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    25 October 2009, Volume 30 Issue 10
    Academic paper
    Estimation and compensation of nonideal front-end effects for MB-OFDM based ultra wideband system
    Liang LIU,Jun ZHOU,Fan YE,Jun-yan REN
    2009, 30(10):  1-7.  doi:1000-436X(2009)10-0001-07
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    Three types of wireless system front-end imperfections, namely carrier frequency offset (CFO), sampling fre-quency offset (SFO) and in-phase/quadrature-phase (I/Q) imbalance were addressed. A time-domain CFO and I/Q imbal-ance estimation and compensation scheme for MB-OFDM based ultra-wideband (UWB) system was proposed. In the scheme, a data-aided CFO estimation algorithm, which was robust to large I/Q imbalance, was presented. Also, a time-domain I/Q imbalance estimation algorithm was introduced. Finally a two-step joint CFO and I/Q imbalance com-pensation scheme was developed. In frequency domain, a residual CFO and SFO estimation algorithm using the time-domain spreading feature of the UWB frame header was presented. The proposed scheme is competent for large front-end imperfections, and the results are confirmed by simulations.

    Multi-power level mobile beacon assisted distributed node localization algorithm
    Qing-jiang SHI,Chen HE
    2009, 30(10):  8-13.  doi:1000-436X(2009)10-0008-06
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    A mobile beacon assisted distributed node localization scheme was proposed. The scheme differs from other mobile beacon based methods that it is range-free with power control. In the scheme, a mobile beacon broadcasts packets with multi-power level on its trajectory, and then unknown nodes that receive packets will derive a set of quadratic ine-quality constraints and run a convex position estimation algorithm. Simulation results show that the proposed method can perform well without range.

    Node adaptive sleeping mechanism of DCF protocol in ad hoc networks
    Lei LEI,Zong-ze XU,Xu LIU
    2009, 30(10):  14-23.  doi:1000-436X(2009)10-0014-10
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    Most of the existing node sleeping mechanisms in ad hoc networks adopt the PA/RT (periodically awake with reserve transmission) strategy, however, this strategy has some shortcomings. To overcome these shortcomings, a node adaptive sleeping mechanism (NASM) of DCF protocol was presented which can be used on both single-hop and multi-hop ad hoc networks. This sleeping mechanism does not rely on the PA/RT strategy, and permits the node to adap-tively adjust the length of sleeping time according to the communication status of the nodes. The simulation results show that NASM can effectively save the average energy consumption of the nodes without significantly impairing the other performance indexes of the network.

    Ant based approach to the optimal deployment in wireless sensor networks
    Wei LIU,L CUI
    2009, 30(10):  24-33.  doi:1000-436X(2009)10-0024-10
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    For the importance of human deployment of sensor nodes in WSN application, presents an approach named Easidesign which is used to get an optimal deployment of sensor nodes. Targeting to solve the scalability problem when use initial ant based approach to apply to sensor node deployment, the greedy scheme, additional pheromone evaporation methods were used. The most attractive ability of Easidesign is that it not only consider the different sink position but also guarantee the wholly connectivity between sink node and deployed sensor nodes. The algorithms key choice and pa-rameters setting to meet different practical requirements for certain applications are also studied through largely simula-tions. Simulation results show that the proposed approach has significant advantage over practical deployment of sensor networks compared with existing works.

    Distributed energy efficient unequal clustering algorithm for wireless sensor networks
    GFeng-jun SHAN,Abolhasan Mehran,Wysocki Tadeusz
    2009, 30(10):  34-43.  doi:1000-436X(2009)10-0034-10
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    A distributed energy-efficient unequal clustering (DEEUC) algorithm was proposed for wireless sensor net-works by research current routing algorithms. The core of DEEUC has three parts. Firstly, when tentative clusterheads are selected, an average energy factor was introduced to balance the residual energy of the whole network nodes so that it may improve the network energy efficiency. Secondly, an energy consumption ratio function was proposed to balance en-ergy-efficient of each node. Finally, an unequal clustering algorithm was proposed for single-hop homogeneous networks. Through both theoretical analysis and numerical results, it is shown that DEEUC prolongs the network lifetime signifi-cantly against the other clustering protocols such as LEACH-C and EECS. Under general instance, DEEUC may prolong the lifetime up to 30% against EECS.

    Localization algorithm based on support vector regression for wirless sensor networks
    Ye-hua WEI,Ren-fa LI,Juan LUO,Bin FU
    2009, 30(10):  44-50.  doi:1000-436X(2009)10-0044-07
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    In some incremental localization algorithms, error can be easily accumulated. Some centralized algorithms needs to collect information of the entire network, thus the communication cost is high. Aiming at these drawbacks, a semi-centralized localization algorithm based on support vector regression was presented. The base node collected the position of nodes and all connectivity information between anchor nodes as training samples to run the training procedure with support vector regression method. As a result, a regression function could be derived and was distributed to all sen-sors in the network. Then, normal nodes could perform the estimation of locations using the function. In order to increase the number of training samples, the normal nodes having minimum three anchor nodes as neighbors was located and be-came to anchor nodes with range based least-square method using RSSI. Analyses and simulation results show that the algorithm can reduce the overheads of communication and decrease the influence of ranging error, and has a high local-ization accuracy.

    Low computational complexity PTS scheme for PAPR reduction in OFDM system
    Ling-yin WANG,Ye-wen CAO
    2009, 30(10):  51-57.  doi:1000-436X(2009)10-0051-07
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    Concerning that the main drawback of conventional PTS was the large computational complexity, a new low computational complexity PTS (LCC-PTS) scheme was proposed. In LCC-PTS, the computation for candidate signals was simplified by making use of the relation between phase weighting sequences, which resulted in reducing computa-tional complexity dramatically. Performance analysis show that, compared with conventional PTS, the proposed LCC-PTS scheme can be implemented with lower computational complexity while at no loss of PAPR(peak-to-average power radio) performance of the system.

    Firmware protocol stack supporting remote boot and storage volumes mapping in IP-SAN
    Huai-liang TAN,Bin YIN
    2009, 30(10):  58-67.  doi:1000-436X(2009)10-0058-10
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    A new remote boot technology based on IP storage area network was designed, and the core technology of it is the firmware protocol stack running under bare machine platform. A non-routing iSCSI/TCP protocol prototype was proposed and implemented based on firmware.At the same time, several optimization algorithms were introduced to en-hance the performance and reliability of remote boot, including optimistic forecast, fixed avoiding retransmit algorithm and output request suspend strategy that solved the problem of reentry. A firmware iSCSI initiator finite state machine model was established which can be easily taken over by kernel mode initiator. Then the firmware protocol stack was in-tegrated into IP-SAN extension BIOS, applied to client host with no local storage devices, and achieves network boot based on IP-SAN. Test results show it has very good performance and reliabrity. Deployment,movement and re-distribution of relations between host and storages become more easily.

    Directions of arrival estimation for multi frequency-hopping signals based on digital channelized receiver and spatial time-frequency analysis
    Li-hu CHEN,Er-yang ZHANG
    2009, 30(10):  68-74.  doi:1000-436X(2009)10-0068-07
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    An algorithm of DOA estimation for multi frequency-hopping signals based on digital channelized receiver and spatial time-frequency analysis was proposed, which can realize exact DOA estimation in underdetermined condition. First, the architecture of digital channelized receiver based on polyphase filter banks was realized. Second, a clear time-frequency representation was gained by time-frequency analysis. Third, effective hops were selected from the time-frequency distribution, and every hop's spatial time-frequency matrix was built. At last every hop's DOA was esti-mated based on spatial time-frequency method. The simulation results demonstrate that the estimation algorithm is effec-tive and efficient.

    Efficiently non-authenticated group key management protocol withstand interruption attack
    Peng XU,Guo-hua CUI,Ming-hui ZHENG
    2009, 30(10):  75-80.  doi:1000-436X(2009)10-0075-06
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    To overcome the fault that the interruption attack from internal participation of BD_3 protocol, a new scheme was constructed by applying the bilinear map and had the provable security with tight reduction. By analyzing and simu-lating, compared with another scheme, it was obvious that the new scheme was more efficiently than that one. Especially in the quantity of message for communication, it could be approximately 0.14 multiple of that one. On the other hand, the process of simulation simply explaines the method how to carry out the bilinear map, especially how to choose the pa-rameters of it and its signification in the security.

    Technical Reports
    Outage probability of multiuser cognitive MIMO system
    Ying-xiao WU,Qi ZHU
    2009, 30(10):  81-88.  doi:1000-436X(2009)10-0081-08
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    To analyze the multi-antenna gain in multiuser cognitive radio system, a multiuser cognitive MIMO frame-work was presented. The outage performance was considered in the multiple-antenna flat Raleigh fading broadcast downlink channel and the closed-form expression of the outage probability of primary and secondary users was derived. The number of transmitter and receiver antenna was carefully analyzed for impacts the outage performance of the pri-mary and secondary user. Simulation verified the theory analyses and results show that the multi-antenna gain improves the system performance.

    Semi-fragile watermark algorithm based on Walsh-Hadamard transformand and convolution coding
    Feng ZHAO,Jian LI,Sheng-hong LI
    2009, 30(10):  89-95.  doi:1000-436X(2009)10-0089-07
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    A semi-fragile watermark algorithm based on the Walsh-Hadamard transform and convolution coding was proposed. In this algorithm, the watermark content of the host image was extracted by differential coding and convolution coding respectively based on the image block before embedding watermark, and was embedded on the energy value of the host image after Walsh-Hadamard transforming. In the case of watermark detection, the tampered place of the image was located by detecting the error bits generated by convolution decoding, and its result was used to recover the tampered image. The efficiency and the influence on the host image quality of the proposed algorithm were discussed theoretically and experimentally. The experimental results show that the proposed algorithm has high robustness against lossy com-pression, can detect and locate the place being maliciously tampered accurately and recover the lost image content roughly.

    Concise Papers
    New fast adaptive algorithm for fast fading channel estimation
    Sheng CHEN,Shu-xiong LEUNG,Yue-sheng ZHU
    2009, 30(10):  96-99.  doi:1000-436X(2009)10-0096-04
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    A new decoupling basis expansion model recursive least-square (D-BEM RLS) algorithm was proposed for fast fading channel estimation in wireless communications in this paper. By using the independent property between multi-path channels, the correlation redundancy of conventional BEM RLS can be removed. Simulation results have shown that the proposed algorithm reduces 80% of the computational complexity with the same estimation accuracy compared with conventional BEM RLS.

    One-way hash function construction based on Chen-type hyper-chaotic system and key-stream
    Hai-peng REN,Yuan ZHUANG
    2009, 30(10):  100-106.  doi:1000-436X(2009)10-0100-07
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    A scheme of constructing one-way hash function based on Chen-type hyper-chaotic system and key-stream was proposed. In this scheme, the plain-text and the secret key were used as the initial values of two hyper-chaotic sys-tems, these values were evolved in a hyper-chaotic way during a predefined period. The results of the evolution were quantified and iterated using key-stream iteration to confuse and diffuse the plain-text with the secret key. Then, the ci-pher block chaining mode was used to generate the 128bit hash value for the plain-text with arbitrary length. Theoretical analysis and experimental results indicate that the proposed algorithm can satisfy the required security performance, such as data compression function, irreversibility, initial value sensitivity forgery resistance and collision resistance. Compared with some existing methods, the proposed scheme possesses better collision resistance performance.

    Iterative algorithm for locating nodes in WSN based on modifying average hopping distances
    Jin-zhao LIN,Xiao-bing CHEN,Hai-bo LIU
    2009, 30(10):  107-113.  doi:1000-436X(2009)10-0107-07
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    Three approaches were put forward to improve the poor locating performance of DV-Hop algorithm which is one of the range-free algorithms in wireless sensor network (WSN) with a dynamic topology. Firstly, the average one-hop distance among beacon nodes was refined by means of least squares method (LSM). Secondly, the average one-hop dis-tance used by each locating node for estimating itself location was modified through weighting the N received average one-hop distances from beacon nodes. Finally, the iterative numerical method with the initial values of estimated node locations was presented by setting proper threshold. The procedure of the iterative locating algorithm based on modifying average hopping distances and the simulation results were also shown. It can be concluded that the improved algorithm has obviously better locating performance in locating precision and precision stability at the cost of increasing appropriate communication and computation overhead, and is a more feasible locating scheme in WSN with both random distributing nodes and dynamic topology.

    PAPR reduction method for SFBC MIMO-OFDM systems
    Yi SHA,Jun-xin CHEN,Guang-xing WANG
    2009, 30(10):  114-117.  doi:1000-436X(2009)10-0114-04
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    The high PAPR is the major drawback of SFBC MIMO-OFDM systems to its practicability. To deal with this problem, a novel method was proposed to reduce the PAPR of SFBC MIMO-OFDM systems. It was called PIP(polyphase inversion and permutation) method. The method treated all transmit antennas as a whole. By dividing, ro-tating, and shifting the sequence twice, the method fully made use of the character of conjugation and shifting of all the antennas' sub-carriers. Meanwhile, PIP method could reduce the complexity of calculation by using the character of IFFT. The simulation result proves the method to be efficient.

    Cryptanalysis of a non-interactive protocol for member expansion in a secret sharing scheme
    Jing-fang XU,Guo-hua CUI,Qi CHENG,Zhi ZHANG
    2009, 30(10):  118-123.  doi:1000-436X(2009)10-0118-06
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    Cryptanalysis of a non-interactive protocol for member expansion in a secret sharing scheme was presented, in which a malicious broadcast receiver might easily recover old t shares, new share and further reconstruct the secret S. The claimed security could not be realized. In addition, a new protocol was proposed, which elaborately eliminates the defect of previous protocol and improved the efficiency of existing schemes.

    Correspondences
    Note on the channel capacity of narrowband subliminal channels in one-way function
    Qing-kuan DONG,Xiao-ping LI,Yan-ming LIU
    2009, 30(10):  124-127.  doi:1000-436X(2009)10-0124-04
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    The channel capacity of narrowband subliminal channels in one-way function was studied to effectively evalu-ate the ability of subliminal channels to transmit subliminal messages. The definition of Kobara and Imai on the practical channel capacity of narrowband subliminal channels in information-theoretic view was analyzed and its limitation that the bit error ratio in one-time subliminal communication was not considered was pointed out. The bit error ratio is very important in one-time subliminal communication. A new method to calculate the size of the narrowband subliminal channels is presented to reduce the above limitation, which is very practical in applications.

    Hierarchical-ring application layer multicast model based on diff-services
    Jian-zhen XU,Ke-hui LIANG,Fu-yan ZHANG
    2009, 30(10):  128-134.  doi:1000-436X(2009)10-0128-07
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    To improve the efficiency of application layer multicast (ALM), an hierarchical-ring ALM model based on diff-services (HRM) was presented. In the model, the ring topology was employed to reduce the control overhead. In the data transmission process, the model used push/pull transmission strategy to reduce transmission delay and increase the bandwidth utilization. Simulation results show that the model provides lower end-to-end delay and link stress and control overhead, which is suitable to those larger scale different types ALM applications.

    Data fusion for cooperative detection in cognitive radio system
    Wei LIN,Jie WU,Qin-yu ZHANG,Nai-tong ZHANG
    2009, 30(10):  135-139.  doi:1000-436X(2009)10-0135-06
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    The cooperative detection in cognitive radio system was investigated based on multi-sensor data fusion. For a certain scale of the online users, an optimal user number participating in data fusion existed. Based on this fact, a meas-ure-based fusion method was proposed. This method dynamically adjusted the user number in fusion according to the re-ceived signal in each detection activity. Simulation shows the performance of over 60% detection is improved by this fu-sion method than the method with fixed fusion user number.

Copyright Information
Authorized by: China Association for Science and Technology
Sponsored by: China Institute of Communications
Editor-in-Chief: Zhang Ping
Associate Editor-in-Chief:
Zhang Yanchuan, Ma Jianfeng, Yang Zhen, Shen Lianfeng, Tao Xiaofeng, Liu Hualu
Editorial Director: Wu Nada, Zhao Li
Address: F2, Beiyang Chenguang Building, Shunbatiao No.1 Courtyard, Fengtai District, Beijing, China
Post: 100079
Tel: 010-53933889、53878169、
53859522、010-53878236
Email: xuebao@ptpress.com.cn
Email: txxb@bjxintong.com.cn
ISSN 1000-436X
CN 11-2102/TN
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