Current Issue

• • 2018, Vol. 41 No. 3 Published date:28 June 2018 Last issue Next issue

  Papers

  • A Hybrid Random Access for Massive Connections in 5G systems
  • DING Ting-ting, LIU Yan-jun, ZHANG Ning-bo, KANG Gui-xia
  • Journal of Beijing University of Posts and Telecommunications. 2018, 41(3): 1-6. DOI:10.13190/j.jbupt.2017-204
  • Abstract ( 476 )     HTML     　　
  • In order to increase the number of access in the fifth-generation systems, a hybrid multiple random access (RA) scheme is proposed. The proposed scheme allows user equipments to select the orthogonal multiple access (OMA) RA or the non-orthogonal multiple access (NOMA) RA by a predicted signal noise ratio and predefined thresholds. In order to improve the performance of interference cancelation, a power back-off scheme is applied to guarantee the received powers of overlapped signals are diverse. In addition, the access performance of hybrid RA is theoretically analyzed. In the simulation, both numerical results and simulation results in practical systems are provided. Simulation results show that the proposed RA procedure significantly improves the number of successful access compared with single OMA RA or NOMA RA.
  • References | Supplementary Material | Related Articles

  • Review Summarization Generation Based on Attention Mechanism
  • SU Fang, WANG Xiao-yu, ZHANG Zhi
  • Journal of Beijing University of Posts and Telecommunications. 2018, 41(3): 7-13. DOI:10.13190/j.jbupt.2017-219
  • Abstract ( 480 )     HTML     　　
  • In order to implement generative review summarization, a research of the neural network model of sequence to sequence learning was conducted, besides, an improved attention mechanism for review summarization based on the model was proposed. By focusing on the feature of review summarization samples, the local attention mechanism is improved which has more attention weights on the start of the source sentence. Then every word of the summarization is generated through the end-to-end model. Experiments show that this approach achieves superior performance on English review summarization in the same category when the length of reviews is less than 200.
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  • A Novel Low Density Superposition Modulation Scheme for Uplink NOMA
  • JIANG Cheng-xin, WU Zhan-ji
  • Journal of Beijing University of Posts and Telecommunications. 2018, 41(3): 14-19. DOI:10.13190/j.jbupt.2017-215
  • Abstract ( 415 )     HTML     　　
  • There may exist short cycles if the matrix dimensions of sparse code multiple access (SCMA) are small, and the regular mapping matrix of SCMA doesn't take near-far effect into consideration. Therefore, a novel uplink non-orthogonal multiple access scheme named low density superposition modulation (LDSM) scheme is proposed to construct a sparser and irregular mapping matrix. The proposed scheme can improve the overall performance and the edge users' performance for it can get diversity gain and coding gain. The analysis of the average mutual information demonstrates LDSM can get signal to noise ratio (SNR) gains over SCMA in theory. Simulation results show that when power difference is 10 dB and overloading is 150%, small dimensional and large dimensional LDSM can get 2.3 dB and 2.46 dB SNR gains over SCMA for overall performance. Both theoretic analysis and simulation results prove the performance of LDSM outperforms that of SCMA.
  • References | Supplementary Material | Related Articles

  • Experimental Investigation of Coupling Interfering System in the Transparent Optical Network
  • TAN Jun, CHEN Wei, LIU Jian-guo, ZHANG Yi-ming, ZHU Ning-hua
  • Journal of Beijing University of Posts and Telecommunications. 2018, 41(3): 20-26. DOI:10.13190/j.jbupt.2017-231
  • Abstract ( 346 )     HTML     　　
  • A coupling interference method was proposed to research the problem of interference occurring with optical cross-connects in the transparent optical network. To quantify the signal quality of the communication system, the operational model was simulated and the influences of interfering source on the legal signal with different traffic rates, interfering power ratio were analyzed based on this method. Multiple verification experiments were established and the experimental results shows that this method are helpful for testing the existence of interfering source and preventing the influence of interfering source on legal signal in the transparent optical network.
  • References | Supplementary Material | Related Articles

  • Manipulator Task Planning Method Based on Improved Graph Planning
  • JIA Qing-xuan, HUANG Xu-dong, CHEN Gang, WANG Yi-fan
  • Journal of Beijing University of Posts and Telecommunications. 2018, 41(3): 27-31. DOI:10.13190/j.jbupt.2017-173
  • Abstract ( 497 )     HTML     　　
  • In order to deal with the complex work scene and diverse task demands of manipulator task, a manipulator task planning method based on improved graph planning is proposed. Firstly a common mathematical model of manipulator task planning is established, and then combined with the task characteristics of manipulator and the improved simulated annealing algorithm, an improved task planning algorithm based on graph planning is proposed, which extends the single planning result of traditional algorithm to the set of task action sequences. Finally, the task execution strategy is solved by fusion of different targets. A simulation of 7-degree of freedom manipulator verifies the correctness and effectiveness of the proposed method. The results show that compared with the traditional task planning algorithm, the proposed method has the ability to prioritize tasks with different targets and can shorten plan time.
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  • A Node Capture Early Detection Scheme for WSN in Asynchronous Sleep Mode
  • ZHANG Zhi-hua, LUO Shou-shan, ZHU Hong-liang, XIN Yang
  • Journal of Beijing University of Posts and Telecommunications. 2018, 41(3): 32-38. DOI:10.13190/j.jbupt.2017-228
  • Abstract ( 370 )     HTML     　　
  • In order to detect the captured nodes as early as possible, just before they rejoin the networks, a node capture early detection method was proposed for wireless sensor networks (WSN) in asynchronous sleep mode. The proposed scheme was based on communication monitoring between neighbor nodes and a Hello message scheduling mechanism was employed to ensure the reception of Hello messages between asynchronous sleep nodes. Moreover, the local collaborative decision of common neighbors was explored to improve the detection accuracy rate. Simulations show that the proposed scheme outperforms other typical methods in terms of effectiveness including detection rate, false positive rate and false negative rate.
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  • Risk Prediction of Power Data Network Based on Entropy Weight-Gray Model
  • LI Wen-jing, LI Meng, XING Ning-zhe, JI Yu-tong, ZENG Xiang-jian
  • Journal of Beijing University of Posts and Telecommunications. 2018, 41(3): 39-45. DOI:10.13190/j.jbupt.2017-125
  • Abstract ( 249 )     HTML     　　
  • Aiming at the present situation that risk prediction model of power data network cannot effectively predict the risk, a risk prediction mechanism of power data network based on entropy weight-gray model is proposed. This paper focuses on risk prediction of the entire network. Firstly, the gray model is used to predict the risk indexes of power data network, and the individual risk index value is determined. Then, the dynamic weight of each index is obtained by entropy weight method. Finally, it can calculate the risk value of the network according to the risk index value and the weight. The simulation results show that the proposed model can guarantee predictive accuracy of dynamic real-time network.
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  • Graph-Based Image Segmentation Based on Superpixels
  • JIA Geng-yun, ZHAO Hai-ying, LIU Fei-duo, LI Xue-ming
  • Journal of Beijing University of Posts and Telecommunications. 2018, 41(3): 46-50. DOI:10.13190/j.jbupt.2017-023
  • Abstract ( 825 )     HTML     　　
  • As graph-based algorithm is inclined to over-segment, a new graph-based image segmentation algorithm based on superpixels called superpixel graph based image segmentation (SGBIS) was proposed and simple linear iterative clustering (SLIC) superpixels segmentation was employed as pre-segmentation. Then, the weighted undirected graph regarding superpixels as nodes was constructed, the Euclidean distance of adjacent superpixels' average color is used as the weight. Finally, the segmentation results are obtained by merging superpixels based on graph-based algorithm. Three indexes variation of information (VI),probabilistic rand index (PRI) and F-measure are introduced to evaluate algorithm. Experiments show that it can get better segmentations. An interactive region merging interface is also introduced, which could meet users need very well.
  • References | Supplementary Material | Related Articles

  • An Adaptive KLMS Traffic Prediction Algorithm for Satellite Network
  • ZHAO Ji-hong, WANG Ming-xin, QU Hua, XIE Zhi-yong, LIU Xi
  • Journal of Beijing University of Posts and Telecommunications. 2018, 41(3): 51-55. DOI:10.13190/j.jbupt.2017-144
  • Abstract ( 540 )     HTML     　　
  • Due to the resource limitation and topology change in satellite network, the article puts forward higher requirements for the accuracy and efficiency of the network traffic prediction algorithm, and the traditional prediction model is no longer suitable for the satellite network. The author presents a kernel least mean square algorithm (KLMS) with adaptive step length and adaptive kernel width, namely AKLMS, which maps the nonlinear data from low dimensional input space to high dimensional feature space through kernel function, and the algorithm will adaptively adjust the step length and kernel width based on the instantaneous error in the iterative process. Simulations show that the AKLMS algorithm has great improvement on the convergence speed and prediction accuracy of the flow compared with the KLMS and least mean square (LMS), which will provide strong decision support for traffic planning and routing design in satellite network.
  • References | Supplementary Material | Related Articles

  • Research on Channel Reciprocity of Massive MIMO Time Division Duplex System
  • CHEN Ying, YIN Liang, SUN Jun, LI Shu-fang
  • Journal of Beijing University of Posts and Telecommunications. 2018, 41(3): 56-62. DOI:10.13190/j.jbupt.2017-164
  • Abstract ( 468 )     HTML     　　
  • In time division duplex massive multiple-input multiple-output (MIMO) systems, the channel estimation and reciprocity calibration determine whether the system can effectively utilize channel reciprocity. In order to analyze the effect of channel estimation on the system performance, the mean square error of channel estimation is deduced and the closed-form expression of uplink and downlink channel capacity in single-user MIMO system is obtained. To reduce the error of on-line calibration, a new mutual coupling interference model was proposed by using the property of mutual coupling. With the help of base station power control and coordination functions, a calibration scheme was designed to reduce the mutual coupling interference. Simulations verify the feasibility of this scheme.
  • References | Supplementary Material | Related Articles

  • A Cluster-Based Resource Allocation Under Hybrid Access Mode in Ultra-Dense Network
  • ZHANG Hai-bo, LI Hu, CHEN Shan-xue, ZOU Jian
  • Journal of Beijing University of Posts and Telecommunications. 2018, 41(3): 69-74. DOI:10.13190/j.jbupt.2017-217
  • Abstract ( 344 )     HTML     　　
  • For the problem of interference and spectrum resource allocation in ultra-dense heterogeneous network under the hybrid access mode, a cluster-based resource allocation scheme was proposed. The scheme consists of two parts:the first part is to use simulated annealing algorithm to divide small cells into different clusters according to the interference between them; the other part is to use the minimum signal to interference plus noise ratio maximization algorithm to allocate sub-channels to the clustered network, and gives the user's resource usage mode under hybrid access mode. Simulations show that the proposed scheme can effectively suppress the interference and improve system performance.
  • References | Supplementary Material | Related Articles

  • SDN-ScaSVNE: Scalable Survivable Virtual Network Embedding Algorithm in SDN
  • LU Mei-lian, GU Yun, LIU Tong
  • Journal of Beijing University of Posts and Telecommunications. 2018, 41(3): 75-80. DOI:10.13190/j.jbupt.2017-213
  • Abstract ( 390 )     HTML     　　
  • Existing survivable virtual network embedding algorithms cannot apply to software defined network (SDN) directly, and most of them only use active protection strategy by augmenting virtual networks, which leads to poor performance. For the problems above, a survivable virtual network embedding algorithm based on residual network resources is proposed for scalable backup virtual resources in SDN. It provides backup resources only for nodes and links that satisfy the backup constraints in the augmented virtual networks, and combines the remaining network resources with backup resources to complete failure recovery. Simulation results show that the algorithm can effectively improve the acceptance rate of virtual network requests and the success rate of failure recovery under the premise of high revenue/cost ratio.
  • References | Supplementary Material | Related Articles

  • Masked Image Inpainting Algorithm Based on Generative Adversarial Nets
  • CAO Zhi-yi, NIU Shao-zhang, ZHANG Ji-wei
  • Journal of Beijing University of Posts and Telecommunications. 2018, 41(3): 81-86. DOI:10.13190/j.jbupt.2017-247
  • Abstract ( 440 )     HTML     　　
  • A masked image inpainting algorithm based on generative adversarial nets was proposed, which can restore the original image from the lacking of a large number of pixels. Unlike other block search restoration algorithms, the algorithm proposed directly generates possible missing elements and restore them. Due to the improved structure of generated model and the calculation method of generating loss on generative adversarial nets, this article has the characteristics of semi-supervised learning. Experiments show that the proposed method outperforms the existing one on the premise of satisfying the overall contour of the image.
  • References | Supplementary Material | Related Articles

  Reports

  • Retrospective Interference Neutralization Scheme for the Two-Cell Multiuser Cellular Interfering Network
  • LU Run-hua, LI Wei
  • Journal of Beijing University of Posts and Telecommunications. 2018, 41(3): 87-91. DOI:10.13190/j.jbupt.2017-208
  • Abstract ( 449 )     HTML     　　
  • For the uplink two-cell multiple-input multiple-output cellular interfering network with delayed feedback, a retrospective interference neutralization (RIN) scheme was proposed by using hybrid channel state information at the transmitter (CSIT). First, each user was scheduled to send fresh data streams to each base station so that each base station can obtain side information. Subsequently, each user used the hybrid CSIT to precode information and sent the precoding information to each base station. Finally, each base station eliminated all inter-cell interference by using the precoding information. The achievable degrees of freedom, the achievable sum rate, the simulation validation and the application conditions of RIN scheme were given. Experiment shows that the proposed RIN scheme can provide significant degrees of freedom gain over the time division multiple access and the existing retrospective interference alignment schemes.
  • References | Supplementary Material | Related Articles

  • Workspace Analysis and Layout Optimization of Multi-station Working Island type Polishing Robot
  • LI Dong-jing, HAO Da-xian, WANG Qi-long, YUN Chao
  • Journal of Beijing University of Posts and Telecommunications. 2018, 41(3): 92-100. DOI:10.13190/j.jbupt.2017-221
  • Abstract ( 489 )     HTML     　　
  • In order to improve the efficiency of the workpiece such as faucet polishing and improve the polishing precision, quality, a new multi station working island type polishing robot was designed. In order to make this robot structure more compact, based on the establishment of the polishing robot's kinematics and inverse kinematics equations, further analysis of robot flexible working space was carried out, multi-objective particle swarm optimization method was also proposed to analyze and optimize the multiple layout parameters of this robot., then the various degree of freedom joint space was obtained by particle swarm optimization method while robot polishing deferent size workpiece. Finally, the dexterous machining points of the polishing robot is analyzed, which is verified that the optimized layout parameters is suitable. Through the above analysis. It is shown that the robot with optimized layout parameters can fully meet the specified workpiece polishing requirements, and there is a large machining allowance, better experimental polishing effect was obtained finally.
  • References | Supplementary Material | Related Articles

  • A Self-Organized Clustering Algorithm Based on Computation and Transmission Node for WSN
  • XUE Han-han, WANG Bai, ZHANG Lei, HUANG Hai
  • Journal of Beijing University of Posts and Telecommunications. 2018, 41(3): 101-106. DOI:10.13190/j.jbupt.2017-202
  • Abstract ( 491 )     HTML     　　
  • A self-organized clustering algorithm based on computation node and transmission node (SCATN) for wireless sensor network (WSN) was proposed to satisfy computation requirement and solve the problem of hot spot and energy hole caused by cluster head overload. SCATN employs computation node and transmission node to undertake the cluster head's function data computation and transmission. The distribution probability of functional nodes is controlled to tackle with the problems raised. The generation and distribution of functional node is controlled by self-organized manner to solve the problem of distribution and connection. The ordinary nodes choose its belonged cluster to adjust the computation node's load. Simulation indicates that SCATN can effectively extend the network lifetime, improve the throughput at the sink and decrease the packet loss rate in comparison with several existing clustering algorithms.
  • References | Supplementary Material | Related Articles

  • A Time-Space Based Rules Placement Method
  • QI Qing-lei, WANG Wen-dong, GONG Xiang-yang, QUE Xi-rong
  • Journal of Beijing University of Posts and Telecommunications. 2018, 41(3): 107-112. DOI:10.13190/j.jbupt.2017-149
  • Abstract ( 402 )     HTML     　　
  • Time-space based rules placement method (TSRPM) is proposed for solving the problem of rules placement utilizing both timeout and wildcard match schemes. The sojourn time and space of a rule are both considered to decide rules placement approach in TSRPM. The results of simulation show that TSRPM can improve the match rate and reduce the packet refused rate.
  • References | Supplementary Material | Related Articles

  • Attribute-Based Encryption Scheme With High Efficient Revocation in Cloud Computing Environment
  • CHEN Hong-song, SHEN Qiang-lei
  • Journal of Beijing University of Posts and Telecommunications. 2018, 41(3): 113-118. DOI:10.13190/j.jbupt.2017-220
  • Abstract ( 408 )     HTML     　　
  • In order to solve the problem of user authorization revocation caused by user attributes change in open cloud computing environment, an attribute-based proxy re-encryption scheme based on proxy re-encryption and key segmentation is proposed. Instant revocation of user authorization is supported in the scheme. When user revocation occurs, it is only necessary to update the ciphertext component in the cloud storage server and unrevoked users' attribute independence private key component in the proxy server. When the user attribute revocation occurs, it is necessary to update the user attribute revocation list from which the user authorization can be limited. Then the workload of updating ciphertext and the user private key is lessen to improve the execution efficiency of re-encryption and access control scheme, at the same time,the privacy information of user attributes are protected.
  • References | Supplementary Material | Related Articles