A Broadband Quadrature-Modulator in Standard 0.13 μm CMOS

A polyphase filtering topology is proposed which uses parallel switchable RC-networks for accurate broadband 90^∘ phasing. A 0.13μm CMOS prototype using the quadrature-generation network in a direct-conversion quadrature-modulator achieves a measured image-rejection ratio of −39 dBc or better in 0.6–2.5 GHz while consuming only 66 mW from a 2.2 V single supply. Esa Tiiliharjuwas born in Rovaniemi, Finland, in 1966. He received the M.Sc. degree in Information Technology in 1995, and the Lic.Tech degree in electrical engineering in 1998, both from Helsinki University of Technology, Finland. From 1996 to July 1997 he was employed as an assistant at Helsinki University of Technology. He has held a position as a research assistant since 1997, and he is currently working towards his Ph.D. degree in the Electronic Circuit Design Laboratory at Helsinki University of Technology. His research interests include the design of integrated low-power circuits for portable telecommunication applications. He has designed and measured several integrated circuits for this application area. He is the author or co-author of several internationally-refereed conference and journal publications on analog integrated circuits. Kari A.I. Halonenwas born in Helsinki, Finland, on May 23, 1958. He received the M.Sc. degree in electrical engineering from the Helsinki University of Technology (HUT) in 1982 and the Ph.D. degree in electrical engineering from the Katholieke Universiteit Leuven, Heverlee, Belgium, in 1987. From 1982 to 1984, he was with HUT as an Assistant and with the Technical Research Center of Finland as a Research Assistant. From 1984 to 1987, he was a Research Assistant with the E.S.A.T. Laboratory, Katholieke Universiteit Leuven, with a temporary grant from the Academy of Finland. Since 1988, he has been with the Electronic Circuit Design Laboratory, HUT, as a Senior Assistant from 1988 to 1990, and as the Director of the Integrated Circuit Design Unit of the Microelectronics Center from 1990 to 1993. He was on leave of absence during the academic year 1992–1993, acting as Research and Development Manager with Fincitec Inc., Finland. From 1993 to 1996, he was an Associate Professor, and since 1997, he has been a full Professor with the Faculty of Electrical Engineering and Telecommunications, HUT. He became the Head of Electronic Circuit Design Laboratory year 1998. He was the Technical Program Committee Chairman for the European Solid-State Circuits Conference in 2000. He is the author or coauthor of over 150 international and national conference and journal publications on analog integrated circuits, and holds several patents on analog integrated circuits. His research interests are in CMOS and BiCMOS analog integrated circuits, particularly for telecommunication applications. Dr. Halonen was an Associate Editor of the IEEE TRANSACTIONS ON CIRCUITS AND SYSTEMS–PART I: FUNDAMENTAL THEORY AND APPLICATIONS from 1997 to 1999. He has been a Guest Editor for the IEEE JOURNAL OF SOLID-STATE CIRCUITS. He received the BeatriceWinner Award from the IEEE International Solid-State Circuits Conference in 2002.[c-halonen.eps]     

Series/Parallel Time-Multiplexed Switched-Capacitor Filters with Programmability Based on Non-Uniform Sampling

This paper presents an improved scheme for programmable time-multiplexed (TM) switched-capacitor (SC) filters. The proposed approach uses a novel sampling technique, which eliminates the need for resolution/area tradeoffs. The programmability of each processing channel is based on the use of non-uniform clock signals with noise-shaped sampling energy. No capacitor values are modified for programming frequency response parameters and, hence, the performance of the TM SC filter is not sacrificed for programmability. Such a sampling technique not only leads to an accurate frequency response control, but also allows the design procedures and the resulting SC circuit implementation to be simplified. A test-chip including a programmable second-order TM SC filter with a multiplexing order of four, which operates in series or in parallel mode, was fabricated in conventional CMOS technology. Measurement results demonstrate the effectiveness and versatility of the proposed technique.     

Signal Space Diversity Augmented Space Time Block Coded Communication System

In this paper we propose the combination of space-time diversity techniques and signal space diversity, in order to improve communication system performance. Specifically, we use prior knowledge of the channel behavior to design a mapping algorithm to generate a two-dimensional constellation with the same number of symbols as MPSK constellations currently used in coherent space time block coding applications, to demonstrate that superior performance can be achieved. This is accomplished by constructing a two-dimensional map that results from the minimization of the estimated symbol error probability when transmission occurs in a fading environment. System performance for each each mapping is assessed in quasi-static Rayleigh fading channels.     

Broadband Wireless Access Solutions - Progressive Challenges and Potential Valueof Next Generation Mobile Networks

The growth in mobile communication will accelerate over the next years. Today most of the mobile subscribers use cellular services only. But this will change in the near future towards broadband wireless access services like WiFi and WiMAX. This paper describes a fundamental overview of the broadband wireless access technologies and outlines the market view, major trends and introduces OFDM technologies. New developments for integration of broadband wireless access into the operators' infrastructure are also discussed.     

New Paradigms in Wireless Communication Systems

This paper discusses what a new paradigm can be in wireless communication systems of the twenty-first century. First, it suggests two directions for the new paradigm; one is “micro- and nano-device communication system” which is the projected scenario considering that the entities in source and destination have been shrinking throughout the history of wireless communication systems. The second direction is “networked robot system”, which emerges as a natural extension of mobile ad hoc networking where the networking is closely related to motion control of robots. Secondly, it shows two interesting research topics, “the new communication protocol design” and “signal processing”, respectively, that arise in the wake of the fusion between the two directions in the novel communication paradigm. Finally, it considers a new science of wireless communications in the twenty-first century. Shinsuke Hara received the B.Eng., M.Eng. and Ph.D. degrees in communications engineering from Osaka University, Osaka, Japan, in 1985, 1987 and 1990, respectively. From April 1990 to March 1997, he was an assistant professor in the Department of Communication Engineering, School of Engineering, Osaka University, and from October 1997 to September 2005, he was an associate professor in the Department of Electronic, Information and Energy Engineering, Graduate School of Engineering, Osaka University. Since October 2005, he has been a professor in the Department of Physical Electronics and Informatics, Graduate School of Engineering, Osaka City University. In addition, from April 1995 to March 1996, he was a visiting scientist at Telecommunications and Traffic Control Systems Group, Delft University of Technology, Delft, The Netherlands. His research interests include wireless communications systems and digital signal processing. Hiroyuki Yomo received B.S. degree in communication engineering from Department of Communication Engineering, Osaka University, Osaka, Japan, in 1997, and M.S. and Ph.D. degrees in communication engineering from Department of Electronic, Information, and Energy Engineering, Graduate School of Engineering, Osaka University, Osaka Japan, in 1999 and 2002, respectively. From April 2002 to March 2004, he was a Post-doctoral Fellow in Department of Communication Technology, Aalborg University, Denmark. From April 2004 to September 2004, he was at Internet System Laboratory, NEC Corporation, Japan. Since October 2004, he has been an Assistant Research Professor in Center for TeleInfrastructure (CTIF), Aalborg University, Denmark. His main research interests are access technologies, radio resource management, and link-layer techniques in the area of short-range communication, cellular network, cognitive radio, and sensor network. Petar Popovski received the Dipl.-Ing. in electrical engineering and M.Sc. in communication engineering from the Faculty of Electrical Engineering, Sts. Cyril and Methodius University, Skopje, Republic of Macedonia, in 1997 and 2000, respectively. He received a Ph.D. degree from Aalborg University, Denmark, in 2004. From 1998 to 2001 he was a teaching and research assistant at the Institute of Telecommunications, Faculty of Electrical Engineering in Skopje. He is currently Assistant Professor at the Department of Communication Technology at the Aalborg University. His research interests are related to the PHY-MAC aspects of wireless protocols, wireless sensor networks, random access protocols, and network coding. Kazunori Hayashi received the B.E., M.E. and Ph.D. degrees in communication engineering from Osaka University, Osaka, Japan, in 1997, 1999 and 2002, respectively. He spent 3 months in 2000 at Aalborg University, Denmark, as a Visiting Scholar. Since 2002, he has been with the Department of Systems Science, Graduate School of Informatics, Kyoto University. He is currently an Assistant Professor there. His research interests include digital signal processing for communications systems.     

相关衰落信道下的一种层间联合自适应SR-ARQ传输机制

传统自适应传输机制在相关慢衰落信道下有较差的系统性能.针对相关衰落信道,提出了一种层间联合自适应传输机制.利用有限状态马尔可夫链来描述相关衰落信道,同时通过构建一个多状态马尔可夫系统模型来分析系统吞吐性能,并对调制方式和传输分组大小进行优化.另外,推导了系统平均吞吐性能的表达式.仿真结果显示所提出的自适应传输机制在相关衰落信道上能获得更好的系统性能.     

多泵浦反向激励的拉曼光纤放大器的实现

在拉曼光纤放大器理论建模的基础上,设计并制作了四波长八泵浦反向激励且带宽为90nm的光纤放大器。利用康宁公司生产的25kmSMF作为增益光纤,得到拉曼增益为(11.5±1)dB。采用在不同泵浦情况下实测得到的信号增益系数谱和泵浦之间的增益系数谱,使理论建模得到的拉曼增益与实测相一致。     

基于FFT的星上多路FDMA/FSK信号解调研究

提出了一种基于FFT的星上多路FDMA/FSK信号解调算法。首先分析了该算法的基本原理,证明了其性能与FSK信号理想非相干解调性能相同,同时提出了利用FFT进行频差估计的算法;对系统进行了性能仿真,仿真结果与理论分析一致;该算法实现简单、复杂度低,适合星上处理。     

基于USB的DDS虚拟频率特性测试仪

提出了基于USB的DDS虚拟频率特性测试仪的原理和实现方法,介绍了DDS信号发生模块的原理,使用的核心芯片AD9762的功能;USB接口模块使用的芯片CY7C64613的功能和接口的实现方法,同时给出了由Lab Windows/CVI实现的频率特性测试仪的面板和频率特性分析的过程及其他功能。最后得出结论,按该方案设计的测试仪可以很好地实现频率特性测试分析,并具有较强的可扩展性。     

甚小天线地面站(VSAT)卫星通信系统高频本振信号源设计

为满足甚小口径天线地面站(Very Small Aperture Terminal,VSAT)卫星通信系统对低噪声高频信号源(10.7~14.5 GHz)的要求,分析了当前频率合成的各种方法,提出了利用Zarlink公司的高频分频器ZL40813和低噪声的单芯片锁相环(PLL)频率合成器SP5769构建一种便宜的低噪声高频信号源方案。