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
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
The increasing prevalence of technology in society has an impact on young people’s language use and development. Greeklish is the writing of Greek texts using the Latin instead of the Greek alphabet, a practice known...The increasing prevalence of technology in society has an impact on young people’s language use and development. Greeklish is the writing of Greek texts using the Latin instead of the Greek alphabet, a practice known as Latinization, also employed for many non-latin alphabet languages. The primary aim of this research is to evaluate the effect of Greeklish on reading time. A sample of 732 young Greeks were asked about their habits when communicating through e-mail and social media with their friends and they then participated in an experiment in which they were asked to read and understand two short texts, one written in Greek and the other in Greeklish. The findings of the research show that nearly one third of the participants use Greeklish. The results of the experiment conducted reveal that understanding is not affected by the alphabet used but reading Greeklish is significantly more time consuming than reading Greek independently of the sex and the familiarity of the participants with Greeklish. The findings suggest that amending social and communication media with software utilities related to Latinization such as language identifiers and converters may reduce reading time and thus facilitate written communication among the users.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
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
Since Pulse Code Modulation emerged in 1937, digitized speech has experienced rapid development due to its outstanding voice quality, reliability, robustness and security in communication. But how to reduce channel wi...Since Pulse Code Modulation emerged in 1937, digitized speech has experienced rapid development due to its outstanding voice quality, reliability, robustness and security in communication. But how to reduce channel width without loss of speech quality remains a crucial problem in speech coding theory. A new full-duplex digital speech communication system based on the Vocoder of AMBE-1000(TM) and microcontroller ATMEL 89C51 is introduced. It shows higher voice quality than current mobile phone system with only a quarter of channel width needed for the latter. The prospective areas in which the system can be applied include satellite communication, IP Phone, virtual meeting and the most important, defence industry.展开更多
Digital technology has significantly facilitated the development of the cultural industry,and the cultural industry has also become one of the most important fields to which digital technology is applied.Conducting an...Digital technology has significantly facilitated the development of the cultural industry,and the cultural industry has also become one of the most important fields to which digital technology is applied.Conducting an analysis of how digital technology empowers consumers,creators,producers,social interaction and cultural communication can help us understand how it has improved the efficiency of the cultural industry,propelling digital contents into becoming the mainstay of the cultural industry and making digital communication the principal channel of cultural transmission.Digital technology has reshaped the structure of the cultural industry,leading to marked changes in the structure of cultural consumption,cultural production,the cultural market,and the proportion of domestic to foreign culture.However,whether this powerful digital technology will result in impressive technological results but lackluster cultural content remains a question.In fact,creative people's pursuit of cultural content and consumers'desire for such content will constantly give rise to outstanding cultural works with rich connotations and lasting influence in the digital era.The integration of digitization and technology can not only foster an open cultural plain filled with diverse and vibrant cultures,but can also create cultural peaks that will exhibit profound thought and superb artistic expression.展开更多
Two communication systems at W-band are introduced, including the system design, the modulation scheme, etc. TV delivery system delivers picture of quality meeting grade 4.5 over 8 km (no rain). Digital communicatio...Two communication systems at W-band are introduced, including the system design, the modulation scheme, etc. TV delivery system delivers picture of quality meeting grade 4.5 over 8 km (no rain). Digital communication system is capable of operating at data rates up to 8.448 Mb/s beyond 10 km under a BER of 10^-6 (clear).展开更多
The co-site interference exists in kinds of communication systems, especially in digital communication systems, also is one of the biggest threats "in electromagnetic compatibility (EMC) designation of the systems....The co-site interference exists in kinds of communication systems, especially in digital communication systems, also is one of the biggest threats "in electromagnetic compatibility (EMC) designation of the systems. Analyzing the co-site interference is an important process in achieving EMC performance of the system. Under the situation, the co-site interference simulation analysis of a vehicular digital communication system based on interference margin (IM) prediction method by bit error ratio (BER) was proposed in the paper. In the simulation analysis, some physical models of the vehicular communication system were established on SIMULINK environment, the upper limit of BER level for audio signals was defined as the IM, three different types of co-site interference was analyzed respectively, and the simulation results were obtained in the form of system interference bandwidth. From these results, the EMC performance evaluation of the vehicular communication system was predicted based on the IM prediction method. By comparing with the actual test results, the correctness of the simulation results was validated and the simulation analysis method can be used for reference by other communication systems was indicated.展开更多
VCSEL Injection locking is demonstrated to increase laser bandwidth and reduce non-linearity and chirp. All these properties enhance analog and digital modulation performance.
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
Recently, a lot of digital subscriber loop systems (DSL) and high rate digital subscriber loop systems (HDSL) have been deployed in digital subscriber access networks. Data echo canceller is extensively used in the D...Recently, a lot of digital subscriber loop systems (DSL) and high rate digital subscriber loop systems (HDSL) have been deployed in digital subscriber access networks. Data echo canceller is extensively used in the DSL and HDSL systems to realize full duplex transmission on twisted cable. In such systems, 2B1Q line code is adopted. Therefore, symbol rate is decreased and digital transmission systems get longer reach. In this paper, a performance evaluation method of the echo canceller is proposed based on an autocorrelation matrix of 2B1Q line code. Using this method, the formula of ratio of data signal to echo residual signal is obtained. According to the formula, the ratio of data signal to echo noise depends on FIR filter tap, convergence factor, adaptive algorithm and the correlation matrix of the line code. Computer simulation is carried out to verify theoretical analysis. The simulation results coincided with the theoretical formula in the process estimating the ratio of signal to noise.展开更多
After decades of living under oppressive dictatorships,the people of the Arab world are rising up against their countries’leadership.For over nine months now,we have been witnessing massive,large scale,and peaceful d...After decades of living under oppressive dictatorships,the people of the Arab world are rising up against their countries’leadership.For over nine months now,we have been witnessing massive,large scale,and peaceful demonstrations spreading all over the Arab Middle Eastern countries.These mass civic demonstrations have been given many names,including the Arab Spring,Arab uprising,turmoil,tumult,chaos,Arab awakening,Arab revolution,revolt,etc.It is a reform movement on the march that was first started in Tunisia,which moved to Egypt,and then swept across the region to include Yemen,Bahrain,Libya and Syria.Activists in the rest of the Arab world such as Algeria,Jordan,Kuwait,Morocco and Saudi Arabia,were also inspired by the revolts and calls for reform which had been sweeping the Arab world.Protesters and human rights groups from these countries congregate frequently at popular places and landmarks to protest against their regimes and call for political,economical and social reforms.展开更多
The Nyquist rate is a limit of transmission for traditional modulation methods from orthogonality restriction. Nonorthogonal modulation techniques (NMT) is proposed, which removes the orthogonality restriction, and ...The Nyquist rate is a limit of transmission for traditional modulation methods from orthogonality restriction. Nonorthogonal modulation techniques (NMT) is proposed, which removes the orthogonality restriction, and as a result, higher bandwidth ef- ficiency than the traditional methods can be achieved. First, the symbol error rate of NMT is introduced by using estimation theory. Then the relation between bandwidth efficiency and signal to noise ratio is discussed. Finally, a design instance of NMT is present and numerical experiment is made. This study explores for new modulation methods and points out a widened direction for modulation theory and applications.展开更多
The multipath fading channel,models are described in this paper in order to investigate their per-formance for digrtal radio transmissions. The simulation model for such fading channels are focused on thepoints as fol...The multipath fading channel,models are described in this paper in order to investigate their per-formance for digrtal radio transmissions. The simulation model for such fading channels are focused on thepoints as follows: 1) Optimal signal desigu; 2) High-performance receiver design; 3) Communication systemperformance analysis; 4) Reliable high-performance equalizing schemes. Finally, the simulation program of64 QAM digital radio with an adaptive equalizer is desigued and the simulation results are presented to showsome conclusrons we have reached.展开更多
The guided scrambling code, a new line code, is deeply studied in this paper. The theory ts provedthat the output characteristics of guided scrambling code is similar to that of 'Mite Notse' in some condi-tio...The guided scrambling code, a new line code, is deeply studied in this paper. The theory ts provedthat the output characteristics of guided scrambling code is similar to that of 'Mite Notse' in some condi-tions. The results of the theory analysis accord with that of fhe experunent. So, the system with the guidedscrambling code would have good performance.展开更多
This paper examines the current trends, challenges, and issues facing all libraries, and discusses the strategies that academic libraries, in particular, are taking to transform their services, manage their organizati...This paper examines the current trends, challenges, and issues facing all libraries, and discusses the strategies that academic libraries, in particular, are taking to transform their services, manage their organizations, and preserve their digital assets. It demonstrates how a network of distributed services, resource sharing, co-investment, and access integration contributes to sustainable library development.展开更多
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.
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.
文摘The increasing prevalence of technology in society has an impact on young people’s language use and development. Greeklish is the writing of Greek texts using the Latin instead of the Greek alphabet, a practice known as Latinization, also employed for many non-latin alphabet languages. The primary aim of this research is to evaluate the effect of Greeklish on reading time. A sample of 732 young Greeks were asked about their habits when communicating through e-mail and social media with their friends and they then participated in an experiment in which they were asked to read and understand two short texts, one written in Greek and the other in Greeklish. The findings of the research show that nearly one third of the participants use Greeklish. The results of the experiment conducted reveal that understanding is not affected by the alphabet used but reading Greeklish is significantly more time consuming than reading Greek independently of the sex and the familiarity of the participants with Greeklish. The findings suggest that amending social and communication media with software utilities related to Latinization such as language identifiers and converters may reduce reading time and thus facilitate written communication among the users.
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.
文摘Since Pulse Code Modulation emerged in 1937, digitized speech has experienced rapid development due to its outstanding voice quality, reliability, robustness and security in communication. But how to reduce channel width without loss of speech quality remains a crucial problem in speech coding theory. A new full-duplex digital speech communication system based on the Vocoder of AMBE-1000(TM) and microcontroller ATMEL 89C51 is introduced. It shows higher voice quality than current mobile phone system with only a quarter of channel width needed for the latter. The prospective areas in which the system can be applied include satellite communication, IP Phone, virtual meeting and the most important, defence industry.
文摘Digital technology has significantly facilitated the development of the cultural industry,and the cultural industry has also become one of the most important fields to which digital technology is applied.Conducting an analysis of how digital technology empowers consumers,creators,producers,social interaction and cultural communication can help us understand how it has improved the efficiency of the cultural industry,propelling digital contents into becoming the mainstay of the cultural industry and making digital communication the principal channel of cultural transmission.Digital technology has reshaped the structure of the cultural industry,leading to marked changes in the structure of cultural consumption,cultural production,the cultural market,and the proportion of domestic to foreign culture.However,whether this powerful digital technology will result in impressive technological results but lackluster cultural content remains a question.In fact,creative people's pursuit of cultural content and consumers'desire for such content will constantly give rise to outstanding cultural works with rich connotations and lasting influence in the digital era.The integration of digitization and technology can not only foster an open cultural plain filled with diverse and vibrant cultures,but can also create cultural peaks that will exhibit profound thought and superb artistic expression.
文摘Two communication systems at W-band are introduced, including the system design, the modulation scheme, etc. TV delivery system delivers picture of quality meeting grade 4.5 over 8 km (no rain). Digital communication system is capable of operating at data rates up to 8.448 Mb/s beyond 10 km under a BER of 10^-6 (clear).
基金supported by EMC&EMB Lab of Beijing University of Posts and Telecommunications and Beijing Institute of Astronautic System Engineeringthe National Natural Science Foundation of China(61171051)
文摘The co-site interference exists in kinds of communication systems, especially in digital communication systems, also is one of the biggest threats "in electromagnetic compatibility (EMC) designation of the systems. Analyzing the co-site interference is an important process in achieving EMC performance of the system. Under the situation, the co-site interference simulation analysis of a vehicular digital communication system based on interference margin (IM) prediction method by bit error ratio (BER) was proposed in the paper. In the simulation analysis, some physical models of the vehicular communication system were established on SIMULINK environment, the upper limit of BER level for audio signals was defined as the IM, three different types of co-site interference was analyzed respectively, and the simulation results were obtained in the form of system interference bandwidth. From these results, the EMC performance evaluation of the vehicular communication system was predicted based on the IM prediction method. By comparing with the actual test results, the correctness of the simulation results was validated and the simulation analysis method can be used for reference by other communication systems was indicated.
文摘VCSEL Injection locking is demonstrated to increase laser bandwidth and reduce non-linearity and chirp. All these properties enhance analog and digital modulation performance.
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.
文摘Recently, a lot of digital subscriber loop systems (DSL) and high rate digital subscriber loop systems (HDSL) have been deployed in digital subscriber access networks. Data echo canceller is extensively used in the DSL and HDSL systems to realize full duplex transmission on twisted cable. In such systems, 2B1Q line code is adopted. Therefore, symbol rate is decreased and digital transmission systems get longer reach. In this paper, a performance evaluation method of the echo canceller is proposed based on an autocorrelation matrix of 2B1Q line code. Using this method, the formula of ratio of data signal to echo residual signal is obtained. According to the formula, the ratio of data signal to echo noise depends on FIR filter tap, convergence factor, adaptive algorithm and the correlation matrix of the line code. Computer simulation is carried out to verify theoretical analysis. The simulation results coincided with the theoretical formula in the process estimating the ratio of signal to noise.
文摘After decades of living under oppressive dictatorships,the people of the Arab world are rising up against their countries’leadership.For over nine months now,we have been witnessing massive,large scale,and peaceful demonstrations spreading all over the Arab Middle Eastern countries.These mass civic demonstrations have been given many names,including the Arab Spring,Arab uprising,turmoil,tumult,chaos,Arab awakening,Arab revolution,revolt,etc.It is a reform movement on the march that was first started in Tunisia,which moved to Egypt,and then swept across the region to include Yemen,Bahrain,Libya and Syria.Activists in the rest of the Arab world such as Algeria,Jordan,Kuwait,Morocco and Saudi Arabia,were also inspired by the revolts and calls for reform which had been sweeping the Arab world.Protesters and human rights groups from these countries congregate frequently at popular places and landmarks to protest against their regimes and call for political,economical and social reforms.
基金the National Natural Science Foundation of China (Grant No. 60272017)
文摘The Nyquist rate is a limit of transmission for traditional modulation methods from orthogonality restriction. Nonorthogonal modulation techniques (NMT) is proposed, which removes the orthogonality restriction, and as a result, higher bandwidth ef- ficiency than the traditional methods can be achieved. First, the symbol error rate of NMT is introduced by using estimation theory. Then the relation between bandwidth efficiency and signal to noise ratio is discussed. Finally, a design instance of NMT is present and numerical experiment is made. This study explores for new modulation methods and points out a widened direction for modulation theory and applications.
文摘The multipath fading channel,models are described in this paper in order to investigate their per-formance for digrtal radio transmissions. The simulation model for such fading channels are focused on thepoints as follows: 1) Optimal signal desigu; 2) High-performance receiver design; 3) Communication systemperformance analysis; 4) Reliable high-performance equalizing schemes. Finally, the simulation program of64 QAM digital radio with an adaptive equalizer is desigued and the simulation results are presented to showsome conclusrons we have reached.
文摘The guided scrambling code, a new line code, is deeply studied in this paper. The theory ts provedthat the output characteristics of guided scrambling code is similar to that of 'Mite Notse' in some condi-tions. The results of the theory analysis accord with that of fhe experunent. So, the system with the guidedscrambling code would have good performance.
文摘This paper examines the current trends, challenges, and issues facing all libraries, and discusses the strategies that academic libraries, in particular, are taking to transform their services, manage their organizations, and preserve their digital assets. It demonstrates how a network of distributed services, resource sharing, co-investment, and access integration contributes to sustainable library development.