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2012 Vol. 34, No. 10
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2012, 34(10): 2287-2292.
doi: 10.3724/SP.J.1146.2012.00542
Abstract:
Femtocell is a promising technology to enhance indoor coverage and system capacity. However, the interference impairs greatly the network performance for spectrum-sharing OFDMA femtocell networks. This paper investigates a power control scheme for the uplink transmission of spectrum-sharing femtocell networks based on cooperative game theoretic framework. Taking into consideration both user fairness and network efficiency, a cooperative Nash bargaining power control game model is formulated, where interference power constraint is imposed to protect cellular users transmission, and minimum Signal-to-Interference-plus-Noise Ratio (SINR) requirements are employed for femtocell users. Then a Kalai-Smorodinsky (KS) bargaining solution is developed, which is a Pareto-optimal solution to the problem. Simulation results show that the proposed algorithm not only maintains fairness among femtocell users and guarantees the minimum SINR requirements of all femtocell users, but also improves the spectrum efficiency.
Femtocell is a promising technology to enhance indoor coverage and system capacity. However, the interference impairs greatly the network performance for spectrum-sharing OFDMA femtocell networks. This paper investigates a power control scheme for the uplink transmission of spectrum-sharing femtocell networks based on cooperative game theoretic framework. Taking into consideration both user fairness and network efficiency, a cooperative Nash bargaining power control game model is formulated, where interference power constraint is imposed to protect cellular users transmission, and minimum Signal-to-Interference-plus-Noise Ratio (SINR) requirements are employed for femtocell users. Then a Kalai-Smorodinsky (KS) bargaining solution is developed, which is a Pareto-optimal solution to the problem. Simulation results show that the proposed algorithm not only maintains fairness among femtocell users and guarantees the minimum SINR requirements of all femtocell users, but also improves the spectrum efficiency.
2012, 34(10): 2293-2298.
doi: 10.3724/SP.J.1146.2012.00314
Abstract:
Performance is analyzed of the multiple two-way relaying systems with three-slot Time Division BroadCast (TDBC) protocol employing adaptive modulation. The end-to-end SINR of the system is presented when channel estimation error exists. Then the distribution of its upper bound is given by transforming the expression to sum of multiple variables which obey exponential distribution through inequality zooming. Upper bound of the close-form expression of average spectrum efficiency is derived employing the distribution. Simulations show that the theoretical analysis matches well with the Monte Carlo results. The average spectrum efficiency decreases when the channel estimation error increases. Error floor will emerge for the self-interference can not be totally eliminated. Whats more, the optimal power allocation strategy at relay to reduce the impact of channel estimation error is proposed.
Performance is analyzed of the multiple two-way relaying systems with three-slot Time Division BroadCast (TDBC) protocol employing adaptive modulation. The end-to-end SINR of the system is presented when channel estimation error exists. Then the distribution of its upper bound is given by transforming the expression to sum of multiple variables which obey exponential distribution through inequality zooming. Upper bound of the close-form expression of average spectrum efficiency is derived employing the distribution. Simulations show that the theoretical analysis matches well with the Monte Carlo results. The average spectrum efficiency decreases when the channel estimation error increases. Error floor will emerge for the self-interference can not be totally eliminated. Whats more, the optimal power allocation strategy at relay to reduce the impact of channel estimation error is proposed.
2012, 34(10): 2299-2305.
doi: 10.3724/SP.J.1146.2012.00184
Abstract:
In this paper, a common process of compressed channel estimation is given by the Bayesian Compressed Sensing (BCS) which is based on the probability principle of Maximum A Posteriori (MAP). In the process, signal reconstruction and measurement matrix design as two separate steps can be combined together by Adaptive BCS (ABCS). Meanwhile a joint mechanism of ABCS and optimized measurement is proposed by reducing the coherence and the adaptive design of measurement matrix to get a better reconstruction performance. Furthermore, the error bars obtained in the process of reconstruction can be used to measure the accuracy of the reconstruction. Simulation results show that under the same conditions, the joint mechanism shows better anti-noise ability and recovery accuracy than those of the traditional reconstruction algorithm.
In this paper, a common process of compressed channel estimation is given by the Bayesian Compressed Sensing (BCS) which is based on the probability principle of Maximum A Posteriori (MAP). In the process, signal reconstruction and measurement matrix design as two separate steps can be combined together by Adaptive BCS (ABCS). Meanwhile a joint mechanism of ABCS and optimized measurement is proposed by reducing the coherence and the adaptive design of measurement matrix to get a better reconstruction performance. Furthermore, the error bars obtained in the process of reconstruction can be used to measure the accuracy of the reconstruction. Simulation results show that under the same conditions, the joint mechanism shows better anti-noise ability and recovery accuracy than those of the traditional reconstruction algorithm.
2012, 34(10): 2306-2313.
doi: 10.3724/SP.J.1146.2012.00128
Abstract:
This paper describes a class of offset carrier modulations for Direct Sequence-Spreal Spectrum (DS- SS) called Harmonic Offset Carrier (HOC) modulations. The spread spectrum waveform of HOC signal is composed of spreading code modulated by harmonic subcarriers. The auto-correlation function of HOC is equal to the envelope multiplied by harmonic factors. The first peak of the auto-correlation function is narrow, and its width is equal to reciprocal of spanned bandwidth of the signal. The closed form auto-correlation function of HOC modulation is given in this paper. This paper indicates that a Binary Offset Carrier (BOC) modulation could be write as a HOC modulation. HOC signal could be disjoined, and each subcarrier could implement in difference time. HOC signal could achieves high performance of anti-jamming, high resolution of time of arrival measurements, and high performance in multiple path environments. HOC signal synthesized in this paper presents a method how to reduce peak power to average power ratio. In final part of this paper, the character of extra spanned bandwidth HOC modulation is discussed.
This paper describes a class of offset carrier modulations for Direct Sequence-Spreal Spectrum (DS- SS) called Harmonic Offset Carrier (HOC) modulations. The spread spectrum waveform of HOC signal is composed of spreading code modulated by harmonic subcarriers. The auto-correlation function of HOC is equal to the envelope multiplied by harmonic factors. The first peak of the auto-correlation function is narrow, and its width is equal to reciprocal of spanned bandwidth of the signal. The closed form auto-correlation function of HOC modulation is given in this paper. This paper indicates that a Binary Offset Carrier (BOC) modulation could be write as a HOC modulation. HOC signal could be disjoined, and each subcarrier could implement in difference time. HOC signal could achieves high performance of anti-jamming, high resolution of time of arrival measurements, and high performance in multiple path environments. HOC signal synthesized in this paper presents a method how to reduce peak power to average power ratio. In final part of this paper, the character of extra spanned bandwidth HOC modulation is discussed.
2012, 34(10): 2314-2319.
doi: 10.3724/SP.J.1146.2012.00341
Abstract:
This paper proposes a scheme of network coding for asymmetric data transmission in three-point cooperative communication system. Since the joint using both cooperative diversity and network coding, the diversity gain and coding gain are achieved in wireless communications transmission system. In this paper, the differences of wireless communication environment are fully considered. The scheme with asymmetric modulation ensures the reliability of communication in the poor environment. Meanwhile, it transmits more data in better links to make full use of system resource. The main idea to realize network coding of asymmetric data transmission is to add prior known information in the relay. The prior known information can enhance the coding performance of the system. Simulations show that the proposed transmission scheme can achieve the diversity gain and reduce the BER compared to non-cooperative transmission system. In addition, it can improve the transmission capacity of the communication system.
This paper proposes a scheme of network coding for asymmetric data transmission in three-point cooperative communication system. Since the joint using both cooperative diversity and network coding, the diversity gain and coding gain are achieved in wireless communications transmission system. In this paper, the differences of wireless communication environment are fully considered. The scheme with asymmetric modulation ensures the reliability of communication in the poor environment. Meanwhile, it transmits more data in better links to make full use of system resource. The main idea to realize network coding of asymmetric data transmission is to add prior known information in the relay. The prior known information can enhance the coding performance of the system. Simulations show that the proposed transmission scheme can achieve the diversity gain and reduce the BER compared to non-cooperative transmission system. In addition, it can improve the transmission capacity of the communication system.
2012, 34(10): 2320-2325.
doi: 10.3724/SP.J.1146.2012.00161
Abstract:
Opportunistic relaying coded cooperation is already an efficient and widely investigated cooperative scheme in multi-relay networks. However, the previous works still have deficiencies, such as high system complexity and low resource utilization. In this paper, a novel opportunistic relaying coded cooperation is proposed to achieve an acceptable tradeoff between resource utilization and system complexity, where the source transmits the parity to the destination adaptively without extra overheads. The analytical expressions of the outage probability and the upper bound of bit error probability over Nakagami fading channels are derived. Simulation results reveal that the proposed scheme, compared with the existing opportunistic relaying coded cooperation schemes, achieves better performance and makes an improvement on both system complexity and resource utilization.
Opportunistic relaying coded cooperation is already an efficient and widely investigated cooperative scheme in multi-relay networks. However, the previous works still have deficiencies, such as high system complexity and low resource utilization. In this paper, a novel opportunistic relaying coded cooperation is proposed to achieve an acceptable tradeoff between resource utilization and system complexity, where the source transmits the parity to the destination adaptively without extra overheads. The analytical expressions of the outage probability and the upper bound of bit error probability over Nakagami fading channels are derived. Simulation results reveal that the proposed scheme, compared with the existing opportunistic relaying coded cooperation schemes, achieves better performance and makes an improvement on both system complexity and resource utilization.
2012, 34(10): 2326-2330.
doi: 10.3724/SP.J.1146.2012.00349
Abstract:
To solve the estimation problem of multipath channel parameters in CDMA mobile satellite communications, a two-dimensional searching algorithm based on maximum likelihood estimation is proposed. The proposed algorithm searches for delays of two paths. Meanwhile, the magnitude of multipath is estimated using de-correlation or Linear Minimum Mean Square Error (LMMSE) algorithm. The optimal delay and amplitude estimation is finally found by maximizing the likelihood function. Simulation results show that the proposed algorithm, which combines a two-dimensional searching with approximate LMMSE estimation of multipath magnitude, performs well.
To solve the estimation problem of multipath channel parameters in CDMA mobile satellite communications, a two-dimensional searching algorithm based on maximum likelihood estimation is proposed. The proposed algorithm searches for delays of two paths. Meanwhile, the magnitude of multipath is estimated using de-correlation or Linear Minimum Mean Square Error (LMMSE) algorithm. The optimal delay and amplitude estimation is finally found by maximizing the likelihood function. Simulation results show that the proposed algorithm, which combines a two-dimensional searching with approximate LMMSE estimation of multipath magnitude, performs well.
2012, 34(10): 2331-2335.
doi: 10.3724/SP.J.1146.2012.00384
Abstract:
For improving communication system power efficiency and spectrum efficiency, an orthogonal Prolate Spheroidal Wave Functions (PSWF) pulse modulation method is proposed. The system power efficiency can be improved by using PSWF with high energy concentration degree as transmission pulse. Orthogonal pulse sets is constructed to transmit information based on PSWF, which is orthogonal in time domain and overlapped in frequency domain. As a result, the bandwidth can be reduced and the spectrum efficiency improved. The theory analysis and simulation results show that the system bandwidth efficiency can be fast closed to 2 Baud/Hz and the modulated signal has high energy efficiency in frequency domain which is important to improve power efficiency and reduce electromagnetic interference on other users.
For improving communication system power efficiency and spectrum efficiency, an orthogonal Prolate Spheroidal Wave Functions (PSWF) pulse modulation method is proposed. The system power efficiency can be improved by using PSWF with high energy concentration degree as transmission pulse. Orthogonal pulse sets is constructed to transmit information based on PSWF, which is orthogonal in time domain and overlapped in frequency domain. As a result, the bandwidth can be reduced and the spectrum efficiency improved. The theory analysis and simulation results show that the system bandwidth efficiency can be fast closed to 2 Baud/Hz and the modulated signal has high energy efficiency in frequency domain which is important to improve power efficiency and reduce electromagnetic interference on other users.
A Multi-stage Motion Estimation Algorithm Based on 3-D Recursive Search for Frame Rate up Conversion
2012, 34(10): 2336-2341.
doi: 10.3724/SP.J.1146.2012.00507
Abstract:
Motion-Compensated Frame Interpolation (MCFI) is a primary method for frame rate up conversion. A multi-stage block-matching motion estimation algorithm based on 3-D Recursive Search (3-D RS) is proposed in this paper to decrease the block artifact in the interpolated frame and to reduce the computational complexity for real-time high-definition video applications. In the proposed algorithm, combining 3-D RS with the bi-directional motion estimation, three-stage motion estimation for successive frames of the video sequence is firstly implemented step by step, and then the motion vector field is smoothened by using a simplified median filter. After that, the interpolated frame is produced via linear interpolation compensation. Compared with the existing algorithms of MCFI, the experimental results show that both objective and visual quality of the interpolated frame produced by the proposed algorithm is improved. It is feasible as well since its low complexity.
Motion-Compensated Frame Interpolation (MCFI) is a primary method for frame rate up conversion. A multi-stage block-matching motion estimation algorithm based on 3-D Recursive Search (3-D RS) is proposed in this paper to decrease the block artifact in the interpolated frame and to reduce the computational complexity for real-time high-definition video applications. In the proposed algorithm, combining 3-D RS with the bi-directional motion estimation, three-stage motion estimation for successive frames of the video sequence is firstly implemented step by step, and then the motion vector field is smoothened by using a simplified median filter. After that, the interpolated frame is produced via linear interpolation compensation. Compared with the existing algorithms of MCFI, the experimental results show that both objective and visual quality of the interpolated frame produced by the proposed algorithm is improved. It is feasible as well since its low complexity.
2012, 34(10): 2342-2347.
doi: 10.3724/SP.J.1146.2011.01297
Abstract:
A scheme is proposed for transmission of wavelet-based progressive image coding over packet erasure channel. The scheme uses layered multiple description coding to improve the error resilience performance of the source coding, and uses channel coding to combat the packet erasure. Post Compression Rate Distortion optimization (PCRD-opt) technique is adopted to optimize source coding. By reordering the source coding symbols and channel coding symbols through permuted systematic RS codes, the layered multiple description coding and channel code are combined efficiently. The same sorting algorithm is adopted at encoder and decoder to reduce the overhead. Experimental results show that the proposed scheme improves the received image quality with less overhead compared to the existing method.
A scheme is proposed for transmission of wavelet-based progressive image coding over packet erasure channel. The scheme uses layered multiple description coding to improve the error resilience performance of the source coding, and uses channel coding to combat the packet erasure. Post Compression Rate Distortion optimization (PCRD-opt) technique is adopted to optimize source coding. By reordering the source coding symbols and channel coding symbols through permuted systematic RS codes, the layered multiple description coding and channel code are combined efficiently. The same sorting algorithm is adopted at encoder and decoder to reduce the overhead. Experimental results show that the proposed scheme improves the received image quality with less overhead compared to the existing method.
A Laplacian-Cauchy Mixture Model for Improved Correlation Noise Modeling in Distributed Video Coding
2012, 34(10): 2348-2352.
doi: 10.3724/SP.J.1146.2012.00317
Abstract:
A novel Laplacian-Cauchy Mixture Distribution (LCMD) model is proposed to characterize the distribution of correlation noise between the original Wyner-Ziv frame and the side information in transform domain distributed video coding schemes. Observing the deviations of traditional Lapalcian modeled distribution on large and small residual coefficients, to reduce the deviations, a LCMD model is proposed by modeling small Discrete Cosine Transform (DCT) coefficients as improved Laplacian distributed while modeling large ones as Cauchy distributed. Two solutions to find parameters of LCMD model are also proposed. Real video experiments demonstrate the improvements of LCMD in terms of both the Rate Distortion (RD) performance and computation complexity.
A novel Laplacian-Cauchy Mixture Distribution (LCMD) model is proposed to characterize the distribution of correlation noise between the original Wyner-Ziv frame and the side information in transform domain distributed video coding schemes. Observing the deviations of traditional Lapalcian modeled distribution on large and small residual coefficients, to reduce the deviations, a LCMD model is proposed by modeling small Discrete Cosine Transform (DCT) coefficients as improved Laplacian distributed while modeling large ones as Cauchy distributed. Two solutions to find parameters of LCMD model are also proposed. Real video experiments demonstrate the improvements of LCMD in terms of both the Rate Distortion (RD) performance and computation complexity.
2012, 34(10): 2353-2357.
doi: 10.3724/SP.J.1146.2012.00242
Abstract:
Private information retrieval is the important issue of secure multi-party computation. Many assumptions of traditional Symmetric Private Information Retrieval (SPIR) are vulnerable in quantum mechanics and the present quantum SPIR protocols are complex to implement. A symmetric quantum SPIR protocol and experiment realization scheme are proposed. This scheme bases on polarized single photons to generate the key, so it has the advantage of simple operation and easy to hardware implement. The unconditional security of the protocol is guaranteed by Heisenberg uncertainty principle and quantum no-cloning theory. Dishonest user detection is involved in the protocol, the dishonest users could not get any information by malicious behavior under the dishonest cooperation model. The proposed scheme has better performance at security, robustness, anti-third party eavesdropping than many classical SPIR schemes.
Private information retrieval is the important issue of secure multi-party computation. Many assumptions of traditional Symmetric Private Information Retrieval (SPIR) are vulnerable in quantum mechanics and the present quantum SPIR protocols are complex to implement. A symmetric quantum SPIR protocol and experiment realization scheme are proposed. This scheme bases on polarized single photons to generate the key, so it has the advantage of simple operation and easy to hardware implement. The unconditional security of the protocol is guaranteed by Heisenberg uncertainty principle and quantum no-cloning theory. Dishonest user detection is involved in the protocol, the dishonest users could not get any information by malicious behavior under the dishonest cooperation model. The proposed scheme has better performance at security, robustness, anti-third party eavesdropping than many classical SPIR schemes.
2012, 34(10): 2358-2362.
doi: 10.3724/SP.J.1146.2012.00329
Abstract:
In this paper, a new class of rotation symmetric Boolean functions with good cryptographic properties are constructed when the number of variables is 2m. These constructed functions are balanced, and have maximum algebraic immunity, optimum algebraic degree and high nonlinearity. They are excellent functions which can satisfy many cryptographic indexes simultaneously.
In this paper, a new class of rotation symmetric Boolean functions with good cryptographic properties are constructed when the number of variables is 2m. These constructed functions are balanced, and have maximum algebraic immunity, optimum algebraic degree and high nonlinearity. They are excellent functions which can satisfy many cryptographic indexes simultaneously.
2012, 34(10): 2363-2368.
doi: 10.3724/SP.J.1146.2012.00497
Abstract:
In view of the fast development of information countermeasure and intelligent communication, recognition of channel coding has been a vital issue in information interception. This paper proposes a new method of recognition in order to recognize the(n,1,m) convolutional codes. Firstly, this method defines the notion of check-sequence, and solves it by an advanced model of matrix, then deduces the matrix of generator polynomial, having recognized the convolutional code, by check-sequence. Finally, examples of simulation show that this method is able to recognize, neither knowing the parameter of code n nor the begin location of coding, all (n,1,m)convolutional codes effectively.
In view of the fast development of information countermeasure and intelligent communication, recognition of channel coding has been a vital issue in information interception. This paper proposes a new method of recognition in order to recognize the(n,1,m) convolutional codes. Firstly, this method defines the notion of check-sequence, and solves it by an advanced model of matrix, then deduces the matrix of generator polynomial, having recognized the convolutional code, by check-sequence. Finally, examples of simulation show that this method is able to recognize, neither knowing the parameter of code n nor the begin location of coding, all (n,1,m)convolutional codes effectively.
2012, 34(10): 2369-2374.
doi: 10.3724/SP.J.1146.2012.00331
Abstract:
Due to the characteristics of the mobile device, it is difficult to implement the existing network discovery algorithm based on clique in mobile social network. In order to solve the problem, through analyzing the mobile user behaviors, an algorithm of community discovery algorithm based on circuit merging is proposed. Firstly, the mobile social network is constructed according to the mobile user behaviors. The method finds the k-circuit as community core by using the k-Elementary Circuits (k-EC) finding algorithm. And then the community cores that have common nodes will be merged according to some given rules. Secondly, the remainder discrete nodes are added to elementary communities according to the mobile user correlation degree. Finally, the algorithm is proved more accurate and feasible in the experiments by using the public data sets and the simulated data sets.
Due to the characteristics of the mobile device, it is difficult to implement the existing network discovery algorithm based on clique in mobile social network. In order to solve the problem, through analyzing the mobile user behaviors, an algorithm of community discovery algorithm based on circuit merging is proposed. Firstly, the mobile social network is constructed according to the mobile user behaviors. The method finds the k-circuit as community core by using the k-Elementary Circuits (k-EC) finding algorithm. And then the community cores that have common nodes will be merged according to some given rules. Secondly, the remainder discrete nodes are added to elementary communities according to the mobile user correlation degree. Finally, the algorithm is proved more accurate and feasible in the experiments by using the public data sets and the simulated data sets.
2012, 34(10): 2375-2381.
doi: 10.3724/SP.J.1146.2012.00361
Abstract:
Wireless Sensor Networks (WSNs) have such characteristics as energy depletion and nodes random failure fault caused by harsh environment. So in this paper, a Fault-tolerant Topology Control Approach (FTCA), which can optimize node energy and random failure simultaneously is proposed. This method can built the fault model based on the node energy depletion and random failure, find the node degree parameter which can satisfy the double requirements of the network lifetime and the tolerance to integrated fault, obtain the target topology to maximize the lifetime, and improve the fault tolerance to the energy depletion and random failure of nodes. Finally, the experimental results show the effectiveness of the FTCA algorithm.
Wireless Sensor Networks (WSNs) have such characteristics as energy depletion and nodes random failure fault caused by harsh environment. So in this paper, a Fault-tolerant Topology Control Approach (FTCA), which can optimize node energy and random failure simultaneously is proposed. This method can built the fault model based on the node energy depletion and random failure, find the node degree parameter which can satisfy the double requirements of the network lifetime and the tolerance to integrated fault, obtain the target topology to maximize the lifetime, and improve the fault tolerance to the energy depletion and random failure of nodes. Finally, the experimental results show the effectiveness of the FTCA algorithm.
2012, 34(10): 2382-2388.
doi: 10.3724/SP.J.1146.2011.01313
Abstract:
Considering the high computational cost and complex object representation problems in human tracking, this paper presents a model-free tracking approach using a combination of multiple spatial-temporal slices. The human is represented with a variable number of components in different spatial-temporal slice images. The component initialization requires no pre-defined object part model. By introducing the spatial-temporal slice method, the original image sequence volume is divided into multiple horizontal spatial-temporal slice images. In each slice image, candidate components are detected and tracked across frames. A combination scheme is proposed to assemble these components into different human objects based on their motion and position consistence. Thus, the traditional human tracking issue in the XYT 3D space is transformed into a combined component tracking issue in the XT 2D space. Experiments show that the proposed method reduces the trajectory errors, is real-time computational efficient and robust to human component missing.
Considering the high computational cost and complex object representation problems in human tracking, this paper presents a model-free tracking approach using a combination of multiple spatial-temporal slices. The human is represented with a variable number of components in different spatial-temporal slice images. The component initialization requires no pre-defined object part model. By introducing the spatial-temporal slice method, the original image sequence volume is divided into multiple horizontal spatial-temporal slice images. In each slice image, candidate components are detected and tracked across frames. A combination scheme is proposed to assemble these components into different human objects based on their motion and position consistence. Thus, the traditional human tracking issue in the XYT 3D space is transformed into a combined component tracking issue in the XT 2D space. Experiments show that the proposed method reduces the trajectory errors, is real-time computational efficient and robust to human component missing.
2012, 34(10): 2389-2395.
doi: 10.3724/SP.J.1146.2011.00789
Abstract:
This paper presents a blind color image watermarking scheme using the combination of the holistic transformation of Quaternion Fourier Transformation (QFT) and Quaternion Singular Value Decomposition (QSVD). The host image is first divided into blocks followed by taking the QFT of each block. Then design watermarks that use the diagonal elements of the two unitary matrices obtained from the followed QSVD of each block and add the watermarks into the singular values of each block. The specially designed watermarks strongly improve the false positive rate of randomly selected images. The real singular values got from QSVD contain both luminance and chrominance information of the color image that ensure the watermarks to spread into all color components in the spatial domain. Experimental results demonstrate that the proposed watermarking scheme performs better than traditional multi-channel watermarking scheme and the existing quaternion-based watermarking scheme in imperceptibility and false positive rate of randomly selected images respectively.
This paper presents a blind color image watermarking scheme using the combination of the holistic transformation of Quaternion Fourier Transformation (QFT) and Quaternion Singular Value Decomposition (QSVD). The host image is first divided into blocks followed by taking the QFT of each block. Then design watermarks that use the diagonal elements of the two unitary matrices obtained from the followed QSVD of each block and add the watermarks into the singular values of each block. The specially designed watermarks strongly improve the false positive rate of randomly selected images. The real singular values got from QSVD contain both luminance and chrominance information of the color image that ensure the watermarks to spread into all color components in the spatial domain. Experimental results demonstrate that the proposed watermarking scheme performs better than traditional multi-channel watermarking scheme and the existing quaternion-based watermarking scheme in imperceptibility and false positive rate of randomly selected images respectively.
2012, 34(10): 2396-2401.
doi: 10.3724/SP.J.1146.2011.01082
Abstract:
Improved Local Tangent Space Alignment (ILTSA) is a recent manifold learning method. In this paper, based on linearization and discriminant extension of ILTSA, a novel feature extraction method named Discriminant ILTSA (DILTSA) is proposed with its theory and algorithm analysis. Based on maximum neighborhood margin criterion and ILTSA, DILTSA can preserve both local within-class and between-class geometry structures. In face recognition application, an augmented Gabor-like complex wavelet transform is proposed, which can efficiently alleviate the illumination and expression variation effect. An approach for face recognition based on the fusion of local and holistic features is developed. Experimental results on Yale and PIE face databases demonstrate the effectiveness of the proposed face recognition method.
Improved Local Tangent Space Alignment (ILTSA) is a recent manifold learning method. In this paper, based on linearization and discriminant extension of ILTSA, a novel feature extraction method named Discriminant ILTSA (DILTSA) is proposed with its theory and algorithm analysis. Based on maximum neighborhood margin criterion and ILTSA, DILTSA can preserve both local within-class and between-class geometry structures. In face recognition application, an augmented Gabor-like complex wavelet transform is proposed, which can efficiently alleviate the illumination and expression variation effect. An approach for face recognition based on the fusion of local and holistic features is developed. Experimental results on Yale and PIE face databases demonstrate the effectiveness of the proposed face recognition method.
2012, 34(10): 2402-2408.
doi: 10.3724/SP.J.1146.2012.00158
Abstract:
In traditional Gaussian Mixture Modeling (GMM) algorithm, the risk that foreground model changes into background model rises with the cumulating of model weight under certain learning rate. That makes the algorithm unable to deal with slow moving object. This paper proposes an algorithm which takes advantage of the foreground models and employs an index of short-term stability measure to make a compound judgment. Each pixel status is decided real-timely considering the information of moving objects contained in foreground models and the pixel-level stability status. The results from different experiments verify that the proposed algorithm achieves a higher detection rate in detecting slow moving objects.
In traditional Gaussian Mixture Modeling (GMM) algorithm, the risk that foreground model changes into background model rises with the cumulating of model weight under certain learning rate. That makes the algorithm unable to deal with slow moving object. This paper proposes an algorithm which takes advantage of the foreground models and employs an index of short-term stability measure to make a compound judgment. Each pixel status is decided real-timely considering the information of moving objects contained in foreground models and the pixel-level stability status. The results from different experiments verify that the proposed algorithm achieves a higher detection rate in detecting slow moving objects.
2012, 34(10): 2409-2414.
doi: 10.3724/SP.J.1146.2012.00357
Abstract:
A new forensics method is proposed to detect asymmetric cropping. According to the method, the inconsistency of the principal point is used as evidence of cropping, and the camera calibration method is introduced to estimate the principal point. The camera calibration model is improved to meet the requirements of image forensics, in the new model, the target objects are selected from those regular figures on different planes, so the principal point coordinate can be estimated from a single image without modeling and measuring the target objects. Experiments show that the proposed method can identify asymmetric cropping of the image effectively.
A new forensics method is proposed to detect asymmetric cropping. According to the method, the inconsistency of the principal point is used as evidence of cropping, and the camera calibration method is introduced to estimate the principal point. The camera calibration model is improved to meet the requirements of image forensics, in the new model, the target objects are selected from those regular figures on different planes, so the principal point coordinate can be estimated from a single image without modeling and measuring the target objects. Experiments show that the proposed method can identify asymmetric cropping of the image effectively.
2012, 34(10): 2415-2420.
doi: 10.3724/SP.J.1146.2012.00286
Abstract:
The orthogonal pulse design based on Prolate Spheroidal Wave Function (PSWF) is hard for hardware design. By the optimization and integration of the pulse solution and orthogonalizaiton procedure, a novel orthogonal PSWF pulse waveform design based on Karhunen-Loeve transform is proposed. The method represents firstly PSWF into a series of Legendre functions, and the factor matrix for orthogonality is achieved by Karhunen-Loeve transform of the cross correlation matrix. On this basis, an efficient hardware implementation of orthogonal PSWF pulse is put forward. The proposed method builds a mapping between orthogonal PSWF pulse and coefficient vector of Legendre polynomial，and the method can be used to design orthogonal PSWF pulses by changing eigenpolynomial coefficients effectively. Meanwhile, the method has good real-time performance and low hardware complexity and provides a fast and efficient scheme for the engineering realization of orthogonal PSWF pulse.
The orthogonal pulse design based on Prolate Spheroidal Wave Function (PSWF) is hard for hardware design. By the optimization and integration of the pulse solution and orthogonalizaiton procedure, a novel orthogonal PSWF pulse waveform design based on Karhunen-Loeve transform is proposed. The method represents firstly PSWF into a series of Legendre functions, and the factor matrix for orthogonality is achieved by Karhunen-Loeve transform of the cross correlation matrix. On this basis, an efficient hardware implementation of orthogonal PSWF pulse is put forward. The proposed method builds a mapping between orthogonal PSWF pulse and coefficient vector of Legendre polynomial，and the method can be used to design orthogonal PSWF pulses by changing eigenpolynomial coefficients effectively. Meanwhile, the method has good real-time performance and low hardware complexity and provides a fast and efficient scheme for the engineering realization of orthogonal PSWF pulse.
2012, 34(10): 2421-2426.
doi: 10.3724/SP.J.1146.2011.01407
Abstract:
To solve the degradation of robustness against array steering vector error with finite snapshot in the adaptive beamformer, a novel single-channel robust adaptive beamforming algorithm based on Compressive Sensing (CS) is derived. A single-channel array system is first presented, and then the array signal module based on CS is build, in which the sensing matrix satisfies the Restricted Isometry Property (RIP). The signal and interference matrix can be recovered by fast Robust Smoothed L0 (RSL0) norm algorithm. Finally, the effective beam can be formed with the objective function and constraint setting to be array sensitivity function and interference matrix respectively.Computer simulation shows that the presented algorithm can suppress interferences with any coherence in case of one single-channel of radio frequency and finite snapshots, confirming the validity and superiority of the proposed algorithm.
To solve the degradation of robustness against array steering vector error with finite snapshot in the adaptive beamformer, a novel single-channel robust adaptive beamforming algorithm based on Compressive Sensing (CS) is derived. A single-channel array system is first presented, and then the array signal module based on CS is build, in which the sensing matrix satisfies the Restricted Isometry Property (RIP). The signal and interference matrix can be recovered by fast Robust Smoothed L0 (RSL0) norm algorithm. Finally, the effective beam can be formed with the objective function and constraint setting to be array sensitivity function and interference matrix respectively.Computer simulation shows that the presented algorithm can suppress interferences with any coherence in case of one single-channel of radio frequency and finite snapshots, confirming the validity and superiority of the proposed algorithm.
2012, 34(10): 2427-2431.
doi: 10.3724/SP.J.1146.2012.00350
Abstract:
The existing algorithms for Prolate Spheroidal Wave Functions (PSWFs) have poor efficiency, high complexity in hardware implementation and especially uncontrollable precision. To overcome the above weaknesses, a new algorithm based on state transition matrix approximation of differential equation is proposed combining the theory of linear time-varying system. In the new algorithm, the state transition matrix on the whole interval is approximated by the ones on very small intervals. After that, the movement track of the system on discrete time spot is attained, and that is the numerical solution of PSWFs. The expression of error to the precise value is deduced theoretically and then the algorithm is improved to get the briefer error expression. The new algorithm is compared and analyzed with the one proposed by Parr and the approximation algorithm of Legendre polynomials on the calculation precision and complexity. The simulation results show that the proposed algorithm has high and controllable precision, low complexity and are easy for hardware implementation.
The existing algorithms for Prolate Spheroidal Wave Functions (PSWFs) have poor efficiency, high complexity in hardware implementation and especially uncontrollable precision. To overcome the above weaknesses, a new algorithm based on state transition matrix approximation of differential equation is proposed combining the theory of linear time-varying system. In the new algorithm, the state transition matrix on the whole interval is approximated by the ones on very small intervals. After that, the movement track of the system on discrete time spot is attained, and that is the numerical solution of PSWFs. The expression of error to the precise value is deduced theoretically and then the algorithm is improved to get the briefer error expression. The new algorithm is compared and analyzed with the one proposed by Parr and the approximation algorithm of Legendre polynomials on the calculation precision and complexity. The simulation results show that the proposed algorithm has high and controllable precision, low complexity and are easy for hardware implementation.
2012, 34(10): 2432-2438.
doi: 10.3724/SP.J.1146.2012.00460
Abstract:
Infrared ship segmentation is very important for automatic infrared ship recognition in the sea. The thresholding based algorithms are widely applied to segmentation due to the intrinsic merits. The threshold is set based on the assumption that the intensity relation between target and background is known, but the assumption is incorrect in the medium wasve infrared images. Because of the sensitivity to the environment, the target in the medium wave infrared images may be bilateral polarity, so the adaptive thresholding can not be realized. Considering the adaptive thresholding ability for segmentation of bilateral polarity ship target, a new maximum two dimensions entropy segmentation algorithm is proposed. The multi-scale local variance-entropy variety and variance of gradient direction are used to build the two dimensions histogram, the optimized threshold vector are obtained by maximizing two dimensions entropy using the particle swarm optimization algorithm. Then the fine segmentation is performed by iterative thresholding on the coarse segmentation results to get the accurate segmentation result. Experimental results indicate that the proposed algorithm can get good performance in bilateral polarity target segmentation.
Infrared ship segmentation is very important for automatic infrared ship recognition in the sea. The thresholding based algorithms are widely applied to segmentation due to the intrinsic merits. The threshold is set based on the assumption that the intensity relation between target and background is known, but the assumption is incorrect in the medium wasve infrared images. Because of the sensitivity to the environment, the target in the medium wave infrared images may be bilateral polarity, so the adaptive thresholding can not be realized. Considering the adaptive thresholding ability for segmentation of bilateral polarity ship target, a new maximum two dimensions entropy segmentation algorithm is proposed. The multi-scale local variance-entropy variety and variance of gradient direction are used to build the two dimensions histogram, the optimized threshold vector are obtained by maximizing two dimensions entropy using the particle swarm optimization algorithm. Then the fine segmentation is performed by iterative thresholding on the coarse segmentation results to get the accurate segmentation result. Experimental results indicate that the proposed algorithm can get good performance in bilateral polarity target segmentation.
2012, 34(10): 2439-2444.
doi: 10.3724/SP.J.1146.2012.00069
Abstract:
In accordance with the problem of failure tracking in coherent composite code tracking loop leaded by greater carrier phase tracking error, a non-coherent tracking loop is proposed in this paper. The methods of constructing composite Pseudo-Noise (PN) code sequences with Binary Offset Carriermodulation (BOC) modulation and the correlation properties are given. The non-coherent discriminator and the loop filter of the tracking loop and the analysis of the loop tracking performance are also presented. The analysis and simulation show that the design of PN code tracking loop can work effectively with the existence of the carrier phase tracking error and also gives a good tracking performance.
In accordance with the problem of failure tracking in coherent composite code tracking loop leaded by greater carrier phase tracking error, a non-coherent tracking loop is proposed in this paper. The methods of constructing composite Pseudo-Noise (PN) code sequences with Binary Offset Carriermodulation (BOC) modulation and the correlation properties are given. The non-coherent discriminator and the loop filter of the tracking loop and the analysis of the loop tracking performance are also presented. The analysis and simulation show that the design of PN code tracking loop can work effectively with the existence of the carrier phase tracking error and also gives a good tracking performance.
2012, 34(10): 2445-2450.
doi: 10.3724/SP.J.1146.2012.00366
Abstract:
Terrain Observation by Progressive scans SAR (TOPSAR) is a new and prospective mode of space-borne SAR. It keeps the wide swath advantage of ScanSAR, and solves the problems as scalloping. The signal of TOPSAR is alias in both frequency domain and time domain, to solve the problems, this article proposes a new full aperture imaging algorithm. The algorithm uses the frequency domain extension to solve the frequency domain alias and uses SPECtral ANalysis (SPECAN) technique to avoid the time domain alias of the output image. It is compact and efficient. Lattice-point targets and distribute targets are simulated to validate the algorithm. The amount of the computation is analyzed and the algorithm is compared with two existing full aperture algorithms to validate the effectiveness.
Terrain Observation by Progressive scans SAR (TOPSAR) is a new and prospective mode of space-borne SAR. It keeps the wide swath advantage of ScanSAR, and solves the problems as scalloping. The signal of TOPSAR is alias in both frequency domain and time domain, to solve the problems, this article proposes a new full aperture imaging algorithm. The algorithm uses the frequency domain extension to solve the frequency domain alias and uses SPECtral ANalysis (SPECAN) technique to avoid the time domain alias of the output image. It is compact and efficient. Lattice-point targets and distribute targets are simulated to validate the algorithm. The amount of the computation is analyzed and the algorithm is compared with two existing full aperture algorithms to validate the effectiveness.
2012, 34(10): 2451-2457.
doi: 10.3724/SP.J.1146.2012.00308
Abstract:
In this paper, the issue of volume scattering overestimation as all known existing in Freeman decomposition is analyzed in detail, and a three-component decomposition model based on de-orientation and a generalized volume scattering model is presented to reduce the overestimation of volume power. Firstly, de-orientation is applied to the covariance matrix to reduce the volume scattering power before it is decomposed into three scattering components. Secondly, a generalized volume scattering model is adopted by considering the change of HH and VV ratio in different forest areas. In addition, power constrain method is added to eliminate negative power completely. The results are validated by using the L band ESAR data in Oberpfaffenhofen area in Germany and comparing with many other methods. The results show that the integrated model can solve the volume scattering overestimation more notable than other decomposition model, and the results are closer to real scattering type.
In this paper, the issue of volume scattering overestimation as all known existing in Freeman decomposition is analyzed in detail, and a three-component decomposition model based on de-orientation and a generalized volume scattering model is presented to reduce the overestimation of volume power. Firstly, de-orientation is applied to the covariance matrix to reduce the volume scattering power before it is decomposed into three scattering components. Secondly, a generalized volume scattering model is adopted by considering the change of HH and VV ratio in different forest areas. In addition, power constrain method is added to eliminate negative power completely. The results are validated by using the L band ESAR data in Oberpfaffenhofen area in Germany and comparing with many other methods. The results show that the integrated model can solve the volume scattering overestimation more notable than other decomposition model, and the results are closer to real scattering type.
2012, 34(10): 2458-2465.
doi: 10.3724/SP.J.1146.2012.00297
Abstract:
Due to wind turbulence and flight instability, the flight trajectories of drones often exhibit highly variety in position and attitude. The deviation from linear stable paths causes non-uniform illuminating energy of Synthetic Aperture Radar (SAR) system on targets, and also the fluctuant SAR image amplitude. In order to suppress the effect of imaging model and revert the scattering features of targets, in this paper the concept of illumination is introduced to denote the radar illumination energy per unit area. Then the expression of illumination is deduced, and shows that image amplitude can be considered as the product of illumination and scattering intensity of targets. Traditional image equalization methods confuse the difference between illumination ununiformity and amplitude of targets, thus the equalization results can not show the real scattering intensity of targets. A novel image equalization method based on illumination is presented to overcome these conditions unconsidered by previous algorithms. In this method the illumination is computed during the Back-Projection (BP) accumulation and the image result is weighted by the illumination. The computer simulation and real data results demonstrate the effectiveness of this approach in suppressing the image amplitude ununiformity caused by variety in position and attitude and resuming the scattering feature of targets.
Due to wind turbulence and flight instability, the flight trajectories of drones often exhibit highly variety in position and attitude. The deviation from linear stable paths causes non-uniform illuminating energy of Synthetic Aperture Radar (SAR) system on targets, and also the fluctuant SAR image amplitude. In order to suppress the effect of imaging model and revert the scattering features of targets, in this paper the concept of illumination is introduced to denote the radar illumination energy per unit area. Then the expression of illumination is deduced, and shows that image amplitude can be considered as the product of illumination and scattering intensity of targets. Traditional image equalization methods confuse the difference between illumination ununiformity and amplitude of targets, thus the equalization results can not show the real scattering intensity of targets. A novel image equalization method based on illumination is presented to overcome these conditions unconsidered by previous algorithms. In this method the illumination is computed during the Back-Projection (BP) accumulation and the image result is weighted by the illumination. The computer simulation and real data results demonstrate the effectiveness of this approach in suppressing the image amplitude ununiformity caused by variety in position and attitude and resuming the scattering feature of targets.
The Long-range Dependence Characteristic Analysis of Sea Clutter Based on the Semivariogram Function
2012, 34(10): 2466-2469.
doi: 10.3724/SP.J.1146.2011.01341
Abstract:
A target detection method based on the long-range dependence characteristic of sea clutter is proposed. By using the semivariogram function, the long-range dependence feature curve of sea clutter versus time is obtained. According to the curve, we suggest the slope and sample mean value of semivariogram curve as parameters to describe the fractal characteristics of the target and sea clutter. The analysis tests show that, with the two parameters, the target could be effectively distinguished from the sea clutter background.
A target detection method based on the long-range dependence characteristic of sea clutter is proposed. By using the semivariogram function, the long-range dependence feature curve of sea clutter versus time is obtained. According to the curve, we suggest the slope and sample mean value of semivariogram curve as parameters to describe the fractal characteristics of the target and sea clutter. The analysis tests show that, with the two parameters, the target could be effectively distinguished from the sea clutter background.
2012, 34(10): 2470-2474.
doi: 10.3724/SP.J.1146.2012.00382
Abstract:
Insufficient samples result in estimation error of covariance matrix for Space-Time Adaptive Process (STAP), a merged method of multi-frequency space-time data is presented to improve the estimation accuracy. Based on the analysis of clutter character in different frequencies, this method modifies the power between frequencies by rebuilding covariance matrix, and merges the multi-frequency space-time data to improve the estimation accuracy. A preliminary result against an airborne simulation data demonstrates the effectiveness of the proposed method.
Insufficient samples result in estimation error of covariance matrix for Space-Time Adaptive Process (STAP), a merged method of multi-frequency space-time data is presented to improve the estimation accuracy. Based on the analysis of clutter character in different frequencies, this method modifies the power between frequencies by rebuilding covariance matrix, and merges the multi-frequency space-time data to improve the estimation accuracy. A preliminary result against an airborne simulation data demonstrates the effectiveness of the proposed method.
2012, 34(10): 2475-2481.
doi: 10.3724/SP.J.1146.2012.00079
Abstract:
In this paper, the preprocessing method for the visibility functions in synthetic aperture radiometer is proposed, including the correction on the AD bias, the inversion of the analog correlation from the raw 3-level digitized correlation, the correction of the quadrature error, and the compensation of the fringe washing effects. The adjustment of the analog correlation from the raw 3-level digitized correlation is particularly introduced, which is the first time that the method is applied to the calibration of the earth observation domain. The Monte-Carlo simulation in time domain on the preprocessing method for the visibility functions is performed. The correctness of the preprocessing algorithm is tested and verified by the Geostationary Interferometric Microwave Sounder system. The bias of the result after adjusted is better than 0.1% of the true value, which could proof that the preprocessing algorithm can be used in the calibration of the Geostationary Interferometric Microwave Sounder for spaceborne system. And the result can easily be used in the inversion of the brightness temperature imaging.
In this paper, the preprocessing method for the visibility functions in synthetic aperture radiometer is proposed, including the correction on the AD bias, the inversion of the analog correlation from the raw 3-level digitized correlation, the correction of the quadrature error, and the compensation of the fringe washing effects. The adjustment of the analog correlation from the raw 3-level digitized correlation is particularly introduced, which is the first time that the method is applied to the calibration of the earth observation domain. The Monte-Carlo simulation in time domain on the preprocessing method for the visibility functions is performed. The correctness of the preprocessing algorithm is tested and verified by the Geostationary Interferometric Microwave Sounder system. The bias of the result after adjusted is better than 0.1% of the true value, which could proof that the preprocessing algorithm can be used in the calibration of the Geostationary Interferometric Microwave Sounder for spaceborne system. And the result can easily be used in the inversion of the brightness temperature imaging.
2012, 34(10): 2482-2488.
doi: 10.3724/SP.J.1146.2012.00276
Abstract:
In order to achieve reasonable and reliable results of directional spectrum used in wave measurement of Acoustic Doppler Current Profiler (ADCP), three practical inversion algorithms based on array measurement are analyzed on performance in theory and used in translating water surface elevation collected by ADCP (both computer simulated and experimental data included) into directional wave spectra for comparison. It is shown that Bayesian Directional spectrum estimation Method (BDM) is most accurate in directional resolution; Maximum Likelihood Method (MLM) reaches sufficient stability of solution; and with long wavelengths, Extended Eigen- Vector (EEV) method can obtain most specific and sharp peaks of directional spectra. Therefore, MLM is suitable for real-time processing of wave data, and BDM could be used when higher accuracy is demanded.
In order to achieve reasonable and reliable results of directional spectrum used in wave measurement of Acoustic Doppler Current Profiler (ADCP), three practical inversion algorithms based on array measurement are analyzed on performance in theory and used in translating water surface elevation collected by ADCP (both computer simulated and experimental data included) into directional wave spectra for comparison. It is shown that Bayesian Directional spectrum estimation Method (BDM) is most accurate in directional resolution; Maximum Likelihood Method (MLM) reaches sufficient stability of solution; and with long wavelengths, Extended Eigen- Vector (EEV) method can obtain most specific and sharp peaks of directional spectra. Therefore, MLM is suitable for real-time processing of wave data, and BDM could be used when higher accuracy is demanded.
2012, 34(10): 2489-2493.
doi: 10.3724/SP.J.1146.2012.00299
Abstract:
This paper presents a method of double-probe electric field in-orbit detection. Differences of three kinds of instrument including double-probe type, antenna type and electron drift type are briefly introduced. The principle，architecture and calibration method of double-probe spaceborne electric field sensor are described in detail. Sensitive probe and signal acquisition processing units are implemented and tested with sensor in-orbit environment simulation through resistive coupling. Experiment results indicate that noise amplitude spectrum intensity of band SLF,VLF,HF are less than 4 Vm-1Hz-1/2,1 Vm-1 Hz-1/2, 0.5 Vm-1Hz-1/2 separately.
This paper presents a method of double-probe electric field in-orbit detection. Differences of three kinds of instrument including double-probe type, antenna type and electron drift type are briefly introduced. The principle，architecture and calibration method of double-probe spaceborne electric field sensor are described in detail. Sensitive probe and signal acquisition processing units are implemented and tested with sensor in-orbit environment simulation through resistive coupling. Experiment results indicate that noise amplitude spectrum intensity of band SLF,VLF,HF are less than 4 Vm-1Hz-1/2,1 Vm-1 Hz-1/2, 0.5 Vm-1Hz-1/2 separately.
2012, 34(10): 2494-2500.
doi: 10.3724/SP.J.1146.2012.00402
Abstract:
Cyber-Physical System (CPS) components substitution is an important issue for CPS troubleshooting and system upgrading. Based on a service-oriented architecture of CPS, this issue is equated to CPS service substitution. A formal method for modeling CPS service is proposed based on time-space-calculus, which is presented through introducing time and space operators into classical-calculus. Then, starting with the relationship between service compatibility and substitution, a decision theorem for CPS service substitution is put forward. Finally, a case study is performed to show that how to apply this theorem to CPS components substitution.
Cyber-Physical System (CPS) components substitution is an important issue for CPS troubleshooting and system upgrading. Based on a service-oriented architecture of CPS, this issue is equated to CPS service substitution. A formal method for modeling CPS service is proposed based on time-space-calculus, which is presented through introducing time and space operators into classical-calculus. Then, starting with the relationship between service compatibility and substitution, a decision theorem for CPS service substitution is put forward. Finally, a case study is performed to show that how to apply this theorem to CPS components substitution.
2012, 34(10): 2501-2507.
doi: 10.3724/SP.J.1146.2012.00099
Abstract:
In the system of Network on Chip (NoC), local systems normally adopt bus-based architectures while global networks use packet-based communications. However, since the natural difference between these two architectures is unavoidable, it introduces performance degradation to the overall system when cores in local systems visit global resources. And the situation will be worse in the enviroment of 3D NoC due to its larger network sizes. In this paper, a 3D NoC based on Statistical Time Division Multiplexing (STDM) is proposed. Firstly, a STDM controller is introduced into the local system. Then the network interface is designed using the mechanism of counting and waiting. Finally, the router is optimized for supporting the STDM better. And novel packet formats are designed to reduce the network load and improve the system performance further. In order to demonstrate the efficiency of the novel method, a systemC model is built on system level and experimental results show that the proposed method can reduce network load and transmission delay sharply. In the best condition, the improvement can reach 45% and 20.5% compared with the conventional one. And for real applications, especially for communication-intensive ones, the proposed architecture can also improve the performance a lot.
In the system of Network on Chip (NoC), local systems normally adopt bus-based architectures while global networks use packet-based communications. However, since the natural difference between these two architectures is unavoidable, it introduces performance degradation to the overall system when cores in local systems visit global resources. And the situation will be worse in the enviroment of 3D NoC due to its larger network sizes. In this paper, a 3D NoC based on Statistical Time Division Multiplexing (STDM) is proposed. Firstly, a STDM controller is introduced into the local system. Then the network interface is designed using the mechanism of counting and waiting. Finally, the router is optimized for supporting the STDM better. And novel packet formats are designed to reduce the network load and improve the system performance further. In order to demonstrate the efficiency of the novel method, a systemC model is built on system level and experimental results show that the proposed method can reduce network load and transmission delay sharply. In the best condition, the improvement can reach 45% and 20.5% compared with the conventional one. And for real applications, especially for communication-intensive ones, the proposed architecture can also improve the performance a lot.
2012, 34(10): 2508-2513.
doi: 10.3724/SP.J.1146.2012.00375
Abstract:
With the deficiency of the efficient of the Boolean SATisfiability (SAT) in the nano-meter CMOS circuit (CMOS/nanowire/MOLecular, CMOL) cell assignment resulted from the huge number of clauses and the big intermediate processing file, a novel approach using Pseudo-Boolean Satisfiability (PBS) to solve the CMOL cell assignment is proposed. The experimental results show that the proposed method can reduce the intermediate processing file efficiently by cutting down the number of the constraints without the additional Boolean variables introduced. The reduction of clauses and the intermediate processing file makes the proposed method work efficiently and improve the ability to deal with bigger circuits in contrast to the traditional SAT-based methods.
With the deficiency of the efficient of the Boolean SATisfiability (SAT) in the nano-meter CMOS circuit (CMOS/nanowire/MOLecular, CMOL) cell assignment resulted from the huge number of clauses and the big intermediate processing file, a novel approach using Pseudo-Boolean Satisfiability (PBS) to solve the CMOL cell assignment is proposed. The experimental results show that the proposed method can reduce the intermediate processing file efficiently by cutting down the number of the constraints without the additional Boolean variables introduced. The reduction of clauses and the intermediate processing file makes the proposed method work efficiently and improve the ability to deal with bigger circuits in contrast to the traditional SAT-based methods.
2012, 34(10): 2514-2519.
doi: 10.3724/SP.J.1146.2012.00447
Abstract:
By researching the adiabatic domino circuit and the adder, a novel design of low power ternary adder on switch-level is proposed. First, the switch-level structure of ternary adders summing circuit and carrying circuit are derived according to the switch-signal theory and the peculiarity of adiabatic domino circuit. The design of the one bit adiabatic Domino adder unit and the four bit adder are obtained. Finally, the circuit is simulated by Spice tool and the results show that the logic function of the four bit adiabatic Domino adder is correct. The energy consumption of the four bit adiabatic Domino adder is 61% less than the conventional Domino counterpart.
By researching the adiabatic domino circuit and the adder, a novel design of low power ternary adder on switch-level is proposed. First, the switch-level structure of ternary adders summing circuit and carrying circuit are derived according to the switch-signal theory and the peculiarity of adiabatic domino circuit. The design of the one bit adiabatic Domino adder unit and the four bit adder are obtained. Finally, the circuit is simulated by Spice tool and the results show that the logic function of the four bit adiabatic Domino adder is correct. The energy consumption of the four bit adiabatic Domino adder is 61% less than the conventional Domino counterpart.
2012, 34(10): 2520-2526.
doi: 10.3724/SP.J.1146.2012.00376
Abstract:
Recently Fang et al. (2011) proposed a password-based remote user authentication scheme using smart cards for resource-constrained environment, and claimed that their scheme was secure and practical. However, it is found that their scheme can not achieve the claimed security, it is vulnerable to offline password guessing attack, parallel session attack and known key attack. In addition, the password change phase of their scheme is not user-friendly and practical. Consequently, an improved scheme is presented and analyzed, the analysis shows that new scheme eliminates the defects of Fang et al.s scheme while keeping the merit of high performance, suitable for resource-constrained and security-concerned application scenarios.
Recently Fang et al. (2011) proposed a password-based remote user authentication scheme using smart cards for resource-constrained environment, and claimed that their scheme was secure and practical. However, it is found that their scheme can not achieve the claimed security, it is vulnerable to offline password guessing attack, parallel session attack and known key attack. In addition, the password change phase of their scheme is not user-friendly and practical. Consequently, an improved scheme is presented and analyzed, the analysis shows that new scheme eliminates the defects of Fang et al.s scheme while keeping the merit of high performance, suitable for resource-constrained and security-concerned application scenarios.
2012, 34(10): 2527-2531.
doi: 10.3724/SP.J.1146.2011.01199
Abstract:
To solve the power allocation collision in decentralized cognitive radio networks with asymmetric channel state information, a new Signaling Games (SG) based power control algorithm is proposed. The competitive secondary users allocate power using signaling games schemes to share channel state information without using common control channel. It could effectively guarantee primary users transmission and avoid power allocation collision among secondary users. Moreover, the equilibrium result is analyzed and the simulation results verify the validity of channel gain estimation and improvement of throughput of secondary users.
To solve the power allocation collision in decentralized cognitive radio networks with asymmetric channel state information, a new Signaling Games (SG) based power control algorithm is proposed. The competitive secondary users allocate power using signaling games schemes to share channel state information without using common control channel. It could effectively guarantee primary users transmission and avoid power allocation collision among secondary users. Moreover, the equilibrium result is analyzed and the simulation results verify the validity of channel gain estimation and improvement of throughput of secondary users.
2012, 34(10): 2532-2536.
doi: 10.3724/SP.J.1146.2012.00290
Abstract:
The performance of subspace estimation algorithms degrades substantially in the presence of mutual coupling and coherent environments by the perturbance of steering matrix and the rank defect of covariance matrix. In order to settle these issues, a novel modified single snapshot algorithm for decorrelation and decoupling using only single snapshot is proposed. The algorithm utilizes single snapshot to constitute equivalent receiving data covariance matrix, the mutual coupling cofficients can be isolated from steering matrix and be absorbed into equivalent signal covariance matrix by decomposing the equivalent receiving data covariance matrix, so the decoupling is accomplished. Equivalent signal covariance matrix is a diagonal matrix, and its diagonal elements are unrelated to the correlation of signals, so the decorrelation is accomplished. The simulation results show that the proposed algorithm can restrain mutual coupling and be applied to high calculation speed scenarios. The performance of the algorithm is equivalent to the performance of the algorithm without mutual coupling.
The performance of subspace estimation algorithms degrades substantially in the presence of mutual coupling and coherent environments by the perturbance of steering matrix and the rank defect of covariance matrix. In order to settle these issues, a novel modified single snapshot algorithm for decorrelation and decoupling using only single snapshot is proposed. The algorithm utilizes single snapshot to constitute equivalent receiving data covariance matrix, the mutual coupling cofficients can be isolated from steering matrix and be absorbed into equivalent signal covariance matrix by decomposing the equivalent receiving data covariance matrix, so the decoupling is accomplished. Equivalent signal covariance matrix is a diagonal matrix, and its diagonal elements are unrelated to the correlation of signals, so the decorrelation is accomplished. The simulation results show that the proposed algorithm can restrain mutual coupling and be applied to high calculation speed scenarios. The performance of the algorithm is equivalent to the performance of the algorithm without mutual coupling.
2012, 34(10): 2537-2540.
doi: 10.3724/SP.J.1146.2012.00141
Abstract:
According to the equivalent circuit of the mushroom-like Electromagnetic Band Gap (EBG) structure, a novel method of inserting the Inter-Digital Capacitor (IDC) to broaden the bandwidth of the stop-band is proposed in this paper. The T-shaped IDC EBG structure is designed to prove the correction and validity of the method. Compared with the mushroom-like EBG, the -30 dB stop-band of the proposed structure is broadened from 6.1 GHz to 7.1 GHz and the lower corner frequency is decreased from 0.9 GHz to 0.29 GHz. It is implemented by increasing the number of planes of IDC and decreasing the thickness of cell without changing the area of EBG cell. The results of the simulation show that the presented TIDC EBG is fit for Simultaneous Switching Noise (SSN) suppression.
According to the equivalent circuit of the mushroom-like Electromagnetic Band Gap (EBG) structure, a novel method of inserting the Inter-Digital Capacitor (IDC) to broaden the bandwidth of the stop-band is proposed in this paper. The T-shaped IDC EBG structure is designed to prove the correction and validity of the method. Compared with the mushroom-like EBG, the -30 dB stop-band of the proposed structure is broadened from 6.1 GHz to 7.1 GHz and the lower corner frequency is decreased from 0.9 GHz to 0.29 GHz. It is implemented by increasing the number of planes of IDC and decreasing the thickness of cell without changing the area of EBG cell. The results of the simulation show that the presented TIDC EBG is fit for Simultaneous Switching Noise (SSN) suppression.
