A number of methods for constructing new plateaued functions from known ones are presented.Byproperly combining the known plateaued functions it is possible to get highly nonlinear resilient plateauedfunctions.The ord...A number of methods for constructing new plateaued functions from known ones are presented.Byproperly combining the known plateaued functions it is possible to get highly nonlinear resilient plateauedfunctions.The order,resiliency and propagation characteristics of the constructed plateaued functions arediscussed.We show the new functions could possess the desirable cryptographic property.展开更多
A new digital communication technology based on the Phase-Offset Overlapped Waves (POOW) has been introduced in this letter. The waves can be considered as a special multicarrier different from traditional ones. The s...A new digital communication technology based on the Phase-Offset Overlapped Waves (POOW) has been introduced in this letter. The waves can be considered as a special multicarrier different from traditional ones. The sub-waves in a coded word's period of the POOW are sine waves and have the same frequencies, but different starting phases. The most important characteristic is that these sub-waves are the piecewise functions and not orthogonal in a code word period. The decoding can be implemented by solving a linear equation group. This code has very high efficiency and thus the data transmission rate is increased greatly.展开更多
Ad-hoc networking has mainly been associated with military battlefield networks. Security has received considerably less attention and the issue needs to be addressed before any successful applications will appear. Du...Ad-hoc networking has mainly been associated with military battlefield networks. Security has received considerably less attention and the issue needs to be addressed before any successful applications will appear. Due to the insecure nature of the wireless link and their dynamically changing topology, wireless ad-hoc networks require a careful and security-oriented approach for designing routing protocols. In this paper, an AODV-based secure routing protocol- ENAODV is presented. A speed-optimized digital signature algorithm is integrated into the routing protocol. The protocol algorithm is implemented with NS-2. The security of the protocol is analyzed. The simulating results show that the performances of ENAODV protocol, such as average node energy consumption, packet delay and packet delivery is nearly the same as standard AODV protocol.展开更多
While capturing a real world scene using a common digital camera, due to limitations of the sensor dynamic range, we will not be able to capture the entire dynamic range of the some. This problem is evident while capt...While capturing a real world scene using a common digital camera, due to limitations of the sensor dynamic range, we will not be able to capture the entire dynamic range of the some. This problem is evident while capturing a picture of a some which has both brightly and poorly illuminated regions. High Dynamic Range (HDR) imaging aims to recover the entire dynamic range of the scene by compositing multi-exposure images. Tone reproduction is required for displaying HDR images as the corresponding Low Dynamic Range(LDR) images on common displays. This paper discusses novel approaches to reconstruct LDR images directly from multi-exposure images. It is assumed that there is no knowledge of camera response function and other camera settings. At last, it is explained how this task can be achieved effectively for static and dynamic scenes.展开更多
Due to variable symbol length of digital pulse interval modulation(DPIM),it is difficult to analyze the error performances of Turbo coded DPIM.To solve this problem,a fixed-length digital pulse interval modulation(FDP...Due to variable symbol length of digital pulse interval modulation(DPIM),it is difficult to analyze the error performances of Turbo coded DPIM.To solve this problem,a fixed-length digital pulse interval modulation(FDPIM) method is provided.The FDPIM modulation structure is introduced.The packet error rates of uncoded FDPIM are analyzed and compared with that of DPIM.Bit error rates of Turbo coded FDPIM are simulated based on three kinds of analytical models under weak turbulence channel.The results show that packet error rate of uncoded FDPIM is inferior to that of uncoded DPIM.However,FDPIM is easy to be implemented and easy to be combined.with Turbo code for soft-decision because of its fixed length.Besides,the introduction of Turbo code in this modulation can decrease the average power about 10 dBm,which means that it can improve the error performance of the system effectively.展开更多
A novel memory efficient path metric update is proposed for Maximum A Posteriori(MAP) decoder of turbo codes to reduce the memory requirement of state metric information calcu-lation. For MAP decoder,the same memory c...A novel memory efficient path metric update is proposed for Maximum A Posteriori(MAP) decoder of turbo codes to reduce the memory requirement of state metric information calcu-lation. For MAP decoder,the same memory can be shared by the forward and backward metrics with this metric update scheme. The forward and backward metrics update can be performed at the same time. And all of the extrinsic information can be calculated at the end of metric update. Therefore,the latency and area in the implementation will be reduced with the proposed metric update method.展开更多
This paper proposes Steepest Decreasing Constant Modulus Algorithm (SDCMA) detection in frequency dornain for MultiCarrier Direct Sequence-Code Division Multiple Access (MC DS-CDMA) systems. The proposed algorithm...This paper proposes Steepest Decreasing Constant Modulus Algorithm (SDCMA) detection in frequency dornain for MultiCarrier Direct Sequence-Code Division Multiple Access (MC DS-CDMA) systems. The proposed algorithm is used to equalize independent ladings of all subcarriers. At the same time we compare the SDCMA blind detection with subspace-based Minimum Mean-Squared Error (MMSE) detection. The simulation results show that the pertbrmance of SDCMA blind detection is superior to that of subspace-based MMSE detection and the complexity of the former is much lower than that of the latter.展开更多
This study proposes a new coding function for the symmetric W state. Based on the new coding function, a theoretical protocol of deterministic quanama communication (DQC) is proposed. The sender can use the proposed...This study proposes a new coding function for the symmetric W state. Based on the new coding function, a theoretical protocol of deterministic quanama communication (DQC) is proposed. The sender can use the proposed coding function to encode his/her message, and the receiver can perform the imperfect Bell measurement to obtain the sender's message. In comparison to the existing DQC protocols that also use the W class state, the proposed protocol is more efficient and also more practical within today's technology. Moreover, the security of this protocol is analyzed to show that any eavesdropper will be detected with a very high probability under both the ideal and the noisy quantum channel.展开更多
基金the National Natural Science Foundation of China(No60773003)the Natural Science Basic Research Plan in Shanxi Province of China
文摘A number of methods for constructing new plateaued functions from known ones are presented.Byproperly combining the known plateaued functions it is possible to get highly nonlinear resilient plateauedfunctions.The order,resiliency and propagation characteristics of the constructed plateaued functions arediscussed.We show the new functions could possess the desirable cryptographic property.
文摘A new digital communication technology based on the Phase-Offset Overlapped Waves (POOW) has been introduced in this letter. The waves can be considered as a special multicarrier different from traditional ones. The sub-waves in a coded word's period of the POOW are sine waves and have the same frequencies, but different starting phases. The most important characteristic is that these sub-waves are the piecewise functions and not orthogonal in a code word period. The decoding can be implemented by solving a linear equation group. This code has very high efficiency and thus the data transmission rate is increased greatly.
基金This work was supported by China Nature Science Fund .Serial No.60073059and60273078
文摘Ad-hoc networking has mainly been associated with military battlefield networks. Security has received considerably less attention and the issue needs to be addressed before any successful applications will appear. Due to the insecure nature of the wireless link and their dynamically changing topology, wireless ad-hoc networks require a careful and security-oriented approach for designing routing protocols. In this paper, an AODV-based secure routing protocol- ENAODV is presented. A speed-optimized digital signature algorithm is integrated into the routing protocol. The protocol algorithm is implemented with NS-2. The security of the protocol is analyzed. The simulating results show that the performances of ENAODV protocol, such as average node energy consumption, packet delay and packet delivery is nearly the same as standard AODV protocol.
文摘While capturing a real world scene using a common digital camera, due to limitations of the sensor dynamic range, we will not be able to capture the entire dynamic range of the some. This problem is evident while capturing a picture of a some which has both brightly and poorly illuminated regions. High Dynamic Range (HDR) imaging aims to recover the entire dynamic range of the scene by compositing multi-exposure images. Tone reproduction is required for displaying HDR images as the corresponding Low Dynamic Range(LDR) images on common displays. This paper discusses novel approaches to reconstruct LDR images directly from multi-exposure images. It is assumed that there is no knowledge of camera response function and other camera settings. At last, it is explained how this task can be achieved effectively for static and dynamic scenes.
文摘Due to variable symbol length of digital pulse interval modulation(DPIM),it is difficult to analyze the error performances of Turbo coded DPIM.To solve this problem,a fixed-length digital pulse interval modulation(FDPIM) method is provided.The FDPIM modulation structure is introduced.The packet error rates of uncoded FDPIM are analyzed and compared with that of DPIM.Bit error rates of Turbo coded FDPIM are simulated based on three kinds of analytical models under weak turbulence channel.The results show that packet error rate of uncoded FDPIM is inferior to that of uncoded DPIM.However,FDPIM is easy to be implemented and easy to be combined.with Turbo code for soft-decision because of its fixed length.Besides,the introduction of Turbo code in this modulation can decrease the average power about 10 dBm,which means that it can improve the error performance of the system effectively.
文摘A novel memory efficient path metric update is proposed for Maximum A Posteriori(MAP) decoder of turbo codes to reduce the memory requirement of state metric information calcu-lation. For MAP decoder,the same memory can be shared by the forward and backward metrics with this metric update scheme. The forward and backward metrics update can be performed at the same time. And all of the extrinsic information can be calculated at the end of metric update. Therefore,the latency and area in the implementation will be reduced with the proposed metric update method.
基金Supported by the National Natural Science Foundation of China (No.60472104).
文摘This paper proposes Steepest Decreasing Constant Modulus Algorithm (SDCMA) detection in frequency dornain for MultiCarrier Direct Sequence-Code Division Multiple Access (MC DS-CDMA) systems. The proposed algorithm is used to equalize independent ladings of all subcarriers. At the same time we compare the SDCMA blind detection with subspace-based Minimum Mean-Squared Error (MMSE) detection. The simulation results show that the pertbrmance of SDCMA blind detection is superior to that of subspace-based MMSE detection and the complexity of the former is much lower than that of the latter.
基金supported by the National Science Council of the Republic of China(Grant No.NSC 98-2221-E-006-097-MY3)
文摘This study proposes a new coding function for the symmetric W state. Based on the new coding function, a theoretical protocol of deterministic quanama communication (DQC) is proposed. The sender can use the proposed coding function to encode his/her message, and the receiver can perform the imperfect Bell measurement to obtain the sender's message. In comparison to the existing DQC protocols that also use the W class state, the proposed protocol is more efficient and also more practical within today's technology. Moreover, the security of this protocol is analyzed to show that any eavesdropper will be detected with a very high probability under both the ideal and the noisy quantum channel.