Current Issue

• • 2021, Vol. 44 No. 4 Published date:28 August 2021 Last issue Next issue

  REVIEW

  • Integration of Communication, Sensing and Computing: the Vision and Key Technologies of 6G
  • YAN Shi, PENG Mu-gen, WANG Wen-bo
  • Journal of Beijing University of Posts and Telecommunications. 2021, 44(4): 1-11. DOI:10.13190/j.jbupt.2021-081
  • Abstract ( 4766 )     HTML( 3710 )     　　
  • The emerging intelligent services such as self-driving, unmanned aerial vehicle emergency communication, immersive extended reality, industrial Internet of things, which rely on multi-dimensional information perception and super computing power, put forward high requirements for transmission rate, end-to-end delay, reliability and power consumption. To meet these ultra-high performance requirements, the sixth generation of mobile communications system (6G) needs to improve the network endogenous intelligent perception and computing adaptive ability, and break through the communication-sensing-computing fusion theory and key technologies. First, the typical 6G communication-sensing-computing integration application requirements are described. Then, the link level and system level key technologies are put forward, including communication-sensing-computing integration, multi-source information data processing, multi-dimensional resource management, etc. The principles, methods and performance are also described. Finally, the technical challenges and future development directions are disscussed.
  • References | Supplementary Material | Related Articles

  PAPERS

  • Parallel Interference Cancellation Technology for F-OFDM under High-Speed Mobility Scenario
  • QIN Wei, HU Chun-jing, PENG Mu-gen, LIU Xi-qing
  • Journal of Beijing University of Posts and Telecommunications. 2021, 44(4): 12-18. DOI:10.13190/j.jbupt.2020-236
  • Abstract ( 770 )     HTML( 564 )     　　
  • The complex propagation environment and high-speed mobility of transceivers in the fifth generation of mobile communications system (5G) can cause severe Doppler spread problem. To suppress the severe inter-carrier interference caused by the Doppler spread, an enhanced parallel interference cancellation scheme based on the filtered orthogonal frequency division multiplex (PIC-F-OFDM) system isproposed. In PIC-F-OFDM, the transmitting data stream is splitted into two brancheswhich are then separately fed into the inverse fast Fourier transform and fast Fourier transform modules. The two branches are then combined by the equal gain combining algorithm at the receiver to improve the signal-to-interference ratio. The simulation results show that PIC-F-OFDM achieves a lower bit error rate than the existing schemes in high-speed mobility scenarios under the 5G radio band. Besides, the proposed PIC-F-OFDM scheme can configure the parameters flexibly for each sub-band, which helps to meet the communication requirements of various service.
  • References | Supplementary Material | Related Articles

  • Indoor Wi-Fi Localization Method Based on Carrier Phase Difference
  • HE Wei, YUE Zi-ying, ZHOU Mu, TIAN Zeng-shan
  • Journal of Beijing University of Posts and Telecommunications. 2021, 44(4): 19-25. DOI:10.13190/j.jbupt.2020-253
  • Abstract ( 788 )     HTML( 426 )     　　
  • Due to the low angular resolution of angle of arrival (AoA), it is challenging for the AoA localization algorithm based on channel state information (CSI) to achieve sub-meter level localization accuracy. To improve the localization accuracy, a precise indoor Wi-Fi localization method based on carrier phase difference is proposed. First, the center frequency carrier phase of CSI and time of flight in line of sight path are extracted, and the carrier phase difference localization model is constructed with virtual reference point, thus achieving the initial target localization.Then, combining the initial localization result of the target, the integer ambiguity solution is realized by using the virtual baseline constraint. Finally, the carrier phase localization optimization algorithm based on the extended Kalman filter is proposed to obtain the precise location of the target. Experimental results for straight lines and arbitrary paths show that the median localization error of the proposed method is within 0.25 m, which is more accurate and reliable than the baseline method.
  • References | Supplementary Material | Related Articles

  • Hybrid Beamforming Based on Switch Structure for Millimeter Wave MIMO System Relying on Lens Antenna Arrays
  • LI Hu, WEI Zai-xue, CHENG Zhen-qiao, YANG Hong-wen
  • Journal of Beijing University of Posts and Telecommunications. 2021, 44(4): 26-33. DOI:10.13190/j.jbupt.2020-242
  • Abstract ( 687 )     HTML( 313 )     　　
  • To solve the complex hardware cost and energy loss issues in millimeter wave massive multiple-input multiple-output (MIMO) communication systems, a lens antenna array beamforming scheme based on an adaptive switch structure is proposed in single-user systems. Compared with the traditional uniform linear array, the proposed scheme can reduce the hardware cost and energy loss of beamforming without significantly degrading the performance. The work further combines the proposed scheme with the block diagonalization zero-forcing algorithm, and the combined hybrid beamforming scheme not only applies to the multi-user communication systems, but also can obtain higher spectrum efficiency.
  • References | Supplementary Material | Related Articles

  • A Hierarchical Category Embedding Based Approach for Fault Classification of Power ICT System
  • LI Jian-gui, LIANG Yue, GAO Peng-fei, LIU Shao-hua, MA Ying-long
  • Journal of Beijing University of Posts and Telecommunications. 2021, 44(4): 34-40. DOI:10.13190/j.jbupt.2020-271
  • Abstract ( 663 )     HTML( 264 )     　　
  • To solve the low classification accuracy oreven misclassification issue in fault diagnosis, a text classification method based on hierarchical category embedding is proposed in information and communication technology (ICT) customer service systems. First, a hierarchical label system is constructed for the failure data in power ICT systems based on the textual data of the work orders.Then, hierarchical deep pyramid convolutional neural networks (HDPCNN) and hierarchical disconnected recurrent neural networks are proposed, which adopt hierarchical category embedding technique for level-by-level fault type classification. The experimental results show that the hierarchical text classification algorithm HDPCNN has the best classification accuracy, which can provide efficient and accurate services for fault type recognition.
  • References | Supplementary Material | Related Articles

  • An Information System Risk Assessment Method Based on Risk Propagation
  • YANG Hong-yu, ZHANG Le, ZHANG Liang
  • Journal of Beijing University of Posts and Telecommunications. 2021, 44(4): 41-48. DOI:10.13190/j.jbupt.2021-019
  • Abstract ( 791 )     HTML( 351 )     　　
  • Traditional information system risk assessment methods do not consider the state change of nodes and the direction of risk propagation, and the accuracy of the evaluation results is affected by the subjectivity of experts. To solve these problems, an information system risk assessment method based on risk propagation is proposed. First, the initial state transition probability matrix of the node is determined, and the node state transition probability is obtained by modifying the matrix according to the attack attributes. Then, the propagation probability of nodes in all directions is calculated based on the topology network and node attribute value.Next, the three-parameter interval number method is used to obtain the quantitative value of node threat events. Finally, the risk value of each node is calculated according to the risk assessment method. Experimental results show that the proposed methodis more objective and reasonable, and it improves the integrity and accuracy of the risk assessment of information systems.
  • References | Supplementary Material | Related Articles

  • Fuzzy-Rough Bireducts Algorithm Based on Particle Swarm Optimization
  • LIU Zhan-feng, PAN Su
  • Journal of Beijing University of Posts and Telecommunications. 2021, 44(4): 49-55. DOI:10.13190/j.jbupt.2020-237
  • Abstract ( 589 )     HTML( 325 )     　　
  • Selecting informative features and removing noise instances are beneficial to gain a clean dataset and promote the performance of subsequent classifiers. A novel algorithm for fuzzy-rough bireducts with particle swarm optimization is proposed. The fitness function with ε-bireduct is employed to evaluate the candidate fuzzy-rough bireducts, which drives the particle swarm optimization search process toward better candidate solutions. The selected optimal bireduct is utilized to construct the subsequent classifier. The experimental results show that the proposed algorithm is superior to the counterpart, which reduces the instances and features effectively, and obtains high-quality bireducts. The classification accuracy of the proposed algorithm is thus better than the counterpart.
  • References | Supplementary Material | Related Articles

  • Electromagnetic Radiation Analysis and Test for Spacecraft Shielded Cable
  • ZHANG Yu-ting, XU Jun, LI Ran
  • Journal of Beijing University of Posts and Telecommunications. 2021, 44(4): 56-61. DOI:10.13190/j.jbupt.2020-232
  • Abstract ( 665 )     HTML( 395 )     　　
  • To reduce the influence of the shielded cable on spacecrafts, a electromagnetic radiation analysis method based on the transfer impedance and common mode signal of shielding layer is proposed. In particular, Kley model is used to analyze the transmission impedance between the inner conductor and the shielding layer. Then, the common mode signal is decomposed by the current element, and the electric field radiation of the cable is analyzed by the Hertz dipole equivalent model. The radiation test method is proposed to test the electromagnetic radiation of the shielded cable to perform in a conventional electromagnetic compatibility laboratory. Both simulations and experiments show that the methods can effectively analyze and test the electromagnetic radiation of shielded cables. These methods can provide electromagnetic compatibility analysis and test guidance for spacecraft cable applications, which has a high application value in practice.
  • References | Supplementary Material | Related Articles

  • Power Allocation Scheme for MIMO-NOMA System Based on QoE
  • HU Xiang-ge, WU Guang-fu, LI Tao, PENG De-yi
  • Journal of Beijing University of Posts and Telecommunications. 2021, 44(4): 62-67. DOI:10.13190/j.jbupt.2020-261
  • Abstract ( 606 )     HTML( 398 )     　　
  • Multiple input multiple output-non-orthogonal multiple access (MIMO-NOMA) systems typically only consider the quality of service (QoS) of users while omits the satisfaction of users. A dynamic pricing power allocation algorithm based on Stackelberg game is proposed to optimize the quality of experience (QoE). In the scenario of web browsing service, the mean opinion score (MOS) value is used to measure the satisfaction of the user terminal. The user is set as the buyer, and the base station is set as the seller. Each user in the cell purchases power from the base station at the instantaneous unit power price to improve their MOS values. At the same time, the seller base station constantly adjusts the unit power price to maximize their own profits and achieve Stackelberg equilibrium. Simulation results show that the fairness of the proposed algorithm is improved by 22.73% compared with the power allocation algorithm based on QoS, and the system performance is improved significantly compared with the traditional pricing algorithm. The time complexity is also reduced significantly compared with the power allocation algorithm based on convex programming.
  • References | Supplementary Material | Related Articles

  • User Association Algorithm for Fog Computing Based on Multiple Attribute Decision Making Model
  • SHEN Bin, LIU Xiao-xiao, HUANG Xiao-ge
  • Journal of Beijing University of Posts and Telecommunications. 2021, 44(4): 68-74. DOI:10.13190/j.jbupt.2020-221
  • Abstract ( 502 )     HTML( 316 )     　　
  • Fog computing enabled heterogeneous cellular networks suffer from the high complexity issue of user associations. To solve the problem, a user association algorithm based on multi-attribute decision model is proposed. The proposed method adjusts the attribute priority by appropriately selecting key performance indicators (KPI), and designing models and the combination weights. Meanwhile, comprehensive evaluation indicator is designed to jointly optimize the six KPIs. Simulation results show that the proposed method can not only achieve a superior trade-off between quality of experience and system performance, but also effectively reduce the association delay and system energy consumption. Moreover, the porposed method also has advantages in load balancing.
  • References | Supplementary Material | Related Articles

  • Three-Dimensional DV-Hop Location Algorithm Based on Genetic-Tabu Search Optimization in WSN
  • YU Xiu-wu, HUANG Lu-ping, LIU Yong, YU Hao, LI Pei
  • Journal of Beijing University of Posts and Telecommunications. 2021, 44(4): 75-81. DOI:10.13190/j.jbupt.2020-217
  • Abstract ( 675 )     HTML( 212 )     　　
  • To enhance the positioning accuracy and stability of wireless sensor network (WSN), a three-dimensional dv-hop positioning optimization algorithm is proposed based on an improved genetic-tabu search method (TDGT). First, the optimal hop number, hop adjustment factor, and anchor node distance error weighted value are used to improve and modify the hop number and average hop number in dv-hop to reduce the positioning error. Then, a fast tabu search is introduced into genetic algorithm to further improve the search efficiency and positioning accuracy. The simulation results show that the TDGT algorithm has better search ability, location accuracy and stability than the existing wireless sensor network localization algorithm.
  • References | Supplementary Material | Related Articles

  • Daily Water Volume Prediction Algorithm of Urban Smart Water Based on Big Data
  • YAO Jun-liang, XUE Hai-tao, LIU Qing
  • Journal of Beijing University of Posts and Telecommunications. 2021, 44(4): 82-88. DOI:10.13190/j.jbupt.2020-137
  • Abstract ( 1101 )     HTML( 668 )     　　
  • According to the actual water supply situation of a small and medium-sized water company in China, the influences of weather and other factors on daily water supply are analyzed by comparing the correlation coefficient, so as to determine the input parameters required for daily water consumption prediction. The application performance of three traditional water volume prediction methods is compared using the actual operating data. To solve the severe errors existing in the traditional methods, an improved method is proposed, which takes the water consumption of the previous day and 8 hours into consideration. The efficiency of the proposed algorithm is verified by the tests in the information system of the water supply company. According to the performance and implementation complexity of the algorithm, a water quantity prediction algorithm and its suitable implementation form for urban water affairs are proposed, which can help the water affair system improve the water quantity prediction accuracy, thus effectively improving the utilization rate of water resources.
  • References | Supplementary Material | Related Articles

  • Prediction Algorithm of Mobile User Channel Capacity Based on Dynamic Mode Decomposition
  • ZHU Jun, TANG Bao-yu, LI Kai
  • Journal of Beijing University of Posts and Telecommunications. 2021, 44(4): 89-94. DOI:10.13190/j.jbupt.2020-188
  • Abstract ( 532 )     HTML( 281 )     　　
  • To predict the channel capacity of mobile users and appropriately allocate user resources in multiple-input-multiple-output systems, a channel capacity prediction method based on dynamic mode decomposition (DMD) is proposed. Meanwhile, a selective normalized dynamic mode decomposition method based on empirical mode decomposition (ESN-DMD)is proposed to optimize the system.. The simulation results show that the DMD algorithm is only suitable for the prediction of user signals at low moving speed and low complex, while the ESN-DMD algorithm can adapt to the prediction of channel capacity of users with different moving speeds.
  • References | Supplementary Material | Related Articles

  • Detection Method for Android Payment Cracked Application
  • TANG Yong-li, LI Xing-yu, ZHAO Zong-qu, LI Yun-feng
  • Journal of Beijing University of Posts and Telecommunications. 2021, 44(4): 95-101. DOI:10.13190/j.jbupt.2020-259
  • Abstract ( 634 )     HTML( 279 )     　　
  • Android cracked applications have the risks of infringing on legitimate software rights and spreading malicious code. To detect the payment cracked applications on Android platform, we propose a detection method based on machine learning. Based on the disassembled bytecode file, the call control flow of payment semantic information and the payment database operation function set are constructed. We use a n-gram statistical method and a repeated code sub-block length statistical method to construct the corresponding feature set, and build a multi-classifier detection model with a decision-making mechanism to identify different payment cracked behaviors in Android applications. The experimental results show that the detection accuracy rate of this model is 85.24%, and the area under curve (AUC) value is 0.87. Compared with the baseline methods, the detection rate of payment cracked applications is significantly improved, which effectively solves the detection problem of payment cracked applications.
  • References | Supplementary Material | Related Articles

  REPORTS

  • Aircraft Formation Networking in High Altitude Based on Terahertz Communications
  • HE Zi-xuan, ZHANG Bi-ling, HANG Bing-qing, WANG Li
  • Journal of Beijing University of Posts and Telecommunications. 2021, 44(4): 102-108. DOI:10.13190/j.jbupt.2020-270
  • Abstract ( 687 )     HTML( 422 )     　　
  • Utilizing the Terahertz wave propagation characteristics, this works studies both the deterministic channel model and the statistical channel model of high-altitude Terahertz channel transmission models for aerial communications. The study considers a given number of hybrid manned and unmanned aircraft formation. The inter-aircraft communication reliability performance of the derived propagation channel model is investigated in terms of the communication outage probability, and the maximum distance of Terahertz communication between aircraft is analyzed under the given outage probability threshold. To carry out the environmental monitoring, a formation deployment scheme that maximizes the formation monitoring area under the reliability index of the high-altitude Terahertz communication system is studied. Simulation results validate the correctness of the theoretical derivation and solve the optimal formation deployment. In particular, the maximum monitoring area is improved by about 8% compared with the defectively considered high-altitude Terahertz channel model, which provides an efficient basis for future high-speed high-altitude networking.
  • References | Supplementary Material | Related Articles

  • Performance Analysis of Narrowband Internet of Things Deployed in Poisson Cluster Process
  • WANG Hong-ming, YAO Yuan-yuan, Wei Xiang, LI Xue-hua
  • Journal of Beijing University of Posts and Telecommunications. 2021, 44(4): 109-114. DOI:10.13190/j.jbupt.2020-264
  • Abstract ( 638 )     HTML( 419 )     　　
  • The co-frequency coexistence design of narrowband Internet of things (NB-IoT) and cellular networks isstudied. Based on the stochastic geometrytheorem, the location of an NB-IoT user node is modeled by the Poisson cluster process. In addition, analytical expressions of the outage probability and the transmission capacity are derived. Moreover, the outage performance of the heterogeneous network is compared with that of the network modeled by Poisson point process. The impacts of the cluster radius and the density of NB-IoT base stations on the outage performance and the network capacity arealso evaluated. Analytical and numerical results demonstrate that the outage performance and the capacity of the coexistence network can be effectively enhanced by adjusting the cluster radius and the density of NB-IoT base stations.
  • References | Supplementary Material | Related Articles

  • Recommendation Model for Fully Combining Review Features Based on Dual Attention
  • LI Jian, LIU Peng, LIU Wei
  • Journal of Beijing University of Posts and Telecommunications. 2021, 44(4): 115-120. DOI:10.13190/j.jbupt.2020-250
  • Abstract ( 565 )     HTML( 336 )     　　
  • To fully combine the features of review text in recommendation systems, a recommendation model fully combining review features based on dual attention (FCRF) is proposed. First, the model encodes the review text by utilizing the encoder model, which is fine-tuned by the sentiment classification task to obtain the corresponding feature embedding. Secondly, to realize the cross combination between user features and item features, the bilinear inner product is adopted to calculate the cross attention of review feature embeddings between the user and the item. Thirdly, to obtain the final feature representation of the user and the item, the multi-head self-attention is adopted to realize the self-combination of the user's review features and the item's review features. Experimental results on four real-world datasets show that the mean square error of FCRF is 1.43% lower than that of the state-of-the-art model, which verifies the effectiveness of FCRF.
  • References | Supplementary Material | Related Articles

  • Trustworthy Identity Authentication Based on Joint Time-Frequency Analysis of Mouse Behavior
  • YI Qian, LI Wei, YI Shu-ping, XIE Jun-dong
  • Journal of Beijing University of Posts and Telecommunications. 2021, 44(4): 121-128. DOI:10.13190/j.jbupt.2020-244
  • Abstract ( 558 )     HTML( 333 )     　　
  • A joint time-frequency analysis (JTFA) based method is proposed to improve the performance of the mouse dynamic trustworthy identity authentication system. Multi-resolution analysis of temporal signals based on wavelet packet transformation (WPT) is used to explore the joint time-frequency distribution characteristics of mouse behavior signals, and the recursive feature elimination method is applied to filter features extracted from users' long-term mouse behavior data. The random forest algorithm isemployed to establish the unique mouse behavior patterns for web users. which can be used to implement trustworthy identity authentication. In the case study, a single factor experiment is conducted, which sets the feature analysis method as the only factor. The mouse behavior data for thirty-one months of forty users is collected, among which the data of eighteen users are usedfor modeling and analysis. Both time series analysis and JTFA are adopted for feature extraction and the same algorithm is used to establish the model. The performance results show that the proposed JTFA based method increases the average value of area under receiver operating characteristic curve from 97.02% to 99.10% compared with the time series analysis based method.
  • References | Supplementary Material | Related Articles

  • Intelligent Identification Method of Legal Case Entity Based on BERT-BiLSTM-CRF
  • GUO Zhi-xin, DENG Xiao-long
  • Journal of Beijing University of Posts and Telecommunications. 2021, 44(4): 129-134. DOI:10.13190/j.jbupt.2020-241
  • Abstract ( 896 )     HTML( 439 )     　　
  • In the past, artificial intelligence natural language processing related technologies often used static feature vector models in the application of intelligent legal systems, which had problems such as low algorithm efficiency and large accuracy deviations. To intelligently identify case entities in legal texts and improve case processing efficiency, the dynamic word vector model is studied, and a recognition method based on the bidirectional encoder representations from transformers model as the input layer is proposed. Based on the fusion of bi-directional long short-term memory and conditional random fields models, a high-precision method of intelligent identification of legal case entities is constructed. The performance of the model is verifiedthrough experiments.
  • References | Supplementary Material | Related Articles

  • Verification of OFEC Code under Open ROADM Standard in 300 Gbit/s FPGA System
  • WU Jiang, XU Ke-feng, LI Yun-bo
  • Journal of Beijing University of Posts and Telecommunications. 2021, 44(4): 135-140. DOI:10.13190/j.jbupt.2020-239
  • Abstract ( 1308 )     HTML( 814 )     　　
  • Through studying open forward error correction code (OFEC) code structure and encoding/decoding algorithm in open reconfigu-rable add drop multiplexor(ROADM) standard, the key parameters that influence OFEC performance and implementation complexity are determined. Employing state-of-the-art field programmable gate array emulations platform with a record 300 Gbit/s throughput, the performance of different decoding schemes is evaluated, and the error floor is analyzed at a bit error ratio below 10^-15, which makes the performance evaluation more accurate.
  • References | Supplementary Material | Related Articles