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25 January 2007, Volume 28 Issue 1

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Papers

Blind channel estimation for the uplink of MC-CDMA systems with timing offset

Hai-feng WU,Xian-hua DAI,Jian-qing LIANG

2007, 28(1):  8-16.  doi:1000-436X(2007)01-0008-09

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A new blind channel estimation scheme was proposed for the uplink of multicarrier code-division multiple ac-cess (MC-CDMA) systems with timing offset (TO).The scheme can cancel TO effects on the channel estimation,and thus work well without synchronizing the system.In addition,the estimation can exploit the knowledge of the spreading sequences to accomplish a blind estimation since the spreading sequences are known for the receiver.In computer simu-lations,the new channel estimation provides a satisfactory performance.

Novel multi-frame fast motion search algorithm based on H.264

Zong-liang GAN,Xiu-chang ZHU

2007, 28(1):  17-21.  doi:1000-436X(2007)01-0017-05

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A fast flexible multi-frame motion search algorithm based on H.264 was presented.The proposed algorithm reduced the computational cost by the initial search point prediction of reference frames and the hexagon search based on multi-frame.The simulation results show that the proposed algorithm can provide better competitive performance than the other search algorithms,and that the computational cost can be reduced efficiently with similar visual quality and bit rate.

Improvement on the XTP public key cryptosystem and communication protocol of provable security

Ze-hui WANG

2007, 28(1):  22-27.  doi:1000-436X(2007)01-0022-06

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A new trace function was proposed,the XTP public key cryptosystem based on the 3-rd order LFSR se-quence(the so-called XTR3 system) was extended to the XTR4 system based on the 4-th order LFSR sequence.XTR4 key was shorter in length than that of the XTR3 system under the same security level.Based on the XTR4 cryptosystem,the key exchange protocol,communication protocol of provable security,and one-time-pad protocol were proposed,which could be employed in variant environments to assure the security,as well as to improve the calculation efficiency.

Anti-worm based on hybrid confronting technology

Chao WANG,Si-han QING,Jian-bo HE

2007, 28(1):  28-34.  doi:1000-436X(2007)01-0001-07

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As a type of confronting Internet worm technology,anti-worm has been focused by malicious code researchers.However active and passive confronting technology used by current anti-worms has several faults,which cause anti-worms cannot defend the propagation of Internet worm effectively and completely.An improved anti-worm based on new hybrid confronting technology was presented.Through constructing a confronting model and several confronting experiments,this technology was analyzed.Then it was proved that this technology can both defend the propagation of Internet worm effectively and reduce the consumption of network resource at the same time.

Speech endpoint detection based on recurrence rate analysis

Run-qiang YAN,Yi-sheng ZHU

2007, 28(1):  35-39.  doi:1000-436X(2007)01-0035-05

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In order to perform speech endpoint detection under extreme noisy and nonstationary conditions,a new algorithm based on the difference of underlying dynamics between speech and noise was proposed.Recurrence rate was taken as the quantification parameter to measure the variation of such difference and double decision thresholds were applied in the deci-sion framework.Comparing with some traditional methods such as short-time energy and cepstral distances,this algorithm shows lower wrong decision rate.This method provides a new way for feature extraction and speech recognition.

BER performance analysis of a cooperative transmit diversity system

Xian-jing ZHAO,Bao-yu ZHENG,Xiao-cong QIAN,Hong-liang FU

2007, 28(1):  40-48.  doi:1000-436X(2007)01-0040-09

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A novel cooperative diversity system combined with distributed space-time block code and multi-carrier code division multiple access (DSTBC-MC-CDMA) techniques was proposed,which works well in multi-user wireless net-works with single-antenna users in frequency selective fading channels.And an analytical model was established to simulate the symbol decoding error between interusers,based on which,a close form expression for theoretical bit error rate (BER) performance of the system was derived.Then the simulation was done to versify the analytic results above,and the simulation also shows that the BER performance of DSTBC-MC-CDMA outgoes non-cooperative MC-CDMA with distinctive gains.Furthermore,the simulation results coincide with the theoretical results well.

COSFoTS:component oriented software framework for telecommunication software

Xing-ping HUANG,Xiang-ming LONG,Peng XU,Fang-chun YANG

2007, 28(1):  49-56.  doi:1000-436X(2007)01-0049-08

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Based on the research of software framework and analysis on telecommunication software,component ori-ented software framework for telecommunication software (COSFoTS) was put forwared.The architecture and the key issues of COSFoTS,such as software bus based kernel design,the orthogonal decomposition of functional components and ALDL(application logic description language)based application logic generation were specified.Moreover,the soft-ware development process using COSFoTS was also introduced.COSFoTS had been put into practice in the development of telecommunication software ＂soft switch controller supporting multimedia and mobile service＂,and was proved to be effective on simplifying the development of telecommunication software and improving the quality of telecommunication software products.

Web service discovery method based on semantic expansion

Zheng ZHANG,Chun ZUO,Yu-guo WANG

2007, 28(1):  57-63.  doi:1000-436X(2007)01-0057-07

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A Web service discovery method based on semantic expansion was provided.It semantically expanded the conception of service description and service request.The semantic expansion way includes equivalent expansion,feature expansion and compose expansion.It gave the definition of extend semantic subsume during the period of input/output matching.The experiment tells that this algorithm can improve the recall while maintaining a high level precision.If sin-gle service can not match the service request,the way can attempt service composition to match service request.The heu-ristic algorithm based on H^*changed the composition problem to searching problem.Because of the adoption of estima-tion function,the efficiency is improved distinctly.

Efficient quantum signature protocol of classical messages

Jian WANG,Quan ZHANG,Chao-jing TANG

2007, 28(1):  64-68.  doi:1000-436X(2007)01-0064-05

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An efficient quantum signature protocol of classical messages which was based on quantum one-time pad and quantum key distribution was presented.The classical messages of any length could be encoded into the quantum infor-mation of determinate length because hash function was used to generate message digests.Especially for a large number of messages,the length of shared keys and the number of qubits were greatly shortened in the present protocol.Moreover,it was unnecessary for the protocol to use entangled states and only von Neumann measurement was needed.Compared with other quantum signature protocols,the efficiency of the present quantum signature protocol was greatly improved.

Novel parallel combinatory system with high compaction multicarrier modulation

Ya-fei HOU,Masanori HAMAMURA,Shi-yong ZHANG

2007, 28(1):  69-74.  doi:1000-436X(2007)01-0069-06

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A novel system named parallel combinatory/high compaction multi-carrier modulation (PC/HC-MCM) system was proposed based on techniques of high compaction multi-carrier modulation (HC-MCM) and parallel combinatory OFDM (PC-OFDM).Compared with PC-OFDM,PC/HC-MCM can dramatically improve the bandwidth efficiency of PC-OFDM system.On the other hand,it simulated the performance of two different PC/HC-MCM systems which can be developed to apply in multi-carrier systems.

Research on hybrid dynamic load balancing algorithm in heterogeneous hierarchical wireless networks

Guo-qin NING,Guang-xi ZHU,Lie-xin PENG,Xiao-feng LU

2007, 28(1):  75-81.  doi:1000-436X(2007)01-0075-07

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A hybrid dynamic load balancing algorithm based on the combination of channel borrowing scheme and load transfer scheme was proposed.The hotspot cells can borrow channels from homogeneous cells with light workload in the compact pattern.At the same time,some ongoing calls can be transferred from hotspot cells into the overlapping hetero-geneous cells with light workload according to certain conditions.The number of borrowed channels and transferred on-going calls per load balancing period was computed by the remainder available channels and new calls arrival rates in the hotspot cell.Simulation results show that the proposed hybrid dynamic load balancing algorithm can decrease the block-ing probabilities,dropping probabilities of hotspot cell system and overall heterogeneous system,the channel utilization of overall heterogeneous system is increased accordingly.

Technical Reports

Dynamic single/dual channel filter with smart temperature set based on electromagnetic tunable FBG

Duo-ying ZHANG,Min LIU,Jian-dong LI

2007, 28(1):  82-86.  doi:1000-436X(2007)01-0082-05

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A cascaded fiber Bragg gratings filter module was proposed,which can act either as a tunable single channel filter with its central wavelength and/or bandwidth being tunable,or as a double channel filter with its central wavelength being tunable.The filter is applied strain by electromagnetic force.The temperature of magnet is controlled by semicon-ductor equipment.The test results show that the filter can realize the optical channel is added/dropped in the MAN optical network simply and flexible.

IP-based high-available mass network storage system

De-zhi HAN,Shun-zheng YU

2007, 28(1):  87-95.  doi:1000-436X(2007)01-0087-09

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An IP-based high-available mass network storage system (MNSS) was introduced,featured by the following advantages:firstly,it integrates multi-NAS and SAN with OSD through a unified multi-protocol file system (UMPFS),with greater capacity and better scalability than each of them; secondly,it simultaneously serves both the file I/O and the block I/O by an iSCSI module,with all the advantages of a NAS and a SAN; thirdly,with an autonomic storage agency (ASA),the MNSS provide two kinds of data channels,i.e.,a server channel and a high-speed network-attached channel,by which the I/O performance is improved and server bottlenecks are reduced; fourthly,high availability is attained by way of a high-available file system.In addition,in the experiment concerned,the MNSS has proved to be a network storage system with great capacity producing an ultra-high-throughput for both the file I/O and the block I/O,characterized by better performance,scalability,availability and cost performance,etc.when compared with those systems already on the market.

Solving degree-constrained multicast routing problem by a heuristic genetic algorithm

Yun PAN,Xing-gang WANG,FENGYan-li ,,Zhen-wei YU

2007, 28(1):  96-102.  doi:1000-436X(2007)01-0096-07

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With the purpose to solve the degree constrained multicast routing model efficiently,the evolutionary strategy was introduced into heuristic search methods by employing the chromosome as the heuristic information for global searching,and then a hybrid genetic algorithm was proposed.The algorithm not only avoids the difficulty of coding for multicast trees,but also possesses fast convergency and global optimizing capability.Meanwhile,the efficiency of the method is supported by a great number of numerical experiments.

Access control policy management based on extended-XACML

Xiao-feng LI,Deng-guo FENG,Zheng XU

2007, 28(1):  103-110.  doi:1000-436X(2007)01-0103-08

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Based on XACML core specification and XACML administrative policy draft,a decision of XACML policy management permission was reduced to a decision of delegation decision request.The delegation decision request schema was defined.It was described that the process of reducing a policy administration request to a delegation decision request and the decision process of delegation decision request.This method can be used to check if a policy administra-tion request is valid and thereby to implement access control policy management based on extended-XACML.

Comprehensive Review

Review of video transcoding for network video applications

Sheng-fa YU,Zeng-ping CHEN,Zhao-wen ZHUANG

2007, 28(1):  111-118.  doi:1000-436X(2007)01-0111-08

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The technical issues about video transcoding,especially the three typical architectures were firstly outlined and compared.Emphasis was put on how to reduce the complexity and improve the video quality by exploiting the informa-tion,which can be easily extracted from the input video bitstream.Other active research topics in recent years such as in-formation,especially watermark and error resilient data,insertion transcoding and H.264 bitstream related video transcoding were discussed in detail.Future directions on this topic were also prospected.

Concise Papers

Improvements on results of representation of elements in cyclotomic subgroup

Zheng-tao JIANG,Jian-wei LIU,Ping-zhi YUAN,Yu-min WANG

2007, 28(1):  119-122.  doi:1000-436X(2007)01-0119-04

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Further investigations on efficient public-key cryptosystems based on discrete logarithm in finite field (exten-sion) were provided,and in case of the degree of field extension being odd,the ordinary results proposed by Wieb Bosma et al were optimized.It was pointed out that even though the degree (k=de) of field extension is odd,the minimal poly nomial over $F_{P^d}$ of any element in cyclotomic polynomial subgroup can still be represented with (e?1)/2 elements of $F_{P^d}$ ,in the case of e=3,no matter what d is,a cryptosystem with optimization 3 can always be constructed based on the dis-crete logarithm in field extension.Further,it was pointed out that for any e,positive or negative,there exists k=de such that Wieb Bosma's conjecture is true.

Performance analysis of UWB-TR receiver

Xin XIANG,Yong-chao WANG,Ke-chu YI,Hong-xin TIAN

2007, 28(1):  123-126.  doi:1000-436X(2007)01-0123-04

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Based on the determination of UWB-STR receiver model,the performance of UWB-STR receiver was ana-lyzed by using a Gaussian approximation of the noise components at the output of the receiver and the analytical expres-sions of bit error rate(BER) performance were derived.The result shows that the receiver performance of BER is relevant to not only signal-to-noise ratio,but also input noise bandwidth and integration time.The characteristics can be applied to other kind of autocorrelation receivers.Finally,the analytical expressions of BER were compared with that in existing literatures and some results were modified.In addition,the expressions of BER for UWB-ATR receiver were given.

Correspondences

Leak bucket based admission control for content adaptation system

Jiang ZHU,Qing-guo SHEN,Li WANG

2007, 28(1):  127-134.  doi:1000-436X(2007)01-0127-08

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Web server do content adaptation according to the characteristic parameters along with the user request.It would cost more system resource once in a heterogeneous environment where the request varied greatly.To avoid the overload of server,admission control technique must be adopted.Based on combining the terminal characteristic,seman-tic characteristic of content object and communication characteristic,user perceived Web page quality under real-time system load was evaluated and used as a reference in admission control.The leak bucket model and PID(proportional-integral-derivative) method were linked together to construct a feedback control loop.Technical analy-sis and analog simulation validate the feasible of the mechanism,and the QoS user achieved are improved in some degree.It opened up new vista of research for this research direction.

Novel multi-rate multicast congestion control algorithm

Deng-yin ZHANG,Qian-qian WANG,Jun LI,Ru-chuan WANG

2007, 28(1):  135-140.  doi:1000-436X(2007)01-0135-06

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A novel congestion control mechanism based on packet-bunch probe and TCP throughput formula (PTMCC) was proposed.This receiver-driven multi-rate multicast congestion control mechanism probes available bandwidth by packet-bunch and gets TCP-friendly rate by TCP throughput formula.A new rate adjustment algorithm was also designed.Simulation results show that the PTMCC make good performance on convergence,TCP-friendliness and response to congestion.