Response Time in Data Broadcast Systems: Mean,Variance and Tradeoff

Data broadcast has been suggested as a promising method of information dissemination [2,33]. In such an environment, the information server cannot afford to serve the requests from a large population of users individually. Instead, the server uses a broadcast channel to deliver information to all users. A single transmission of a data item satisfies all pending requests for that item. The response time of a request depends on the broadcast time of the desired data item, which is scheduled by the server according to the overall demands for various data items. Therefore, the response time may vary in a large range. We argue that, in addition to mean response time, the variance of response time should also be taken into account by the broadcast scheduler. In this paper, we address the issue of variance optimization in regard to response time. Building on our previous research on mean response time optimization, we propose an algorithm which can minimize the variance of response time. Furthermore, we evaluate an algorithm that facilitates a tradeoff between the mean and variance of response time. Numerical examples that illustrate the performance of our algorithms are also presented.     

调幅广播附加信息的传输

在调幅声音广播中,除了传送正常的广播节目外,还可兼容传送其它附加信息,提供新的服务。本文综述了近年来国外这项技术的研究发展概况,介绍了传送附加信息的方法、基本原理及应用,并讨论了其它有关问题。     

硬盘机在消费电子产品中的应用

随着消费电子产品数字化与网络化的快速进展,硬盘机在这个产品领域的应用正在扩展之中。从最初的个人录像机到现今的高级机顶盒等等,硬盘机的应用极大地丰富了这类产品的功能,并在一定程度上改变了人们享受节目内容的方式。     

无线电数据系统

欧广联(EBU)的无线电数据系统(RDS),是为在FM立体声广播中兼容传输附加信息而设计的。本文介绍了RDS的研究、发展与应用概况,阐述了RDS信号的产生、可传输的信息及其编码方法、数据格式和RDS接收机。     

三峡左厂电站及大坝火灾自动报警控制系统配置

概述了电站及大坝中火灾自动报警系统的总体构成及功能、探测器的选配、消防联动设备及控制要求，分析了三峡左厂电站及大坝火灾自动报警系统的特点。     

基于IP网络的景观绿道公共广播设计

结合某景观长廊工程实例,分析景观绿道公共广播的特点,比选广播系统方案：模拟广播、数字广播、IP广播系统,最终选择了IP广播系统。并介绍IP广播方案下该景观长廊广播系统的具体设计方案,总结基于IP网络的景观绿道公共广播具有的优势。     

Compressive image broadcasting in MIMO systems with receiver antenna heterogeneity

In this work we consider image delivery in MIMO broadcast networks with diverse channel quality and varying numbers of antennas across receivers. In such systems, performance is normally constrained by the weakest users with either a low channel SNR or only a single receive antenna. To address both dimensions of heterogeneity, we propose a new analog image delivery system that adapts seamlessly along both dimensions simultaneously. Our sender scales the DWT coefficients according to a power allocation strategy, and generates linear combinations of the coefficients using compressive sensing (CS), before transmitting them with amplitude modulation. On the receiving side, the received physical layer symbols are passed directly to the source decoder without conventional MIMO decoding, and the DWT coefficients are recovered using a CS decoder.There are two main contributions of our system. First, integrating CS into MIMO transmission ensures that the reconstructed image quality at the receivers is commensurate with both the channel SNR and the MIMO channel dimension. Second, we introduce a power allocation strategy to achieve a performance tradeoff between receivers with different antenna numbers. Experimental results show that the proposed system outperforms both the analog reference SoftCast and the conventional digital system known as HM-STBC. The average gain is 2.92 dB over SoftCast for single-antenna users and 1.53 dB over HM-STBC for two-antenna users.     

电视综艺节目环绕声直播的声音创作观(下)

"电视综艺节目环绕声直播的声音创作观(上)"就哈里斯先生在环绕声电视综艺节目直播的声音创作实践与观念,讲述了格莱美颁奖典礼电视直播混音二十年的发展历程与变革。"电视综艺节目环绕声直播的声音创作观(中)"和"电视综艺节目环绕声直播的声音创作观(下)"分别回顾了在中影基地进行杜比培训期间,同大师关于电视环绕声创作的交流,以及对电视综艺节目环绕声直播的声音创作观念的若干思考。     

DRA分层音频编码技术

提出了一种与DRA编码算法兼容的分层音频编码算法,其中环绕声分层编码采用了声道分类方式,而单声道/立体声分层编码则以残差再编码作为增强层的框架。分析和测试结果表明该DRA分层编码算法能够提供较好的声音质量,可作为信源编码与信道编码和分层调制技术完美结合应用于我国数字音频广播。     

传统广播与移动宽带融合网络的4种方案解析

长期以来,地面电视广播与移动通信有着截然不同的业务形态、管制方式、产业链结构、网络架构、终端形态等。而当下,随着业务层面、终端层面等的融合,传统经典广播网络与移动宽带网络相融合已成发展趋势。介绍了国内外所提出的4种融合型网络解决方案(基于UHF频段的4G电视广播、叠加型网络、共用广播系统、NGB-W)及其研究现状。