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25 March 2012, Volume 33 Issue 3

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Papers

Cooperative MIMO transmission scheme for clustered ad hoc networks

Wen-jiang FENG,Wei ZHAO,Dong WANG

2012, 33(3):  1-9.  doi:1000-436X(2012)03-0001-09

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The potential of cooperative multiple-input multiple-output (CMIMO) transmission was explored.An according CMIMO transmission scheme was proposed for clustered ad hoc networks,including two critical aspects.The first was weighted cooperative node selection algorithm,which synthesized the asymmetrical bi-directional channel state information (CSI) between nodes,as well as the nodes’ residual energy and connectivity.Consequently,a set of optimal nodes was selected to develop the CMIMO system mentioned above.The second was the mechanism of establishing and maintaining virtual link between two virtual nodes.Simulation shows that the proposed CMIMO transmission scheme affords higher capacity against SISO,and the scheme with node selection is more energy-efficient than that without node selection for the 70% energy saved.

Adaptive energy-saving routing algorithm for inter-clustering communications in WSN

Wen-feng LI,Lian-feng SHEN,Jing HU

2012, 33(3):  10-19.  doi:1000-436X(2012)03-0010-10

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An adaptive routing algorithm was proposed for saving nter-clustering communication energy in wireless sensor networks (WSN).In the network,the end-to-end route discovery mechanism was based on the primary principle of the minimum communication costs.An algorithm was prop sed for inter-clustering communication optimization by adaptively selecting the most energy-efficient communication mode among direct,relaying and cooperative communications.The proposed routing algorithm guarantees that the source node can discover the minimum or sub-minimum energy consumption route to the base station.It also decreases the probability that the communications are interrupted due to the coverage holes.Compared with the other routing algorithms,the simu tion results show that the proposed routing algorithm makes WSN consume less energy in each round under the same throughput and bit error ratio (BER).It can also prolong the network lifetimes and operation times under the different node densities.

Performance of multiple-source single-relay ultra-wideband networks based on space-time focusing transmission

Ya-fei TIAN,Chen-yang YANG

2012, 33(3):  20-27.  doi:1000-436X(2012)03-0020-08

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Space-time focusing transmission can reduce multi user interference in ultra-wideband (UWB) communications.Thus enable one relay forwarding the data from multiple sources to multiple destinations.Performance of relay networks with space-time focusing transmission was studied.The outage probabilities in multiple-access phase and broadcasting phase were derived,respectively.The explicit connection between the network throughput and the user number,distance between nodes,UWB pulse width,signal frame duration,and the received signal-to-interferenceand-noise ratio was obtained.By maximizing the network throughput and ana zing the optimization results,some design guidelines for the transmission scheme were provided.The outage probabilities in the two phases were verified through simulations under different path loss factors.

Maximum mean square deviation adaptive filtering algorithm with the same step-size via convex combination

Guo-sheng RUI,Jun MIAO,Yang ZHANG,Lin WANG

2012, 33(3):  28-34.  doi:1000-436X(2012)03-0028-07

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Aimed at poor tracking performance of NLMS filter and filter under time-varying channel,a same step-size convex combination of the maximum mean square deviation algorithm was presented.The algorithm convexly combined two different adaptive filters with the same step-size based on a criterion of maximum mean square deviation.So the proposed filter could keep good dynamic performance in the time-varying channel and stability of mean square characteristics in convergence stage.Theoretical analysis and simulation results show that in the sparse and non-sparse state the proposed algorithm indicates the fastest convergence rate compared with NLMS,PNLMS and IPNLMS algorithm.In the fuzzy state,the performance of proposed algorithm is superior to the above three.Additionally,the steady-state performance of mean square also keeps well.

Approach for reduced test suite generation based on predicate abstraction

Xi GUO,Huan-guo ZHANG

2012, 33(3):  35-43.  doi:1000-436X(2012)03-0035-09

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Aim to the problem of status space explosion due to the growing number of status transition of large scale software system,a reduced test suite generation approach based on predicate abstraction was proposed,which divided the status space of the software model according to the gi predicates to get the equivalence classes.The reduced abstract status was settled using the mapping between the status sets,and generated the reduced test suite based on the transition of the status.The results of experiments indicate tha this approach can reduce the status of the model efficiently,and generate smaller size of test suite.

De-noising algorithms for the raised cosine pulse signal using the minimum-energy frame in the discrete signal space

Ying-hai XIE,Wei YANG,Ting-ting FAN

2012, 33(3):  44-51.  doi:1000-436X(2012)03-0044-08

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The de-noising algorithms were proposed for the raised cosine pulse signal using minimum-energy(wavelet) frame in the discrete signal space.For the given two minimum-energy frames,the decomposition coefficients of sampled sequence appeared significant statistical characteristics difference between the raised cosine pulse signal and additive Gaussian noise under the frames’sub-sequences.Based on this,two threshold de-noising algorithms were provided to makes full use of the merit that the frame was fit for the de-noising work,they removed partial noise component while keeping the component of original signal and got effic nt de-noising result.The simulation results show that,when the modulating method is BPSK and its raised cosine pulse signal is polluted by the additive Gaussian noise,then if add a pre-processing link to denoise the receiving waveform using the algorithms,the receiver can greatly increase the signal-to-noise ratio of receiving signal and have about 3.1dB and 2.7dB performance gain of bit error ratio,respectively.

Minimum energy consumption multicast routing in ad hoc networks based on particle swarm optimization

Xiao-jian ZHU,Jun SHEN

2012, 33(3):  52-58.  doi:1000-436X(2012)03-0052-07

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In wireless ad hoc networks,because devices are powered by batteries,and multicast applications are constantly emerging,how to construct a multicast tree of the minimum energy consumption is an important problem.For the effect of the different choices of relay nodes to the construction of the minimum energy consumption multicast tree,a discrete particle swarm optimization algorithm to optimize the construction of the minimum energy consumption multicast tree was proposed.In order to avoid the premature convergence of the discrete particle swarm optimization algorithm,an inertia weight strategy was introduced to balance the global searchin ability and the local searching ability.The results of simulated experiments show that the modified discrete particle swarm optimization algorithm has strong optimization ability,and can effectively optimize the construction of the minimum energy consumption multicast tree.

Access control security model based on behavior in cloud computing environment

Guo-yuan LIN,Shan HE,Hao HUANG,Ji-yi WU,Wei CHEN

2012, 33(3):  59-66.  doi:1000-436X(2012)03-0059-08

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In view of the current popular cloud computing technology,some security problems were analyzed.Based on BLP(Bell-LaPadula) model and Biba model,using the access control technology based on behavior to dynamic adjusting scope of subject's visit,it put forward the CCACSM ( cloud omputing access control security model).The model not only guarantees the cloud computing environment information privacy and integrity,and makes cloud computing environment with considerable flexibility and practical.At last,it gives the model's part,safety justice and realization process.

Resource allocation algorithm based on non-cooperative game theory in uplink OFDMA multi-hop relay networks

Zheng XIANG,Xu-ming FANG,Peng XU

2012, 33(3):  67-74.  doi:1000-436X(2012)03-0067-08

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Resource allocation issue in uplink OFDMA multi-hop relay networks was investigated.Firstly,with constraints such as maximum transmission power being imposed,a multi-cell optimization model for resource allocation in uplink OFDMA multi-hop relay networks was formulated.By applying non-cooperative game and pricing theories,the optimization is transformed into the case where power was independently allocated on each sub-channel.The existence and uniqueness of Nash equilibrium for power allocation model which was based on non-cooperative was proven,and accordingly a distributed algorithm was proposed.Simulation results show that,the proposed algorithm can improve the system throughput effectively while profoundly reducing total system transmission power,thus achieving much higher energy efficiency ratio.

Threshold ring signature for wireless sensor networks

Jun-fang XIAO,Jian LIAO,Gui-hua ZENG

2012, 33(3):  75-81.  doi:1000-436X(2012)03-0075-07

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Compared with traditional network,the wireless sensor nodes are limited in the storage,mobility,computation,energy,and so on.A threshold ring signature scheme suitable for wireless sensor networks based on bilinear pairings was proposed.Assuming the abstrusity of computational Diffie-Hellman problem,the secure proof was shown in the model of random oracles using the reduction to the contravention.Proposed scheme also had other characteristics,such as robustness,multi-signature and parallel computation.

Robust video watermarking algorithm for H.264/AVC based on texture feature

Wei-wei ZHANG,Ru ZHANG,Jian-yi LIU,Xin-xin NIU,Yi-xian YANG

2012, 33(3):  82-89.  doi:1000-436X(2012)03-0082-08

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On the basis of analyzing some existing video watermarking al ithms and combining with the new features of the H.264/AVC video coding standard,a new robust video watermarking algorithm based on texture feature was proposed.The proposed algorithm firstly performs the 4×4 integer discrete cosine transform on the current frame in purpose of identifying whether it is the texture block.Then the watermarking is embedded by adopting the way of differential energy for selecting the appropriate coefficients adaptively.The experimental result shows that the proposed algorithm has little impact on the video quality and bit-rate,moreover,its robustness can effectively resist the common attacks such as the gauss noise,low pass filter and re-coded performed on the video watermarking.

Network traffic classification using decision tree based on minimum partition distance

Zhe YANG,Ling-zhi LI,Qi-jin JI,Yan-qin ZHU

2012, 33(3):  91-102.  doi:1000-436X(2012)03-0090-13

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Before data communications,every application protocol to handshake at application layer and transmit some parameters.This process is quite different according to the protocols,such as the packet direction,payload size and the information entropy of each packet payload.So according to these features,decision tree algorithm based on minimum partition distance was used to train the classifier.The results of the offline experiments on real network traces and the online classification experiments in campus network indicate that,analyzing the first four or six packets of each flow is enough to classify eight common used application protocols with high overall accuracy and low cost.Contrast to other machine learning algorithms,decision tree can achieve better ent traces and low classification time.So it is very suitable for real-time traffic classification.

Multi-mobile-beacon assisted distributed node localization scheme

Huan-qing CUI,Ying-long WANG,Qiang GUO,Jia-liang LV

2012, 33(3):  103-111.  doi:1000-436X(2012)03-0103-09

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To improve the localization precision and avoid scanning unknown nodes repeatedly in mobile beacon assisted localization method,a multi-mobile-beacon assisted localization scheme was proposed.The ons keep a certain relative position while traversing the network and ranging with TDoA,and provide information to unknown nodes to estimate locations.Two path planning methods based on optimal coverage strategy were introduced.Simulation resu that the proposed scheme and paths perform well.

Automatic proof of resistance of denial of service attacks in protocols

Bo MENG,Wei HUANG,De-jun WAND,Fei SHAO

2012, 33(3):  112-121.  doi:1000-436X(2012)03-0112-10

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First,the applied PI calculus was extended from two aspects:attacker contexts and process expression,then from the view of protocol state,the protocols were modeled with the extended applied PI calculus and a automatic method of proof of resistance of denial of service attacks based on theorem proof with first order theorem prover ProVerif was presented,finally resistance of denial of service attacks in JFK protocol and IEEE 802.11 four-way handshake protocol were analyzed.The results obtained are that JFK protocol is resistance of denial of service attack and IEEE 802.11 four-way handshake protocol is not.At the same time a new al of service attack in IEEE 802.11 four-way handshake protocol was found.The methods to prevent resistance of denial of service attacks in IEEE 802.11 four-way handshake protocol were proposed.

Novel DOA estimation method for coherent wideband LFM signals

Peng,LIUKai-hua LUO,Jie-xiao YU,Yong-tao MA

2012, 33(3):  122-129.  doi:1000-436X(2012)03-0122-08

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A novel direction of arrival (DOA) estimation method for coherent wideband linear frequency modulation (LFM) signals was proposed.Based on the dechirping property of LFM signal in fractional Fourier domain,a new array data model was constructed,then the matrix reconstruction and MUSIC algorithm were used to estimate the DOA of coherent LFM signals.If there were multiple groups of coherent LFM signals incident,separated them in different energy-concentrated domains first,then carried the DOA estimation on each of the groups.Owing to fully excavating the time-frequency information included in observed signals,this method has good resolution ability and anti-noise performance,and the number of DOA that can be resolved is also increased.In addition,this method has no array redundancy and aperture loss,and can be applied to arbitrary array manifold.Simulation results show that this method can obtain nearly 8dB signal-to-noise ratio gain compared with the conventional method.

Technical Reports

Equivalent spectral bandwidth concept in ubiquitous networks and applications in vertical handoff algorithms

Su PAN,Qiang YE,Sheng-mei LIU

2012, 33(3):  130-136.  doi:1000-436X(2012)03-0130-07

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Future wireless telecommunication system will integrate heterogeneous wireless access networks and provide ubiquitous services.The concept of equivalent bandwidth for heterogeneous wireless networks was proposed to describe the resource occupation of users.This concept was adopted in the vertical handoff control algorithm with the Markov decision process model.The simulation results show that the proposed algorithm leads to larger revenue compared with the threshold based handoff algorithms.

Upper processing gain bound of the spreading signal in multipath fading channels

Wan-zhi MA,Jun WANG,You-xi TANG

2012, 33(3):  137-145.  doi:1000-436X(2012)03-0137-09

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Using the joint algorithm of coherent detection and non-coherent detection,the upper processing gain bound of the spreading signal,which is two-dimensional spread spectrum signal relative to BPSK and transmitted in rich scattering multipath fading channel,was sought.Firstly,the expression of the processing gain of the spreading signal was calculated.Secondly,with increasing signal bandwidth or symbol period unlimitedly,the processing gain was bounded.At last,it was obtained that the upper processing gain bound is determined by the channel parameters and signal noise io.By analysis and simulation,the processing gain of the spreading signal,relative to BPSK and transmits in rich scattering multipath fading channel,is not more than 30dB,when the signal noise ratio is 20dB,the maximum doppler shift is 100Hz,and the negative exponential factor is 5×10^?6.

Cloud scheduling algorithm based on fuzzy clustering

Wen-juan LI,Qi-fei ZHANG,Ling-di PING,Xue-zeng PAN

2012, 33(3):  146-154.  doi:1000-436X(2012)03-0146-09

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In order to better serve cloud’s objective of providing low-cost and on-demand services,a two-level and fuzzy clustering based cloud scheduling algorithm named FCTLBS(fuzzy clustering and two level based task scheduling algorithm) was proposed.Scheduling was divided into two levels:user scheduling and task cheduling.It used fuzzy clustering method to cluster resources according to their capabilities and computed tasks’resource bias coefficient according to their parameters.Thus tasks with different resource preference were able to choose different capability resources in the corresponding clusters.The new algorithm reduces the scale of resource choice,better reflects cloud tasks’ service requirements.Simulation results show that the proposed algorithm has some advantages compared to other kindred algorithms.

Confidential communications technique based on message block precoder in multi-user MIMO systems

Yao ZHU,Yi-jun ZHU,Shui-lian ZHANG,Yong-gang LIU

2012, 33(3):  155-162.  doi:1000-436X(2012)03-0155-08

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For confidential communications in a multi-user MIMO wiretap channel,though no information regarding the illegitimate receiver was presumed at the transmitter,an artificial interference and a precoding technique based on message block were proposed.Except for confidentiality,the effectivity and efficiency of confidential communications were also taken into consideration.The artificial interference selectively degraded the passive illegitimate receiver’ signal while did not effect every legitimate receiver.The precoding technique combined the existed zero-forcing method that used to eliminate the multi-user interference with singular value decomposition (SVD)-based linear precoder so that enhances the efficiency of confidential communications.ulation result shows that this precoding method degrades the illegitimate receiver’ signal to interference plus noise ratio (SINR) even more and enhances the capacity of multi-user MIMO system compared with the precoding method based on single message symbol.

Correspondences

S-Vivaldi:a space repairing based Internet delay space embedding algorithm

Zhan-feng WANG,Ming CHEN,Chang-you XING,Hua-li BAI,Xiang-lin WEI

2012, 33(3):  163-170.  doi:1000-436X(2012)03-0163-08

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To counteract TIV’s influence on the Internet delay space models,an Internet delay space embedding algorithm based space repairing S-Vivaldi (scaling-Vivaldi) was proposed.S-Vivaldi firstly applied an exponent transformation on the delay matrix D,retrieved a matrix D'almost without TIV,and then embedded D'by the Vivaldi algorithm.The delay between any two nodes could be computed by a series of inverse transformation.Experimental results show that S-Vivaldi could improve the prediction accuracy apparently in the most case.

Explicit construction of girth-eight QC-LDPC codes and its application in CRT method

Guo-hua ZHANG,Rong SUN,Xin-mei WANG

2012, 33(3):  171-176.  doi:1000-436X(2012)03-0171-06

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For arbitrary code lengths of the form PL(P≥3L²/4+L-1),a new family of (4,L)-regular quasi-cyclic (QC) low-density parity-check (LDPC) codes was proposed explicitly with girth ight.Employing the new code as a component code in the construction method of Chinese remainder theorem (CRT),a novel class of compound QC-LDPC codes was presented with both girth at least eight and very flexible code lengths.Simulation results show that the new compound codes with rate 1/2 and moderate code lengths perform very well over the additive white Gaussian noise (AWGN) channel.

Control of the periodical quantum echo of atom bit with arbitrary initial states in two-photon channel

Bing-ju ZHOU,Xiao-juan LIU,Jie ZHAN,Ren-long ZHOU

2012, 33(3):  177-182.  doi:1000-436X(2012)03-0177-06

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By means of the full quantum theory,the conditions of generating a periodical quantum echo in the two-photon channel of a atom bit with arbitrary (pure or mixed) initial states was investigated,in coherent light field.Having studied the effects both the atom bit initial state and the surroundings parameter on its fidelity evolution,respectively,the parameter for control the periodical quantum echo of the atom bit was got and discuss its physical characters was discussed,that may be as a possible theoretical basis to the realization of a high fidelity output of quantum information.

Underdetermined blind source separation based on null-space representation and maximum likelihood

Rong-jie WANG,Yi-ju ZHAN,Hai-feng ZHOU

2012, 33(3):  183-190.  doi:1000-436X(2012)03-0183-08

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Aiming to the estimation of source numbers,mixing mat ix and source signals under underdetermined case,and a method of underdetermined blind source separation with an unknown number of sources was proposed.Firstly,an algorithm based on S transforms and clustering technology was introduced to estimate the number of sources and mixing mixtures.Then sources were represented as null space form,the recovery of source signals usi a method based on maximum likelihood.The simulation results show that the proposed method can separate sources of super-Gaussian distribution and sub-Gaussian distribution,and compared to other conventional algorithms,estimated mixing matrix and separated sources with higher accuracy.