非合作通信中OFDM系统盲均衡的方法  

Enterprise Internal Forum Copyright Protection Technology Research Based on QR Code

作　　者：姚亦韬 陈志刚[1,2] 吴嘉[1,2] 

机构地区：[1]中南大学软件学院,长沙410075 [2]“移动医疗”教育部-中国移动联合实验室,湖南长沙410083

出　　处：《电脑与信息技术》2016年第3期1-5,10,共6页Computer and Information Technology

基　　金：国家自然科学基金资助项目（61271299）；国家博士后科学基金资助项目（2014M562372）；国家“863”高技术研究发展计划资助项目（2007AA01Z288）；高等学校学科创新引智计划资助项目（B08038）

摘　　要：针对传统的正交频分复用（OFDM）系统盲均衡方法中存在接收数据短、收敛速度慢的问题，提出了一种基于符号间干扰变步长迭代的多模混合算法的 OFDM 系统盲均衡新方法。该方法首先将接收数据进行了分段复用，然后将修正的恒模算法与判决引导算法进行多模混合，并在均衡过程中采用了基于符号间干扰的变步长迭代方式。仿真结果表明，在非合作通信中，该方法不但加快了收敛速度并且保证了稳态收敛性能。Focused on the issue of the protection of enterprise internal forum＇s information, an information hiding system based on QR Code and block DCT picture fusion algorithm was proposed, which at first transformed core information of webpage to image and converted user＇s id to QR Code, and then simplify and isolated QP. Code as watermark, and fusion all watermark information into low-frequency part of non-blank DCT block, and finally proposed two strategies to optimize embedding efficiency and to correct extracted watermark image. The issue that information protection when users simply parse texts or capture screen which cannot be solved by the information hiding algorithms based on webpage source code, and the issue that information capacity is limited and information protection when users simply parse texts cannot he solved by the algorithms based on text formatting are both solved by this technology. Experiments and attack simulation indicated that this optimized system shows better user experience and low perception, and maintains a satisfactory robustness under normal attacks.

关 键 词：盲均衡 正交频分复用 多模混合 符号间干扰 非合作通信 

分 类 号：TN929.5[电子电信—通信与信息系统]