一种基于PIFA结构多频段手机天线的设计

设计了一款基于PIFA结构的手机天线,以多支节和增加寄生单元方式实现天线的小型化和多频段要求。采用HFSS13.0高频电磁仿真软件对天线进行仿真优化,最终得到天线的尺寸为33 mm×13 mm×8 mm,同时天线在多个频点处谐振。仿真结果表明,谐振点位置S11≤-10 dB,天线和馈线匹配良好,天线带宽足够同时覆盖GSM850、DCS1800、PCS1900、LTE2300/2500、ISM/Bluetooth、WLAN(2.4GHz)工作频段。对设计天线进行了加工和实测,实测与仿真结果吻合良好,验证了本设计的可靠性。     

Data Converter for Multistandard Mobile Phones

This paper describes an analog to digital converter (ADC) for mobile communication systems using a direct down conversion architecture. The ADC can be programmed to meet the requirements of different communication standards, including GSM (Global System for Mobile communication) and WCDMA (Wideband Code Division Multiple Access). The ADC is realized with a pipeline ADC architecture for WCDMA and a Sigma-Delta architecture for GSM. In order to have an optimized area and power consumption, the basic building blocks (opamps) of the converters are shared between the two converter architectures. The entire ADC consumes about 5.5 mW and occupies an active area of about 0.36 mm². A test circuit has been developed and fabricated and measurements show that both the required programmability and the required performance can be obtained using the proposed configurations.     

移动电话机用的彩色显示屏

本文讨论了在移动电话机中采用彩色显示屏的必要性，介绍了STN与TFT液晶显示屏的应用状况，并展望了有机EL显示屏的应用前景。     

3G移动电话的系统级LSI

引言 无线移动电话仅具备语音功能的时代已经离我们远去了.目前的3G手机更多的是作为多媒体系统,提供彩显、游戏、音频、视频、相机、蓝牙、GPS、WLAN、高速广域数据服务以及其他高级特性.由于功能非常之多,因此处理新型3G电话比处理仅有语音功能的2G电话要复杂5倍至10倍,在应用处理方面则要求更高.     

Programmable Baseband Filter for Multistandard Mobile Phones

This paper describes a channel selection filter for mobile communication systems using a direct downconversion architecture. The filter can be programmed to meet the requirements of different communicationstandards, including GSM (Global System for Mobile communication), WCDMA (Wideband Code DivisionMultiple Access), and Bluetooth. The filter includes a novel DC offset compensation circuit that combinesoffset sampling in GSM mode with high pass filtering in WCDMA mode. The filter can be programmed to different noiseperformance levels by programming the impedance level and power consumption of the input transconductor. The entirefilter consumes between 2.5 mW and 7.5 mW, depending on the desired noise performance. It is implemented in astandard 0.25 m CMOS process. A test circuit has been developed and fabricated and measurements show that boththe required programmability and the required transfer functions can be obtained from the designedcircuit.     

Analysis of Dual-Band Helical Antenna for Diversity on Mobile Phones

Antenna diversity on a mobile phone is considered using two dual-band, GSM900/1800, helical antennas. The received signals in mobile Rayleigh fading channel are modeled using a new field simulation technique that involves the three-dimensional (3D) radiation pattern of antennas, 3D angle of arrivals (AoAs) and Doppler frequency. Statistical tools prove the validity of the field simulator. The signals correlation coefficient and diversity gain are computed for different mobile propagation environments by considering AoAs. It is shown that the diversity gain is slightly influenced by the environment models. The experimental prototype is developed and measured. Antenna characteristics: return loss, coupling, 3-D radiation patterns and antenna efficiency are obtained by the measurements and simulations. The diversity performance of the array configuration is measured in the rich wave scattering environment of a reverberation chamber (RC). Results including: signals correlation coefficient, average power of diversity branches, apparent/effective diversity gain and antenna efficiency in RC are provided. The influence of the mobile user is measured as well. Diversity gain of the helical array in both operating frequencies is fairly good. The signals correlation with user’s head increases in GSM900 and slightly decreases in GSM1800. In the former band, the diversity gain loss due to imbalance branch powers is found more important than in the later.

A Comparison of Digital Speech Coding Methods for Mobile Radio Systems

Subjective quality measurements on three digital speech coders, simulated with mobile radio channel transmission, were performed using the "mean opinion score (MOS)" method. The three speech coding methods tested were: continuously variable slope deltamodulation (CVSD) coding, adaptive predictive coding (APC), and residually excited linear predictive (RELP) coding. Several versions of each coder, with transmission rates in the range of 7.3 to 16.1 kbits/s, were simulated. Five different channel conditions, including three derived from land mobile radio field experiments, were applied to the speech coders' encoded output to study the effects. The results show that of the three coders, the CVSD coder is the most robust to channel errors, but produces reconstructed output speech of unacceptable quality. The 14.4 kbit/s RELP coder produces relatively good Output speech quality, exhibits a mild degree of robustness to mobile radio channel errors, and is slightly less complex than the APC coder. Of the three digital speech coders tested, the RELP coder appears the most suitable for use with land mobile radio. However none of the three coders was able to produce speech of telephone toll quality in a mobile radio environment.     

A Video Streaming System for Mobile Phones: Practice and Experience

This paper presents a case of video streaming system for mobile phone which has actually been implemented and deployed for commercial services in CDMA2000 1X cellular phone networks. As the computing environment and the network connection of cellular phones are significantly different from the wired desktop environment, the traditional desktop streaming method is not applicable. Therefore, a new architecture is required to suit the successfully streaming in the mobile phone environment. We have developed a very lightweight video player for use in mobile phone and the related authoring tool for the player. The streaming server has carefully been designed to provide high efficiency, reliability and scalability. Based on a specifically-designed suite of streaming protocol, the server employs an adaptive rate control mechanism which transmits the media packets appropriately into the network according to the change in network bandwidth.Hojung Cha is currently a professor in computer science at Yonsei University, Seoul, Korea. His research interests include multimedia computing system, multimedia communication networks, wireless and mobile communication systems and embedded system software. He received his B.S. and M.S. in computer engineering from Seoul National University, Korea, in 1985 and 1987, respectively. He received his Ph.D. in computer science from the University of Manchester, England, in 1991.Jongmin Lee is a Ph.D. candidiate in computer science at Yonsei University, Seoul, Korea. His research interests include wireless multimedia system, QoS architecture, multimedia communication networks. He received his B.S. and M.S. in computer science from Kwangwoon University in 1999 and 2001, respectively.Jongho Nang is a professor in the Department of Computer Science at Sogang University. He received his B.S. degree from Sogang University, Korea, in 1986 and M.S. and Ph.D. degree from KAIST, in 1988 and in 1992, respectively. His research interests are in the field of multimedia systems, digital video library, and Internet technologies. He is a member of KISS, ACM, and IEEE.Sung-Yong Park is an associate professor in the Department of Computer Science at Sogang University, Seoul, Korea. He received his B.S. degree in computer science from Sogang University, and both the M.S. and Ph.D. degrees in computer science from Syracuse University. From 1987 to 1992, he worked for LG Electronics, Korea, as a research engineer. From 1998 to 1999, he was a research scientist at Telcordia Technologies (formerly Bellcore) where he developed network management software for optical switches. His research interests include high performance distributed computing and systems, operating systems, and multimedia.Jin-Hwan Jeong received the B.S. and M.S. degrees in computer science from Korea University, Seoul, Korea, in 1997, and 1999, respectively. He is currently in Ph.D. course at Korea University. His research interests include video processing for thin devices, multimedia streaming and operating systems.Chuck Yoo received the B.S. degree in electronics engineering from Seoul National University, Seoul, Korea and the M.S. and Ph.D. in computer science in University of Michigan. He worked as a researcher in Sun Microsystems Lab. from 1990 to 1995. He joined the Computer Science and Enginnering Department, Korea University, Seoul, Korea in 1995, where he is currently a professor. His research interests include high performance network, multimedia streaming, and operating systems.Jin-Young Choi received the B.S. degree from Seoul National University, Seoul, Korea, in 1982, the M.S. degree from Drexel University in 1986, and the Ph.D. degree from University of Pennsylvania, in 1993. He is currently a professor of Computer Science and Engineering Department, Korea University, Seoul, Korea. His current research interests are in real-time computing, formal methods, programming languages, process algebras, security, software engineering, and protocol engineering.     

基于数据预测的手机总全向灵敏度(TIS)的快速测试

手机总全向灵敏度（TIS）是OTA测试的重要指标之一。而基于CTIA的步进测试法,测试非常耗时。本文在深入研究基站发射功率和误码率关系的基础上,得出具有一定通用性的拟合函数,进而提出了一种基于数据预测的TIS测试方法。通过编写相应自动测试软件,实现快速测试。该法将大大提高测试效率,有很高的应用和推广价值。     

LG飞利浦已研制出用于手机的TFT-LCD

LG. Philips LCD （LPL） announced at Sept. 13th 2006, it has developed the industry＇s fastest TFT-LCD panel for mobile phones, which will permit next-generation handsets to display TV and video content with less motion blur.     

Analysis of Social Interactions Through Mobile Phones

Equipment of mobile phones with various kinds of sensors is transforming these devices from mere capabilities of voice and internet access to devices capable of sensing a number of phenomena pertaining to their users. In this paper we make use of these capabilities of phones to detect social interactions between people and analyze social context by using embedded sensors found in typical smart phones. Work carried out in this area has typically used dedicated hardware to establish social interactions, and we contend on the suitability of mobile phone, since additional devices that user is not familiar with influence natural user behavior and thus their social interaction patterns. Our work shows that two parameters that can be detected through mobile phone sensing, namely interpersonal distance and relative body orientation, provide a solid basis for inferring social interactions. We describe how these factors are acquired using smart phones and describe our analysis. The experiments demonstrate that we can recognize not only whether a social interaction is taking place, but also the type of social interaction, distinguishing between formal and informal social settings.     

移动电话内容服务系统的设计与实现

移动电话内容服务系统允许移动用户通过移动互联技术浏览、购买和下载系统内容，是当前移动增值领域研究的热点。文中介绍了一个基于WEB和WAP技术的移动电话内容服务系统的设计与实现．并对系统的基本框架结构和主要功能模块进行了详细介绍。最后介绍了系统实现所采用的几项关键技术。     

六频段4G 手机天线设计*

设计了一款应用于4G 手机终端新型六频段天线。采用倒L 型、U 型、S 型辐射枝节获得多频特性;短路加载技 术让低于谐振频率的点达到阻抗匹配;耦合馈电方式代替传统的直接馈电以减小阻抗波动,获得较宽频带。该天线尺寸仅占 70 mm×16 mm×1.5 mm,能够覆盖手机通信的6 个频段：LTE700,CDMA/GSM850,GSM900,DCS1800,PCS1900,WCDMA/ UMTS2100。测试结果表明,在工作频段内,散射参数S11≤-6dB,电压驻波比VSWR≤3,均达到工程要求的指标,验证了设计的 可行性。     

基于Co2-Z铁氧体材料的DVB-H折叠手机天线

采用传统的固相反应法制得了一种低损耗的Z型铁氧体材料（Sr1Ba2-xBixCo2＋xFe24O41,其中x=0,0.15）,基于此材料设计得到一近似全方向辐射模式,在470～702MHz频段平均增益大于-3dB,且在此频段的辐射效率为33.5%～67.3%的小型化天线,该天线完全满足DVB-H（数字视频广播手持终端传输技术）的应用。     

手机电磁兼容测试常见问题分析及相关性能改进

针对手机电磁兼容测试中经常出现的问题,包括静电放电抗扰度试验、电快速瞬变脉冲群抗扰度试验、辐射骚扰及传导骚扰性能测试中经常发现的问题进行了分析,并提出了相应的改善手机电磁兼容性能的建议。     

Esmertec:Java技术在手机业所扮演的角色

Esmertec是业内领先的嵌入式Java解决方案供应商；Esmertec公司亚太区业务副总裁苏瑞熙在此次研讨会上介绍了Java技术在手机行业的应用情况。     

高性能移动电话音频功率放大芯片分析与设计

文章成功地将一种全差分析叠式共源共栅运算放大器结构应用于移动电话音频功率放大芯片的设计中。仿真表明，该音频功率放大芯片的电源抑制比（PSRR）在20Hz～20kHz频段始终高于60dB；尤其是在217Hz的频率上，其PSRR值达到了82dB。该设计提高了音频芯片的抗电源噪声能力，改善了通话语音质量。芯片采用华润上华（CSMC）0．6μm、3．3V／5V电源电压、2层多晶2层金属CMOS工艺制造。     

WCDMA_ GSM七频段手机射频前端的简化设计

通过分析使用SPgT天线开关实现WCDMA_ GSM双模七频段的典型手机射频电路,提出了一种采用SP4T天线开关的简化设计方案.该设计在保证性能的前提下,极大地降低了成本和器件面积.测试结果表明,该方案各项射频指标,包括发射功率、灵敏度、PVT、频率误差、相位误差、调制频谱和开关频谱等,全部符合3GPP的通信标准,完全...     

欺诈类手机恶意软件识别方法研究

提出了一种欺诈类手机恶意软件多维度检测模型,通过静态检测识别和动态运行验证的双重验证法确保恶意软件的精准识别。建立签名信息、权限、分组名等多个维度的应用软件特征识别库,根据特征库将应用软件打上正常软件和恶意软件的标签,最大限度完善现有欺诈类手机恶意软件安全防护手段,支撑第三方应用软件商店规范发展,有效提升用户对欺诈类手机恶意软件防范意识和保护手机使用安全起到积极作用。     

不同制式手机SAR值测试与分析

介绍了各种主流移动通信制式的手机样品抽样SAR值测试的情况,并对测试结果进行了分析和研究。