最新刊期
卷 40 ， 期 4 ， 2024
- 摘要：The technology of direct-to-handset satellite is developing rapidly, which is the result of many factors such as the breakthrough of payload technology, the innovation in mobile phone technology, and the standards verification. Through the introduction of direct-to-handset satellite, two technical routes and three realization methods of direct-to-handset satellite were summarized. According to the technical problems of satellite-ground frequency sharing, space-borne antenna and space-borne base station, the key research contents were given based on the actual system and application scenarios. As the component of 5G communication and the basic of 6G communication, the future development of direct-to-handset satellite were discussed.关键词：direct-to-handset satellite;non-terrestrial network;frequency sharing;space-borne antenna;space-borne base station1322|1482|0更新时间：2024-06-05
- 摘要：Nowadays, the demand of consumers and industrial users for satellite-terrestrial integrated communications is evolving to achieve seamless coverage and anytime, anywhere access, and the integration of satellite and terrestrial communication capabilities will be the development direction of future mobile phones. The application scenarios for direct-to-handset connectivity, domestic and international development paths, and related technical solutions were introduced. Subsequently, the network architecture and key technology for realizing direct-to-handset connectivity with respect to the 3GPP NTN standard scheme were analyzed. The requirements and potential improvement schemes for multi-mode terminals in satellite communication scenarios in terms of integrated design, antenna capabilities, voice capabilities and power saving, were also identified. Finally, by exploring the key regulatory challenges (e.g. radio-frequency spectrum) related to direct-to-handset communications, feasible pathways for the future development of satellite-terrestrial integrated terminals were provided.关键词：non-terrestrial network;5G;satellite-terrestrial integrated;direct-to-handset satellite communication678|1206|0更新时间：2024-06-05
- 摘要：Satellite-terrestrial integrated wireless network (STIN) is a pivotal approach in achieving worldwide wireless connectivity. To guide base stations deployment of STIN, an analysis of the uplink coverage probability was conducted. Stochastic geometry was used to modeled the STIN under a setting of distinct frequencies. The satellite stations modeled as a one-dimensional Poisson point process (PPP) on orbit, base stations and users were represented as two-dimensional PPP. The expression for the uplink coverage probability was derived in terms of parameters such as base station density and orbital inclination. The correctness of the derived expression was verified through experimental simulations, and the impact of network parameters on the uplink coverage probability were analyzed.关键词：stochastic geometry;STIN;uplink coverage probability684|611|0更新时间：2024-06-05
- 摘要：To address the long distance and significant loss in satellite-to-ground wireless link, new demands are imposed on satellite phased arrays by direct-to-handset satellite. By analyzing the practical requirements of direct-to-handset satellite, the advantages and disadvantages of various beamforming architectures were outlined, then the proper selection strategy of beamforming architecture was proposed. Subsequently, dual-band shared-aperture circularly-polarized antenna arrays under frequency division duplexing (FDD) were discussed. In addition, the stacking and integration architecture of phased arrays was reviewed, and several key fabrication technologies for components and chips were introduced. Finally, the outlook and key technologies of satellite phased arrays for direct-to-handset satellite were presented.关键词：direct-to-handset satellite;phased array;beamforming;antenna array362|1897|0更新时间：2024-06-05
- 摘要：In recent years, satellite Internet has developed rapidly, with major countries around the world actively promoting the construction of satellite Internet. The integration of satellite and terrestrial networks has become an important trend in the evolution towards 6G, and direct-to-handset satellite services has also become a selling point for terminal manufacturers. The current state of global direct-to-handset satellite services was summarized, three development routes for direct-to-handset satellite technology were proposed, and the challenges faced by direct-to-handset satellite connections were analyzed, including the integration of terminal chips, integration of satellite and terrestrial networks, and sharing of frequencies between satellite and terrestrial systems. The key technologies that need to be mastered for direct-to-handset satellite services were also outlined, such as time-frequency synchronization technology, random access technology, HARQ retransmission technology, and mobility management technology, and the future trends of direct-to-handset satellite services were assessed.关键词：satellite Internet;direct-to-handset satellite;the integration of satellite and terrestrial318|1767|0更新时间：2024-06-05
- 摘要：Direct-to-handset satellite service is one of the important applications for low earth orbiting (LEO) satellite constellation systems. The overview on the main technology routes, application scenarios, and business types of satellite communication service for direct-to-handset was provided. The construction cost, capacity and operating income of LEO satellite constellation system were analyzed. The main applications of direct-to-handset satellite in China should focus on wide coverage and massive connections. Furthermore, there was a risk of commercial closed-loop in high traffic and broadband satellite applications. Finally, the technology trend was discussed associated with application requirements.关键词：direct-to-handset satellite;low earth orbiting satellite constellation system;low-altitude economy;non-terrestrial network300|1252|0更新时间：2024-06-05
- 摘要：In non-terrestrial network, leveraging resources such as satellite-to-earth links, satellite payloads, and ground terminals of low earth orbit (LEO) communication satellites to achieve positioning calculations is one of the important technical means for realizing the integration of sensing and communication in future 6G network. In scenarios such as direct-to-handset satellite, terminal designs were often configured to communicate with only one satellite, making the exploration of single-satellite positioning methods of urgent significance. Addressing the challenges of poor positioning accuracy, difficulty in clock synchronization, and slow convergence speed associated with previous single-satellite continuous observation, a bidirectional measurement differential positioning method was proposed in the context of low-orbit constellations. Additionally, a position updating strategy based on the satellite position accuracy factor was designed. Utilizing the satellite-to-earth link, the method employed a one-way bidirectional ranging technique to eliminate clock errors and compensated for the spatial deficiency of single-satellite observation through cumulative time measurement and random terminal switching, thereby optimizing terminal positioning performance. The results show that measurement through random satellite switching, compared to terminals that maintain single-satellite measurement without switching, enhances positioning performance by nearly 100%. By jointly solving multiple observation data over time, the accuracy convergence speed can be increased, and positioning error can be reduced. Within a simulation time of 180 s, using 512 observation data, with a terminal switching frequency of 19 times, the optimal positioning accuracy can reach 299.5 m.关键词：low earth orbit communication satellite;bidirectional measurement;single-satellite positioning;random switching263|672|0更新时间：2024-06-05
direct-to-handset satellite communication
- 摘要：To further improve the physical layer security (PLS) performance of decode-and-forward (DF) cooperative device-to-device (D2D) network that shared spectrum resources with cellular network, a modify-and-forward (MF) cooperative D2D-cellular PLS model was proposed which the D2D transmitter adopted transmit antenna selection (TAS). The D2D transmitter equipped with multiple transmit antennas which adopted TAS technology, then the antenna with the maximum signal-to-interference-plus-noise ratio between the D2D transmitter and MF relay link was selected to send signal. The relay used MF protocol to modify the decoded legal information before forwarding, to avoid passive eavesdropper decoding the legitimate information sent at this stage, which improved the PLS performance of D2D network. The analytical expressions of secrecy outage probability, probability of non-zero secrecy capacity and asymptotic secrecy outage probability of MF cooperative D2D network were derived, and the PLS performance of DF cooperative D2D network was compared and analyzed. The numerical and simulation results show that the PLS performance of MF cooperative D2D network is better than that of DF cooperative D2D network. The PLS performance of D2D network can be enhanced by increasing the number of transmit antennas at the D2D transmitter.关键词：device-to-device;transmit antenna selection;physical layer security;modify-and-forward;secrecy outage probability155|311|0更新时间：2024-06-05
- 摘要：The 5G era has brought opportunities for the rapid development of the Internet of things. Identity authentication is the basis for ensuring the security of the Internet of things. However, in the face of quantum attacks due to the large number of nodes in the Internet of things, the signcrypt-based identity authentication scheme will consume a lot of resources to generate node keys, which is difficult to meet the low cost requirements of the Internet of things. Therefore, a lightweight lattice-based group signcryption authentication scheme was designed. In the key generation stage, the improved trapdoor diagonal matrix was designed to optimize the original image sampling algorithm required for key generation and reduce the overall time required for generating a large number of keys. In the identity authentication stage, based on the residual Hash lemma and the signcryptic property, the message was signed and encrypted in one logical step at the same time, and the interaction flow of dot multiplication and Hash operation with low frequency was proposed to complete the access authentication performed by the group leader on behalf of the group members. Simulation experiments show that this scheme reduces the number of interactions during the access of Internet of things devices, reduces the computing cost of identity authentication stage, and reduces the total cost of signcryption and decryption by more than 7% compared with the existing schemes. Furthermore, the simulation results prove that this scheme can resist quantum attacks in the Internet of things.关键词：group authentication;quantum-resistant;Internet of things;lightweight66|262|0更新时间：2024-06-05
- 摘要：To solve the current problems of inefficiency, low utilization of intensive network resources, and high system cost in handling multi-user applications, a multi-user fine-grained task offloading scheduling approach under cloud-edge-end collaboration was proposed. Latency, energy consumption, and server rental costs were jointly considered. Application tasks were firstly divided and subtask priorities were designed. Then, a multi-user subtask scheduling scheme was proposed and an improved simulated annealing particle swarm algorithm was designed to minimize the total system cost to achieve the optimal offloading decision. Experimental results show that the proposed method reduces the total cost by at least 12.28% and 7.42% compared to other methods such as particle swarm and simulated annealing binary particle swarm, respectively.关键词：edge computing;task offloading;cloud-edge-end collaboration;multi-user;fine-grained scheduling292|526|0更新时间：2024-06-05
- 摘要：The rapid advancement of mobile communications and artificial intelligence has catalyzed an exponential increase in intelligent devices and data generation. This surge necessitates enhance the computational resource capabilities, particularly in the Internet of things (IoT) environments, where there are pressing demand for improved resource management in terms of computation, latency, and energy efficiency. The concept of a computility network, which leverages interconnected computing nodes for resource sharing and optimization based on a unified measurement standard and task scheduling strategy, offers a promising solution for augmenting IoT systems' computational performance. However, the current models for computing resource measurement, predominantly focused on computational capacity, fall short in addressing the diverse and collaborative needs of various IoT devices. These devices often differ in network connectivity modes and exhibit sensitivity to power consumption. Moreover, prevalent task scheduling methods in computility network predominantly rely on centralized network routing nodes or management platforms. Such approaches are not well-suited for the unique characteristics of IoT devices, which are typically dispersed and constrained in resources. To address these challenges, a novel architecture for computing resource measurement tailored to IoT devices was introduced. A comprehensive and unified framework for measuring diverse aspects of computing resources in heterogeneous IoT environments was provided, including computation, storage, communication, power consumption, and power supply metrics. Building on this foundation, a distributed task scheduling strategy that intelligently aligned the disparate computing resources with specific business scenario requirements was proposed, thereby facilitating efficient resource management and task scheduling for IoT devices. To validate the effectiveness of the proposed architecture, it was applied to a smart home scenario. The empirical results demonstrate that the proposed architecture significantly enhances the sharing and scheduling of computing resources among IoT devices. It elevates the overall efficiency of IoT computing while concurrently reducing energy consumption, thereby offering a robust solution to the evolving demands of IoT systems.关键词：computility network;computing resource measurement;IoT;task scheduling136|806|0更新时间：2024-06-05
- 摘要：The existing modulation recognition algorithms based on deep learning theory require a large number of IQ signal samples during the training phase. It is difficult to obtain a large number of samples in complex electromagnetic environments, resulting in a decrease in the generalization performance of modulation recognition algorithms based on deep learning. A signal enhancement based modulation recognition (SEBMR) algorithm was proposed to address the issue of poor network generalization ability. Firstly, a feature extraction and reconstruction module was designed to capture the global features of IQ signals. Secondly, an IQ signal enhancement network based on auxiliary classifier generative adversarial network (ACGAN) was proposed to achieve dual enhancement of sample quantity and quality. Finally, the support vector machine algorithm was employed to achieve modulation recognition and classification. To achieve recognition of debugging signals in complex channels, reconstructed signals representing global features were for training, and IQ baseband signals which experienced wireless fading were used for testing. The experimental results show that the proposed method can achieve better recognition accuracy performance in small sample training sets and fading channel environments compared to existing recognition methods based on long short-term memory (LSTM), convolutional neural network (CNN), attention mechanism, etc.关键词：modulation recognition;attention mechanism;signal enhancement;generative adversarial network138|733|0更新时间：2024-06-05
Research and Development
- 摘要：Information and communication technology underwent rapid evolution, experiencing three stages: source innovation, iterative innovation, and convergence innovation. These three stages were sequentially ordered yet overlapped with each other. An overall technology development framework was proposed, based on the current development of new-generation information communications and related technologies. Then, an outlook for technology development trends was made in several aspects. Overall, the development of information and communications technology was found to be more diversified, converged, and integrated than it had previously been.关键词：information and communications technology;computility network;artificial intelligence;convergence;low-carbon green life;network security525|710|0更新时间：2024-06-05
- 摘要：With the rise of the metauniverse, extended reality has become the multimedia application technology vigorously promoted by the industry. To realize extended reality, it is necessary to enhance the existing wireless network technology to meet the requirements of extended reality services. Firstly, the characteristics of extended reality technology and standard progress in 3GPP were analyzed. In addition, the challenges posed by extended reality services to the 5G-Advance network were explored. To meet the challenges posed by extended reality services, the XR-awareness mechanism, power saving enhancement mechanism, and capacity improvement technologies were investigated. Specifically, based on the packet data unit related parameters, jitter, etc. assistance information, the network can be aware of the XR traffic. In addition, the power consumption can be reduced by introducing the non-integer discontinuous reception mechanism and the playout buffer. And the capacity can be improved by introducing the new buffer status table and enhanced configured grant. Finally, the simulation results and performance analysis show that the proposed enhancement mechanisms can better support the extended reality services.关键词：extended reality;XR-awareness;power saving enhancement;capacity improvement211|790|0更新时间：2024-06-05
- 摘要：Driven by both business and technology, the communication industry is focused on smart network operations. It is an industry consensus to promote network intelligent operation with autonomous networks as the driving force. It was analyzed that operational support system (OSS) was the core component of the three-layer architecture of autonomous network, and the key to improve the level of autonomous networks was to enhance the intelligence capability of OSS. Specific implementation schemes such as the definition method of OSS product business scope, the analysis of the shortcoming of OSS product ability,and systematic improvement of OSS product capabilities driven by autonomous networks were elaborated. The solution was described in detail using the digital operation value scenario of broadband services as an example. Finally, the intelligent ability map of OSS driven by autonomous network was discussed. Improving the intelligence capability of OSS for autonomous network can effectively promote the research and development direction of OSS, and guide the planning and research and development of OSS products for operators.关键词：smart operation;autonomous network;OSS product;capability improvement318|667|0更新时间：2024-06-05
Engineering and Application
- Technical support is provided by Beijing Founder electronics co., LTD 京ICP备09064830号-19
京公网安备11010802024621 - It is recommended to read the content of this site in Chrome&IE9+. Please switch to extreme mode in browser 360.
- Cookies We use cookies to help provide and enhance our service and tailor content. By continuing, you agree to the use of cookies.
- Total Visits：1034978 Visits Today：3027
0