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2004 Vol. 26, No. 9
Display Method:
2004, 26(9): 1345-1350.
Abstract:
An effective algorithm is proposed to estimate multipath time delays in a CDMA chip under low SNR environment. Firstly, a power delay profile of multipath is constructed which can restrain effect of noise. Then the estimation algorithm that has super...
An effective algorithm is proposed to estimate multipath time delays in a CDMA chip under low SNR environment. Firstly, a power delay profile of multipath is constructed which can restrain effect of noise. Then the estimation algorithm that has super...
2004, 26(9): 1351-1357.
Abstract:
A new expression for the Bit Error Rate(BER) of a Direct-Sequence Code-Division Multiple-Access (DS-CDMA) system with non-ideal channel estimation in a frequency-selective Rayleigh fading channel is derived and evaluated. The analysis assumes an arbi...
A new expression for the Bit Error Rate(BER) of a Direct-Sequence Code-Division Multiple-Access (DS-CDMA) system with non-ideal channel estimation in a frequency-selective Rayleigh fading channel is derived and evaluated. The analysis assumes an arbi...
2004, 26(9): 1358-1363.
Abstract:
This paper proposes a general model and approach to analyze the bidirectional call-overflow scheme for an arbitrary Hierarchical Cellular System (HCS) with N layers, as illustrated by a 4-layer HCS. By setting different parameters, the proposed appro...
This paper proposes a general model and approach to analyze the bidirectional call-overflow scheme for an arbitrary Hierarchical Cellular System (HCS) with N layers, as illustrated by a 4-layer HCS. By setting different parameters, the proposed appro...
2004, 26(9): 1364-1370.
Abstract:
A method of position locating and tracking using pilot .sequence transmitted by the single CDMA Base Stations(BS) for 3-D moving targets is presented in this paper. First, based on the fact that the interfering component is different from the signal ...
A method of position locating and tracking using pilot .sequence transmitted by the single CDMA Base Stations(BS) for 3-D moving targets is presented in this paper. First, based on the fact that the interfering component is different from the signal ...
2004, 26(9): 1371-1375.
Abstract:
In mobile communication systems, the work upon grouping multipath signal is very important always. An algorithm is proposed which firstly separates user signals and multipath signals in system, then estimates DOA of them. Because this algorithm does ...
In mobile communication systems, the work upon grouping multipath signal is very important always. An algorithm is proposed which firstly separates user signals and multipath signals in system, then estimates DOA of them. Because this algorithm does ...
2004, 26(9): 1376-1382.
Abstract:
The time-varying channel estimation methods for OFDM systems based on pilot tones are investigated. Grouped and equispaced pilot tones are used to estimate the Channel Impulse Response (CIR) of some given moments. The CIR of other moments over one OF...
The time-varying channel estimation methods for OFDM systems based on pilot tones are investigated. Grouped and equispaced pilot tones are used to estimate the Channel Impulse Response (CIR) of some given moments. The CIR of other moments over one OF...
2004, 26(9): 1383-1388.
Abstract:
Based on the Least Mean Squares (LMS) principle, an online calibration algorithm with an auxiliary signal source is presented, and its improved algorithm is also given. These algorithms can be applied to the non-uniform array, and to the number of us...
Based on the Least Mean Squares (LMS) principle, an online calibration algorithm with an auxiliary signal source is presented, and its improved algorithm is also given. These algorithms can be applied to the non-uniform array, and to the number of us...
2004, 26(9): 1389-1394.
Abstract:
In this paper the optimum design of an adaptive modulation based on uncoded MQAM modulation assisted by wireless channel prediction for the flat Rayleigh fading chan-nel is discussed. By studying how a known prediction error variance will affect the ...
In this paper the optimum design of an adaptive modulation based on uncoded MQAM modulation assisted by wireless channel prediction for the flat Rayleigh fading chan-nel is discussed. By studying how a known prediction error variance will affect the ...
2004, 26(9): 1395-1400.
Abstract:
By using an m-sequence controlling a traditional feedforward stream cipher, this paper constructs a new feedforward network whose sequences have ideal balance, large period and linear complexity, it can also resist on linear approaching attack and co...
By using an m-sequence controlling a traditional feedforward stream cipher, this paper constructs a new feedforward network whose sequences have ideal balance, large period and linear complexity, it can also resist on linear approaching attack and co...
2004, 26(9): 1401-1406.
Abstract:
In this paper, the encryption property of the chaotic system in terms of the techniques developed in the analysis of chaotic time series is studied. Then, the typical Lorenz system is analyzed. It is found that the larger sampling interval is of huge...
In this paper, the encryption property of the chaotic system in terms of the techniques developed in the analysis of chaotic time series is studied. Then, the typical Lorenz system is analyzed. It is found that the larger sampling interval is of huge...
2004, 26(9): 1407-1412.
Abstract:
This article analyzes the main security problems that current mobile agent sys-tems face with and existing solving methods, then a secure transport model of mobile agent based on hybrid encryption HESTM is brought forward. The model comprises two par...
This article analyzes the main security problems that current mobile agent sys-tems face with and existing solving methods, then a secure transport model of mobile agent based on hybrid encryption HESTM is brought forward. The model comprises two par...
2004, 26(9): 1413-1419.
Abstract:
In order to solve problems of modular algorithm, a multi-dimensional packet classification algorithm that uses trees divided by value is presented in this paper. It supports increment of rules dimension and scale. Moreover, it can deal with prefix ma...
In order to solve problems of modular algorithm, a multi-dimensional packet classification algorithm that uses trees divided by value is presented in this paper. It supports increment of rules dimension and scale. Moreover, it can deal with prefix ma...
2004, 26(9): 1420-1425.
Abstract:
The cascades model proposed recently from self-similar and multifractal model stem can be used to analyze network traffic comprehensively. This- paper, therefore, puts forward an integrated process using cascades model in pattern of wavelet transform...
The cascades model proposed recently from self-similar and multifractal model stem can be used to analyze network traffic comprehensively. This- paper, therefore, puts forward an integrated process using cascades model in pattern of wavelet transform...
2004, 26(9): 1426-1432.
Abstract:
By using the relation of neighboring data, an improved Viterbi algorithm is proposed and extended it to SOVA decoding of Turbo code in this paper. Simulation results show that, the improved algorithm has reduced-implementation-complexity and lower po...
By using the relation of neighboring data, an improved Viterbi algorithm is proposed and extended it to SOVA decoding of Turbo code in this paper. Simulation results show that, the improved algorithm has reduced-implementation-complexity and lower po...
2004, 26(9): 1433-1439.
Abstract:
This paper proposes the optimum detection algorithm for a multiple antenna system based on the Maximum A Posteriori (MAP) criterion. It makes symbol-by-symbol decisions so that the probability of a symbol error is minimized. It also shows that the ra...
This paper proposes the optimum detection algorithm for a multiple antenna system based on the Maximum A Posteriori (MAP) criterion. It makes symbol-by-symbol decisions so that the probability of a symbol error is minimized. It also shows that the ra...
2004, 26(9): 1440-1448.
Abstract:
In this paper, an image content based perceptual watermarking model using ridgelet transform is presented. It provides a new visual model, which can exactly evaluate the Just Noticeable Distortion (JND) tolerance of human visual system. The watermark...
In this paper, an image content based perceptual watermarking model using ridgelet transform is presented. It provides a new visual model, which can exactly evaluate the Just Noticeable Distortion (JND) tolerance of human visual system. The watermark...
2004, 26(9): 1449-1454.
Abstract:
Based on the analyzing of the relation between interferoinetric SAR coherence map classification and two-dimensional phase unwrapping, coherence map classification is applied in two-dimensional phase unwrapping. A K-mean and Markov random field combi...
Based on the analyzing of the relation between interferoinetric SAR coherence map classification and two-dimensional phase unwrapping, coherence map classification is applied in two-dimensional phase unwrapping. A K-mean and Markov random field combi...
2004, 26(9): 1455-1460.
Abstract:
This paper analyzes ambiguities in Synthetic Aperture Radar(SAR) and its impact on the image quality. The definition of ambiguities is described in detail. The influence of system parameters on ambiguities is analyzed and the relationship between gho...
This paper analyzes ambiguities in Synthetic Aperture Radar(SAR) and its impact on the image quality. The definition of ambiguities is described in detail. The influence of system parameters on ambiguities is analyzed and the relationship between gho...
2004, 26(9): 1461-1467.
Abstract:
In a transient signal system, the TX/RX coupled interference is one of principle interferences and has great influence to the system capability, especially to the near field remote sensing system such as Surface Penetrating Radar(SPR). Suppression of...
In a transient signal system, the TX/RX coupled interference is one of principle interferences and has great influence to the system capability, especially to the near field remote sensing system such as Surface Penetrating Radar(SPR). Suppression of...
2004, 26(9): 1468-1473.
Abstract:
In this paper, the applicability of biomimetic pattern recognition to informa-tion processing of abstract objects is studied, and then a DOA estimation method based on biomimetic pattern recognition is advanced. In this method, the output signals of ...
In this paper, the applicability of biomimetic pattern recognition to informa-tion processing of abstract objects is studied, and then a DOA estimation method based on biomimetic pattern recognition is advanced. In this method, the output signals of ...
2004, 26(9): 1474-1479.
Abstract:
In this paper, a new method of hyperspectral anomaly detection based u* project pursuit is presented. The Generalized Likelihood Ratio Test(GLRT) is used to estab-lish a binary hypotheses detector and estimates the unknown parameters that represent t...
In this paper, a new method of hyperspectral anomaly detection based u* project pursuit is presented. The Generalized Likelihood Ratio Test(GLRT) is used to estab-lish a binary hypotheses detector and estimates the unknown parameters that represent t...
2004, 26(9): 1480-1486.
Abstract:
A simulation computation method for calculating the impedance matrix of cou-pling double gap cavity of broadband klystron is developed in this paper. The method is used to calculate the impedance matrix and equivalent gap impedance of the double gap ...
A simulation computation method for calculating the impedance matrix of cou-pling double gap cavity of broadband klystron is developed in this paper. The method is used to calculate the impedance matrix and equivalent gap impedance of the double gap ...
2004, 26(9): 1487-1494.
Abstract:
Considering azimuthal higher order modes in non-vane area and helical tape thickness, using field matching method and boundary condition of the ridge-loaded ring-piano slow wave structure, the dispersion equation of vane-load helical slow-wave struct...
Considering azimuthal higher order modes in non-vane area and helical tape thickness, using field matching method and boundary condition of the ridge-loaded ring-piano slow wave structure, the dispersion equation of vane-load helical slow-wave struct...
2004, 26(9): 1495-1503.
Abstract:
Robustness is the key issue of digital watermarking technology. Up to now, various watermarking algorithms are proposed with much emphasis on the robustness. However, the robustness claimed in most of algorithms is only against common signal processi...
Robustness is the key issue of digital watermarking technology. Up to now, various watermarking algorithms are proposed with much emphasis on the robustness. However, the robustness claimed in most of algorithms is only against common signal processi...
2004, 26(9): 1504-1508.
Abstract:
After summarizing and analyzing the existing signal detection methods in a-stable noise, several innovative signal detection methods based on Fractional Low Order Moments (FLOMs) are proposed in this paper, which are the improved moment-type method a...
After summarizing and analyzing the existing signal detection methods in a-stable noise, several innovative signal detection methods based on Fractional Low Order Moments (FLOMs) are proposed in this paper, which are the improved moment-type method a...
2004, 26(9): 1509-1512.
Abstract:
Considering the uncertain for rotating velocity of spatial target and sample period of radar observation, there exists sampling rate variance between radar returns and template data, which decreases the degree of matching. In this paper, the ARMA mod...
Considering the uncertain for rotating velocity of spatial target and sample period of radar observation, there exists sampling rate variance between radar returns and template data, which decreases the degree of matching. In this paper, the ARMA mod...
