本期目录

2010年 17卷 4期 刊出日期：2010-08-30



Wireless

Novel modified min-sum decoding algorithm for low-density parity-check codes

刘海洋 曲文泽 刘彬 李江鹏 罗士栋 陈杰

中国邮电高校学报(英文), 2010, 17 (4). doi： 10.1016/S1005-8885(09)60479-9

摘要 ( 3707 )

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The problem of improving the performance of min-sum decoding of low-density parity-check (LDPC) codes is considered in this paper. Based on min-sum algorithm, a novel modified min-sum decoding algorithm for LDPC codes is proposed. The proposed algorithm modifies the variable node message in the iteration process by averaging the new message and previous message if their signs are different. Compared with the standard min-sum algorithm, the modification is achieved with only a small increase in complexity, but significantly improves decoding performance for both regular and irregular LDPC codes. Simulation results show that the performance of our modified decoding algorithm is very close to that of the standard sum-product algorithm for moderate length LDPC codes.

Outage analysis of opportunistic multi-antenna relay selection in decode-and-forward relay networks

王晓湘 郑子云

中国邮电高校学报(英文), 2010, 17 (4). doi： 10.1016/S1005-8885(09)60480-5

摘要 ( 2611 )

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This article studies the closed-form expressions of outage performance for opportunistic relay under aggregate power constraint in decode-and-forward (DF) relay networks over Rayleigh fading channels, assuming that multiple antennas are available at the relay node. According to whether instantaneous signal-to-noise ratio (SNR) or average SNR can be utilized for relay selection, two opportunistic relay schemes, opportunistic multi-antenna relay selection (OMRS) and average best relay selection (ABRS) are proposed. The performances of both two schemes are evaluated by means of theoretical analysis and simulation. It is observed that OMRS is outage-optimal among multi-antenna relay selection schemes and closely approaches the beamforming (BF) scheme known as theoretical outage-optimal. Compared with previous single-antenna opportunistic relaying (OR) scheme, OMRS brings remarkable performance improvement, which is obtained from maximum ratio combining (MRC) and beamforming techniques. It is also shown that the performance of ABRS in asymmetric channels is close to OMRS in the low and median SNR range.

Research on the low complexity adaptive power allocation algorithm in cooperative systems

王亮 解维浩 武卓 陈惠民

中国邮电高校学报(英文), 2010, 17 (4). doi： 10.1016/S1005-8885(09)60481-7

摘要 ( 3126 )

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Cooperative diversity is a new technology to improve bit error rate (BER) performance in wireless communications. A new power allocation algorithm to improve BER performance in cellular uplink has been proposed in this paper. Some existing power allocation schemes were proposed for the purpose of maximizing the channel capacity or minimizing the outage probability. Different from these schemes, the proposed algorithm aims at minimizing the BER of the systems under the constraint of total transmission power. Besides this characteristic, the proposed algorithm can realize a low complexity real-time power allocation according to the fluctuation of channels. Simulation results show that the proposed algorithm can decrease the BER performance of the systems effectively.

Combined energy detection and one-order cyclostationary feature detection techniques in cognitive radio systems

岳文静 郑宝玉 孟庆民 岳文杰

中国邮电高校学报(英文), 2010, 17 (4). doi： 10.1016/S1005-8885(09)60482-9

摘要 ( 3285 )

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One of the main requirements of cognitive radio systems is the ability to detect the presence of the primary user with fast speed and precise accuracy. To achieve that, a possible two-stage spectrum sensing scheme is suggested in this paper. More specifically, a fast spectrum sensing algorithm based on the energy detection is introduced focusing on the coarse detection. A complementary fine spectrum sensing algorithm adopts one-order cyclostationary properties of primary user’s signals in time domain. Since the one-order feature detection is performed in time domain, the real-time operation and low-computational complexity can be achieved. Also, it drastically reduces hardware burdens and power consumption as opposed to two-order feature detection. The sensing performance of the proposed method is studied and the analytical performance results are given. The results indicate that better performance can be achieved in proposed two-stage sensing detection compared to the conventional energy detector.

Resource scheduling scheme with QoS support in two-hop relay-enhanced OFDMA systems

刘伟 纪红 李亭

中国邮电高校学报(英文), 2010, 17 (4). doi： 10.1016/S1005-8885(09)60483-0

摘要 ( 2162 )

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As the system performance is obviously improved by introducing the concept of relay into the traditional orthogonal frequency division multiple access (OFDMA) systems, resource scheduling in relay-enhanced OFDMA systems is worthy of being studied carefully. To solve the optimization problem of achieving the maximum throughput while satisfying the quality of service (QoS) and guaranteeing the fairness of users, a novel resource scheduling scheme with QoS support for the downlink of two-hop relay-enhanced OFDMA systems is proposed. The proposed scheme, which is considered both in the first time sub-slot between direct link users and relay stations, and the second time sub-slot among relay link users, takes QoS support into consideration, as well as the system throughput and the fairness for users. Simulation results show that the proposed scheme has good performance in maximizing system throughput and guaranteeing the performance in the service delay and the data loss rate.

Network boundary recognition via relative azimuth angle

贾瑞武 石庚辰

中国邮电高校学报(英文), 2010, 17 (4). doi： 10.1016/S1005-8885(09)60484-2

摘要 ( 2500 )

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To recognize the boundary of wireless networks to meet some specific needs, relative azimuth angles of nodes distributed in the 1-hop neighborhood of each node in one network were used to recognize the boundary of the network. A novel recognition algorithm based on local generalized convex hull was proposed for one node to decide if it self is a boundary node. The flexibility, efficiency and consistency of the algorithm are shown in its performance by extensive simulations.

Improved QO-STBC for three and four transmit antennas

贾明儒 肖丽萍

中国邮电高校学报(英文), 2010, 17 (4). doi： 10.1016/S1005-8885(09)60485-4

摘要 ( 2113 )

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A new quasi-orthogonal space-time block code (QO-STBC) based on ABBA code with lower decoding complexity and higher bit error statistics (BER) performance was proposed by U. Park recently, which can obtain full transmission rate and full diversity. In this article, the authors proposed an improved U. Park scheme based on rotational ABBA code. For eliminating the interference terms resulting from neighboring signals during signal detection, two different matrixes are used. And independent decoding can be realized when maximum-likelihood decoding at the receiver is used. Simulation results demonstrate that the BER performance is improved dramatically without increasing the decoding complexity compared with U. Park scheme.

Tracking application about singer model based on marginalized particle filter

周非 何伟俊 FAN Xin-yue

中国邮电高校学报(英文), 2010, 17 (4). doi： 10.1016/S1005-8885(09)60486-6

摘要 ( 2400 )

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This article deals with the problem of maneuvering target tracking which results in a mixed linear/non-linear model estimation problem. For maneuvering tracking system, extended Kalman filter (EKF) or particle filter (PF) is traditionally used to estimate the states. In this article, marginalized particle filter (MPF) is presented for application in a mixed linear/non-linear model estimation problem. MPF is a combination of Kalman filter (KF) and PF. So it holds both advantage of them and can be used for mixed linear/non-linear substructure, where the conditionally linear states are estimated using KF and the nonlinear states are estimated using PF. Simulation results show that MPF guarantees the estimation accuracy and alleviates the potential computational burden problem compared with PF and EKF in maneuvering target tracking application.

Artificial Intelligence

Efficient reconstruction scheme for transform domain Wyner-Ziv video coding

王凤琴 樊养余 JIA Meng, CHEN Yan

中国邮电高校学报(英文), 2010, 17 (4). doi： 10.1016/S1005-8885(09)60487-8

摘要 ( 2085 )

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To minimize the errors of the reconstructed values and improve the quality of decoded image, an efficient reconstruction scheme for transform domain Wyner-Ziv (WZ) video coding is proposed. The reconstruction scheme exploits temporal correlation of the coefficient bands, the WZ decoded bits stream and the side information efficiently. When side information is outside the decoded quantization bin, the reconstructed value is derived using expectation of the WZ decoded bit stream and the side information. When side information is within the decoded quantization bin, the reconstructed value is derived using the biased predictor. Simulation results show that the proposed reconstruction scheme gains up to 1.32 dB compared with the commonly used boundary reconstruction scheme at the same bit rates and similar computation cost.

Frequency hopping sequences based on d-form functions

柯品惠 张胜元

中国邮电高校学报(英文), 2010, 17 (4). doi： 10.1016/S1005-8885(09)60488-X

摘要 ( 2001 )

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By using d-form function, a new construction of frequency hopping sequence with optimal Hamming correlation is presented in this article, which generalizes the results presented by Ding (2007). Furthermore, a new class of non-power function style d-form function is proposed and an upper bound of the Hamming autocorrelation of the corresponding sequence is also derived

Modeling and analysis of Internet worm propagation

苏飞 林昭文 马严

中国邮电高校学报(英文), 2010, 17 (4). doi： 10.1016/S1005-8885(09)60489-1

摘要 ( 2264 )

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Although the frequency of Internet worm’s outbreak is decreased during the past ten years, the impact of worm on people’s privacy security and enterprise’s efficiency is still a severe problem, especially the emergence of botnet. It is urgent to do more research about worm’s propagation model and security defense. The well-known worm models, such as simple epidemic model (SEM) and two-factor model (TFM), take all the computers on the internet as the same, which is not accurate because of the existence of network address translation (NAT). In this paper, we first analyze the worm’s functional structure, and then we propose a three layer worm model named three layres worm model (TLWM), which is an extension of SEM and TFM under NAT environment. We model the TLWM by using deterministic method as it is used in the TFM. The simulation results show that the number of NAT used on the Internet has effects on worm propagation, and the more the NAT used, the slower the worm spreads. So, the extensive use of NAT on the Internet can restrain the worm spread to some extent.

Key technologies of new malicious code developments and defensive measures in communication networks

李鹏 王汝传 张伟

中国邮电高校学报(英文), 2010, 17 (4). doi： 10.1016/S1005-8885(09)60490-8

摘要 ( 2091 )

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This article is focused on analyzing the key technologies of new malicious code and corresponding defensive measures in the large-scale communication networks. Based on description of the concepts and development of the malicious code, the article introduces the anti-analysis technology, splitting and inserting technology, hiding technology, polymorph virus technology, and auto production technology of the malicious code trends with intelligence, diversity and integration. Following that, it summarizes the security vulnerabilities of communication networks from four related layers aspects, according to the mechanisms of malicious code in the communication networks. Finally, it proposes rapid response disposition of malicious code attacks from four correlated steps: building up the network node monitoring system, suspicious code feature automation analysis and extraction, rapid active malicious code response technique for unknown malicious code, and malicious code attack immunity technique. As a result, it actively defenses against the unknown malicious code attacks and enhances the security performance of communication networks.

Efficient ID-based TPM key loading scheme for trusted platform

宋成 刘冰 胡正名 辛阳 杨义先 尹瀚

中国邮电高校学报(英文), 2010, 17 (4). doi： 10.1016/S1005-8885(09)60491-X

摘要 ( 2174 )

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One important function in trusted computing is protected storage, which can protect unlimited amount of data and keys. In the existing trusted platform module (TPM) key loading scheme for trusted platform, a computing platform with TPM as its trusted anchor, the total times of loading operation is the same as the number of the loaded target object’s ancestors, resulting in low efficiency of loading a TPM key which has many ancestors. To improve efficiency, an identity-based TPM key loading scheme is proposed. In this scheme, the times of loading operation is only two when any TPM key is loaded into TPM. Therefore, the required time cost for loading a TPM key can be reduced, especially for complex TPM key storage hierarchy. By analyzing the correctness, security, efficiency and feasibility, the proposed scheme has the better theoretical and application value.

Cryptanalysis of dragon scheme

袁峰 胡予濮 王艳 欧海文

中国邮电高校学报(英文), 2010, 17 (4). doi： 10.1016/S1005-8885(09)60492-1

摘要 ( 2450 )

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Patarin proposed the dragon scheme, pointed out the insecurity of the dragon algorithm with one hidden monomial and suggested a candidate dragon signature algorithm with a complicated function. This paper presents an algebraic method to attack the candidate dragon signature algorithm. The attack borrows the basic idea of the attack due to Kipnis and Shamir, and utilizes the underlying algebraic structure of the candidate dragon signature algorithm over the extension field to derive a way to enable the variable Y be viewed as a fixed value. The attack recovers the private keys efficiently when the parameters are and

Others

WPANFIS: combine fuzzy neural network with multiresolution for network traffic prediction

李锐 陈建亚 刘韵洁 王振凯

中国邮电高校学报(英文), 2010, 17 (4). doi： 10.1016/S1005-8885(09)60493-3

摘要 ( 2352 )

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A novel methodology for prediction of network traffic, WPANFIS, which relies on wavelet packet transform (WPT) for multi-resolution analysis and adaptive neuro-fuzzy inference system (ANFIS) is proposed in this article. The widespread existence of self-similarity in network traffic has been demonstrated in earlier studies, which exhibits both long range dependence (LRD) and short range dependence (SRD). Also, it has been shown that wavelet decomposition is an effective tool for LRD decorrelation. The new method uses WPT as extension of wavelet transform which can decoorrelate LRD and make more precisely partition in the high-frequency section of the original traffic. Then ANFIS which can extract useful information from the original traffic is implemented in this study for better prediction performance of each decomposed non-stationary wavelet coefficients. Simulation results show that the proposed WPANFIS can achieve high prediction accuracy in real network traffic environment.

Energy-balanced unequal clustering protocol for wireless sensor networks

蒋畅江 石为人 向敏 唐贤伦

中国邮电高校学报(英文), 2010, 17 (4). doi： 10.1016/S1005-8885(09)60494-5

摘要 ( 4198 )

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Clustering provides an effective way to prolong the lifetime of wireless sensor networks. One of the major issues of a clustering protocol is selecting an optimal group of sensor nodes as the cluster heads to divide the network. Another is the mode of inter-cluster communication. In this paper, an energy-balanced unequal clustering (EBUC) protocol is proposed and evaluated. By using the particle swarm optimization (PSO) algorithm, EBUC partitions all nodes into clusters of unequal size, in which the clusters closer to the base station have smaller size. The cluster heads of these clusters can preserve some more energy for the inter-cluster relay traffic and the ‘hot-spots’ problem can be avoided. For inter-cluster communication, EBUC adopts an energy-aware multihop routing to reduce the energy consumption of the cluster heads. Simulation results demonstrate that the protocol can efficiently decrease the dead speed of the nodes and prolong the network lifetime.

Fuzzy Q-learning in continuous state and action space

徐明亮 XU Wen-bo

中国邮电高校学报(英文), 2010, 17 (4). doi： 10.1016/S1005-8885(09)60495-7

摘要 ( 2056 )

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An adaptive fuzzy Q-learning (AFQL) based on fuzzy inference systems (FIS) is proposed. The FIS realized by a normalized radial basis function (NRBF) neural network is used to approach Q-value function, whose input is composed of state and action. The rules of FIS are created incrementally according to the novelty of each element of the pair of state-action. Moreover the premise part and consequent part of the FIS are updated using extended Kalman filter (EKF). The action that impacts on environment is the one with maximum output of FIS in the current state and generated through optimization method. Simulation results in the wall-following task of mobile robots and the inverted pendulum balancing problem demonstrate that the superiority and applicability of the proposed AFQL method.

Method for replica creation in data grids based on complex networks

陈丹伟 周书桃 任勋益 KONG Qiang

中国邮电高校学报(英文), 2010, 17 (4). doi： 10.1016/S1005-8885(09)60496-9

摘要 ( 2242 )

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In order to reduce makespan and storage consumption in data grids, a node selection model for replica creation is proposed. The model is based on the degree distribution of complex networks. We define two candidate replica nodes: a degree-based candidate pool and a frequency-based candidate pool, through which a degree-based candidate pool is defined in consideration of onsidering the access frequency; a candidate pool-based frequency is also defined. The data replica is copied to the node with the minimum local cost in the two pools. Further, this paper presents and proves a replica creation theorem. A dynamic multi-replicas creation algorithm (DMRC) is also provided. Simulation results show that the proposed method may simultaneously reduce makespan and data used in space storage consumption.

Autonomic failure prediction based on manifold learning for large-scale distributed systems

卢旭王慧强 周仁杰 葛宝玉

中国邮电高校学报(英文), 2010, 17 (4). doi： 10.1016/S1005-8885(09)60497-0

摘要 ( 1965 )

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This article investigates autonomic failure prediction in large-scale distributed systems with nonlinear dimensionality reduction to automatically extract failure features. Most existing methods for failure prediction focus on building prediction models or heuristic rules by discovering failure patterns, but the process of feature extraction before failure patterns recognition is rarely considered due to the increasing complexity of modern distributed systems. In this work, a novel performance-centric approach to automate failure prediction is proposed based on manifold learning (ML). In addition, the ML algorithm named supervised locally linear embedding (SLLE) is applied to achieve feature extraction. To generalize the dimensionality reduction mapping, the nonlinear mapping approximation and optimization solution is also proposed. In experimental work a file transfer test bed with fault injection is developed which can gather multilevel performance metrics transparently. Based on the runtime monitoring of these metrics, the SLLE method can automatically predict more than 50 % of the central processing unit (CPU) and memory failures, and around 70 % of the network failure.

Centralized light-wave WDM-PON employing DQPSK downstream and OOK remodulated upstream signals

张为峰 忻向军 张琦 张子兴 佴炜 SHI Yan

中国邮电高校学报(英文), 2010, 17 (4). doi： 10.1016/S1005-8885(09)60498-2

摘要 ( 2061 )

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A novel architecture for wavelength-division-multiplexing passive optical network (WDM-PON) with centralized light-wave is proposed and demonstrated. At the optical line terminal (OLT) session of this architecture, optical differential quadrature phase shift keying (DQPSK) modulated signal with constant-intensity at 10 Gbit/s is utilized for downstream transmission. At the optical network unit (ONU), part of the downstream optical power is remodulated with on-off keying (OOK) intensity modulation at 10 Gbit/s for upstream without additional laser. Simulation results show that the power penalties of the downstream for 20 km single-mode fiber (SMF) transmission and multi-channels are negligible. While for the upstream, the power penalties are obvious. The simulation results and analysis also reflect that by reducing the launch power of DQPSK transmitters, power penalties can be reduced, although the transmission distance is limited.