A new metric for performance evaluation of transport control protocol(TCP) overwireless channels based on the interference-limited characteristics of code division multipleaddress(CDMA) system is proposed.According to...A new metric for performance evaluation of transport control protocol(TCP) overwireless channels based on the interference-limited characteristics of code division multipleaddress(CDMA) system is proposed.According to the new metric,the performance of TCP over CDMAcorrelated channel for different protocol parameters and different versions is investigated.The resultsshow that appropriate selection of protocol parameters and packet error rate(PER) operation point canimprove significantly the capacity of packet-switched CDMA-based network.展开更多
An optical PPM CDMA communication system with an optical hard limiter in front of the correlator of a receiver is proposed in order to reduce multi user interference. The performance of the system is evaluated ...An optical PPM CDMA communication system with an optical hard limiter in front of the correlator of a receiver is proposed in order to reduce multi user interference. The performance of the system is evaluated when the effects of both multi user interference and photo detector shot noise are considered. An upper bound on the bit error rate is derived. The comparison of the performance of the above receiver with that of the optical PPM CDMA system without an optical hard limiter is made. Simulation results show that the performance of the system with an optical hard limiter is superior to that of the conventional one.展开更多
In this paper, a new image encryption scheme is presented based on time-delay chaos synchronization. Compared with existing methods, a new method is pro- posed and a lot of coupled items can be taken as zero items to ...In this paper, a new image encryption scheme is presented based on time-delay chaos synchronization. Compared with existing methods, a new method is pro- posed and a lot of coupled items can be taken as zero items to simplify the whole system. A simple linear controller is introduced to realize time-delay chaos synchronization and image encryption. The positions of the image pixels are firstly shuffled and then be hidden in the cartier image. The address codes of the chaotic sequences are adopted to avoid the disturbances induced by the initial value and computer accuracy error. Simulation results for color image are provided to illustrate the effectiveness of the proposed method. It can be seen clearly that the system can converge quickly and the image can be encrypted rapidly.展开更多
To deal with the junk e-mail problem caused by the e-mail address leakage for a majority of Internet users, this paper presents a new privacy protection model in which the e-mail address of the user is treated as a pi...To deal with the junk e-mail problem caused by the e-mail address leakage for a majority of Internet users, this paper presents a new privacy protection model in which the e-mail address of the user is treated as a piece of privacy information concealed. Through an interaction pattern that involves three parties and uses an e-mail address code in the place of an e-mail address, the proposed model can prevent the e-mail address from being leaked, thus effectively resolving the junk e-mail problem. We compare the proposed anti-spam method with the filtering technology based on machine learning. The result shows that 100% spams can be filtered out in our scheme, indicating the effectiveness of the proposed anti-spam method.展开更多
文摘A new metric for performance evaluation of transport control protocol(TCP) overwireless channels based on the interference-limited characteristics of code division multipleaddress(CDMA) system is proposed.According to the new metric,the performance of TCP over CDMAcorrelated channel for different protocol parameters and different versions is investigated.The resultsshow that appropriate selection of protocol parameters and packet error rate(PER) operation point canimprove significantly the capacity of packet-switched CDMA-based network.
文摘An optical PPM CDMA communication system with an optical hard limiter in front of the correlator of a receiver is proposed in order to reduce multi user interference. The performance of the system is evaluated when the effects of both multi user interference and photo detector shot noise are considered. An upper bound on the bit error rate is derived. The comparison of the performance of the above receiver with that of the optical PPM CDMA system without an optical hard limiter is made. Simulation results show that the performance of the system with an optical hard limiter is superior to that of the conventional one.
基金Acknowledgments Supported by the National Natural Science Foundation of China （Grant Nos. 51375293, 31570998）, and the Science and Technology Commission of Shanghai Municipality （Grant No. 16511108600）.
文摘In this paper, a new image encryption scheme is presented based on time-delay chaos synchronization. Compared with existing methods, a new method is pro- posed and a lot of coupled items can be taken as zero items to simplify the whole system. A simple linear controller is introduced to realize time-delay chaos synchronization and image encryption. The positions of the image pixels are firstly shuffled and then be hidden in the cartier image. The address codes of the chaotic sequences are adopted to avoid the disturbances induced by the initial value and computer accuracy error. Simulation results for color image are provided to illustrate the effectiveness of the proposed method. It can be seen clearly that the system can converge quickly and the image can be encrypted rapidly.
基金Supported by National Natural Science Foundation of China(U1736116,61272500,60373075)the National High-Tech R&D Program(863 Program)(2015AA017204)
文摘To deal with the junk e-mail problem caused by the e-mail address leakage for a majority of Internet users, this paper presents a new privacy protection model in which the e-mail address of the user is treated as a piece of privacy information concealed. Through an interaction pattern that involves three parties and uses an e-mail address code in the place of an e-mail address, the proposed model can prevent the e-mail address from being leaked, thus effectively resolving the junk e-mail problem. We compare the proposed anti-spam method with the filtering technology based on machine learning. The result shows that 100% spams can be filtered out in our scheme, indicating the effectiveness of the proposed anti-spam method.
