Table of Content

20 December 2010 Volume 37 Issue 6

  

Original Articles

Intra prediction method for reducing prediction mode information

YUAN Hui;CHANG Yi-lin;LU Zhao-yang;LI Ming

J4. 2010, 37(6):  981-986+1016.  doi:10.3969/j.issn.1001-2400.2010.06.001

Abstract ( 1722 )   PDF (948KB) ( 1422 )   Save

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A new intra prediction method is proposed for H.264/AVC intra frame coding. The sum of absolute differences (SAD) between each predicted block and the DC predicted block is used to determine whether those predicted blocks are similar. The average of those predicted blocks is used as the final predicted result if the predicted blocks are similar, and it is useless to encode the prediction mode. Experimental results demonstrate that compared with H.264/AVC, the bit rate can be reduced 2.40％ on average, while the PSNRs of reconstructed videos are the same. At the same time, the encoding time is reduced by 25.83％ on average.

Throughput optimization of a cognitive radio system based on cooperative sensing with soft combination

ZHANG Wen;YANG Jia-wei;YAN Qi;XIAO Li-yuan

J4. 2010, 37(6):  987-992+1010.  doi:10.3969/j.issn.1001-2400.2010.06.002

Abstract ( 2273 )   PDF (703KB) ( 1249 )   Save

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In order to maximize the throughput for a cognitive radio network, the cognitive radio network based on cooperative sensing with equal gain combination are taken as an example to establish a throughput optimization model, with the constraint that the primary users are sufficiently protected. The optimization parameters are local sensing time and the number of cooperative users. We have proved that the throughput is a concave function of the local sensing time by the optimization theory. Based on the conclusion, a searching method is proposed to obtain the maximal throughput. Simulation results have validated the theoretical results, and the maximal throughput and the corresponding parameters are given under different sensing overheads.

Performance analysis of opportunistic relaying with multiple interferers

SI Jiang-bo;LI Zan;LIU Zeng-ji;YIN Jing

J4. 2010, 37(6):  993-998.  doi:10.3969/j.issn.1001-2400.2010.06.003

Abstract ( 3379 )   PDF (711KB) ( 1306 )   Save

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With multiple interferers on both the relays and the destination,three opportunistic relaying protocols are proposed to minimize the outage probability in distinct cases:with direct transmission negligible,selection combining (SC) deployed at the destination,and maximum ratio combining (MRC) deployed at the destination.The exact outage probabilities of opportunistic relaying protocols are derived over independent identically distributed and independent non-identically distributed Rayleigh fading channels.Finally,simulation results validate our analysis and show that,in terms of outage probability,when the channels between the source and the relays are in deep fading,the opportunistic relaying protocol with SC is better than the other two protocols. Conversely,the opportunistic relaying protocol with MRC is the best.

Novel estimation and equalization of time-variant channels for OFDM system

CHEN Dong-hua;QIU Hong-bing

J4. 2010, 37(6):  999-1004.  doi:10.3969/j.issn.1001-2400.2010.06.004

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This paper considers the orthogonal frequency division multiplexing (OFDM) transmission operated in highly mobile channels. We propose a time-domain channel estimator based on the Karhunen-Loeve basis expansion model (KL-BEM). The proposed estimator adopts the KL-BEM to approximate the channels' time variation within several OFDM symbols. The KL-BEM coefficients are estimated by using a group of short-time pilot clusters that are inserted between two successive OFDM symbols. The properly designed pilot clusters pattern enables accurate channel estimation and higher throughput. Following this, we adopt an improved linear minimum mean squared error equalizer with sorted serial interference cancellation (LMMSE-SIC) to recover the transmit symbol. Preceding the LMMSE-SIC, time-domain windowing is applied to shorten the intercarrier interference (ICI) support, thereby improving the equalization performance and reducing the complexity as well. Simulation results show that the proposed scheme can significantly improve the system performance in highly mobile channels.

Construction and decoding of nonbinary quantum LDPC codes

SHAO Jun-hu;BAI Bao-ming;LIN Wei;ZHOU Lin

J4. 2010, 37(6):  1005-1010.  doi:10.3969/j.issn.1001-2400.2010.06.005

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Nonbinary quantum codes are more suitable for error-correction in multi-level quantum systems. Based on stabilizer formalism over the finite field, a class of nonbinary quantum LDPC codes is presented in this paper. And the BP iterative decoding algorithm for these codes is described under the quantum depolarizing channel with the Monte Carlo simulation method. For example, a class of CSS structure 4-ary quantum LDPC codes is given with code rates 1/2 and 1/4. Compared with the present binary quantum LDPC codes of equivalent codelength, the channel threshold with 10-5FER is improved from 0.016 to 0.025.

Subband MCRASC-MGSC algorithm for speech enhancement with the mini-typed microphone array

ZENG Qing-ning;OUYANG Shan

J4. 2010, 37(6):  1011-1016.  doi:10.3969/j.issn.1001-2400.2010.06.006

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Speech enhancement with the mini-typed microphone array is of great value in speech communication and speech recognition with mini-typed devices. By employing the Multi-channel Crosstalk Resistant Adaptive Signal Cancellation(MCRASC) technique, a more efficient module for signal blocking is presented for the subband Modified Generalized Sidelobe Cancellation(MGSC) method, and thus a more feasible algorithm is proposed for mini-typed array based speech enhancement. Theoretic analysis and experimental results in real environment have verified the availability and advantages of the proposed algorithm. The signal to noise ratio has been improved by 12.5dB for the enhanced speech by the proposed algorithm compared with the subband MGSC algorithm in the experiment.

Novel method for increasing the nonlinearity of S-Boxes

GAO Sheng;MA Wen-ping;GUO Na;YAN Ya-jun

J4. 2010, 37(6):  1017-1021.  doi:10.3969/j.issn.1001-2400.2010.06.007

Abstract ( 1770 )   PDF (572KB) ( 1215 )   Save

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An S-box is an important nonlinear component of block cipher algorithms.Using the idea of swapping two output vectors to increase nonlinearity of the S-Boxes, we propose a method for improving the nonlinearity by swapping three output vectors, namely, a new three-point hill-climbing algorithm.This method is simple and more efficient in implementation. Moreover, it could further improve the nonlinearity when William Millan's two-point hill-climbing could not. On the basis of this, an optimization algorithm based on the hill-climbing algorithm for improving the nonlinearity of the S-Boxes is presented, which overcomes the disadvantage of existing algorithms that cannot improve the nonlinearity further. Numerical results of testing for some small variables S-Boxes show the correctness and efficiency of the proposed algorithm.

Method for achieving high resolution ISAR imaging with short aperture data via compressed sensing

QUAN Ying-hui;ZHANG Lei;LIU Ya-bo;ZHANG Long;BAO Zheng

J4. 2010, 37(6):  1022-1026+1110.  doi:10.3969/j.issn.1001-2400.2010.06.008

Abstract ( 2866 )   PDF (1031KB) ( 1449 )   Save

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Compressed sensing suggests that exact recovery of a sparse signal is possible from very limited measurements. Based on this idea, a new method for high-resolution inversed synthetic aperture radar (ISAR) imaging with short aperture data is presented. This approach converts ISAR imaging into the problem of reconstructing the sparse signal with an orthogonal basis, then compressed sensing is applied to reconstruct the high resolution image optimally. And a conceptive upper bound of resolution is derived in detail. Experiments using real ISAR data of ship and plane are performed, whose results confirm the validity of the proposal in high resolution ISAR imaging with limited data.

Novel imaging method using compressed sensing for the inverse synthetic aperture imaging ladar

ZANG Bo;ZHANG Lei;TANG Yu;XING Meng-dao

J4. 2010, 37(6):  1027-1032.  doi:10.3969/j.issn.1001-2400.2010.06.009

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Limited by the laser modulation technique, the coherence between transmitting pulses of the inverse synthetic aperture imaging ladar (ISAIL) can not be kept, which leads to the unfocused image in the azimuth direction. Here, an instantaneous imaging algorithm is proposed to achieve the high resolution with less echo data in a short coherence time. Based on the theory of compressed sensing, the ISAIL imaging is converted into a reconstruction issue using the orthogonal base. The reconstruction of the target is resolved by optimizing the function. Under the situation of a low SNR, the performance of the imaging algorithm is improved by constructing a weighted matrix. Experimental results using measured data of the indoor ISAIL system validate the feasibility and effectiveness of our method.

Analysis of the characteristics of geosynchronous SAR in the elliptic orbit and a study of imaging methods

BAO Min;LI Ya-chao;XING Meng-dao;WANG Wan-lin;LI Cai-pin

J4. 2010, 37(6):  1033-1041+1064.  doi:10.3969/j.issn.1001-2400.2010.06.010

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The elliptic orbit module and property of motion of geosynchronous synthetic aperture radar (GEOSAR) are analyzed. The paper discusses in detail the Doppler property of the GEOSAR target in the elliptical orbit. Satellite attitude changes have significant effects on GEOSAR imaging. By deducing the Doppler parameters expression with the satellite attitude variety, it is discovered that we should enhance the measurement precision of the pitch angle and roll angle. The nonlinear motion of the satellite orbit should be taken into account in GEOSAR imaging, so that the SPECAN algorithm, RD algorithm and back-projection algorithm are compared and analyzed, and it is proved that the three imaging approaches are feasible in GEOSAR imaging. Computer simulation results validate the  conclusions obtained through analysis and the imaging method.

Quasi-Monte-Carlo Gaussian particle filter based target tracking for the multiple passive sensor

GUO Hui;JI Hong-bing;WU Bin

J4. 2010, 37(6):  1042-1047.  doi:10.3969/j.issn.1001-2400.2010.06.011

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This paper employs Quasi-Monte-Carlo (QMC) sampling to replace conventional Monte-Carlo (MC) sampling, thus improving the performance of the Gaussian Particle Filter (GPF). A multi-passive-sensor target tracking algorithm based on the Quasi-Monte-Carlo Gaussian Particle Filter (QMC-GPF) is proposed in connection with the multi-sensor centralized fusion strategy, which resolves the strong nonlinearity and weak observability problem in a multi-passive-sensor tracking system more efficiently. The algorithm not only reduces the computational complexity, but also improves the accuracy and stability of the tracking algorithm, thus getting fast convergence. Moreover, because of the parallel structure, which makes it easier to realize with large-scale integrated circuits.

Performance analysis of two passive radar tracking algorithms

LI Hong-wei;WANG Jun;LIU Yu-chun

J4. 2010, 37(6):  1048-1052.  doi:10.3969/j.issn.1001-2400.2010.06.012

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Since the passive radar based on the FM radio station has a low tracking precision, this paper proposes that the time of arrival(TOA) location method be combined with the Extended Kalman Filter(EKF) and Particle Filter(PF) respectively to improve passive tracking performance. Tracking performance of the two algorithms and their calculation time are studied, and factors that affect the tracking precision including glint noise and site-deploying are also discussed. Simulation results and real data show that the PF is more adaptive to glint noise environment. Nevertheless, the EKF can satisfy real time processing. Moreover, a reasonable site-deploying scheme will further provide a better tracking precision.

New method for improving the performance of range-spread target detection

XU Shu-wen;SHUI Peng-lang

J4. 2010, 37(6):  1053-1058.  doi:10.3969/j.issn.1001-2400.2010.06.013

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Aimed at the shortage of the conventional hard threshold of the binary integrator, a new method based on the local fuzzy thresholding map is proposed. The new method utilizes the local fuzzy threshold in range dimension to suppress noise-only cells and preserve target's strong scattering cells. Then, the energy integration in the range-pulse domain realizes multi-pulse integration to improve the detection performance. Compared with the commonly-used spatial scattering density generalized likelihood ratio test (SSD-GLRT), by the proposed method one needn't know any a priori information on targets and this method has the constant false alarm rate (CFAR) characteristic. Experimental results show that the gain by the proposed method is increased about 2dB with respect to that by SSD-GLRT, and about 4dB with respect to that by the binary integrator.

New denoising method for pulsar signal

SUN Jing-rong;XU Lu-ping;WANG Ting

J4. 2010, 37(6):  1059-1064.  doi:10.3969/j.issn.1001-2400.2010.06.014

Abstract ( 1720 )   PDF (639KB) ( 1188 )   Save

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In order to improve the signal-to-noise ratio(SNR) of the pulsar signal, this paper proposes a denoising algorithm based on bispectrum reconstruction for the pulsar signal. First, the noisy pulsar signal is transformed into the bispectral domain. The bispectrum phase and amplitude are filtered by the α-trimmed filter. Then, the power spectrum and phase of the pulsar signal can be recovered from the filtered bispectrum. Results indicate that this method can eliminate noise in the pulsar signals, and improve the SNR notably.

Research on the ISAR imaging used statistical RELAX method

ZHANG Long;LI Ya-chao;SU Jun-hai;XING Meng-dao

J4. 2010, 37(6):  1065-1070+1124.  doi:10.3969/j.issn.1001-2400.2010.06.015

Abstract ( 1681 )   PDF (954KB) ( 1139 )   Save

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For ISAR Super-resolution imaging, using energy as the detection threshold to judge the number of scatterers in the range cell can result in fake scatterers or missing detection. Aiming at solving these problem, a statistical Relax super-resolution (S-Relax) imaging method is proposed. The statistical characteristic of background noise and clutters is investigated, and then Gaussian test is performed to all range cells by using the presetting desired probability of the false rate (PFA). Finally, scatterers are extracted by the S-Relax method and a high resolution ISAR image is generated. Experimental results indicate that the number of fake scatterers by the S-Relax method is considerably less than that by conventional Relax methods and the details of a target can be represented by the proposed method.

SAR image multilevel segmentation based on local similarity measure

LIU Han-qiang;JIAO Li-cheng;ZHAO Feng

J4. 2010, 37(6):  1071-1076.  doi:10.3969/j.issn.1001-2400.2010.06.016

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Aiming at the high computational complexity of spectral clustering algorithms and their unsuitablity to synthetic aperture radar image segmentation, a novel SAR image multilevel segmentation based on local similarity measure is proposed which utilizes the equivalence of spectral clustering and weighted kernel k-means. First, the wavelet texture features of every pixel are extracted from the image and the sparse adjacent matrix among pixels is constructed by computing the local scale parameter of each pixel, and then multilevel merging, basic clustering and multilevel refining operations are used to cluster the image pixels, and finally the image segmentation result is obtained. Experimental results on artificial texture images and SAR images show that the proposed method can avoid the sensitivity of traditional spectral clustering to the scale parameters and obtain a better segmentation performance.

RCS reduction of the array antenna by optimizing element spacing

WANG Wen-tao;LIU Ying;GONG Shu-xi;ZHANG Yu-jie;WANG Xing

J4. 2010, 37(6):  1077-1081.  doi:10.3969/j.issn.1001-2400.2010.06.017

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The method of array synthesis is used in radar cross section (RCS) reduction of an array antenna, and the radiation performance and low scattering property of an array antenna are optimized by adjusting the element spacing of a non-uniform array. The differential evolution (DE) algorithm is adopted as the optimization tool, while the method of moments (MoM) is applied to calculate the radiation and scattering parameters of each candidate solution. The objective function for combining antenna radiation with scattering is used to synthesize an array with a low side lobe and low scattering property. Finally, the optimization examples of the dipole and bowtie show that the array RCS can be reduced more than 5dB by this method.

Crosstalk noise estimation of two adjacent RC interconnects with process variations

DONG Gang;YANG Yang;CHAI Chang-chun;YANG Yin-tang

J4. 2010, 37(6):  1082-1087+1131.  doi:10.3969/j.issn.1001-2400.2010.06.018

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Based on the six-node template circuit of coupling interconnects, a novel method for analyzing the statistical crosstalk noise of RC interconnects with process variations is proposed. Analytical expressions for mean and standard deviation of the statistical crosstalk noise are derived for a given fluctuation range of interconnect parameters. Simulation results show that the time of calculation is greatly shortened with a good calculating precision using the proposed statistical model as compared to the widely used Monte Carlo method. Calculated results also indicate that the errors of the mean and standard deviation are less than 2.36％ and 7.23％ respectively.

Analysis of far-field properties for a high-power laser diode

SHANG Ji-min;ZENG Xiao-dong

J4. 2010, 37(6):  1088-1091.  doi:10.3969/j.issn.1001-2400.2010.06.019

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To design an optical system for high power laser diodes, its far field distribution should be acquired exactly. Using the vector Rayleigh-Sommerfeld far-field diffraction integral formula, a vector model for describing the propagation of a high-power laser diode is proposed. Through the analysis of the properties of the TM-mode propagation, the expressions for the optical intensity and divergence angle are deduced, and the error is also analyzed compared with the scalar theory. It is found that the far-field intensity distribution and the divergence angle between the vector and scalar model are different. The error of intensity distribution is proportional to the coordinate perpendicular to the junction plane and inversely proportional to the propagation distance, and the difference of the divergence angle is related to the constants of the waveguide structure.

Novel structure design of the passive UHF RFID tag-chip

LIU Wei-feng;ZHUANG Yi-qi;TANG Long-fei;JIN Zhao

J4. 2010, 37(6):  1092-1097.  doi:10.3969/j.issn.1001-2400.2010.06.020

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A novel structure for the passive UHF RFID tag-chip design is presented for reducing the chip power-consumption and increasing the system operating distance. The tag-chip designed based on the new structure can automatically and synchronously recover the decoding clock out of the data sent from the interrogator and can well generate the backscatter link clock with the values of TRcal and DR specified in the query command that initiates an inventory round. The backscatter link clock frequency has no connection with manufacturing technology and chip working conditions, so it needs no calibration during operation. Since there are no requirements of high frequency sampling-clock or complex frequency-division circuits, which are necessary for conventional structure, the proposed structure is characterized by a smaller circuits scale and lower power-consumption. The chip is designed and fabricated using the TSMC 0.18μm mixed signal process. Simulation and test results show that the new structure is ten percent smaller in area and thirty percent lower in power comsumption.

Robustness-tracking algorithm for the infrared target under complex background noise

GAO Guo-wang;LIU Shang-qian;QIN Han-lin

J4. 2010, 37(6):  1098-1102.  doi:10.3969/j.issn.1001-2400.2010.06.021

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A tracking algorithm for the Infrared target is proposed that is the combination of edge detection and the improved Mean Shift method. After the edge of the original infrared image is detected roughly, the non-linear edge detection algorithm is presented that eliminates the most original image noise and could lead to a high-quality image. Based on this image, the improved Mean-Shift algorithm that focuses on renewing the target model, background-weightedness of the target template and Kernal Function-weightedness of the selected target region is applied to implement quick-tracking of a fast-moving target so that the algorithm is not sensitive to moving background noise, and thus it improves tracking procedure stability and robustness to background noise of the algorithm. Experimental results show that the combination of the non-linear edge detection algorithm and Mean Shift tracking algorithm not only reduces the operand of algorithms and improves the tracking speed, but also has a strong robustness to background noise.

Network storage system in multi-domain environments

DUAN Xin-dong;MA Jian-feng

J4. 2010, 37(6):  1103-1106+1118.  doi:10.3969/j.issn.1001-2400.2010.06.022

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The OSD and SAN have their own disadvantage in constructing the mass storage system. In this paper, a network storage system in multi-domain environments based on NASD is proposed. Such a system will realize authentication and issue capabilities in different servers, which can improve the expansibility and the bottleneck of the server for the original system. At the same time, a secure storage network protocol for the new system is proposed and analyzed by using the CK model. Results show that the new system has a high bandwidth, low latency, expansibility, large-scale, high security and low cost so that it is suitable for a mass storage system.

One class of highly nonlinear cryptographic functions

HE Ye-feng;MA Wen-ping

J4. 2010, 37(6):  1107-1110.  doi:10.3969/j.issn.1001-2400.2010.06.023

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A class of semi-bent functions with four trace terms is constructed by using the Hadamard transform and the values of Kloosterman sums. Moreover, it is shown that the new semi-bent functions with n variables have the degree n/2. These semi-bent functions have not only high nonlinearity but also high algebraic degrees, so that they provide more available functions for designing the filter generators of stream ciphers.

Algorithm based attribute-value-tree for calculation of core and attribute reduction

WANG Xiao-fan;WANG Bao-shu;CHAI Hui-min

J4. 2010, 37(6):  1111-1118.  doi:10.3969/j.issn.1001-2400.2010.06.024

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In order to get attribute reduction or calculate the core of rough sets quickly, a new algorithm of attribute reduction and computing core is brought forward based on the attribute-value-tree model and its correctness is proved. The greatest advantage of the algorithm is that the time and space complexity are reduced efficiently by using the method of merging trees. The computational complexity of reduction is changed from O(|U||C|2) to O(|U||C|) where |U| and |C| are the numbers of objects and attributes.

Real-time routing algorithm for multi-layer optical networks

ZHENG Wei;LIU San-yang;QI Xiao-gang;CHEN Xiao-hui

J4. 2010, 37(6):  1119-1124.  doi:10.3969/j.issn.1001-2400.2010.06.025

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An ACO-based differentiated integrated routing (ADIR) algorithm is presented for solving the problem of real-time routing. First, the algorithm simplifies the RWA problem into a routing problem with a layered-graph model. Then, we search for routes for the routing problem. The ants used in our algorithm are transported in a control plane, so we can search for routes in the control plane and transport traffic in the data plane synchronously. And the route for a connection request can be determined in real-time. The hops and congestion of routes are also considered in our algorithm, so the blocking probability is reduced. Finally, we use different kinds of ants with the motivation of bandwidth differentiation so that the low bandwidth request traffic can use the key link and the high bandwidth request traffic selects a detour path, and therefore the blocking probability can also be reduced. Simulation results show that ADIR performs better than other routing approaches in terms of traffic blocking probability and traffic blocking fairness.

Game theoretical packet forwarding algorithm in wireless sensor networks

ZHAO Yong-hui;SHI Hao-shan

J4. 2010, 37(6):  1125-1131.  doi:10.3969/j.issn.1001-2400.2010.06.026

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A packet forwarding algorithm based on the dynamic Bayesian game named PFDBG is presented for wireless sensor networks. Packet forwarding is regarded as a multi-stage game with incomplete information and observable actions, the adjacent nodes take the Bayesian amendment method to reasonably calculate and predict the opponent's energy level (private type) based on evaluation of its historical actions, and use the predicted value to obtain the solution which maximizes the expected utility function. The solution is also the optimal forwarding strategy that the nodes will adopt in the next stage of the game; the existence of the Bayesian Nash Equilibrium in the game is proved. Theoretical analysis and experimental results show that the PFDBG algorithm not only ensures the higher throughput of nodes, but also adapts well to the network size, and that it has a small computational overhead, high transmission reliability and low energy consumption, with its performance superior to that of other existing algorithms.

Digital modulated signal recognition based on intrisic time-scale decomposition parameters

LI Xue;TIAN Bin;ZHAN Yi;SUN Yong-jun

J4. 2010, 37(6):  1132-1136.  doi:10.3969/j.issn.1001-2400.2010.06.027

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A digital modulation recognition algorithm using intrinsic time-scale decomposition and the parameters separability for feature extraction and selection is proposed. Simulation results show that the average recognition rate is higher than 94％ using only three feature parameters when the SNR is above 5dB. This algorithm is not sensitive to the carrier frequency offset and symbol synchronization with low complexity and real-time realization, and it is suitable for the signal reconnaissance system and interference reconstruction concellation system.

Combination of  Wigner-Ville distribution and its application to blind parameter estimation of frequency-hopping signals

FENG Tao;YUAN Chao-wei

J4. 2010, 37(6):  1137-1142.  doi:10.3969/j.issn.1001-2400.2010.06.028

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To estimate the parameters of frequency-hopping signals, a new combination of Wigner-Ville distribution based on frequency decomposition is put forward according to the characteristics of frequency-hopping signals. First, a multi-component frequency-hopping signal is decomposed into multiple single-component signals with a group of band filters. Then the WVD of each component is summed up to form a new time-frequency distribution. Theoretical analysis and simulation result show that the new combination of Wigner-Ville distribution is effective to the reduction in cross-term interference of frequency-hopping signals. Compared with the existing method, this new method preserves a higher time-frequency resolution. Therefore, it is more suitable to time-frequency analysis and parameter estimation of frequency-hopping signals.

Routing algorithm based on the smallest transmission delay for cognitive radio networks

LI Yun;QIN Feng-xie;LI Yuan-yuan;CAO Bin

J4. 2010, 37(6):  1143-1147.  doi:10.3969/j.issn.1001-2400.2010.06.029

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Aiming to the shortcoming of traditional route protocols in cognitive radio networks, a smallest delay cognitive routing (SDCR) algorithm is proposed. According to the characteristic of a cognitive network, SDCR calculates the transmission delay in every link for a given packet, and uses the classic Dijkstra algorithm to find the smallest transmission delay route. Simulation results show that the End-to-End delay of SDCR is less than that by the traditional routing algorithm.

Camera calibration based on the circular pattern and ellipse fitting

LI Long;HE Ming-yi;LI Na

J4. 2010, 37(6):  1148-1154.  doi:10.3969/j.issn.1001-2400.2010.06.030

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A novel camera calibration method based on the circular pattern and ellipse fitting is proposed, which combines the advantages of camera calibration based on the planar pattern and one dimensional object. The proposed method designs a new circular pattern, which needs three images of the pattern to calibrate the camera. Ellipse fitting is introduced to locate the feature points in the circular pattern precisely and nonlinear optimization is utilized, and thus the calibration precision has been improved significantly. Experimental results for synthetic data show that the proposed strategy is both accurate and robust. Experimental results for real images prove the performance of the proposed algorithm.