Steganography based on bits-modification of speech frames is a kind of commonly used method, which targets at RTP payloads and offers covert communications over voice-over-IP(Vo IP). However, direct modification on fr...Steganography based on bits-modification of speech frames is a kind of commonly used method, which targets at RTP payloads and offers covert communications over voice-over-IP(Vo IP). However, direct modification on frames is often independent of the inherent speech features, which may lead to great degradation of speech quality. A novel frame-bitrate-change based steganography is proposed in this work, which discovers a novel covert channel for Vo IP and introduces less distortion. This method exploits the feature of multi-rate speech codecs that the practical bitrate of speech frame is identified only by speech decoder at receiving end. Based on this characteristic, two steganography strategies called bitrate downgrading(BD) and bitrate switching(BS)are provided. The first strategy substitutes high bit-rate speech frames with lower ones to embed secret message, which introduces very low distortion in practice, and much less than other bits-modification based methods with the same embedding capacity. The second one encodes secret message bits into different types of speech frames, which is an alternative choice for supplement. The two strategies are implemented and tested on our covert communication system Steg Vo IP. The experiment results show that our proposed method is effective and fulfills the real-time requirement of Vo IP communication.展开更多
飞利浦集团日前与 GA 公司签署备忘录,联手开发超宽带无线通信芯片组,并将率先推出符合 IEEE802.15.3a 等新标准的芯片组,以支持标准化过程的实现。根据此备忘录,飞利浦集团和 GA 公司开发的无线通信芯片组主要针对高达到480Mbps 的高...飞利浦集团日前与 GA 公司签署备忘录,联手开发超宽带无线通信芯片组,并将率先推出符合 IEEE802.15.3a 等新标准的芯片组,以支持标准化过程的实现。根据此备忘录,飞利浦集团和 GA 公司开发的无线通信芯片组主要针对高达到480Mbps 的高比特率网络。这两家公司合作的结果将加快 UWB 芯片组的上市速度。作为一种高速度。展开更多
Y98-61409-177 9913562铜线上基于复用转换器的高比特率传输的线性和判决反馈 MIMO 均衡=Linear and decision-feedback MIMOequalization for transmultiplexer-based high bit ratetransmission over copper wires[会,英]/Louveaux,J....Y98-61409-177 9913562铜线上基于复用转换器的高比特率传输的线性和判决反馈 MIMO 均衡=Linear and decision-feedback MIMOequalization for transmultiplexer-based high bit ratetransmission over copper wires[会,英]/Louveaux,J.&Vandendorpe,L.//1998 Proceedings of the InternationalZurich Seminar on Broadband Communications.展开更多
0107969一种独立机型的 H.324终端实现[刊]/方红波//电视技术.—2001,(1).—30～32(L)提出了 H.324终端的一种实现方案,并对所实现的终端硬件结构和软件结构进行了分析,描述了系统软硬件的关系以及系统核心模块的实现。参5Y2001-62644-1...0107969一种独立机型的 H.324终端实现[刊]/方红波//电视技术.—2001,(1).—30～32(L)提出了 H.324终端的一种实现方案,并对所实现的终端硬件结构和软件结构进行了分析,描述了系统软硬件的关系以及系统核心模块的实现。参5Y2001-62644-17 0107970移动与基地台的新天线超高比特率数据传输用的新蜂房式无线系统原理=New cellular wireless system con-cept for very high bit rate data transmission with smartantennas at the mobile and base station[会,英]/展开更多
基金Project(2011CB302305)supported by National Basic Research Program(973 Program)of ChinaProjects(61232004,61302094)supported by National Natural Science Foundation of China+2 种基金Project(ZQN-PY115)supported by Promotion Program for Young and Middle-aged Teacher in Science and Technology Research of Huaqiao University,ChinaProject(JA13012)supported by Education Science Research Program for Young and Middle-aged Teacher of Fujian Province of ChinaProject(2014J01238)supported by Natural Science Foundation of Fujian Province of China
文摘Steganography based on bits-modification of speech frames is a kind of commonly used method, which targets at RTP payloads and offers covert communications over voice-over-IP(Vo IP). However, direct modification on frames is often independent of the inherent speech features, which may lead to great degradation of speech quality. A novel frame-bitrate-change based steganography is proposed in this work, which discovers a novel covert channel for Vo IP and introduces less distortion. This method exploits the feature of multi-rate speech codecs that the practical bitrate of speech frame is identified only by speech decoder at receiving end. Based on this characteristic, two steganography strategies called bitrate downgrading(BD) and bitrate switching(BS)are provided. The first strategy substitutes high bit-rate speech frames with lower ones to embed secret message, which introduces very low distortion in practice, and much less than other bits-modification based methods with the same embedding capacity. The second one encodes secret message bits into different types of speech frames, which is an alternative choice for supplement. The two strategies are implemented and tested on our covert communication system Steg Vo IP. The experiment results show that our proposed method is effective and fulfills the real-time requirement of Vo IP communication.
文摘飞利浦集团日前与 GA 公司签署备忘录,联手开发超宽带无线通信芯片组,并将率先推出符合 IEEE802.15.3a 等新标准的芯片组,以支持标准化过程的实现。根据此备忘录,飞利浦集团和 GA 公司开发的无线通信芯片组主要针对高达到480Mbps 的高比特率网络。这两家公司合作的结果将加快 UWB 芯片组的上市速度。作为一种高速度。
文摘Y98-61409-177 9913562铜线上基于复用转换器的高比特率传输的线性和判决反馈 MIMO 均衡=Linear and decision-feedback MIMOequalization for transmultiplexer-based high bit ratetransmission over copper wires[会,英]/Louveaux,J.&Vandendorpe,L.//1998 Proceedings of the InternationalZurich Seminar on Broadband Communications.
文摘0107969一种独立机型的 H.324终端实现[刊]/方红波//电视技术.—2001,(1).—30～32(L)提出了 H.324终端的一种实现方案,并对所实现的终端硬件结构和软件结构进行了分析,描述了系统软硬件的关系以及系统核心模块的实现。参5Y2001-62644-17 0107970移动与基地台的新天线超高比特率数据传输用的新蜂房式无线系统原理=New cellular wireless system con-cept for very high bit rate data transmission with smartantennas at the mobile and base station[会,英]/
