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25 June 2011, Volume 32 Issue 6

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Papers

Data transmission strategy of P2P pattern live video media streaming system

Zhi-xin SUN,Ya-dang CHEN,Zhi-guang REN

2011, 32(6):  1-9.  doi:1000-436X(2011)06-0001-09

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An algorithm optimization was made with improved simulated annealing algorithm aimed at data transmission strategy of streaming media system in P2P networks.According with global layout,a mathematic model have been established for data transmission strategy of streaming media system in P2P networks named VMDTSA-P2P,which completely have considered the affection of both the out-bandwidth and the available time,and take them as the object function for getting the optimum solution.It also optimized the solutions with improved simulated annealing algorithm.Compared with traditional data transmission strategies,this improved algorithm accelerates the speed of new nodes choose the data provider from its partner nodes when there are lots of users and insures the solution of the data provider is approximate the best.Thus,the play delay of the streaming media system is decreased and the quality of video playback i increased.By realizing it in a simulated P2P system,the accuracy and the efficiency were both verified in the simulation.

Modeling the distance error and performance analysis in IR-UWB positioning system

Jing MENG,Qin-yu ZHANG,Nai-tong ZHANG,Ping CHEN,Ning-ning LIU

2011, 32(6):  10-16.  doi:1000-436X(2011)06-0010-07

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The multipath and NLOS distance errors in indoor positioning due to the propagation characteristics of IR-UWB were analyzed,based on the coherent TOA ranging a gorithm.Utilized the statistical information of IEEE 802.15.4a channel model,the multipath error was modeled in terms of system bandwidth in both LOS and NLOS environment.And the NLOS extra distance error was derived in terms of bstacle thickness,transceiver distance and the incidence angle as the IR-UWB signal propagated through walls.The positioning performance via triangulation was analyzed as given the prior information of the NLOS distance error in completely NLOS environment.

Improved AC-GA based data association method for multi-target tracking

Dong-hui YUAN,Da-you LIU,Shi-qun SHEN

2011, 32(6):  17-23.  doi:1000-436X(2011)06-0017-07

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An AC-GADA(ant colony-genetic algorithm data association) algorithm was proposed to deal with the data association problem for multi-target tracking.This algorithm designed difference pheromone for each ant and improved global pheromone increment model,and combined crossover and mutation strategy with fitness of population model in order to improve rate of convergence and avoid the appearance of local extremum.The comparison with ACDA (ant colony data association)and JPAD (joint pobabilistic data association)proved its efficiency and superiority.

Design and implement on the HFEM public key scheme

Yong-zhe ZHAO,Bo ZHAO,Shi-hui PEI,Zhan-hua JIANG

2011, 32(6):  24-31.  doi:1000-436X(2011)06-0024-08

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A new public key scheme named HFEM (hidden field ergodic matrices’ public key cryptography) was proposed,which was based on the difficulty of BMQ (bisectional multivariate quadratic equations) problem and the relation between the matrix and vector over finite field.The constraints on the matrix sets was given,and the methods used to construct the matrix sets that satisfy the corresponding constraints was also proposed.Comparing to other MPKC schemes,the HFEM has the following characteristics:the design of trapdoor was novel,the algorithm is simple,the exponential and other complex operations are not involved,the eff iency of encryption algorithm is similar to that of decryption algorithm,the central map is hard to abstract,the space of key,plaintext and cipher are large,etc.

Parallel time-delay estimation algorithm for GMSK mixing signals

Guo-sheng RUI,Bin XU,Song ZHANG

2011, 32(6):  32-37.  doi:1000-436X(2011)06-0032-06

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Parallel time-delay estimation algorithm was proposed for GMSK mixin signals based on linear approximation approach.Parallel estimation equations were built in flat-fading channel according to autocorrelation of over-sampling based mixing signals and then Cramer-Rao bound for parallel time-delay estimation was deduced.Polynomial fitting method was uesed to simplifying nonlinear complexity of GMSK shaping filter and estimation equations were resolved numerically by gradient descent algorithm with fast convergence.Simulation results show that its estimating performance is good and the variance of estimation error is close to Cramer-Rao bound.As a non-preamble aided algorithm with lower complexity it is significant for the next blind processing.

Novel low-delay scheme for parallel Turbo decoding

De-feng REN,Jian-hua GE,Feng-kui GONG,Yong WANG

2011, 32(6):  38-44.  doi:1000-436X(2011)06-0038-07

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In order to decrease decoding delay because of the iterative and recursive computation in MAP class algorithms,a novel parallel decoding scheme was proposed.The key of the novel scheme was to design a novel collision-free (CF) interleaver.After the analysis of the CF criterion,the design criterion and an implementation approach of the CF interleaver based on the window were proposed by using the idea of the sliding window.The novel CF interleaver allowed extrinsic information immediately as priori information to start the next component decoding so as to decrease decoding delay.Finally,simulation results show the BER performance of novel parallel decoding scheme.

Design of distributed implementation and performance a alysis of asymptotic optimality for cooperative two-way relaying networks

Chun-guo LI,Chong-xian ZHONG,Lv-xi YANG,Yue PAN

2011, 32(6):  45-52.  doi:1000-436X(2011)06-0045-08

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The realization scheme in the distributed manner was researched for the cooperation transmission of the multiple two-way relays,moreover the performance analysis of the asymptotic optimali was also presented.First of all,an upper-bound function was obtained for the true value of the average mean squared error of the whole system by the SNR approximations.Furthermore,a mathematical model was established based on this bound function.Secondly,an optimal solution was obtained for the established problem by using the matrix transform and mathematical derivations.Finally,the realization scheme was obtained in the distributed manner.The proposed scheme avoided the strict requirement that every relay must know the full channel state information (CSI) of the whole networks,while can easily achieve the gain of the relays cooperation by requiring every relay know its local CSI consisted of its forward and backward CSI.Therefore,the proposed scheme not only avoided the central control as required by the central manner and the large amount of the feedback overheads,but also achieved much gain.Theory analysis shows that the proposed scheme is asymptotically optimal.

Cooperative beamforming in multi-hop multi-relay wireless networks

Lei CHEN,Ju LIU,Guo-wei ZHANG

2011, 32(6):  53-59.  doi:1000-436X(2011)06-0053-07

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A cooperative beamforming solution for the multi-hop multi-relay wireless networks was propsed.In such net-works was proposed,the communication between source and destination was accomplished by a three-hop channel with aid of two relay clusters under amply-and-forward (AF) protocol.In order to maximize the receive signal-noise ratio at destination,the proposed method first formulated the inal optimization problem,then a suboptimal solution could be obtained by semidefinite programming (SDP).An improved solution was also proposed in combination w th bisection search.Finally,the effectiveness of proposed method is verified through computer simulations.

Robust image hashing method from global perception features of human visual cortex

Rui SUN,Xiao-xing YAN,Jun GAO

2011, 32(6):  60-66.  doi:1000-436X(2011)06-0060-07

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Firstly,the image was filtered low-passly and re-scaled to fixed size.Then the image was divided into key-dependent overlapping blocks.According to the hierarchical structure of HVS primary visual cortex,directional contour responses were extracted through layer-by-layer processing of visual pathway,and global perception features could be obtained by associating with the surface color of each blocks.These features included image direction and color information.The relation of adjacent entries was invariant to ordinary image processing.It could be used to quantize and permute these feature to get the binary image hash.Test results indicate that the proposed method is robust against content-preserving modifications such as JPEG compression and filtering,at the same time,is capable of localizing image malicious tampering.Hashes of different images have very low collision probability.

Traversal trajectory based on grid in wireless sensor networks field

Qing LUO,Ya-ping LIN,Bo YIN

2011, 32(6):  67-77.  doi:1000-436X(2011)06-0067-11

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Utilizing grid and label setting routing mechanism,an approximate optimization approach was proposed for finding traversal trajectory of target.The algorithm can calculate the approximate optimal trajectory of intelligent target with a constraint on the trajectory length,where the trajectory length from start to destination is less than special threshold.Theoretical analysis and extensive experiments results show that the proposed scheme is able to find e approximate minimal exposure trajectory with constraints and improve accuracy of the trajectory by increase order of grid.

Content-based effective event matching algorithm

Ji-ming CHEN,Shi-guang JU,Jin-gui PAN,Zhi-wen ZOU,Zhen-yu GONG

2011, 32(6):  78-85.  doi:1000-436X(2011)06-0078-08

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Based on the study of characteristics of the distributed virtual environment and current event matching algorithms,a content-based effective event matching(CEEM)algorithm was proposed.By considering the efficiency of both subscription processing and event matching,this algorithm can solve the symmetric event matching efficiently,so as to make the content-based publish/subscribe model fit the virtual environment better.Finally,experiments and performance analysis show that CEEM is both practical and effective.

New method to improve the channel capacity and capacit ability of 4-element MIMO systems with close antenna spacing

Yue-heng LI,Jing ZHAO,Mei-yan JU,Xing-hui YIN

2011, 32(6):  86-92.  doi:1000-436X(2011)06-0086-07

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With respect to the problems that the severe mutual coupling (MC) caused by close antenna sapcing will decrease the channel capactiy of the traditional 4-element uniform linear array (ULA) MIMO systems,and that the capacity will also decrease rapidly with the increment of incoming wave’s mean angle of arrival (AoA),a new method to improve the system’s capacity performance by reconstructing the ULA array layout was proposed based on deeply investigating the reason of the distortion of equivalent antenna rad ion pattern.Both theoretical analysis and numerical results show that compared with the traditional 4-element ULA,this 4-element squared antenna array (SAA) with spatially sym ic structure can not only improve the final channel capacity when there is severe MC effect in the case of small antenna spacing,but also have the advantage of keeping nearly unchanged channel capacity as the mean AoA of the incoming waves varies.

Technical Reports

Design and implementation of national security vulnerability database

Yu-qing ZHANG,Shu-ping WU,Qi-xu LIU,Fang-fang LIANG

2011, 32(6):  93-100.  doi:1000-436X(2011)06-0093-08

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Base on both domestic and overseas research on vulnerability database,considering our national conditions and the security requirements,a security vulnerability database model was proposed.It’s compatible with multiple standards,and could be used to classify vulnerability attributes through groups.The national security vulnerability database was implemented based on the model and applied to security warning and emergency response.This work has brought satisfactory effects in practice.

Optimal payload lengths of reliable multicast schemes

Feng ZHU,Ling-shuang WU,Yuan-tao GU

2011, 32(6):  101-106.  doi:1000-436X(2011)06-0101-06

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Using total transmission time-the time needed to guarantee reliable data dissemination--as judgment criterion,the payload length selection problem was investigated for three multicast solutions which are based on simple feedback retransmission,Reed-Solomon codes,and LT fountain codes,respectively,with the consideration of packet overhead.A theoretical analysis method was proposed to determine the optimal load lengths,which was verified by simulations.Analyses and simulations indicate,for variable packet overhead sizes and link bit error rates,each method considered has its optimal payload length.As link bit error rate increases,the performance gain brought by the selection of optimal payload lengths becomes more significant.Among the three solutions,the reliable multicast solution based on LT fountain codes has the most outstanding performance.

IEEE 802.15.4 based topology control and routing for mobile Sink wireless sensor networks

Jie TONG,Fan YANG,De-pei QIAN

2011, 32(6):  107-115.  doi:1000-436X(2011)06-0107-09

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Based on the standard of IEEE 802.15.4b,a cross-layer protocol design combining cluster-tree formatting and mobile routing was proposed for query-driven wireless sensor networks with mobile Sink(s).Firstly,energy consumption,network connectivity,load balancing and sub-tree depth were employed as the evaluation factors.A topology evaluation function under a multi-objective optimization model was defined to construct the stable and optimal underlying cluster-tree network.Secondly,the beacon frame scheduling based distributed sleep synchronization algorithm in IEEE 802.15.4 MAC was improved,which was used to maintain the network synchronization and topology correction on low duty-cycle.Thirdly,the parent-child relationships established during the topology formatting according to “first beacon”,“best links”,“top level”rules were exploited to build the two-way routing paths between mobile Sink(s)and the nodes within N-Hop range.Eventually,the topology control schemes at MAC layer and the query routing approach at network layer were completely implemented in the protocol stack of TinyOS.The experimental results show that the evaluation function can effectively reflect the quality of network formatting.Jointed with the sleep synchronization mechanism under the topology generated using the rule of “best links”,the N-Hop reactive routing exhibits high energy-efficiency.

Performance analysis of amplify-and-forward cooperative communication systems with imperfect channel estimation

Lei WANG,Yue-ming CAI,Wei-wei YANG,Jia TU

2011, 32(6):  116-123.  doi:1000-436X(2011)06-0116-08

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The impact of channel estimation errors on the performance for two-hop multi-relays assisted amplify-and-forward (AF) cooperative communication systems was investigated.Closed-form expressions of the average symbol error rate,as well as the diversity gain under different channel estimation quality orders for both opportunistic relaying (OPR) and all-participate relaying (APR) schemes were derived.Average signal-to-noise-ratio (SNR) gap ratio is investigated for the two types of cooperative communication systems,which lead to a conclusion that the OPR scheme is more susceptible to channel estimation errors than the APR scheme.Numerical results verify the theoretical analysis.

Improvement of the anonymity formalization based on strand space model

Xue-wen DONG,Wen-sheng NIU,Jian-feng MA,Hui XIE,Li-qiang MAO

2011, 32(6):  124-131.  doi:1000-436X(2011)06-0124-08

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In order to make the strand space model satisfy the special needs of anonymity analysis,based on equivalent bundles and view of observer,two kinds of sender anonymities as well as recipient anonymities were defined;relation anonymity were defined in two ways:emphasis on sender anonymity or recipient anonymity.Thus,an anonymity forma-lization framework based on strand space model was ext ion,the difference among anonym-ity degrees of these anonymities were qualitatively researched and the anonymity of a zone-based k-anonymity routing protocol was analyzed to verify the correctness and efficiency.

Performance analysis of cost function based energy-efficient routing protocol in WSN

Xing-cheng LIU,Dong-sheng YUAN,Ping-yuan LIANG,Xiao-yu ZHANG

2011, 32(6):  132-140.  doi:1000-436X(2011)06-0132-09

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In CEERP (cost-based energy-efficient routing protocol),the routing which had superior performance in WSN (wireless sensor network)could be found through calculating and comparing the cost function values.The cost function,energy consumption and delay performances of the previously proposed protocol,CEERP,were analyzed.The lower-and upper-bound of communication rounds performed by the WSN system and the calculation formula of delay were derived.The performance of various similar protocols was compared and discussed under the premise of the performance evaluation criterion,i.e.,the product of energy consumption and delay.At the same time,the performance of CEERP was simulated further on condition that the sensor nodes were deployed sparsely and the channels were non-ideal respectively.The results show that the comprehensive performance in terms of the product of energy consumption and delay of the CEERP outperforms that of other similar protocols.

Collaborative probability based multimodel target identification in wireless sensor networks

Xin-yao SUN,Xue WANG,Sheng WANG

2011, 32(6):  141-147.  doi:1000-436X(2011)06-0141-07

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A collaborative probability based multimodel target iden ification method for the applications in wireless sen-sor networks was proposed.Wavelet package was used to extract the features of the target information sample,and in or-der to decrease the computing complexity and reserve the key information as well,feature compaction,which achieved by principal components analysis,was carried out before learning.Different types of Gaussian classifier were developed for classifier learning.To gain global optimal results,committee decision was employed to select and combine individual decisions with dynamically adjusted weights.The exper ment results verified that the method introduced can adapt to the interference factor of the environment and can impleme et identification accurately and stably.

Fast inter prediction algorithm applied in quality SVC

Da-yong WANG,Jian SHU

2011, 32(6):  148-156.  doi:1000-436X(2011)06-0148-09

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Based on the characteristics of quality scalable video coding,a fast inter encoding algorithm was proposed on the enhancement layer for the medium-grain quality scalability (MGS).Firstly,based on the base layer macroblock mode and rate-distortion,the order of the coding mode for the current macro block was proposed.Then based on the encode structure,the correlation between layers,and the spatial correlation,desicions for the Direct coding mode,layer mode,and adjacent mode were proposed,respectively.Finally,the macroblocks were encoded in the order predicted,with the proposed three decisions to improve on the coding speed by early termination.The experimental results show that the computational complexity of the algorithm is reduced by 68% on the average compared to that of the standard method,with only negligible coding loss and bit-rate increase.

Approximate algorithm for median query based on WSN

Cai-ping LIU,Jian-xu MAO,Ren-fa LI,Bin FU

2011, 32(6):  157-164.  doi:1000-436X(2011)06-0157-08

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An approximate algorithm for median query (AAMQ) based on WSN was proposed.In AAMQ,each node could estimate the value of the distinct number,and created a subsequence samples which get K percent of the most commonly used values in its own observed values,and then broadcasted its subsequence to the parents.Finally,these samples were combined to a single sample in the root node which its data structure was far smaller than the size of the whole data set.The approximate value for median query could be introduced from the sample quickly.Experimental results show that the proposed algorithm can greatly reduce the communication,has the advantages of low error range,and is able to significantly prolong system life.

Correspondences

Fuzzy adaptive LS channel estimation for GO-MC-CDMA

Yan WANG,Hong-li LIU,Jie ZHAN

2011, 32(6):  165-171.  doi:1000-436X(2011)06-0165-07

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The channel frequency response was constructed by choosing a certain number of the first estimate value which was handled by FFT interpolation.Therefore,the model mismatch error could be compensated effectively.In addition,the relationship between the mean-squared error (MSE) and the number of chosen first estimate value was analyzed by considering the influence of the noise on LS Estimation method.Thus,the optimal criterion for obtaining the optimum number of first estimate value was explored with a fuzzy algorithm.The simulations demonstrate that the fuzzy adaptive LS channel estimation performs is much better than the traditional LS Channel Estimation and that it is more robust with noise.

Improved FSM-based method for protocol conformance testing

Lei XIE,Jiao-long WEI,Guang-xi ZHU

2011, 32(6):  172-176.  doi:1000-436X(2011)06-0172-05

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An improved FSM-based method was introduced to generate the conformance test sequences.This FSM-based method is a mixture version of unique input output (UIO) method and T method.The UIO method has better capability than T method,but the length of conformance test sequences of that is much longer.The simulation results have shown that the improved method has same fault coverage than method,while the length of the test sequences is close to T method.

Digital video passive forensics for its authenticity and source

Wei-bing CHEN,Gao-bo YANG,Ri-chao CHEN,Ning-bo ZHU

2011, 32(6):  177-183.  doi:1000-436X(2011)06-0177-07

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The characteristics of various video forgery operations and their influences to video passive forensics were analyzed.From two aspects of authenticity and source identifications,typical approaches in passive video forensics,such as those video forgery trails-based and video capturing device-based techniques,are summarized.The main problems exiting in current research field and some urgent topics for future research are also investigated in detail.

Research on the format-preserving encryption modes

Zhe-li LIU,Chun-fu JIA,Jing-wei LI

2011, 32(6):  184-190.  doi:1000-436X(2011)06-0184-07

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FPE(format-preserving encryption) was discussed,and it was shown that how to reduce domain complexity was the direction of designing FPE modes.A new FPE mode named coding-then-encipher mode was proposed and its operating principle and security were described in detail,and it was pointed out that the key for this mode was finding efficient encode and decode algorithms on domain.Furthermore,a scheme under coding-then-encipher mode which can resolve FPE problem in charsⁿwas presented,the encode and decode algorithms were described,and their efficiency were analyzed.