最新刊期
卷 37 ， 期 1 ， 2021
- 摘要：ICT Innovation, industrial development and the new information infrastructure construction, represented by 5G, artificial intelligence, and integrated space-air-ground networks will play an important role in the implementation of the national strategy of building a powerful communications network and comprehensively building a modern socialist country.Based on the current technological development in the ICT field, the China Institute of Communications summarized and sorted out the key directions of technological innovation in this field, including a new generation of mobile communications, network enabling, quantum communications, satellite internet, smart network operation and maintenance, cyberspace security, and the internet of things and the internet of vehicles, network cost reduction and efficiency enhancement, and basic technologies, etc., providing references for all walks of life to understand the technological development in the ICT field.关键词：5G;information communication;scientific and technological innovation;science and technology award;trend of development850|1224|0更新时间：2024-06-05
- 摘要：With the development of mobile internet and the popularization of video applications, the mobile content distribution network (MCDN) emerged as the times require.Prefetching technology is one of the key technologies for content distribution.It predicts the user’s future requests and prefetches the predicted content to the network edge in advance, thereby reducing the data acquisition delay and improving the quality of experience (QoE).In order to elaborate on the development status of mobile video prefetching technology, the latest research results of mobile video prefetching technology were introduced from the perspectives of user’s mobile behavior perception, content attribute perception, and network resource perception.And finally its main advantages and disadvantages were analyzed and the direction of further research in the future was pointed out.关键词：mobile content distribution network;video prefetching;mobility of users;quality of experience755|1247|0更新时间：2024-06-05
- 摘要：Deep learning and reinforcement learning are limited by small sample data set, which is impossible to realize the strong generalization learning ability.Meta-learning can make up for their shortcomings effectively.The values formed by accumulated experience feedback the corresponding signals to promote the model to adjust itself.It allows the artificial intelligence to learn to complete complex tasks quickly, which implements true artificial intelligence.Firstly, the basic principles of meta-learning were outlined.Secondly, according to the different forms of meta-knowledge, the research status of various methods was analyzed in depth.Finally, the application potential and the future development trends of meta-learning was discussed .关键词：small sample data set;strong generalization;meta-learning;artificial intelligence2190|2984|0更新时间：2024-06-05
- 摘要：Aiming at the problem of inconsistent biometric multi-modal fusion technology framework for mobile devices and lack of standards, a unified technical framework of multi-modal fusion standards was proposed.Firstly, the current status of standardization related to biometric used with mobile device was analyzed.Secondly, the local recognition and remote recognition application modes of mobile device biometrics standards were studied, and then four sub-multimodal fusion classification methods of multi-feature, multi-algorithm, multi-instance, and multi-sensor were analyzed and proposed.Then, four levels of multi-modal fusion were researched and proposed: sample-level fusion, feature-level fusion, score-level fusion, and decision-level fusion, and a standard technical framework for biometric multi-modal fusion for mobile devices was proposed.Finally, prospects for the application of biometric multi-modal fusion technology were given.关键词：biometric;multi-modal fusion;standard;mobile device859|1350|0更新时间：2024-06-05
Comprehensive Review
- 摘要：For high-speed mobile orthogonal frequency division multiplexing (OFDM) systems, a novel time-varying channel prediction method based on deep learning was proposed.To avoid the influence caused by random initialization of network parameters, the proposed method firstly obtains an ideal channel estimation based on data and pilot, and then pre-trains the back propagation (BP) neural network based on the channel estimation to obtain the ideal network initial parameters.Then, based on the initial network value obtained by pre-training, the proposed method uses the channel estimation based on pilot to train the BP neural network again.Finally, the proposed method realizes the single-time-and multi-time prediction of time-varying channels through on-line prediction.Simulation results show that the proposed method can significantly improve the prediction accuracy of time-varying channels and has a low computational complexity.关键词：high-speed mobility;OFDM;deep learning;BP neural network;time-varying channel prediction;pre-training1040|1203|0更新时间：2024-06-05
- 摘要：Existing multi-band spectrum sensing methods often use the sparsity of broadband spectrum.However, high spectrum occupancy rate of primary users degrades their performance severely.To address this issue, a novel multi-band spectrum sensing method was proposed by exploiting the state correlation among adjacent frequency bands.Firstly, a sticky hidden Markov model (SHMM) was established by regarding the multi-band states and measured energies as hidden and observed variables.In the SHMM, a sticky factor was introduced to represent the state correlation among adjacent frequency bands.Secondly, iterative expressions for the parameters of SHMM were derived.Finally, multi-band spectrum sensing was implemented by obtaining the posterior mean of observations from every frequency bands.Simulation results show that the proposed method outperforms existing methods, and when the false alarm probability is 0.1, the average frequency band occupancy rate is 50%, and the average signal-to-noise ratio is -12 dB, the detection probability can reach close to 0.99, which is about 30% higher than the detection probability of other methods.In addition, the proposed method had a faster convergence rate than existing methods and therefore has lower computational complexity.关键词：cognitive radio;multi-band spectrum sensing;sticky hidden Markov model603|539|0更新时间：2024-06-05
- 摘要：To reduce the coding computational complexity of the rate and distortion calculations in HEVC, a fast TU level rate model with higher accuracy was proposed.The contribution percentages of different syntax elements in entropy coding were evaluated, and syntax element-wise accurate rate models were individually developed to construct the whole TU level model.In addition, coefficient levels were weighted adaptively to distinguish the nonuniform contributions of different coefficients in terms of rate profiling.Moreover, position-wise parameter was defined to depict the distribution patterns for possible non-zero coefficients within one block.The final linear rate model was developed by fine-tuning the model parameters from great amounts of samples in a statistical way.Finally, the transform domain distortion model was also established to bypass unnecessary reconstruction process.Experimental results show that the proposed algorithm can achieve 49.76% complexity reduction with 1.74% BD-BR increase for RA configuration.关键词：HEVC;RDO;rate estimation;distortion estimation;video coding357|736|0更新时间：2024-06-05
- 摘要：Aiming at the problem of SON coverage self-optimization proposed in 3GPP, a method based on artificial bee colony algorithm was proposed to optimize the azimuth and down-tilt angles of base station antenna at the same time.Firstly, the base station determined the area to be optimized according to the MR data reported by user equipment, and established the objective function of the average gain of the base station antenna area to be optimized.Secondly, the artificial bee colony algorithm was used to solve the objective function, and the optimal solution of the base station antenna azimuth and down-til tangle was got.Finally, the base station antenna azimuth and down-tiltangles were adjusted to the optimal value to achieve the coverage self-optimization of the base station.Through system modeling, simulation and field verification, taking the RSRP received by the user’s equipment as the index, the identification method using the artificial bee colony algorithm was improved, 6.81 dB higher than the initial parameters which were not optimized, and 4.35 dB higher than the method based on artificial experience.The experimental results show that the optimization method proposed can accurately and timely adjust the azimuth and down-tiltangles of the base station antenna according to the user distribution, and improve the signal strength received by the user equipment.关键词：artificial bee colony algorithm;cover self-optimization;MR;azimuth angle,;down-tilt angle696|699|0更新时间：2024-06-05
- 摘要：Aiming at the problem of low registration caused by image rotation or background transformation in large-scale image classification processing, a convolutional neural network image classification method based on edge enhancement was proposed.This method extracted image features through the VGG19 network model, and used cosine similarity for image classification judgment, used edge enhancement to highlight the edge features of image subject, and reduced the impact of image rotation or background transformation on the classification performance of the VGG19 network.Experiments prove that this method can effectively improve the similarity between the same subject rotated image and background transformed image and the original image, and is suitable for the classification of various images.关键词：convolutional neural network;VGG19;cosine similarity;edge enhancement453|347|0更新时间：2024-06-05
- 摘要：In order to improve the performance of hybrid precoding scheme based on fully connected structure in millimeter-wave massive MIMO system, a hybrid precoding scheme based on an equivalent channel with two-step design method was proposed.Firstly, the equivalent channel was constructed by combining the analog precoding matrix at the transmitter, the analog combining matrix and the channel matrix at the receiver, and the analog part of the transceiver was designed to maximize the equivalent channel gain.Furthermore, the least squares criterion was applied to derive the digital precoding matrix and the digital combination matrix column by column to design the digital part of the transceiver.Simulation results show that the proposed algorithm can approximate the optimal digital precoding scheme and has lower complexity and stronger fault tolerance.关键词：massive MIMO;equivalent channel gain;least squares criterion;fault tolerance350|468|0更新时间：2024-06-05
- 摘要：During the process of monitoring video surveillance, potential risks of leaking personal privacy information may occur due to the exposure of facial information to the surveillance video.It is necessary to mosaic the pedestrian privacy information in the real-time video stream.At present, the commonly used coding method based on face detection is heavily affected by pedestrian appearances and illumination, which often leads to weak real-time performance and undetected errors.To solve the problems above, a multi-detection model was proposed, combining face detection algorithm, target object detection algorithm and pre-frame association detection method, and compared with the traditional face detection model.Experimental results show that the recall rate of the proposed model is 532% higher than that of the traditional face detection algorithm.关键词：face privacy protection;face mosaic;object detection639|580|0更新时间：2024-06-05
- 摘要：5G is an important development direction of the new generation of communication technology, which introduces a new arena of global technology and industry competition.Korea, United States, United Kingdom, Switzerland, and China are pioneers which launched their commercial 5G networks in 2019.However, the global competition in 5G development is a long-term race.Major countries and regions released their own 5G development strategies gradually.An overview and the implementation status of the spectrum strategy of America’s 5G FAST plan leading by the chairman of FCC (Federal Communications Commission) were provided, as well as some inspired thoughts on the development of 5G and its future evolution.关键词：5G system;development strategy;spectrum management666|1075|0更新时间：2024-06-05
- 摘要：A method of 5G cell station spacing for high-speed railways with simplified restriction conditions was presented that balance the gap between theoretical research and practical use.To begin, the influencing factors of 5G cell station spacing for high-speed railways were analyzed, such as incident angle, downtilt angle, station height, station gauge distance and coverage distance.Then, a simple station spacing calculation method was obtained with the restriction conditions simplified to a single parameter (coverage distance) by analyzing the correlation between available station height, gauge and coverage distance.Comparison and verification show that the cell station spacing calculation done with the proposed method has high accuracy, with a calculation error of only 3 m and an accuracy of 99.14%.关键词：5G;high-speed railway communication;simplified restriction condition;coverage distance701|659|0更新时间：2024-06-05
Research and Development
- 摘要：From the requirements of enterprise digital transformation and the challenges faced by big data platform, the construction ideas and principles of unified data lake were expounded.A unifid data lake construction scheme based on BSS/MSS/OSS cross domain fusion was proposed, which adopted logical unification, physical dispersion, unified data directory, unified security management and application of decoupling fusion.The construction practice of unified data lake was described in recent two years.关键词：data lake;edge computing;data catalog;agile development617|1353|0更新时间：2024-06-05
- 摘要：The modern communication network technology represented by 5G and the accompanying mobile edge computing technology play a crucial role in the connection of the industrial internet, closely integrating production factors and exerting the value of collaborative operations.By describing the basic development status and technical characteristics of 5G edge computing, the application method for the industrial internet field and the comparison with the traditional model were explained, a reference implementation solution for industry services was proposed, and the expected application scenarios were summarized.关键词：5G;industrial Internet;edge computing1038|1706|0更新时间：2024-06-05
- 摘要：The status of SD-WAN technology was introduced, the SD-WAN advantages with traditional line were compared.The basic technical features of SD-WAN, the software definition network controllers of SD-WAN, security encryption and tenant isolation, the SD-WAN industry standards were described.The relevant technologies of SD-WAN main manufacturers were also analyzed, the tunnel technology used by SD-WAN was compared.And private IPSec tunnel , VxLAN over IPSec, NvGRE over IPSec, SSL tunnel network project used by the different companys was compared and analyzed, the optimized tunnel technology project was given, and optimizational suggestions on how to use tunnel technology to complete networking project were further put forwarded, combined with the advantages of Internet service product in establishing SD-WAN, the POP network and peer-to-peer networking solutions were given.Finally, it make future development prospect for SD-WAN standards, Internet service product and SD-WAN manufacturers trends.关键词：SD-WAN;VxLAN;IPSec;NvGRE875|1800|0更新时间：2024-06-05
- 摘要：The quality of user experience in adaptive video streaming, to a large extent, depends on the accuracy of the end-to-end bandwidth estimation.However, bandwidth estimation is very challenging in highly dynamic LTE network.LTE resource-aware dynamic adaptive wireless multimedia streaming system was designed and implemented in which the LTE resource block monitor module keeps monitoring the cell-wide physical layer resource utility.The rate scaling mechanism mapped the throughput to an estimation of available bandwidth and the rate adaption algorithm selected the most appropriate representation combining current available bandwidth with buffer state and played a trade-off between video quality and the risk of stalling.The experimental results on the prototype system show that comparing with the two baseline algorithms, the proposed system achieves the highest average video bitrate while maintaining a fairly low stalling rate, and effectively enhances the quality of experience.关键词：LTE;adaptive streaming;MPEG-DASH;USRP339|617|0更新时间：2024-06-05
Engineering and Application
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