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Interference to DTTV reception by first adjacent channels 总被引:1,自引:0,他引:1
Planning for digital terrestrial television (DTTV) service in a crowded spectrum requires that power limits be placed on all adjacent channels, and in particular on first adjacent channels. Realistic power limits based on intermodulation products generated at the receiver by the desired and undesired signals are proposed. The proposed limits are a function of the fundamental power in the desired and undesired channels and the receiver's 3rd order Intercept Point (IP/sub 3/). The analysis shows that in many markets present Desired/Undesired (D/U) ratios underestimate the expected interference from strong signals, and that the receiver's IP/sub 3/ should be at least 16 dBm for the dynamic range expected in the U.S. Additional improvement can be attained by minimizing the sideband splatter generated by the transmitter of the first adjacent channel and by designing a "smart" front-end receiver. 相似文献
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我于 2 0 0 1年 11月 2 6日~ 12月1日参加了亚太广播发展学院AIBD在泰国曼谷举办的为期 5天的数字地面电视 DVB T频率规划培训。时间虽然很短 ,但信息量很大。培训主要分为两部分内容 :第一部分是由 AIBD的 CART SEN先生讲述数字电视技术的主要特点及与其模拟技术的区别 ,涉及视频信号的数字化、信源编码、多工复用、信道编码及加密、解密过程。内容侧重于DVB T标准 ;第二部分是介绍频率规划的方法和计算工具 ,由德国 L & S公司的 MORGEN先生介绍该公司的频率规划软件。主要内容包括 DVB T的规划参数、干扰分析及对一些数字… 相似文献
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Angueira P. Ma Velez M. de la Vega D. Prieto G. Guerra D. Matias J.M. Ordiales J.L. 《Broadcasting, IEEE Transactions on》2004,50(1):42-48
This paper presents a field measurement campaign developed to study the influence of the special features of a Single Frequency Network (SFN) reception in the C/N thresholds applicable to portable DTV reception. The measurements presented here were performed inside coverage areas of the nationwide SFN which broadcasts DTV (COFDM 8 K mode) services in Spain. The aim of this paper is to present some network planning reference values for portable reception in urban environments where both multipath and multiple transmitter reception have to be taken into account to ensure a good quality of service. 相似文献
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《Broadcasting, IEEE Transactions on》2004,50(1):71-75
This paper describes an array which is concealable with a TV set or set-top box. The array is made of small active antennas which can provide space and polarization diversity by phase switching alone. The array can be manually or automatically controlled to maximize the signal-noise ratio of the desired channel and minimize the interference from undesired channels. The combination of automatically adjustable dual diversity and small physical size makes this device suitable for mobile reception. 相似文献
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随着广播电视无线数字化覆盖工程实施的逐步深入,地面数字电视频率规划工作已成为各级广播电视管理和技术部门面对的重要课题.本文通过辽宁单频网规划方案的分析介绍,针对规划中遇到的问题展开研究,并提出了解决方法,为其他省市的单频网规划提供了参考. 相似文献
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本文介绍了地面数字电视及数字移动多媒体广播发射系统的基本组成、系统覆盖等相关技术;详细论述了构成发射系统对主要设备-数字电视发射机的技术要求、数字发射机技术的现状、设计理念和采用的新技术,供各级电视台作为模拟电视数字化的参考。 相似文献
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Angueira P. Velez M.M. De La Vega D. Arrinda A. Landa I. Ordiales J.L. Prieto G. 《Broadcasting, IEEE Transactions on》2003,49(1):81-86
The paper presents the measurement results obtained in an extensive field test campaign developed in two large cities of Spain (Madrid and Bilbao) with the aim of characterizing the portable outdoor reception of digital terrestrial television (COFDM - coded orthogonal frequency division multiplexed) and continue the studies carried out by the authors during the past years. 相似文献
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Barber P.C. Martin P.M. Moore T.A. 《Electronics & Communication Engineering Journal》1998,10(5):221-228
The case for using radio in the local loop has been well documented, with obvious attractions for both developed and developing countries. Although trial systems of the various technologies exist in many countries throughout the world, operational networks are fewer in number. In June 1996, Ionica launched its service as a public telecommunications operator (PTO) in the UK, using radio in the local loop. This paper describes the experience gained in planning and operating that network. The importance of the access network in maintaining a truly competitive market is discussed. Radio propagation issues are considered, for these play a significant role in the strategic planning of the network, and then in its operational performance. The paper describes the special procedures, and the hardware and software systems, which are required for planning, building and managing the network 相似文献
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Guerra G. Angueira P. Velez M.M. Guerra D. Prieto G. Ordiales J.L. Arrinda A. 《Broadcasting, IEEE Transactions on》2005,51(2):171-179
This paper presents a study developed to obtain several parameters of the small scale fading of the wideband propagation channel applied to the portable and mobile reception of Digital Terrestrial Television (DTV) services in an urban Single Frequency Network (SFN) environment. The study is focused on the calculation of some relevant parameter values related to the multipath behavior of the channel, using field data collected in a real network. Mean values for the Root mean square Delay Spread (RDS) and the frequency domain Level Crossing Rate (LCR) are given, together with an analysis of the influence of the specific environment and network (SFN) features. 相似文献
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