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| Articles
by
Zheming Lu |
Total Records (
2 ) for
Zheming Lu |
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Jixin Liu
and
Zheming Lu
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In this study, a covert communication applying the vector quantization based information hiding algorithm and the Public Switching Telephone Network (PSTN) is implemented. The system aims at offering good security of the secret binary image message and the real-time performance that is very important for the speech calling of the telephone service. Therefore, we adopt a simple and effective encryption method for the secret binary image message prior to the embedding process. The embedding position is also protected by using a secret key. By using these methods, the requirement of short-term protection in the bursting phone call communication for the secret binary image message and the real-time encryption are both fulfilled. Furthermore, an information hiding algorithm based on vector quantization is proposed and the advantage of it is discussed. We evaluate the system with the ITU-T G.729a standard speech codec in StegoPhone, which is our platform for research on covert communication technology via PSTN. The experimental results show that our method has negligible hearing effects on the conversation speech and meet the requirement of the real-time calling conversation communication via PSTN. |
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Qin Zheng
,
Yongheng Shang
,
Zhiyu Wang
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Jiarui Liu
,
Min Zhou
,
Xiuqin Xu
,
Liping Wang
,
Hua Chen
,
Zhengliang Huang
,
Zheming Lu
and
Faxin Yu
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In this study, an automated testing system for a reflection-type Vector Modulators (VM) comprised of a Field Programmable Gate Array (FPGA) and a LabVIEW based testing software is presented. The testing system with a friendly Graphic User Interface (GUI) is able to evaluate all the functionality of the VMs and allows the user to test the FPGA module step-by-step or to automate the testing in a sequential way. In case of multiple VM testing, all the VMs can be tested in one time by automatically sending the control commands to manipulate the bias voltage of each VM. Only one FPGA based hardware is needed in the testing system for the bias voltage control. This present testing system is highly efficient for VM testing and can be easily generalized to the testing of other VMs. |
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