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2002 Vol. 24, No. 9
Display Method:
A QoS-based routing and wavelength assignment algorithm in survivable WDM optical transport networks
2002, 24(9): 1153-1160.
Abstract:
This paper considers the survivability of WDM layer according to the client layers QoS requirements. A novel priority-based protection strategy is presented, and a QoS-based layered graph method is developed in the WDM optical transport network to reduced the blocking probability of the connection request. Based on them, a QoS-based RWA strategy in survivable WDM networks is proposed. Simulation results of the network performance in different dynamic traffic load are given. The results show that this algorithm can not only meet the different QoS requirements of the client layers service, but also utilize the finite networking resources efficiently with the reduced blocking probability.
This paper considers the survivability of WDM layer according to the client layers QoS requirements. A novel priority-based protection strategy is presented, and a QoS-based layered graph method is developed in the WDM optical transport network to reduced the blocking probability of the connection request. Based on them, a QoS-based RWA strategy in survivable WDM networks is proposed. Simulation results of the network performance in different dynamic traffic load are given. The results show that this algorithm can not only meet the different QoS requirements of the client layers service, but also utilize the finite networking resources efficiently with the reduced blocking probability.
2002, 24(9): 1161-1166.
Abstract:
In this paper, a novel blind adaptive multiuser detection is proposed, the computing complex of this algorithm is O(NL), where N is the spread grain, and L is the window length. The simulation shows that this algorithm has good steady state performance and it converges very fast, and can be used when the environment varies, so it is a very good multiuser detection.
In this paper, a novel blind adaptive multiuser detection is proposed, the computing complex of this algorithm is O(NL), where N is the spread grain, and L is the window length. The simulation shows that this algorithm has good steady state performance and it converges very fast, and can be used when the environment varies, so it is a very good multiuser detection.
2002, 24(9): 1167-1171.
Abstract:
A MultiWavelet-based Code-Division Multiple-Access (MW-CDMA) scheme is presented based on the application of recent results in multiwavelet analysis filter, preprocessing and balancing to communications area. In MW-CDMA, at first, the received signal is decomposed into the components in the orthogonal wavelet spaces, and then the multiuser demodulation is implemented in each wavelet space. Theoretical analyses and experimental results show that MW-CDMA systems suppress multiple-access interference and ambient noise well. Moreover, the scheme gives a new guideline of thought to reduce the computation for demodulating.
A MultiWavelet-based Code-Division Multiple-Access (MW-CDMA) scheme is presented based on the application of recent results in multiwavelet analysis filter, preprocessing and balancing to communications area. In MW-CDMA, at first, the received signal is decomposed into the components in the orthogonal wavelet spaces, and then the multiuser demodulation is implemented in each wavelet space. Theoretical analyses and experimental results show that MW-CDMA systems suppress multiple-access interference and ambient noise well. Moreover, the scheme gives a new guideline of thought to reduce the computation for demodulating.
2002, 24(9): 1177-1184.
Abstract:
This paper studies the security evaluation against differential and linear attacks for a class of generalized Feistel ciphers. If the round function is bijective and its maximum differential and linear characteristic probabilities are p and q, then the upper bounds of maximum differential and linear characteristic probabilities for 16-round ciphers are p7 and q7. If the round function is bijective and SP structure, the maximum differential and linear characteristic probabilities of S-boxes are pS and qS, the branch number of P is Pd, then the upper bounds of maximum differential and linear characteristic probabilities for 16-round ciphers are (pS)3Pd+1 and (qS)3Pd+1.
This paper studies the security evaluation against differential and linear attacks for a class of generalized Feistel ciphers. If the round function is bijective and its maximum differential and linear characteristic probabilities are p and q, then the upper bounds of maximum differential and linear characteristic probabilities for 16-round ciphers are p7 and q7. If the round function is bijective and SP structure, the maximum differential and linear characteristic probabilities of S-boxes are pS and qS, the branch number of P is Pd, then the upper bounds of maximum differential and linear characteristic probabilities for 16-round ciphers are (pS)3Pd+1 and (qS)3Pd+1.
2002, 24(9): 1185-1189.
Abstract:
This paper discusses the characterizations of multi-output correlation-immune functions. We first give a decomposition formula of the probability distribution of binary random vectors by using Walsh transform. Then the equivalence of the two different definitions of multi-output correlation-immune functions is proved. Furthermore, a class of keystream generators is constructed which can resist the linear and correlation attacks.
This paper discusses the characterizations of multi-output correlation-immune functions. We first give a decomposition formula of the probability distribution of binary random vectors by using Walsh transform. Then the equivalence of the two different definitions of multi-output correlation-immune functions is proved. Furthermore, a class of keystream generators is constructed which can resist the linear and correlation attacks.
2002, 24(9): 1190-1196.
Abstract:
A new frame line detection algorithm based on the structural image element-Directional Single-Connected Chain (DSCC) is proposed. Taking advantages of the global statistical property of the edges of the DSCCs, and their local mutual relations, the algorithm is able to accurately extract frame lines from scanned form images. It demonstrates the desired performance of insensitive to line slant, breaks as well as touches from character strokes inside the form cells. Based on this algorithm, a frame line removal approach is presented, by which the frame line can be removed without affecting the touched character strokes.
A new frame line detection algorithm based on the structural image element-Directional Single-Connected Chain (DSCC) is proposed. Taking advantages of the global statistical property of the edges of the DSCCs, and their local mutual relations, the algorithm is able to accurately extract frame lines from scanned form images. It demonstrates the desired performance of insensitive to line slant, breaks as well as touches from character strokes inside the form cells. Based on this algorithm, a frame line removal approach is presented, by which the frame line can be removed without affecting the touched character strokes.
2002, 24(9): 1197-1121.
Abstract:
This paper proposes a third-order cumulant-based criterion of goodness, and gives a third-order cumulant-based gradient-type adaptive filtering algorithm by using the steepest descent method on the criterion. The algorithm is applied to identify stationary and non-stationary MA (Moving Average) model by computer simulation. Simulation results indicate that the algorithm has better convergence property as well as the tracking capability for time varying system.
This paper proposes a third-order cumulant-based criterion of goodness, and gives a third-order cumulant-based gradient-type adaptive filtering algorithm by using the steepest descent method on the criterion. The algorithm is applied to identify stationary and non-stationary MA (Moving Average) model by computer simulation. Simulation results indicate that the algorithm has better convergence property as well as the tracking capability for time varying system.
2002, 24(9): 1202-1208.
Abstract:
This paper studies the design and optimization of LPPR-FIR filter banks by liftingscheme. It can be commutated into a quadratic optimization problem. Then, lifting scheme is generalized to the case of M-band perfect-reconstruction (PR) FIR filter banks. Last, some examples will be given to demonstrate how to construct LPPR-FIR filter banks.
This paper studies the design and optimization of LPPR-FIR filter banks by liftingscheme. It can be commutated into a quadratic optimization problem. Then, lifting scheme is generalized to the case of M-band perfect-reconstruction (PR) FIR filter banks. Last, some examples will be given to demonstrate how to construct LPPR-FIR filter banks.
2002, 24(9): 1209-1217.
Abstract:
In this paper, a neural equation with discrete time delay is studied, The transcendental equation corresponding to the above-mentioned linearized system is analyzed. The linear stability for this model has been investigated. For the case with inhibitory influence from the past state, it is found that Hopf bifurcation occurs when this influence varies and passes through a sequence of critical values. The stability of bifurcating periodic solutions and the direction of Hopf bifurcation are determined by applying the normal form theory and the center manifold theorem. Some numerical examples illustrated those results.
In this paper, a neural equation with discrete time delay is studied, The transcendental equation corresponding to the above-mentioned linearized system is analyzed. The linear stability for this model has been investigated. For the case with inhibitory influence from the past state, it is found that Hopf bifurcation occurs when this influence varies and passes through a sequence of critical values. The stability of bifurcating periodic solutions and the direction of Hopf bifurcation are determined by applying the normal form theory and the center manifold theorem. Some numerical examples illustrated those results.
2002, 24(9): 1218-1224.
Abstract:
In this paper wavelet transform is applied to pitch detection of Chinese trisyllabic word with characteristic of continuous speech, a new algorithm for pitch detection of speech signals using wavelet transform is proposed for the question appearing in pitch extraction. It is made up of the following processes: calculating discrete wavelet transform, selecting pitch points and determining the first pitch point based on voting strategy, checking pitch, modifying abnormal pitch point, processing pitch miss point at the beginning and end of a frame of speech signals, relocation of pitch point based on voting strategy. It has been found that this algorithm is valid, and very suits to process continuous speech. But it needs much time for computation, so it is not suit for real-time system.
In this paper wavelet transform is applied to pitch detection of Chinese trisyllabic word with characteristic of continuous speech, a new algorithm for pitch detection of speech signals using wavelet transform is proposed for the question appearing in pitch extraction. It is made up of the following processes: calculating discrete wavelet transform, selecting pitch points and determining the first pitch point based on voting strategy, checking pitch, modifying abnormal pitch point, processing pitch miss point at the beginning and end of a frame of speech signals, relocation of pitch point based on voting strategy. It has been found that this algorithm is valid, and very suits to process continuous speech. But it needs much time for computation, so it is not suit for real-time system.
2002, 24(9): 1225-1232.
Abstract:
Reduced-rank STAP has been a key technology in air-borne radar to cancel the clutter. Several methods have been presented through these years. In this paper, those methods are classified into two basic forms-one is based on the generalized sidelobe canceller(GSC), the other is based on the direct form. The differences in the performances and potential of these two catalogs of methods are compared through theoretical analysis. Simulation results in ideal situations and with limited sample are presented.
Reduced-rank STAP has been a key technology in air-borne radar to cancel the clutter. Several methods have been presented through these years. In this paper, those methods are classified into two basic forms-one is based on the generalized sidelobe canceller(GSC), the other is based on the direct form. The differences in the performances and potential of these two catalogs of methods are compared through theoretical analysis. Simulation results in ideal situations and with limited sample are presented.
2002, 24(9): 1233-1237.
Abstract:
A software self-calibration method of the channel amplitude of HF ground wave radar based on the received sea echo data is developed in this paper, in accordance with the characteristics of sea echo and the actual performance of the Ocean State Measuring and Analyzing Radar (OSMAR2000). The method does not need auxiliary signal source and can real-time calibrate channel amplitude for every range cell. Using the method, the radar system can give out warning information in the case of channel failure. The quality of spatial spectra improves much after channel amplitude calibration by the method. Some processing results of the OSMAR2000 field measurement and their comparison are illustrated in this paper.
A software self-calibration method of the channel amplitude of HF ground wave radar based on the received sea echo data is developed in this paper, in accordance with the characteristics of sea echo and the actual performance of the Ocean State Measuring and Analyzing Radar (OSMAR2000). The method does not need auxiliary signal source and can real-time calibrate channel amplitude for every range cell. Using the method, the radar system can give out warning information in the case of channel failure. The quality of spatial spectra improves much after channel amplitude calibration by the method. Some processing results of the OSMAR2000 field measurement and their comparison are illustrated in this paper.
2002, 24(9): 1238-1244.
Abstract:
The time-domain response of the induced currents on a scattering object irradiated by a plane wave with a Gaussian pulse in time is expanded as an associate Hermite series in this paper. Using the isomorphism of the associate Hermite function and its Fourier transform, the frequency-domain information can be obtained similarly to the time-domain expansion. According to the corresponding relation between time-domain analysis and frequency-domain analysis, and using the early-time response and the low-frequency information of the induced currents, the non-known coefficients in the expansion series can be decided. The entire responses of the induced currents on the scattering object in both time and frequency domains can be obtained at one time by simultaneous extrapolation computation using both the early-time response and the low-frequency information of the induced currents. Electromagnetic scattering of multi-cylinders are calculated and analyzed based on this extrapolation methodology in this paper.
The time-domain response of the induced currents on a scattering object irradiated by a plane wave with a Gaussian pulse in time is expanded as an associate Hermite series in this paper. Using the isomorphism of the associate Hermite function and its Fourier transform, the frequency-domain information can be obtained similarly to the time-domain expansion. According to the corresponding relation between time-domain analysis and frequency-domain analysis, and using the early-time response and the low-frequency information of the induced currents, the non-known coefficients in the expansion series can be decided. The entire responses of the induced currents on the scattering object in both time and frequency domains can be obtained at one time by simultaneous extrapolation computation using both the early-time response and the low-frequency information of the induced currents. Electromagnetic scattering of multi-cylinders are calculated and analyzed based on this extrapolation methodology in this paper.
2002, 24(9): 1245-1250.
Abstract:
Missile radome is a device for protecting the antenna system from influence of outside airflow when missile is flying with high speed. But the radome itself will produce some inverse effect on the property of antenna indeed, and the far directional pattern of radome could be used to assess the affect of the property by means of a numerical method. Based on the plane wave spectrum surface integration method, the electric property of the radome is analyzed and the method how to determine the integral area for numerical calculation of the pattern is presented in the paper.
Missile radome is a device for protecting the antenna system from influence of outside airflow when missile is flying with high speed. But the radome itself will produce some inverse effect on the property of antenna indeed, and the far directional pattern of radome could be used to assess the affect of the property by means of a numerical method. Based on the plane wave spectrum surface integration method, the electric property of the radome is analyzed and the method how to determine the integral area for numerical calculation of the pattern is presented in the paper.
2002, 24(9): 1251-1256.
Abstract:
This paper studies chaotic phenomena of phase-locked frequency detector that is used extensively in radio technology and modern communication fields. By Melnikovs method, phase-locked frequency detector will output chaotic signal when the systems parameter and the parameters of input signal satisfy certain conditions. By circuit experiment, when the circuit outputs chaotic signal, the continuous spectrum of the voltage-controlled oscillators output is observed from frequency spectrograph. The fact of phase-locked frequency detector exists chaotic phenomena is father verified. The experimental results and theory analysis correspond excellently with one another. The conclusion in this paper has importance directive significance for practical design and application of the phase-locked frequency detector.
This paper studies chaotic phenomena of phase-locked frequency detector that is used extensively in radio technology and modern communication fields. By Melnikovs method, phase-locked frequency detector will output chaotic signal when the systems parameter and the parameters of input signal satisfy certain conditions. By circuit experiment, when the circuit outputs chaotic signal, the continuous spectrum of the voltage-controlled oscillators output is observed from frequency spectrograph. The fact of phase-locked frequency detector exists chaotic phenomena is father verified. The experimental results and theory analysis correspond excellently with one another. The conclusion in this paper has importance directive significance for practical design and application of the phase-locked frequency detector.
2002, 24(9): 1257-1262.
Abstract:
This paper describes the method of measuring signal in extremely unstable chaotic system. Due to sensitive dependence on parameter, the tiny change in parameter can be obtained by measuring distance of the corresponding chaotic orbits.
This paper describes the method of measuring signal in extremely unstable chaotic system. Due to sensitive dependence on parameter, the tiny change in parameter can be obtained by measuring distance of the corresponding chaotic orbits.
2002, 24(9): 1263-1269.
Abstract:
A new hardware realization methodology of fuzzy controller based on Multiple-Valued Logic (MVL) circuits is proposed. To the methodology, the hardware fuzzy inference process for different rule is executed in different time. The combination of the inference results of different rules makes fuzzy output, then it is changed to general output by defuzzification. According to this methodology, the complexity of the controller is free from the number of rules and the executive speed free from the dimension of fuzzy variables, furthermore, the choice of membership functions is free and the adjustment of fuzzy control rules is easy. The new methodology can be easily realized by using the very-large-scale-integration technique.
A new hardware realization methodology of fuzzy controller based on Multiple-Valued Logic (MVL) circuits is proposed. To the methodology, the hardware fuzzy inference process for different rule is executed in different time. The combination of the inference results of different rules makes fuzzy output, then it is changed to general output by defuzzification. According to this methodology, the complexity of the controller is free from the number of rules and the executive speed free from the dimension of fuzzy variables, furthermore, the choice of membership functions is free and the adjustment of fuzzy control rules is easy. The new methodology can be easily realized by using the very-large-scale-integration technique.
2002, 24(9): 1270-1275.
Abstract:
In this paper, controlling lasing chaos with pump periodic modulation is proposed in an injected-semiconductor laser. Different modulation depths and frequencies have been found to be effective to control lasing chaos into stable periodic orbits (limit cycles) and convert lasing chaotic oscillation frequencies into the modulation frequencies. Different lasing chaotic waveforms are produced with the modulation controlling.
In this paper, controlling lasing chaos with pump periodic modulation is proposed in an injected-semiconductor laser. Different modulation depths and frequencies have been found to be effective to control lasing chaos into stable periodic orbits (limit cycles) and convert lasing chaotic oscillation frequencies into the modulation frequencies. Different lasing chaotic waveforms are produced with the modulation controlling.
2002, 24(9): 1282-1286.
Abstract:
A fast codebook training algorithm using local clustering, named the LC algorithm, is presented in this paper. Comparing with the LBG algorithm, it is simple and fast. The experiment using typical test, images Lena and Barbara shows that the algorithm is 14.61 ~ 13.6 times faster than the LBG algorithm, with its PSNR being reduced by 2% approximately from the LBG algorithm only. The reconstructed images between the LC and the LBG algorithms have no obvious differences at the 0.375 bit/pixel condition.
A fast codebook training algorithm using local clustering, named the LC algorithm, is presented in this paper. Comparing with the LBG algorithm, it is simple and fast. The experiment using typical test, images Lena and Barbara shows that the algorithm is 14.61 ~ 13.6 times faster than the LBG algorithm, with its PSNR being reduced by 2% approximately from the LBG algorithm only. The reconstructed images between the LC and the LBG algorithms have no obvious differences at the 0.375 bit/pixel condition.
2002, 24(9): 1287-1290.
Abstract:
This paper analyzes the essence of a sort of algorithm on image enhancement with fuzzy sets, presents the concept of the bounded histogram and applies them to the sonar image enhancement with fuzzy sets of a small target on the sea bed. The realizing process and experimental results on image enhancement with fuzzy sets are given. The concept of histogram is one of the most important basic concepts in digital image processing. The concept of the bounded histogram presented in the paper will develop the concept of histogram.
This paper analyzes the essence of a sort of algorithm on image enhancement with fuzzy sets, presents the concept of the bounded histogram and applies them to the sonar image enhancement with fuzzy sets of a small target on the sea bed. The realizing process and experimental results on image enhancement with fuzzy sets are given. The concept of histogram is one of the most important basic concepts in digital image processing. The concept of the bounded histogram presented in the paper will develop the concept of histogram.
2002, 24(9): 1291-1293.
Abstract:
The design keys of digital communication system are introduced briefly, which has been used for radio link at Ka-band. The system scheme, key technique and behaviour are recommended in detail. The communication distance exceeds 30km. The bit rate is 4x2048kb/s.
The design keys of digital communication system are introduced briefly, which has been used for radio link at Ka-band. The system scheme, key technique and behaviour are recommended in detail. The communication distance exceeds 30km. The bit rate is 4x2048kb/s.
2002, 24(9): 1294-1296.
Abstract:
Orthornorphic permutations have good charateristic in cryptosystems.In this paper, by using of knowledge about finite group to investigate the constructions and enumerations of orthormophic permutations, several results are obtained.
Orthornorphic permutations have good charateristic in cryptosystems.In this paper, by using of knowledge about finite group to investigate the constructions and enumerations of orthormophic permutations, several results are obtained.
2002, 24(9): 1172-1176.
Abstract:
The dispersive characteristics of the wireless channel is a major problem in wireless communication. The authors has developed a wireless channel simulator and used it to predict the channel characteristics of the specific micro-cell. The characteristics include delay spread, angular spread and path loss. After the study of simulation, the author got some descriptions of the major characteristics of the wireless channel in micro-cell environment.
The dispersive characteristics of the wireless channel is a major problem in wireless communication. The authors has developed a wireless channel simulator and used it to predict the channel characteristics of the specific micro-cell. The characteristics include delay spread, angular spread and path loss. After the study of simulation, the author got some descriptions of the major characteristics of the wireless channel in micro-cell environment.
2002, 24(9): 1276-1281.
Abstract:
This paper describes the principles of a few types of erasure codes, and analyzes their merits, drawbacks and relationships systematically. It is shown that if MDS codes are chosen as erasure codes, a receiver can reconstruct the original source data once it receives any portion of the encoding data equal to the length of message. The analysis shows that loss-resilient codes and Tornado codes can not only be both encoded and decoded successfully in linear time, but also can come arbitrarily close to the channel capacity. Finally, some problems on loss-resilient codes which remain to be solved are presented. These analyses and conclusions provide theoretical base and new ideas for further studying erasure codes.
This paper describes the principles of a few types of erasure codes, and analyzes their merits, drawbacks and relationships systematically. It is shown that if MDS codes are chosen as erasure codes, a receiver can reconstruct the original source data once it receives any portion of the encoding data equal to the length of message. The analysis shows that loss-resilient codes and Tornado codes can not only be both encoded and decoded successfully in linear time, but also can come arbitrarily close to the channel capacity. Finally, some problems on loss-resilient codes which remain to be solved are presented. These analyses and conclusions provide theoretical base and new ideas for further studying erasure codes.
