This paper presents a method to detect the quantization index modulation(QIM) steganography in G.723.1 bit stream.We show that the distribution of each quantization index(codeword) in the quantization index sequence h...This paper presents a method to detect the quantization index modulation(QIM) steganography in G.723.1 bit stream.We show that the distribution of each quantization index(codeword) in the quantization index sequence has unbalanced and correlated characteristics.We present the designs of statistical models to extract the quantitative feature vectors of these characteristics.Combining the extracted vectors with the support vector machine,we build the classifier for detecting the QIM steganography in G.723.1 bit stream.The experiment shows that the method has far better performance than the existing blind detection method which extracts the feature vector in an uncompressed domain.The recall and precision of our method are all more than 90% even for a compressed bit stream duration as low as 3.6 s.展开更多
With the shrink of the technology into nanometer scale, network-on-chip （NOC） has become a reasonable solution for connecting plenty of IP blocks on a single chip. But it suffers from both crosstalk effects and sing...With the shrink of the technology into nanometer scale, network-on-chip （NOC） has become a reasonable solution for connecting plenty of IP blocks on a single chip. But it suffers from both crosstalk effects and single event upset （SEU）, especially crosstalk-induced delay, which may constrain the overall performance of NOC. In this paper, we introduce a reliable NOC design using a code with the capability of both crosstalk avoidance and single error correction. Such a code, named selected crosstalk avoidance code （SCAC） in our previous work, joins crosstalk avoidance code （CAC） and error correction code （ECC） together through codeword selection from an original CAC codeword set. It can handle possible error caused by either crosstalk effects or SEU. When designing a reliable NOC, data are encoded to SCAC codewords and can be transmitted rapidly and reliably across NOC. Experimental results show that the NOC design with SCAC achieves higher performance and is reliable to tolerate single errors. Compared with previous crosstalk avoidance methods, SCAC reduces wire overhead, power dissipation and the total delay. When SCAC is used in NOC, it can save 20% area overhead and reduce 49% power dissipation.展开更多
In the present communication, we have obtained the optimum probability distribution with which the messages should be delivered so that the average redundancy of the source is minimized. Here, we have taken the case o...In the present communication, we have obtained the optimum probability distribution with which the messages should be delivered so that the average redundancy of the source is minimized. Here, we have taken the case of various generalized mean codeword lengths. Moreover, the upper bound to these codeword lengths has been found for the case of Huffman encoding.展开更多
Interference cancellation scheme without feedback is proposed for X channels with four antennas at each user. Space-time codeword with Alamouti structure is designed for each user. Codewords are combined according a c...Interference cancellation scheme without feedback is proposed for X channels with four antennas at each user. Space-time codeword with Alamouti structure is designed for each user. Codewords are combined according a certain rule. The unwanted codewords are cancelled by linear operation on the received signals. Then, multi-user interference is mitigated by the orthogonal property of the Alamouti code. Comparing with the existing scheme for the same scene, feedback information is not required in the proposed scheme. So the transmission efficiency is improved.展开更多
The present communication offers a method to determine an unknown discrete probability distribution with specified Tsallis entropy close to uniform distribution. The relative error of the distribution obtained has bee...The present communication offers a method to determine an unknown discrete probability distribution with specified Tsallis entropy close to uniform distribution. The relative error of the distribution obtained has been compared with the distribution obtained with the help of mathematica software. The applications of the proposed algorithm with respect to Tsallis source coding, Huffman coding and cross entropy optimization principles have been provided.展开更多
As the complexity of space exploration missions augments,how to enhance the overall performance of communication,ranging or other functions has become a challengeable problem.Considering the integration of communicati...As the complexity of space exploration missions augments,how to enhance the overall performance of communication,ranging or other functions has become a challengeable problem.Considering the integration of communication and ranging,we present a bit-level composite signal for simultaneous ranging and communication.In this composite method,through a specially designed mapping scheme using low-weight codewords,the information sequence is converted to a sparse sequence which is then superimposed on the ranging code.For ranging,the correlation characteristics of the ranging code component can be maintained to calculate the transmitter-receiver distance.For communications,the sparse sequence can be extracted without interference by eliminating the ranging code component.Simulation results show that the proposed composite signal can support communication and ranging simultaneously with limited sacrifice of ranging performance,and the performance loss of ranging can be controlled and minimized by lowering the density of information sequences using different sparsification encoding methods.展开更多
In this paper, we show that if Wmax 〈 6 for the Hamming code Ham （r, 2）, then all of the nonzero codewords of Ham （r, 2） are minimal and if Wrnax 〈 8 for the extended Hamming code Hfim （r, 2）, then all of the ...In this paper, we show that if Wmax 〈 6 for the Hamming code Ham （r, 2）, then all of the nonzero codewords of Ham （r, 2） are minimal and if Wrnax 〈 8 for the extended Hamming code Hfim （r, 2）, then all of the nonzero codewords ofHfim （r, 2） are minimal, where Wmax is the maximum nonzero weight in Ham （r, 2） and Hfim （r, 2）.展开更多
Cyclic codes form an important class of codes. They have very interesting algebraic structure. Furthermore, they are equivalent to many important codes, such as binary Hamming codes, Golay codes and BCH codes. Minimal...Cyclic codes form an important class of codes. They have very interesting algebraic structure. Furthermore, they are equivalent to many important codes, such as binary Hamming codes, Golay codes and BCH codes. Minimal codewords in linear codes are widely used in constructing decoding algorithms and studying linear secret sharing scheme. In this paper, we show that in the binary cyclic code all of the codewords are minimal, except 0 and 1. Then, we obtain a result about the number of minimal codewords in the binary cyclic codes.展开更多
For a binary linear code,a new relation between the intersection and(2,2)-separating property is addressed,and a relation between the intersection and the trellis complexity is also given.Using above relations,the aut...For a binary linear code,a new relation between the intersection and(2,2)-separating property is addressed,and a relation between the intersection and the trellis complexity is also given.Using above relations,the authors will apply several classes of binary codes to secret sharing scheme and determine their trellis complexity and separating properties.The authors also present the properties of the intersection of certain kinds of two-weight binary codes.By using the concept of value function,the intersecting properties of general binary codes are described.展开更多
基金Project supported by the National Natural Science Foundation of China (No. 60970148)the National High-Tech R&D (863)Program of China (No. 2011AA010704)
文摘This paper presents a method to detect the quantization index modulation(QIM) steganography in G.723.1 bit stream.We show that the distribution of each quantization index(codeword) in the quantization index sequence has unbalanced and correlated characteristics.We present the designs of statistical models to extract the quantitative feature vectors of these characteristics.Combining the extracted vectors with the support vector machine,we build the classifier for detecting the QIM steganography in G.723.1 bit stream.The experiment shows that the method has far better performance than the existing blind detection method which extracts the feature vector in an uncompressed domain.The recall and precision of our method are all more than 90% even for a compressed bit stream duration as low as 3.6 s.
基金supported in part by the National Natural Science Foundation of China (NSFC) under Grant Nos. 60606008,60633060, and 60776031the National Basic Research 973 Program of China under Grant No. 2005CB321604+1 种基金the National High Technology Research and Development 863 Program of China under Grant Nos. 2007AA01Z476, 2007AA01Z109 and 2007AA01Z113Co-Building Program of Beijing Municipal Education Commission
文摘With the shrink of the technology into nanometer scale, network-on-chip （NOC） has become a reasonable solution for connecting plenty of IP blocks on a single chip. But it suffers from both crosstalk effects and single event upset （SEU）, especially crosstalk-induced delay, which may constrain the overall performance of NOC. In this paper, we introduce a reliable NOC design using a code with the capability of both crosstalk avoidance and single error correction. Such a code, named selected crosstalk avoidance code （SCAC） in our previous work, joins crosstalk avoidance code （CAC） and error correction code （ECC） together through codeword selection from an original CAC codeword set. It can handle possible error caused by either crosstalk effects or SEU. When designing a reliable NOC, data are encoded to SCAC codewords and can be transmitted rapidly and reliably across NOC. Experimental results show that the NOC design with SCAC achieves higher performance and is reliable to tolerate single errors. Compared with previous crosstalk avoidance methods, SCAC reduces wire overhead, power dissipation and the total delay. When SCAC is used in NOC, it can save 20% area overhead and reduce 49% power dissipation.
文摘In the present communication, we have obtained the optimum probability distribution with which the messages should be delivered so that the average redundancy of the source is minimized. Here, we have taken the case of various generalized mean codeword lengths. Moreover, the upper bound to these codeword lengths has been found for the case of Huffman encoding.
文摘Interference cancellation scheme without feedback is proposed for X channels with four antennas at each user. Space-time codeword with Alamouti structure is designed for each user. Codewords are combined according a certain rule. The unwanted codewords are cancelled by linear operation on the received signals. Then, multi-user interference is mitigated by the orthogonal property of the Alamouti code. Comparing with the existing scheme for the same scene, feedback information is not required in the proposed scheme. So the transmission efficiency is improved.
文摘The present communication offers a method to determine an unknown discrete probability distribution with specified Tsallis entropy close to uniform distribution. The relative error of the distribution obtained has been compared with the distribution obtained with the help of mathematica software. The applications of the proposed algorithm with respect to Tsallis source coding, Huffman coding and cross entropy optimization principles have been provided.
基金This work was supported in part by National Natural Science Foundation of China(61671324)the Director’s Funding from Pilot National Laboratory for Marine Science and Technology(Qingdao)(QNLM201712)Zhan Xu was supported in part by National Natural Science Foundation of China(61620106001).
文摘As the complexity of space exploration missions augments,how to enhance the overall performance of communication,ranging or other functions has become a challengeable problem.Considering the integration of communication and ranging,we present a bit-level composite signal for simultaneous ranging and communication.In this composite method,through a specially designed mapping scheme using low-weight codewords,the information sequence is converted to a sparse sequence which is then superimposed on the ranging code.For ranging,the correlation characteristics of the ranging code component can be maintained to calculate the transmitter-receiver distance.For communications,the sparse sequence can be extracted without interference by eliminating the ranging code component.Simulation results show that the proposed composite signal can support communication and ranging simultaneously with limited sacrifice of ranging performance,and the performance loss of ranging can be controlled and minimized by lowering the density of information sequences using different sparsification encoding methods.
文摘In this paper, we show that if Wmax 〈 6 for the Hamming code Ham （r, 2）, then all of the nonzero codewords of Ham （r, 2） are minimal and if Wrnax 〈 8 for the extended Hamming code Hfim （r, 2）, then all of the nonzero codewords ofHfim （r, 2） are minimal, where Wmax is the maximum nonzero weight in Ham （r, 2） and Hfim （r, 2）.
文摘Cyclic codes form an important class of codes. They have very interesting algebraic structure. Furthermore, they are equivalent to many important codes, such as binary Hamming codes, Golay codes and BCH codes. Minimal codewords in linear codes are widely used in constructing decoding algorithms and studying linear secret sharing scheme. In this paper, we show that in the binary cyclic code all of the codewords are minimal, except 0 and 1. Then, we obtain a result about the number of minimal codewords in the binary cyclic codes.
基金supported by the National Science Foundation of China under Grant Nos.11171366 and 61170257
文摘For a binary linear code,a new relation between the intersection and(2,2)-separating property is addressed,and a relation between the intersection and the trellis complexity is also given.Using above relations,the authors will apply several classes of binary codes to secret sharing scheme and determine their trellis complexity and separating properties.The authors also present the properties of the intersection of certain kinds of two-weight binary codes.By using the concept of value function,the intersecting properties of general binary codes are described.
