最新刊期
卷 39 ， 期 5 ， 2023
- 摘要：Visible light communication (VLC), primarily based on light emitting diode (LED), supports the information transmission and networking through the existing infrastructure of the illumination network.The constellation optimization and the power resource optimization were investigated under lighting constraints with multiple LEDs for indoor environment.Moreover, the optical intelligent reflection surface was also researched to regulate reflection channels dynamically, improving both the transmission data rate and the coverage of the VLC system.In the meantime, the preliminary study revealed the flicker effect of low-frequency modulated optical signals on the human body, and the results suggest that the LED photo-biological effect should be considered comprehensively in the future signal design.关键词：visible light communication;light emitting diode;optical intelligent reflecting surface;flicker effect693|1066|0更新时间：2024-06-05
- 摘要：Signals are susceptible to nonlinear effects in the process of underwater visible light communication (UVLC) channel transmission.In order to improve the communication performance of the system, it is very important to recover the received signals.A bidirectional gated recurrent unit model based on Bayesian optimization algorithm (BO-BiGRU) was proposed as post equalizer in UVLC system, which could automatically find the optimal hyperparameters.BO-BiGRU model was applied to the 1.2 m underwater experimental platform.64 quadrature amplitude modulation (QAM)-carrierless amplitude-and-phase modulation (CAPM) was adopted, and 3.10 Gbit/s rate of data transfer was achieved under the condition that the bit error ratio (BER) of the system was less than 3.8×10-37% forward error correction (FEC), which is 128 Mbit/s higher than the traditional post equalization method.关键词：underwater visible light communication;nonlinear effect;waveform level post equalizer;Bayesian optimization;bidirectional gated recurrent unit895|1376|0更新时间：2024-06-05
- 摘要：In order to achieve zero energy consumption of visible light labels, MATLAB and MULTISIM were used to simulate the impedance matching of the receiver, matching the input impedance of the first-order equalization circuit with the internal resistance of solar panel, while expanding the system bandwidth and ensuring the highest output power of the solar panel.The simulation results show that the output power of the solar panel is increased by 86.2% when the input impedance of the equalization circuit matches solar panel, compared to the common 50 Ω.The prototype system of zero-energy optical label of visible light was built.A 15 W LED lamp was used to send characters at 115 200 Baud, and a cadmium telluride solar panel was used to collect energy and receive signals at a distance of 1.3 m.Low-power microcontroller was used to recover data through ADC and computation, and OLED screens were used to display the received label characters.The signal reception, processing computing, and screen display energy of the receiver were all provided by solar panel, without the need for batteries or external power supply.The visible light label display service with zero energy consumption has been implemented.关键词：IoT;zero power;visible light communication572|878|0更新时间：2024-06-05
- 摘要：Visible light communication is expected to be one of the key alternative technologies for 6G with the advantages of abundant spectrum resources, less susceptibility to electromagnetic pollution and green safety, which also provides a new idea for high-precision indoor positioning.However, the positioning accuracy can be significantly degraded in the harsh indoor environment where LED that can be used as an anchor is insufficient or severely blocked.Therefore, a robust visible light intelligent positioning method based on multi-node cooperation was investigated.Considering the non-line-of-sight propagation of visible light and the dynamic change of user terminal orientation, a cooperative localization mechanism between user terminals was established to obtain mutual information gain and a convolutional-recurrent neural network was designed, and the theoretical analysis of cooperative localization accuracy performance was carried out.Simulation results show that the introduction of the cooperative localization mechanism can effectively improve positioning performance under harsh conditions.关键词：visible light positioning;cooperative localization;convolutional-recurrent neural network;non-line-of sight propagation632|644|0更新时间：2024-06-05
- 摘要：As a key submarine-based communication platform, unmanned underwater vehicle (UUV) can facilitate underwater wireless optical communication (UWOC).However, fluctuating characteristics of water body, different water qualities, multi-user access present challenges to UUV-assisted UWOC systems, which could be alleviated by an appropriate path planning to maximize the system and each user performance.Deep reinforcement learning (DRL) technology was applied in the path planning of autonomous vehicles, a trajectory planning scheme for UUV-assisted UWOC systems was proposed.The UUV automatically decides the navigation direction through deep Q-network (DQN) method, thereby improving the communication capacity of the system and each user.The impact of distinct water qualities on the capacity enhancement was also investigated.Simulation results suggest that the outputted strategy of DQN can improve the link capacity of the system and each user.This capacity improvement in clear seawater is better than that in pure seawater but lower than that in coastal water.关键词：UUV;optical wireless communication;DRL;trajectory planning426|656|0更新时间：2024-06-05
- 摘要：Underwater wireless optical communication (UWOC) has been widely used in the construction of underwater communication network for the advantages of high data rates, small latency, high flexibility and scalability.However, due to the absorption and scattering effects of seawater, the spatial characteristics of UWOC links have not been studied extensively, especially in multiple-input multiple-output (MIMO) scenario.A linear array MIMO UWOC link geometry was considered and a weighted exponential function polynomial (WEFP) model was proposed to characterize the photon irradiance distribution at the receiving plane of general MIMO UWOC links with arbitrary numbers of light sources.Numerical results suggest that the proposed WEFP model fits well with the results of Monte Carlo simulations in turbid water environment.关键词：underwater wireless optical communication;multiple-input multiple-output;irradiance;Monte Carlo simulation407|888|0更新时间：2024-06-05
- 摘要：Visible light wireless technology transmits information through visible light, utilizing light-emitting diode (LED) light sources to achieve communication and positioning while illuminating.Visible light communication positioning integration (VLCP) technology is one of the key supporting technologies for future large-scale Internet of things (IoT) applications.Orthogonal frequency division multiplexing (OFDM) technology can be used to allocate different spectral resources to visible light communication (VLC) and visible light positioning (VLP) systems, while achieving communication and positioning functions.Resource allocation is the key to improving the efficiency of VLCP systems and expanding their applicability.A new resource allocation method based on error vector magnitude(EVM) was proposed.EVM was utilized to allocate subcarriers for positioning and communication in VLCP systems, communication and positioning performance was dynamically adjusted based on channel parameters, system quality of service (QoS) was ensured, and system channel utilization was improved.The experimental results indicate that at 1.5 m×1.5 m×1.5 m indoor environment, the proposed resource allocation algorithm can improve channel utilization by at least 19.5% compared to fixed resource allocation algorithms.Under the premise of comparable performance to algorithms that use signal-to-noise ratio (SNR) for resource allocation, it greatly saves system resources and is easy to apply in practice.关键词：visible light communication positioning;subcarrier allocation;channel utilization;error vector magnitude342|723|0更新时间：2024-06-05
Topic: Visible Light Communication
- 摘要：The release of ChatGPT, sparked a wave of generative AI, representing the arrival of the singularity moment of general artificial intelligence and highly likely restructuring the information industry ecosystem.The domestic industry has strengthened the research in the field of intelligent computing represented by ChatGPT, and operators have become the main force in the construction of computing network infrastructure, ushering in new opportunities for the development of intelligent computing.A detailed analysis of the capabilities, development status, and application prospects of generative AI were provided, and the technical elements behind generative AI, the demands for computing network resources, the impact on the communication industry, the opportunities and challenges faced by operators in the development wave of generative AI were thought about.Finally, the positioning and response strategies of operators were discussed.关键词：ChatGPT;generative AI;telecom industry;intelligent computing1197|2292|0更新时间：2024-06-05
- 摘要：The technology development trend of intelligent customer service for operators was discussed, and automatic speech recognition (ASR) transcription error correction technology, semantic extraction technology, encrypted database, and agent access control technology were introduced.Two different research directions of error detection and automatic error correction for speech recognition were analyzed, two directions of supervised learning and unsupervised learning were discussed, and big data encryption and agent access control technologies were introduced.At the same time, the technical directions of multimodal interaction technology, intelligent recommendation technology and disabled-oriented services were prospected.In conclusion, the development and innovation of intelligent customer service technology will bring a more efficient and convenient service experience to the communication industry and strongly promote the progress of the industry service level.关键词：AI customer service;key technology;AI589|1347|0更新时间：2024-06-05
Review
- 摘要：With the growing maturity of millimeter wave technology and high-throughput satellite communication technology, as well as the urgent need for global broadband communication services, the construction of LEO giant communication constellation has attracted great attention, and up to thousands of satellites have been deployed.A large number of LEO communication satellites have realized multiple and repeated coverage of high-frequency radio frequency signals on the ground.At the same time, ground communication resources provide a hardware platform for signal reception and create conditions for the development of integrated communication and navigation.The status quo, opportunities and challenges of the integrated LEO navigation constellation were discussed, and the differences of resources required by the integrated LEO navigation constellation and the global navigation satellite system were emphatically expounded.In terms of space segment, ground segment and user segment, the conclusions and prospects for future research were presented.关键词：communication and navigation integration;LEO constellation;navigation and positioning;constellation design;orbit determination791|2458|0更新时间：2024-06-05
- 摘要：Personalized recommendation is one of the most effective means to extract specific information.Aiming at the problem that lacking of users feature in traditional recommendation methods, a hybrid recommendation model of generalized matrix factorization and deep long short-term memory network based on multi-features fusion (HMF) was proposed.The model used potential eigenvector factors to characterize the selective impact of age and occupation on the project, highlighting user personalization.Long short-term memory (LSTM) was used to obtain the temporal characteristics between users and projects, and then the deep temporal nonlinear higher-order interaction relationship was mined by multi-layer perceptron.The simple nonlinear low-order interaction obtained by generalized matrix factorization (GMF) was fused with the complex time-series nonlinear high-order interaction, and the final prediction score was obtained through the full connection layer.HMF effectively utilized the user’s multi-feature and user-project interaction information to realize personalized dynamic and accurate recommendation.In order to verify the validity and feasibility of the model, the test was conducted on the public dataset MovieLens-1M.The simulation experiment shows that when the potential eigenvector factors of HMF is 50 and the MLP layer is 7, HR@10 and NDCG@10 are 0.983 1 and 0.974 9 respectively, which are 27.61% and 54.29% higher than the optimal solution of the traditional single feature model NCF.关键词：personalized recommendation;multi-features fusion;deep learning341|633|0更新时间：2024-06-05
- 摘要：In recent years, emotion recognition methods based on deep learning and electroencephalogram (EEG) have achieved good results.However, existing methods still have issues such as incomplete extraction of emotional features from EEG and significant impact from artificially mislabeled emotional labels.A parallel separable convolution and label smoothing regularization (PSC-LSR) network model was proposed.Firstly, through the attention mechanism, EEG important time points and important channels were given greater weight to obtain shallow emotional features of EEG.Secondly, a parallel separable convolution module was used to comprehensively extract EEG emotional information and obtain deep emotional features.Finally, the emotion label smoothing regularization method was used to optimize the model parameters, which increased model’s fault tolerance probability for incorrect labels, enhanced the generalization and robustness of the network model, and improved accuracy of EEG emotion recognition.The proposed method has been validated in two datasets, in which the average accuracy rates of arousal and valence dimensions in the DEAP dataset reaches 99.23% and 99.13%, respectively.In the Dreamer dataset, the average accuracy rates for both arousal and valence dimensions reaches 97.33% and 97.25%.关键词：EEG;emotional recognition;label smoothing regularization;attention mechanism228|1057|0更新时间：2024-06-05
- 摘要：The interference coupling of power line broadband carrier communication aggravates the frequency domain tailing between subcarriers, reduces the sensitivity of suppression methods, and the communication quality is poor.Therefore, a cooperative suppression method of interference coupling of power line broadband carrier communication based on improved variational modal decomposition was proposed.Based on the channel characteristics of power line broadband carrier communication, a communication channel model with multipath propagation and Doppler effect was established, the communication signal was simulated, the original signal was preprocessed by using the improved variational modal decomposition algorithm, and the suppression problem was transformed into a variational problem.At the same time, the signal was expressed in the discrete form of unconstrained variational problem.The variational problem was continuously updated to complete the separation and processing of the signal, and realize the cooperative suppression of communication interference.The experimental results show that the proposed method has low bit error rate, small frequency offset, and practical application value.关键词：variational modal decomposition;power line bandwidth;carrier communication;interference;coupling, cooperative suppression159|324|0更新时间：2024-06-05
- 摘要：The damage toughness assessment method of power backbone communication network based on power big data was studied, and the damage toughness assessment results were used to formulate protection strategies and improve the network survivability.The power backbone communication network and the attacker were set as the two sides of the game, and the Nash equilibrium strategy of both sides was determined by the minimax method.The damage probability of nodes was obtained by the Nash equilibrium strategy, and the node damage probability was transformed into the network damage form.According to the network damage pattern, the repair conditions contained in the power big data were obtained by cloud computing technology.According to the importance of each node, the repair resources and repair budget were allocated to the nodes in order.The performance time-history response curve of the power backbone communication network was constructed, and the dynamic evaluation results of the network damage toughness were output.The experimental results show that all operations using cloud computing technology to process massive power big data can not exceed 330 ms.When the repair budget and repair resources are the highest, the damage toughness of the power backbone communication network can reach 0.925 at most, indicating that this method can effectively evaluate the damage toughness of the power backbone communication network.关键词：power big data;backbone communication network;damage toughness;assessment method;the two sides of the game;cloud computing291|590|0更新时间：2024-06-05
Research and Development
- 摘要：By referring to the service network architecture and interoperation scheme of VoWi-Fi under 4G, the differences of the service network architecture and interoperation scheme of VoWi-Fi under 5G were studied and analyzed.Under the current situation that the network and terminal industry chain didn’t support the interoperability between standalone (SA) and Wi-Fi, a workaround scheme for interoperation in the transitional period was proposed, and the terminal and network side configuration suggestions were given to realize the interoperation between VoWi-Fi and VoLTE based on 5G network to ensure that users were unaware.The feasibility of this scheme was verified by practical tests.It provides reference for the actual deployment of VoWi-Fi.关键词：5G;VoWi-Fi;VoNR;VoLTE;handover299|799|0更新时间：2024-06-05
- 摘要：The China Media Group backbone network is a key infrastructure that connects the headquarters, data centers, hubs/journalists at home and abroad, and “hundreds cities and thousands of screens” across the country, and IPv6+ is the main technical route of the next-generation IP network.The present situation and challenges of the backbone network of the headquarters were mainly analyzed, the principle, advantages and technical characteristics of the core of IPv6+ were introduced, and how IPv6+ technology adapts to the development of broadcast and television services was discussed.Finally, the conception and suggestion of constructing and deploying the next generation broadcast TV backbone network based on IPv6+ were put forward.It provided a new idea to simplify the protocol and speed up the service opening for the future construction of backbone network of radio and television stations.关键词：backbone network;IPv6+;network slicing;iFIT;APN6;wide connection;ultra-broadband286|532|0更新时间：2024-06-05
Engineering and Application
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