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31.
近年来十分火热的搜索映射式无载体信息隐藏虽具有一定的鲁棒性,但其隐藏容量较低、传输负载大且算法复杂度高。针对以上问题,该文章提出一种基于Arnold置乱和离散余弦变换(discrete cosine transform,DCT)编码的无载体信息隐藏方法。该算法先对图片进行Arnold置乱,再对DCT后的低频系数进行编码,接着更换置乱参数来构建索引表。选择索引表中与秘密信息相同的编码值所对应的参数构建候选队列,最后筛选出鲁棒性强的参数作为密钥发送给接收方。实验结果表明,该方法与现有方法相比大大提高了嵌入容量,拥有更强的抗JPEG压缩性能。并且减少了传输负载,算法简捷,具有较强的应用价值。 相似文献
32.
Jesús Gutirrez-Gutirrez Fernando M. Villar-Rosety Xabier Insausti Marta Zrraga-Rodríguez 《Entropy (Basel, Switzerland)》2022,24(5)
In the era of the Internet of Things, there are many applications where numerous devices are deployed to acquire information and send it to analyse the data and make informed decisions. In these applications, the power consumption and price of the devices are often an issue. In this work, analog coding schemes are considered, so that an ADC is not needed, allowing the size and power consumption of the devices to be reduced. In addition, linear and DFT-based transmission schemes are proposed, so that the complexity of the operations involved is lowered, thus reducing the requirements in terms of processing capacity and the price of the hardware. The proposed schemes are proved to be asymptotically optimal among the linear ones for WSS, MA, AR and ARMA sources. 相似文献
33.
针对激光目标指示器在进行多目标指示时,激光束之间有相互干扰的缺点,提出了一种基于walsh矩阵的多目标指示激光束编码方案.walsh矩阵的每一行或每一列都相互正交,是伪随机序列,自相关值最大,而互相关值为0.哈达马序walsh矩阵的结构特点使得可编程电路很容易生成该矩阵的某一行或某一列.通过简单的数值设置,可以让不同的目标指示器生成Walsh矩阵的不同行,即得到不同的伪随机序列.利用伪随机序列的相关特性,使用walsh矩阵的不同行对激光束进行编码,则可消除激光束间的串扰.该方案具有抗干扰能力强、保密性好、易于实现等优点,也适用于多路遥控系统. 相似文献
34.
35.
Future wired-wireless multimedia networks require diverse quality-of-service (QoS) support. To this end, it is essential to
rely on QoS metrics pertinent to wireless links. In this paper, we develop a cross-layer model for adaptive wireless links,
which enables derivation of the desired QoS metrics analytically from the typical wireless parameters across the hardware-radio
layer, the physical layer and the data link layer. We illustrate the advantages of our model: generality, simplicity, scalability
and backward compatibility. Finally, we outline its applications to power control, TCP, UDP and bandwidth scheduling in wireless
networks.
The work by Q. Liu and G. B. Giannakis are prepared through collaborative participation in the Communications and Networks
Consortium sponsored by the U.S. Army Research Laboratory under the Collaborative Technology Alliance Program, Cooperative
Agreement DAAD19-01-2-0011. The U.S. Government is authorized to reproduce and distribute reprints for Government purposes
notwithstanding any copyright notation thereon. The work by S. Zhou is supported by UConn Research Foundation internal grant
445157.
Qingwen Liu (S’04) received the B.S. degree in electrical engineering and information science in 2001, from the University of Science
and Technology of China (USTC). He received the M.S. degree in electrical engineering in 2003, from the University of Minnesota
(UMN). He currently pursues his Ph.D. degree in the Department of Electrical and Computer Engineering at the University of
Minnesota (UMN).
His research interests lie in the areas of communications, signal processing, and networking, with emphasis on cross-layer
analysis and design, quality of service support for multimedia applications over wired-wireless networks, and resource allocation.
Shengli Zhou (M’03) received the B.S. degree in 1995 and the M.Sc. degree in 1998, from the University of Science and Technology of China
(USTC), both in electrical engineering and information science. He received his Ph.D. degree in electrical engineering from
the University of Minnesota, 2002, and joined the Department of Electrical and Computer Engineering at the University of Connecticut,
2003.
His research interests lie in the areas of communications and signal processing, including channel estimation and equalization,
multi-user and multi-carrier communications, space time coding, adaptive modulation, and cross-layer designs. He serves as
an associate editor for IEEE Transactions on Wireless Communications since Feb. 2005.
G. B. Giannakis (Fellow’97) received his Diploma in Electrical Engineering from the National Technical University of Athens, Greece, 1981.
From September 1982 to July 1986 he was with the University of Southern California (USC), where he received his MSc. in Electrical
Engineering, 1983, MSc. in Mathematics, 1986, and Ph.D. in Electrical Engineering, 1986. After lecturing for one year at USC,
he joined the University of Virginia in 1987, where he became a professor of Electrical Engineering in 1997. Since 1999 he
has been a professor with the Department of Electrical and Computer Engineering at the University of Minnesota, where he now
holds an ADC Chair in Wireless Telecommunications.
His general interests span the areas of communications and signal processing, estimation and detection theory, time-series
analysis, and system identification -- subjects on which he has published more than 200 journal papers, 350 conference papers
and two edited books. Current research focuses on transmitter and receiver diversity techniques for single- and multi-user
fading communication channels, complex-field and space-time coding, multicarrier, ultra-wide band wireless communication systems,
cross-layer designs and sensor networks.
G. B. Giannakis is the (co-) recipient of six paper awards from the IEEE Signal Processing (SP) and Communications Societies
(1992, 1998, 2000, 2001, 2003, 2004). He also received the SP Society’s Technical Achievement Award in 2000. He served as
Editor in Chief for the IEEE SP Letters, as Associate Editor for the IEEE Trans. on Signal Proc. and the IEEE SP Letters, as secretary of the SP Conference Board, as member of the SP Publications Board, as member and vice-chair of the Statistical
Signal and Array Processing Technical Committee, as chair of the SP for Communications Technical Committee and as a member
of the IEEE Fellows Election Committee. He has also served as a member of the IEEE-SP Society’s Board of Governors, the Editorial
Board for the Proceedings of the IEEE and the steering committee of the IEEE Trans. on Wireless Communications. 相似文献
36.
印制电路板应变测量用应变片选用方法研究 总被引:2,自引:0,他引:2
应变测量由于它的众多优点在电子产品可靠性领域的应用越来越广泛,但电阻应变片的类型繁多,功能各异,以至于使用者很难找到满足自己测试目的和测试环境的应变片。文章提出的选用方法从应变片种类、敏感栅材料、基底材料、电阻值、尺寸、敏感栅结构型式和测试量境温度等方面,综合考虑并结合生产商的应变片型号编码系统,可以快捷地找到适合的印制电路板应变测量用应变片,同时针对绝大多数电子制造商不具备专业应变片检定设备的现实,介绍了一套简单可行的应变片检定工具,并通过两个实例证明该检定方法的可行性。 相似文献
37.
网络编码打破了传统的独立比特不能再被压缩的传统理论,该理论指出在多播系统中,通过允许中间节点对数据进行编码组合,可以进一步的提高网络吞吐量。现今,虽然网络编码在抗搭线窃听、抗拜占庭攻击和网络纠错码等网络安全领域已展开应用,但仍需进一步发展。针对这一现象,这里对网络编码的安全问题进行综述并加以分析,同时针对网络编码较容易受到的一种攻击——网络污染攻击,指出全同态加密方案在解决该问题上的应用。 相似文献
38.
39.
提出了一种无线mesh网中最小网络编码代价低时延多播路由协议(MNCLDMR, minimal network coding and low delay multicast routing)。MNCLDMR的目标是选择合适的网络编码节点,最小化网络编码代价,降低网络时延。MNCLDMR主要思想是引入拓扑关键节点和网络编码关键节点的概念,以下一跳的节点是否是网络编码关键节点或拓扑关键节点作为路由判据,采用MNCLD算法构造多播树。仿真结果表明,MNCLDMR可以达到预定目标,合理形成网络编码机会,能实现最小网络编码代价低时延多播路由。 相似文献
40.
基于IFS分形理论的信源编码技术的研究 总被引:5,自引:1,他引:5
本文首次系统地研究了基于IFS分形理论的信源压缩编码与传统方法的关系。 相似文献