard, multi-tierintegration of W-CDMA cellular systems, high speed wireless LANs, and home wireless networks.There are many challenges in mapping these advanced communicationalgorithms to real-time hardware computing platforms.In this paper, we present current work on the developmentof a reconfigurable baseband physical layer containing DSP processorsand FPGA accelerators. Our goal is the design of amulti-tier network interface card (mNIC) which is capableof exploiting efficient, low-power reconfiguration.     

W-CDMA 多业务传输中的码片均衡技术

介绍了一种新的W-CDMA中的抗多径接收技术，即码片均衡技术，它特别针对视频点播等高速业务，适用于下行链路多业务传输。并研究了码片均衡器的现状，探讨了码片均衡的发展趋势。     

Region Division Assignment: A New OVSF Code Reservation and Assignment Scheme for Downlink Capacity in W-CDMA Systems

This work focuses on the efficient management of orthogonal-variable-spreading-factor (OVSF) codes for multimedia communications in the W-CDMA systems. Because these systems must assign only OVSF codes that are mutually orthogonal, even if they have sufficient transmission capacity they block connections for which no orthogonal OVSF codes are available. This code blocking can, with extra overhead, be eliminated by reassigning codes, but in this paper we propose an OVSF code management scheme designed to not reassign codes. This scheme, called Region Division Assignment, cannot eliminate code blocking but can reduce the overhead for code assignment. Computer simulations based on the multiple access protocol in UMTS/IMT-2000 show that the proposed scheme can efficiently provide variable-rate services as well as low-rate services. This paper was presented in part at the IEEE Vehicular Technology Conference Fall 2001, October 7-11, 2001, Atlantic City, NJ USA. Rujipun Assarut received his BE from Chularongkorn University, Thailand, in 1997 and his MS from Gunma University, Japan, in 2002. Currently, he is working as a software engineer for NEC communication systems. His current project is the development of IP phone for enterprise applications. Ken’ichi Kawanishi is a research associate with Gunma University, Japan. His current research interests include queueing theory and stochastic processes. He is a member of ORSJ, JSIAM and IEICE. Ushio Yamamoto received a bachelor’s degree in information engineering, and a master’s degree and Ph.D. degree in information science from Tohoku University in 1992, 1994 and 1997, respectively. He is now an associate professor in Dept. of Computer Science, Gunma University. He has been engaged in research on wireless ad hoc networks, multimedia communication networks, load balancing on computer networks and intelligent agents. He is a member of IPSJ and JSAI. Yoshikuni Onozato is a Professor with Gunma University. His research interests are in satellite systems, computer communication networks and distributed computing systems and span the entire spectrum from the design and performance evaluation of these systems to their implementation. He is a member of IEEE, ACM, IPSJ, ORSJ and IEICE.     

Near Optimum Power Control Scheme for Downlink in the W-CDMA Cellular System

The downlink power control problem in W-CDMA is studied using a new near optimum power control scheme (model). The downlink cell capacity is given for both the old given by Gejji and our new model. A capacity increase of 7.5% for the special case = 0 (no orthogonality between users) and a generalization of the old model are obtained using the new model.     

Forward link partial-balance power control algorithm for W-CDMA communication

Balance power control is based on the idea of balancing Carrier to Interference Ratio (CIR) of all wireless links. Unbalance power control means that different traffics can achieve different CIR at receivers. This paper proposes a forward link partial-balance power control algorithm, which can provide necessary Quality of Service (QoS) for multimedia traffics in Wideband CDMA(W-CDMA) systems. The proposed algorithm is the integration of grading traffics priority and allocating and adjusting forward link power levels. For higher priority traffics, the unbalance power control is used. Whereas for lower priority traffics, balance power control is adopted. Computer simulation results show that the proposed algorithm can guarantee the special QoS requirements of the traffics with higher priority orders and maximize the CIR of the traffics with lower priority orders.     

数字版权管理及其在3G手机中的应用研究

通过对W-CDMA等3G手机的技术现状和当前的相关技术进展的介绍,分析了3G终端的新的业务应用.在详细分析3G手机和OMA数字版权管理的系统架构的基础上,结合两者的实现要求和软硬件基础,提出了在W-CDMA手机上实现DRM的方案.     

第三代移动通信系统与宽带CDMA技术

我们正在走向一个信息化的社会,人们希望能够随时随地的进行广泛的话音、图像、数据等多媒体信息交换,由于第三代移动通信系统可以通过无线连接提供越高速的数据通信,因此它将成为实现全球移动信息与通信社会的核心推动力量。本文将介绍几种第三代通信系统以及作为其技术基础的宽带码分多址技术。     

Multitier Wireless Communications

Next-generation computing systems will be highly integrated using wireless networking. The Rice Everywhere NEtwork (RENÉ) project is exploring the integration of WCDMA cellular systems, high speed wireless LANs, and home wireless networks to produce a seamless multitier network interface. We are currently developing a simulation acceleration testbed and a multitier network interface card (mNIC) consisting of DSP processors, custom VLSI ASICs, and FPGAs for baseband signal processing to interact with the various RF units and the host processor. This testbed will also allow us to explore high performance algorithm alternatives through computer aided design tools for rapid prototyping and hardware/software co-design of embedded systems.