盐城地面数字电视发射传输网络系统分析

主要以广播电视信号的流程为顺序,从信号的传输、编码器的设置、发射机的组成、激励器的设置、天馈线系统的选择和地面数字电视信号的接收6个方面,对系统的组成做了详细介绍。在介绍各个环节的同时,根据运行、维护经验,针对该部分设备中的不同选项对发射和接收会产生怎样的影响做了详细说明。     

地面数字电视信号与GPS相结合的定位系统

为了解决在城市楼宇间可见GPS卫星常常不足4颗而导致无法定位的问题,通过使用地面数字电视信号,实现了这种恶劣环境下的成功定位.而当GPS卫星数大干4颗时,利用数字地面电视信号可以改善GDOP,提高定位精度.介绍了系统的工作原理,通过计算机软件仿真实现了地面数字电视信号的模拟及单点和多点的移动定位,结果表明通过地面数字电视和GPS结合的定位系统可以提高定位精度,解决CPS卫星不足的问题.     

数字卫星电视接收天线仰角方位角极化角调试探讨

数字电视正以迅猛之势发展,目前数字电视信号主要是通过卫星传输,数字卫星电视信号的接收方法与模拟卫星电视信号的接收方法相同,利用室外抛物面状天线将数字卫星电视信号——电磁波接收下来,但由于数字电视信号的特点,接收数字电视卫星信号时的“寻星”过程远比接收模拟卫星电视信号困难得多,为此对数字卫星电视接收天线仰角、方位角、极化角的调试进行探讨。     

一种新的数字阵列雷达接收机技术

高速ADC和先进DSP器件的进展使数字波束形成智能天线的实现成为现实。在传统的M单元天线阵系统中,每一单元都有各自的接收通道和ADC,设备量大。文中提出了一种适合于多通道数字阵列雷达接收系统的新型数字接收机结构,其主要思想是基于多个不同信号的带通采样原理实现数字阵列雷达接收机,新接收机结构使IF接收通道和基带采样ADC显著减少,功耗大大降低。阐述了数字阵列接收的数据模型和工作原理,分析了多信号带通采样信号频率和采样率的关系,给出了采样率选取的约束条件。新接收机在降低设备量的同时,还减小了接收系统通道间幅一相不一致性失真。     

A Novel Receiver Architecture for DBF Antenna Array

The developments of the high speed analog to digital converters （ADC） and advanced digital signal processors （DSP） make the smart antenna with digital beamforming （DBF） a reality. In conventional M-elements array antenna system, each element has its own receiving channel and ADCs. In this paper, a novel smart antenna receiver with digital beamforming is proposed. The essential idea is to realize the digital beamforming receiver based on bandpass sampling of multiple distinct intermediate frequency （IF） signals. The proposed system reduces receiver hardware from M IF channels and 2M ADCs to one IF channel and one ADC using a heterodyne radio frequency （RF） circuitry and a multiple bandpass sampling digital receiver. In this scheme, the sampling rate of the ADC is much higher than the summation of the M times of the signal bandwidth. The local oscillator produces different local frequency for each RF channel The receiver architecture is presented in detail, and the simulation of bandpass sampling of multiple signals and digital down conversion to baseband is given. The principle analysis and simulation results indicate the effectiveness of the new proposed receiver.     

浅析地面无线数字电视广播系统建设

地面无线数字电视发展迅速,特别是随着国标的出台,地面无线数字电视的发展将迎来新一轮快速发展的时代.发展地面无线数字电视,是加速推进广播电视“村村通”工程的有效方式.首先概述了地面无线数字电视,然后介绍地面无线数字电视的优势,最后从建设需求、标准选择、系统结构和组成、信号覆盖情况等多方面,阐述新余市广播电视台的地面数字电视广播系统建设情况.     

Hybrid MUSIC Dolph–Chebyshev algorithm for a smart antenna system

This paper presents practical design of a smart antenna system based on direction‐of‐arrival estimation and Dolph–Chebyshev beam forming. Direction‐of‐arrival estimation is based on the multiple signal classification algorithm for identifying the directions of the source signals incident on the sensor array comprising the smart antenna system. The smart antenna system design involves a hardware part, which provides real data measurements of the incident signals received by the sensor array. This paper presents the Dolph–Chebyshev method for the synthesis and design of antenna arrays with periodic element spacing. A Field‐Programmable Gate Array implementation is presented for an antenna array application employing digital beamforming. The array comprises 10 elements, equal in number receiving radio frequency and intermediate frequency components, as well as a Spartan‐3E Field‐Programmable Gate Array‐based unit, which is responsible for the control of the array. Low‐cost and switched‐beam, and fully adaptive antenna array suitable for 2‐GHz applications are proposed in this paper. Copyright © 2013 John Wiley & Sons, Ltd.     

基于DTMB的多屏互动业务技术模式探析

地面无线广播技术一直是广播电视传输覆盖、实施公共服务的主要手段之一,面对智能终端的快速普及,本文提出了一种基于地面数字电视广播的多屏互动业务技术模式,能够充分利用现有宝贵的无线频率资源,实现视频服务由面向电视机或接收机单一终端到面向电视机、笔记本电脑、平板电脑、智能手机等多终端的扩展,实现地面数字电视广播的跨屏融合应用。     

关于乡镇模数转换的几点思考

目前全国的城市社区都已经普及了数字电视,但在一些偏远的乡镇,还在使用一些天线、卫星电视接收器等接收模拟电视节目。利用天线等接收设备,只能收看到为数不多的电视频道,在一些特别偏远的地区,甚至接收不到电视信号,更谈不上数字电视,为此就乡镇的模数转换进行讨论,并提出一些建议和想法。     

NICAM728数字声电视广播

NICAM 728数字声电视广播系统是由BBC研究开发的,它可用于I、B、G、H等制式的电视系统,除传送电视图像和模拟调频单声信号外,还可传送两路高质量数字编码声音信号。目前,已有不少国家和地区采用了NICAM 728系统,一些国家也正在研究并考虑NICAM 728的应用。本文详细介绍了NICAM 728基带编码方案,调制、传输参数,以及系统的总体轮廊。     

石嘴山地区地面数字电视单频网实施方案与收视报告

介绍宁夏石嘴山地区地面数字电视单频网示范网工程的具体实施方案，说明影响无线发射覆盖范围的因素以及发射天线高度、型号、发射机等参数的选定，并具体说明神州SHDMBT-28037 O高清地面数字机顶盒的实地接收情况。     

地面数字电视系统

近年来,广播电视领域正处在从模拟电视向数字电视转化过程中,在经历了数年的努力后,我国的数字地面电视广播传输系统国家标准已经成熟并公布。在此介绍了地面数字广播的标准,并对其系统组成进行了阐述。     

The Japanese scene [digital HDTV]

Japan is the only country, so far, to be actually broadcasting high-definition television services. MUSE (multiple sub-Nyquist sampling encoding) is the basis for systems applying bandwidth compression to the transmission of both analog and digital signals. It encodes a signal of 1125 lines and 60 fields per second, a high-definition television (HDTV) signal into an 8-Hz bandwidth. Experimental MUSE broadcasts started in 1990 and have continued ever since. Meanwhile, work has been in progress in areas other than MUSE. Enhanced-definition television, a terrestrial system, is entering its second generation. Integrated digital broadcasting looks to spin many services into a single digital thread for transmission over a single channel. Digital sound broadcasting and hierarchical television transmission will also come in for consideration. The MUSE system depends on digital technology for signal processing, but the HDTV signal that is broadcast is analog, the outcome of frequency modulation     

数字电视机顶盒的组成原理及设计方案研究

数字电视机顶盒是传统模拟电视时代向数字电视时代过度的必然选择,它由硬件平台、软件平台和智能卡三部分组成,主要完成数字电视信号的解调、解码和表现等功能.分析其组成原理的基础上,提出了数字电视机顶盒的一种优化设计方案.     

Adjacent and co-channel interference disturbances from a digitalterrestrial television signal (COFDM-8K system) on analogue PAL systems

This paper presents some results of a measurement campaign in the service area of the digital terrestrial television (COFDM-8K system) experimental network of Madrid (Spain). The purpose of this survey has been to determine the degradation suffered by analogue PAL-G signals in the presence of co-channel and adjacent channel digital emissions. The result is a curve that estimates the protection ratios between analogue and digital received power levels     

数字电视地面广播系统信息解析算法

数字电视地面广播系统提供了多种传输模式,用以满足不同的业务和不同的组网环境对信号质量的要求,从而实现运营的灵活性和经济性,这些模式参数都通过系统信息来指示。准确地进行系统信息解析是系统终端实现正常接收的关键,提出了一种数字电视地面广播的系统信息解析算法。实验结果表明,该算法具有很高的可靠性,其与系统最低载噪比门限之间的裕度大于1 dB,可以有效保证系统终端的正常接收。     

Design parameter analysis for ATSC 1.0 single frequency networks based on receiver multipath handling performance

This work proposes suitable network configurations for single frequency networks (SFNs) with ATSC 1.0 based on network coverage calculations and the laboratory multipath handling performance of commercial receivers. SFNs are widely used for delivering terrestrial digital television services because of their efficient use of the spectrum. In Mexico the analogue television transmissions switch-off occurred on 31 December 2016. Thus it is expected the adopted ATSC 1.0 system will be in force for the next several years despite the recent standardization of the ATSC 3.0 system. As ATSC 1.0 uses 8-VSB modulation the multipath handling capability of receivers is critical for the design of SFNs. The presented network planning results help develop technical normativity for implementing SFNs in Mexico and other countries that use ATSC 1.0. SFNs with transmitter separation up to 130 km are fully covered for outdoor reception mainly due to the directivity of the receiving antenna. Moreover for indoor reception at least 70% of an SFN coverage area can be achieved with a transmitter separation of up to 60 km depending on the radiated power and the transmitter antenna height.     

浅谈智能天线与移动电视

阐述了智能天线技术和移动电视技术,提出了把智能天线技术应用于移动电视,对已有的移动电视方案进行了优缺点比较,指出了今后的研究方向.     

基于FPGA的智能天线数字波束形成设计

通讯系统的频谱资源日益紧张,智能天线是增加系统容量最有希望的解决方法之一。智能天线的数字波束形成是通讯系统实现空分多址的基础。在介绍了数字波束形成的基本原理基础上,提出了一种基于FPGA实现的实时数字波束形成方法,并使用嵌入式逻辑分析仪进行了实测分析。实验结果表明,该数字波束形成设计能实时调整各通道的幅度和相位,实现数字波束形成。     

CDMA系统智能天线的设计与仿真

智能天线是在软件无线电基础上提出的天线设计新概念,是数字多波束形成技术与软件无线电相结合的产物,它对提高无线通信系统容量具有巨大潜力。提出了在CDMA系统实际应用中LMS智能天线的结构,进行了性能分析并给出了仿真结果。