An electro-absorption(EA)modulator is one of key components for optical fiber communications due to the high speed,small size,low voltage and integration ability with other semiconductor devices.A 40 Gb/s InGaAsP/InP ...An electro-absorption(EA)modulator is one of key components for optical fiber communications due to the high speed,small size,low voltage and integration ability with other semiconductor devices.A 40 Gb/s InGaAsP/InP multiplequantum-well(MQW)EA modulator monolithically integrated with a semiconductor optical amplifier(SOA)was fabricated for digital communications.The modulator capacitance was reduced to obtain 40 GHz bandwidth,and the SOA section helped reduce the insertion loss from 18 dB to 3 dB.InGaAlAs/InP MQW EA modulators have also been fabricated and characterized for analog optical fiber communications.A low driving voltage of 2.7 V and high spurious free dynamic range of 107 dB·Hz2/3 were estimated by static and dynamic measurements.展开更多
This paper summarizes the requirements for modem maritime wireless communication networks in the marine environments including the sea- to-sea and sea-to-shore communication scenarios. The existing maritime wireless c...This paper summarizes the requirements for modem maritime wireless communication networks in the marine environments including the sea- to-sea and sea-to-shore communication scenarios. The existing maritime wireless communication sys- tems are presented and the development of the state-of-the-art maritime communication systems is surveyed. Furthermore, a hierarchical and integrated maritime network architecture is proposed to satisfy the increasing various classes of services which demand different Quality of Service （QoS）. Finally, the open issues for further development of maritime communications are identified.展开更多
As modern communication technology advances apace,the digital communication signals identification plays an important role in cognitive radio networks,the communication monitoring and management systems.AI has become ...As modern communication technology advances apace,the digital communication signals identification plays an important role in cognitive radio networks,the communication monitoring and management systems.AI has become a promising solution to this problem due to its powerful modeling capability,which has become a consensus in academia and industry.However,because of the data-dependence and inexplicability of AI models and the openness of electromagnetic space,the physical layer digital communication signals identification model is threatened by adversarial attacks.Adversarial examples pose a common threat to AI models,where well-designed and slight perturbations added to input data can cause wrong results.Therefore,the security of AI models for the digital communication signals identification is the premise of its efficient and credible applications.In this paper,we first launch adversarial attacks on the end-to-end AI model for automatic modulation classifi-cation,and then we explain and present three defense mechanisms based on the adversarial principle.Next we present more detailed adversarial indicators to evaluate attack and defense behavior.Finally,a demonstration verification system is developed to show that the adversarial attack is a real threat to the digital communication signals identification model,which should be paid more attention in future research.展开更多
The digital communication in a system of two multi-mode solid state chaotic lasers is investigated theoretically. If the usual method working well in a single-mode laser system is applied to a multi-mode laser system,...The digital communication in a system of two multi-mode solid state chaotic lasers is investigated theoretically. If the usual method working well in a single-mode laser system is applied to a multi-mode laser system, the memory effect of the two nearest digits can cause high rate of mistakes when the digits are decoded through the subtraction of receiver output from the transmittal. By introducing the deviations of two nearest maximum and minimum fluctuationsof the signal to decode the digit, the message can be decoded correctly. Also, this communication method does not critically depend on the quality of the chaotic synchronization of the two multi-mode lasers.展开更多
The low voltage powerline is becoming a powerful solution to home network, building automation, and internet access as a result of its wide distribution, easy access and little maintenance. The character of powerline ...The low voltage powerline is becoming a powerful solution to home network, building automation, and internet access as a result of its wide distribution, easy access and little maintenance. The character of powerline channel is very complicated because it is an open net. This article analysed the character of the powerline channel,introduced the basics of OFDM(Orthogonal Frequency Division Multiplexing), and studied the OFDM applied into powerline high speed digital communication.展开更多
For the performance issues of satellite transceivers suffering passive intermodulation interference,a novel and effective digital suppression algorithm is presented in this paper.In contrast to analog approaches,digit...For the performance issues of satellite transceivers suffering passive intermodulation interference,a novel and effective digital suppression algorithm is presented in this paper.In contrast to analog approaches,digital passive intermodulation（PIM） suppression approaches can be easily reconfigured and therefore are highly attractive for future satellite communication systems.A simplified model of nonlinear distortion from passive microwave devices is established in consideration of the memory effect.The multiple high-order PIM products falling into the receiving band can be described as a bilinear predictor function.A suppression algorithm based on a bilinear polynomial decorrelated adaptive filter is proposed for baseband digital signal processing.In consideration of the time-varying characteristics of passive intermodulation,this algorithm can achieve the rapidness of online interference estimation and low complexity with less consumption of resources.Numerical simulation results show that the algorithm can effectively compensate the passive intermodulation interference,and achieve a high signal-to-interference ratio gain.展开更多
The three core issues in the“digital human rights”debate are whether“digital human rights”are possible,necessary,and feasible.Both sides of the debate focus on discovering the value of“digital human rights”to in...The three core issues in the“digital human rights”debate are whether“digital human rights”are possible,necessary,and feasible.Both sides of the debate focus on discovering the value of“digital human rights”to individuals from a semantic level,but ignore the significance of“digital human rights”to the whole society and its subsystems at the level of social structure.By introducing Niklas Luhmann's System Theory,this observation blind spot can be eliminated.Fundamental rights are devoted to directly shaping not a physiological-psychological“individual”as a social environment but a social“person”that can be included by social systems.It is clear that digital human rights are the right to participate in digital communication of a“human”as a“person”,so they are possible in terms of conceptual definition.Digital human rights can help“people”lower the threshold for participation in digital communication,limit the excessive expansion of social systems,and promote the free and complete expression of body and mind,so they are necessary for social functions.There are limitations in the existing two ideas of“incorporating digital human rights into the constitution”.Based on the new construction idea of System Theory of Law,digital human rights as the right to participate in digital communication can be typified into digital communication in social sub-fields such as politics,economy,science,and art.The right to participate constructs a complete digital human rights system,making it feasible on the basis of the constitution.展开更多
In the field of intangible cultural heritage＇ s digital protection, a lot of research work has been made by all countries in the world, while the research on the digital commuuication of intangible cultural heritage ...In the field of intangible cultural heritage＇ s digital protection, a lot of research work has been made by all countries in the world, while the research on the digital commuuication of intangible cultural heritage is few and especially rarely seen in China. Under the premise, in this paper, the factors influencing intangible cultural heritage in the communication process are analyzed based on the information characteristics of intangible cultural heritage and the advantages of I-Space framework model in researching information transfer. Also, combined with the birch bark making technology in Heilongjiang province, the knowledge-based and signified communication strategy of intangible cultural heritage is proposed, aiming at providing new ideas for the researches on the digital communication of intangible cultural heritage.展开更多
The digital communication of two-dimensional messages is investigated when two solid state multi-mode chaotic lasers are employed in a master-slave configuration. By introducing the time derivative of intensity differ...The digital communication of two-dimensional messages is investigated when two solid state multi-mode chaotic lasers are employed in a master-slave configuration. By introducing the time derivative of intensity difference between the receiver （carrier） and the transmittal （carrier plus signal）, several signals can be encoded into a single pulse. If one signal contains several binary bits, two-dimensional messages in the form of a matrix can be encoded and transmitted on a single pulse. With these improvements in secure communications using chaotic multi-mode lasers, not only the transmission rate can be increased but also the privacy can be enhanced greatly.展开更多
Karl Marx and Friedrich Engels introduced the theory of spiritual communication in their influential work,The German Ideology,thereby establishing the Marxist perspective on communication.This theory has a distinct hi...Karl Marx and Friedrich Engels introduced the theory of spiritual communication in their influential work,The German Ideology,thereby establishing the Marxist perspective on communication.This theory has a distinct historical context,meaning,and significance.As society advances,driven by the proliferation of commodity-based economies and advancements in science and technology,humanity has entered the digital information age.The prevailing mode of communication in this era,centered around the Internet and big data,brings great convenience to society but also raises concerns about the potential alienation of both subjective and objective aspects of communication,as well as social relationships.Against this backdrop,the rethinking of Marx’s communication theory in the 21st century provides a logical framework and theoretical basis for critiquing the contemporary form of spiritual communication through the digital communication of the information age.展开更多
This article analyzes the concentration of production and distribution of information, from the analysis of the news in major international news agencies.The biopolitics is more and more interconnected to social, cult...This article analyzes the concentration of production and distribution of information, from the analysis of the news in major international news agencies.The biopolitics is more and more interconnected to social, cultural, economical, and political matters, which led us to see in the contemporary scenario the creation of new forms of social organization which will determine how we interact with each other and how we face the world. Additionally, questions emerge about the usage of the means of communication, particularly those related to Technology of Communication and Information （TICs）. The influence of the media over the social-cultural activities tends to create homogenizations of senses, aiming a planetary visibility in a process that can not only disfigure but destroy many symbolic representations and cultural forms. On the other hand, globalization tends to, instead of minimize the differences in the world, ended up creating new conflicts that, through the usage of new technologies of communication, expresses and articulate themselves.展开更多
Along with the mature development of the domestic computer technology and communication technology, it is an inevitable trend to integrate the two major information technologies together in the future reform of the so...Along with the mature development of the domestic computer technology and communication technology, it is an inevitable trend to integrate the two major information technologies together in the future reform of the social communication model. Under this background, the principle of digital communication is introduced first in this paper, and accordingly the role of the communication network resources sharing is analyzed, and finally the sharing management of digital communication network resources is proposed. Hopefully. this paper can play a help in the future subsequent study.展开更多
Along with the mature development of the domestic computer technology and communication technology, it is an inevitable trend to integrate the two major information teclmologies together in the future reform of the so...Along with the mature development of the domestic computer technology and communication technology, it is an inevitable trend to integrate the two major information teclmologies together in the future reform of the social communication model. Under this background, the principle of digital co,nmunication is introduced first in this paper, and accordingly the role of the communication network resources sharing is analyzed, and finally the sharing management of digital communication network resources is proposed. Hopefully, this paper can play a help in the future subsequent study.展开更多
The era of mobile Internet is coming, broadband digital communication technology is in the stage of continuous development and progress, with us moving towards the era of mobile Internet. This paper first analyzes the...The era of mobile Internet is coming, broadband digital communication technology is in the stage of continuous development and progress, with us moving towards the era of mobile Internet. This paper first analyzes the connotation and characteristics of broadband digital communication technology, then analyzes the concept of signaling and multi-channel communication technology, establishes a wide range of digital communication receiving channel model that can perform high performance, and discusses simulation. Finally, in view of this communication technology, the development of the possible realization of their own prospects in the future, for the development of broadband digital communication technology and practical application to provide relevant data support.展开更多
With the rapid development of digital communication and the widespread use of the Internet of Things,multi-view image compression has attracted increasing attention as a fundamental technology for image data communica...With the rapid development of digital communication and the widespread use of the Internet of Things,multi-view image compression has attracted increasing attention as a fundamental technology for image data communication.Multi-view image compression aims to improve compression efficiency by leveraging correlations between images.However,the requirement of synchronization and inter-image communication at the encoder side poses significant challenges,especially for constrained devices.In this study,we introduce a novel distributed image compression model based on the attention mechanism to address the challenges associated with the availability of side information only during decoding.Our model integrates an encoder network,a quantization module,and a decoder network,to ensure both high compression performance and high-quality image reconstruction.The encoder uses a deep Convolutional Neural Network(CNN)to extract high-level features from the input image,which then pass through the quantization module for further compression before undergoing lossless entropy coding.The decoder of our model consists of three main components that allow us to fully exploit the information within and between images on the decoder side.Specifically,we first introduce a channel-spatial attention module to capture and refine information within individual image feature maps.Second,we employ a semi-coupled convolution module to extract both shared and specific information in images.Finally,a cross-attention module is employed to fuse mutual information extracted from side information.The effectiveness of our model is validated on various datasets,including KITTI Stereo and Cityscapes.The results highlight the superior compression capabilities of our method,surpassing state-of-the-art techniques.展开更多
A new digital communication technology based on the Phase-Offset Overlapped Waves (POOW) has been introduced in this letter. The waves can be considered as a special multicarrier different from traditional ones. The s...A new digital communication technology based on the Phase-Offset Overlapped Waves (POOW) has been introduced in this letter. The waves can be considered as a special multicarrier different from traditional ones. The sub-waves in a coded word's period of the POOW are sine waves and have the same frequencies, but different starting phases. The most important characteristic is that these sub-waves are the piecewise functions and not orthogonal in a code word period. The decoding can be implemented by solving a linear equation group. This code has very high efficiency and thus the data transmission rate is increased greatly.展开更多
Digital Communications, in relation to wireless networks, have taken off in recent years due to the expanding need to communicate faster and more efficiently. A popular way to achieve this is by using wireless Multipl...Digital Communications, in relation to wireless networks, have taken off in recent years due to the expanding need to communicate faster and more efficiently. A popular way to achieve this is by using wireless Multiple Input Multiple Output (MIMO) communication systems. MIMO systems utilize Space Time Block Codes (STBC) as one of the leading ways to obtain higher data rates with limited bandwidth and power. With several STBC methods currently available, this paper analyzes simulations using Orthogonal Space Time Block Codes (OSTBC) in Rayleigh fading channels to evaluate the performance of MIMO systems. The selection to use a Rayleigh fading channel as a model for a non-line-of-sight (nLOS) environment is selected to mimic installations where a large number of signal paths and reflections are expected. All simulations are coded, generated and plotted using MATLAB resulting in graphical data representing the bit-error rate (BER) to signal-to-noise ratio (Eb/N<sub>0</sub>) or SNR. Each simulation captures how different configurations of key variables including code rate, diversity and antenna count can impact system performance. Four modulation schemes (BPSK, QPSK, 16-QAM and 64-QAM) are included in each simulation. Conclusive evidence based upon these simulations suggests higher diversity gains were achieved with a greater number of antennas. The most significant factor for increasing system performance was using a lower count of transmit antennas with a higher count of receive antennas.展开更多
The expansion of smart cities,facilitated by digital communications,has resulted in an enhancement of the quality of life and satisfaction among residents.The Internet of Things(IoT)continually generates vast amounts ...The expansion of smart cities,facilitated by digital communications,has resulted in an enhancement of the quality of life and satisfaction among residents.The Internet of Things(IoT)continually generates vast amounts of data,which is subsequently analyzed to offer services to residents.The growth and development of IoT have given rise to a new paradigm.A smart city possesses the ability to consistently monitor and utilize the physical environment,providing intelligent services such as energy,transportation,healthcare,and entertainment for both residents and visitors.Research on the security and privacy of smart cities is increasingly prevalent.These studies highlight the cybersecurity risks and the challenges faced by smart city infrastructure in handling and managing personal data.To effectively uphold individuals’security and privacy,developers of smart cities must earn the trust of the public.In this article,we delve into the realms of privacy and security within smart city applications.Our comprehensive study commences by introducing architecture and various applications tailored to smart cities.Then,concerns surrounding security and privacy within these applications are thoroughly explored subsequently.Following that,we delve into several research endeavors dedicated to addressing security and privacy issues within smart city applications.Finally,we emphasize our methodology and present a case study illustrating privacy and security in smart city contexts.Our proposal consists of defining an Artificial Intelligence(AI)based framework that allows:Thoroughly documenting penetration attempts and cyberattacks;promptly detecting any deviations from security standards;monitoring malicious behaviors and accurately tracing their sources;and establishing strong controls to effectively repel and prevent such threats.Experimental results using the Edge-IIoTset(Edge Industrial Internet of Things Security Evaluation Test)dataset demonstrated good accuracy.They were compared to related state-of-theart works,which highlight the relevance of our proposal.展开更多
in this paper a chaotic secure communication System using a feedback controlling subsystem is presented.The transmitter and the receiver are built with Chua's circuits.We find that,using feedback controlling,the t...in this paper a chaotic secure communication System using a feedback controlling subsystem is presented.The transmitter and the receiver are built with Chua's circuits.We find that,using feedback controlling,the time for the receiver to obtain the Synchronization with the transmitter can be obviously decreased.Thecorrelation between the time and the feedback coefficient is presented at the end of this paper.展开更多
基金supported by National ScienceFoundation Programs(60536020,60723002)"973"State Key Basic Research Programs(2006CB302800,2006CB921106)
文摘An electro-absorption(EA)modulator is one of key components for optical fiber communications due to the high speed,small size,low voltage and integration ability with other semiconductor devices.A 40 Gb/s InGaAsP/InP multiplequantum-well(MQW)EA modulator monolithically integrated with a semiconductor optical amplifier(SOA)was fabricated for digital communications.The modulator capacitance was reduced to obtain 40 GHz bandwidth,and the SOA section helped reduce the insertion loss from 18 dB to 3 dB.InGaAlAs/InP MQW EA modulators have also been fabricated and characterized for analog optical fiber communications.A low driving voltage of 2.7 V and high spurious free dynamic range of 107 dB·Hz2/3 were estimated by static and dynamic measurements.
基金the "Program for Promoting Maritime Economies with Science and Technology" in Tianjin，the National Natural Science Foundation of China，the Tianjin Research Program of Application Foundation and Advanced Technology，the National Science and Technology Major Project，Seed Foundation of Tianjin University
文摘This paper summarizes the requirements for modem maritime wireless communication networks in the marine environments including the sea- to-sea and sea-to-shore communication scenarios. The existing maritime wireless communication sys- tems are presented and the development of the state-of-the-art maritime communication systems is surveyed. Furthermore, a hierarchical and integrated maritime network architecture is proposed to satisfy the increasing various classes of services which demand different Quality of Service （QoS）. Finally, the open issues for further development of maritime communications are identified.
基金supported by the National Natural Science Foundation of China(61771154)the Fundamental Research Funds for the Central Universities(3072022CF0601)supported by Key Laboratory of Advanced Marine Communication and Information Technology,Ministry of Industry and Information Technology,Harbin Engineering University,Harbin,China.
文摘As modern communication technology advances apace,the digital communication signals identification plays an important role in cognitive radio networks,the communication monitoring and management systems.AI has become a promising solution to this problem due to its powerful modeling capability,which has become a consensus in academia and industry.However,because of the data-dependence and inexplicability of AI models and the openness of electromagnetic space,the physical layer digital communication signals identification model is threatened by adversarial attacks.Adversarial examples pose a common threat to AI models,where well-designed and slight perturbations added to input data can cause wrong results.Therefore,the security of AI models for the digital communication signals identification is the premise of its efficient and credible applications.In this paper,we first launch adversarial attacks on the end-to-end AI model for automatic modulation classifi-cation,and then we explain and present three defense mechanisms based on the adversarial principle.Next we present more detailed adversarial indicators to evaluate attack and defense behavior.Finally,a demonstration verification system is developed to show that the adversarial attack is a real threat to the digital communication signals identification model,which should be paid more attention in future research.
基金The project supported by Natural Science Foundation of Jiangsu Province of China under Grant No.BK2001138
文摘The digital communication in a system of two multi-mode solid state chaotic lasers is investigated theoretically. If the usual method working well in a single-mode laser system is applied to a multi-mode laser system, the memory effect of the two nearest digits can cause high rate of mistakes when the digits are decoded through the subtraction of receiver output from the transmittal. By introducing the deviations of two nearest maximum and minimum fluctuationsof the signal to decode the digit, the message can be decoded correctly. Also, this communication method does not critically depend on the quality of the chaotic synchronization of the two multi-mode lasers.
文摘The low voltage powerline is becoming a powerful solution to home network, building automation, and internet access as a result of its wide distribution, easy access and little maintenance. The character of powerline channel is very complicated because it is an open net. This article analysed the character of the powerline channel,introduced the basics of OFDM(Orthogonal Frequency Division Multiplexing), and studied the OFDM applied into powerline high speed digital communication.
基金supported by the National Natural SciencFoundation of China(Nos.U1636125,61601027)
文摘For the performance issues of satellite transceivers suffering passive intermodulation interference,a novel and effective digital suppression algorithm is presented in this paper.In contrast to analog approaches,digital passive intermodulation（PIM） suppression approaches can be easily reconfigured and therefore are highly attractive for future satellite communication systems.A simplified model of nonlinear distortion from passive microwave devices is established in consideration of the memory effect.The multiple high-order PIM products falling into the receiving band can be described as a bilinear predictor function.A suppression algorithm based on a bilinear polynomial decorrelated adaptive filter is proposed for baseband digital signal processing.In consideration of the time-varying characteristics of passive intermodulation,this algorithm can achieve the rapidness of online interference estimation and low complexity with less consumption of resources.Numerical simulation results show that the algorithm can effectively compensate the passive intermodulation interference,and achieve a high signal-to-interference ratio gain.
基金a phased achievement of the research project“Research on the Basic Issues of Digital Rule of Law from the Perspective of System Theory”(Project Approval Number 22AZD149)。
文摘The three core issues in the“digital human rights”debate are whether“digital human rights”are possible,necessary,and feasible.Both sides of the debate focus on discovering the value of“digital human rights”to individuals from a semantic level,but ignore the significance of“digital human rights”to the whole society and its subsystems at the level of social structure.By introducing Niklas Luhmann's System Theory,this observation blind spot can be eliminated.Fundamental rights are devoted to directly shaping not a physiological-psychological“individual”as a social environment but a social“person”that can be included by social systems.It is clear that digital human rights are the right to participate in digital communication of a“human”as a“person”,so they are possible in terms of conceptual definition.Digital human rights can help“people”lower the threshold for participation in digital communication,limit the excessive expansion of social systems,and promote the free and complete expression of body and mind,so they are necessary for social functions.There are limitations in the existing two ideas of“incorporating digital human rights into the constitution”.Based on the new construction idea of System Theory of Law,digital human rights as the right to participate in digital communication can be typified into digital communication in social sub-fields such as politics,economy,science,and art.The right to participate constructs a complete digital human rights system,making it feasible on the basis of the constitution.
文摘In the field of intangible cultural heritage＇ s digital protection, a lot of research work has been made by all countries in the world, while the research on the digital commuuication of intangible cultural heritage is few and especially rarely seen in China. Under the premise, in this paper, the factors influencing intangible cultural heritage in the communication process are analyzed based on the information characteristics of intangible cultural heritage and the advantages of I-Space framework model in researching information transfer. Also, combined with the birch bark making technology in Heilongjiang province, the knowledge-based and signified communication strategy of intangible cultural heritage is proposed, aiming at providing new ideas for the researches on the digital communication of intangible cultural heritage.
基金Project supported by the Natural Science Foundation of Jiangsu Province, China （Grant No BK2001138）.
文摘The digital communication of two-dimensional messages is investigated when two solid state multi-mode chaotic lasers are employed in a master-slave configuration. By introducing the time derivative of intensity difference between the receiver （carrier） and the transmittal （carrier plus signal）, several signals can be encoded into a single pulse. If one signal contains several binary bits, two-dimensional messages in the form of a matrix can be encoded and transmitted on a single pulse. With these improvements in secure communications using chaotic multi-mode lasers, not only the transmission rate can be increased but also the privacy can be enhanced greatly.
基金“Academic Project Fund of Beijing Key Marxist College of Communication University of China”(012010040201)“Political Science Thesis Workshop for Graduate Students of Communication University of China”(JG229071).
文摘Karl Marx and Friedrich Engels introduced the theory of spiritual communication in their influential work,The German Ideology,thereby establishing the Marxist perspective on communication.This theory has a distinct historical context,meaning,and significance.As society advances,driven by the proliferation of commodity-based economies and advancements in science and technology,humanity has entered the digital information age.The prevailing mode of communication in this era,centered around the Internet and big data,brings great convenience to society but also raises concerns about the potential alienation of both subjective and objective aspects of communication,as well as social relationships.Against this backdrop,the rethinking of Marx’s communication theory in the 21st century provides a logical framework and theoretical basis for critiquing the contemporary form of spiritual communication through the digital communication of the information age.
文摘This article analyzes the concentration of production and distribution of information, from the analysis of the news in major international news agencies.The biopolitics is more and more interconnected to social, cultural, economical, and political matters, which led us to see in the contemporary scenario the creation of new forms of social organization which will determine how we interact with each other and how we face the world. Additionally, questions emerge about the usage of the means of communication, particularly those related to Technology of Communication and Information （TICs）. The influence of the media over the social-cultural activities tends to create homogenizations of senses, aiming a planetary visibility in a process that can not only disfigure but destroy many symbolic representations and cultural forms. On the other hand, globalization tends to, instead of minimize the differences in the world, ended up creating new conflicts that, through the usage of new technologies of communication, expresses and articulate themselves.
文摘Along with the mature development of the domestic computer technology and communication technology, it is an inevitable trend to integrate the two major information technologies together in the future reform of the social communication model. Under this background, the principle of digital communication is introduced first in this paper, and accordingly the role of the communication network resources sharing is analyzed, and finally the sharing management of digital communication network resources is proposed. Hopefully. this paper can play a help in the future subsequent study.
文摘Along with the mature development of the domestic computer technology and communication technology, it is an inevitable trend to integrate the two major information teclmologies together in the future reform of the social communication model. Under this background, the principle of digital co,nmunication is introduced first in this paper, and accordingly the role of the communication network resources sharing is analyzed, and finally the sharing management of digital communication network resources is proposed. Hopefully, this paper can play a help in the future subsequent study.
文摘The era of mobile Internet is coming, broadband digital communication technology is in the stage of continuous development and progress, with us moving towards the era of mobile Internet. This paper first analyzes the connotation and characteristics of broadband digital communication technology, then analyzes the concept of signaling and multi-channel communication technology, establishes a wide range of digital communication receiving channel model that can perform high performance, and discusses simulation. Finally, in view of this communication technology, the development of the possible realization of their own prospects in the future, for the development of broadband digital communication technology and practical application to provide relevant data support.
基金supported by the National Natural Science Foundation of China(Key Program)(No.11932013)the Tianjin Science and Technology Plan Project(No.22PTZWHZ00040)。
文摘With the rapid development of digital communication and the widespread use of the Internet of Things,multi-view image compression has attracted increasing attention as a fundamental technology for image data communication.Multi-view image compression aims to improve compression efficiency by leveraging correlations between images.However,the requirement of synchronization and inter-image communication at the encoder side poses significant challenges,especially for constrained devices.In this study,we introduce a novel distributed image compression model based on the attention mechanism to address the challenges associated with the availability of side information only during decoding.Our model integrates an encoder network,a quantization module,and a decoder network,to ensure both high compression performance and high-quality image reconstruction.The encoder uses a deep Convolutional Neural Network(CNN)to extract high-level features from the input image,which then pass through the quantization module for further compression before undergoing lossless entropy coding.The decoder of our model consists of three main components that allow us to fully exploit the information within and between images on the decoder side.Specifically,we first introduce a channel-spatial attention module to capture and refine information within individual image feature maps.Second,we employ a semi-coupled convolution module to extract both shared and specific information in images.Finally,a cross-attention module is employed to fuse mutual information extracted from side information.The effectiveness of our model is validated on various datasets,including KITTI Stereo and Cityscapes.The results highlight the superior compression capabilities of our method,surpassing state-of-the-art techniques.
文摘A new digital communication technology based on the Phase-Offset Overlapped Waves (POOW) has been introduced in this letter. The waves can be considered as a special multicarrier different from traditional ones. The sub-waves in a coded word's period of the POOW are sine waves and have the same frequencies, but different starting phases. The most important characteristic is that these sub-waves are the piecewise functions and not orthogonal in a code word period. The decoding can be implemented by solving a linear equation group. This code has very high efficiency and thus the data transmission rate is increased greatly.
文摘Digital Communications, in relation to wireless networks, have taken off in recent years due to the expanding need to communicate faster and more efficiently. A popular way to achieve this is by using wireless Multiple Input Multiple Output (MIMO) communication systems. MIMO systems utilize Space Time Block Codes (STBC) as one of the leading ways to obtain higher data rates with limited bandwidth and power. With several STBC methods currently available, this paper analyzes simulations using Orthogonal Space Time Block Codes (OSTBC) in Rayleigh fading channels to evaluate the performance of MIMO systems. The selection to use a Rayleigh fading channel as a model for a non-line-of-sight (nLOS) environment is selected to mimic installations where a large number of signal paths and reflections are expected. All simulations are coded, generated and plotted using MATLAB resulting in graphical data representing the bit-error rate (BER) to signal-to-noise ratio (Eb/N<sub>0</sub>) or SNR. Each simulation captures how different configurations of key variables including code rate, diversity and antenna count can impact system performance. Four modulation schemes (BPSK, QPSK, 16-QAM and 64-QAM) are included in each simulation. Conclusive evidence based upon these simulations suggests higher diversity gains were achieved with a greater number of antennas. The most significant factor for increasing system performance was using a lower count of transmit antennas with a higher count of receive antennas.
文摘The expansion of smart cities,facilitated by digital communications,has resulted in an enhancement of the quality of life and satisfaction among residents.The Internet of Things(IoT)continually generates vast amounts of data,which is subsequently analyzed to offer services to residents.The growth and development of IoT have given rise to a new paradigm.A smart city possesses the ability to consistently monitor and utilize the physical environment,providing intelligent services such as energy,transportation,healthcare,and entertainment for both residents and visitors.Research on the security and privacy of smart cities is increasingly prevalent.These studies highlight the cybersecurity risks and the challenges faced by smart city infrastructure in handling and managing personal data.To effectively uphold individuals’security and privacy,developers of smart cities must earn the trust of the public.In this article,we delve into the realms of privacy and security within smart city applications.Our comprehensive study commences by introducing architecture and various applications tailored to smart cities.Then,concerns surrounding security and privacy within these applications are thoroughly explored subsequently.Following that,we delve into several research endeavors dedicated to addressing security and privacy issues within smart city applications.Finally,we emphasize our methodology and present a case study illustrating privacy and security in smart city contexts.Our proposal consists of defining an Artificial Intelligence(AI)based framework that allows:Thoroughly documenting penetration attempts and cyberattacks;promptly detecting any deviations from security standards;monitoring malicious behaviors and accurately tracing their sources;and establishing strong controls to effectively repel and prevent such threats.Experimental results using the Edge-IIoTset(Edge Industrial Internet of Things Security Evaluation Test)dataset demonstrated good accuracy.They were compared to related state-of-theart works,which highlight the relevance of our proposal.
文摘in this paper a chaotic secure communication System using a feedback controlling subsystem is presented.The transmitter and the receiver are built with Chua's circuits.We find that,using feedback controlling,the time for the receiver to obtain the Synchronization with the transmitter can be obviously decreased.Thecorrelation between the time and the feedback coefficient is presented at the end of this paper.
