Code converters are essential in digital nano communication;therefore,a low-complexity optimal QCA layout for a BCD to Excess-3 code converter has been proposed in this paper.A QCA clockphase-based design technique wa...Code converters are essential in digital nano communication;therefore,a low-complexity optimal QCA layout for a BCD to Excess-3 code converter has been proposed in this paper.A QCA clockphase-based design technique was adopted to investigate integration with other complicated circuits.Using a unique XOR gate,the recommended circuit’s cell complexity has been decreased.The findings produced using the QCADesigner-2.0.3,a reliable simulation tool,prove the effectiveness of the current structure over earlier designs by considering the number of cells deployed,the area occupied,and the latency as design metrics.In addition,the popular tool QCAPro was used to estimate the energy dissipation of the proposed design.The proposed technique reduces the occupied space by∼40%,improves cell complexity by∼20%,and reduces energy dissipation by∼1.8 times(atγ=1.5EK)compared to the current scalable designs.This paper also studied the suggested structure’s energy dissipation and compared it to existing works for a better performance evaluation.展开更多
Gap junction(GJ)has been indicated to have an intimate correlation with adhesion junction.However,the direct interaction between them partially remains elusive.In the current study,we aimed to elucidate the role of N-...Gap junction(GJ)has been indicated to have an intimate correlation with adhesion junction.However,the direct interaction between them partially remains elusive.In the current study,we aimed to elucidate the role of N-cadherin,one of the core components in adhesion junction,in mediating connexin 43,one of the functional constituents in gap junction,via transforming growth factor-β1(TGF-β1)induction in osteoblasts.We first elucidated the expressions of N-cadherin induced by TGF-β1 and also confirmed the upregulation of Cx43,and the enhancement of functional gap junctional intercellular communication(GJIC)triggered by TGF-β1 in both primary osteoblasts and MC3T3 cell line.Colocalization analysis and Co-IP experimentation showed that N-cadherin interacts with Cx43 at the site of cell–cell contact.Knockdown of N-cadherin by siRNA interference decreased the Cx43 expression and abolished the promoting effect of TGF-β1 on Cx43.Functional GJICs in living primary osteoblasts and MC3T3 cell line were also reduced.TGF-β1-induced increase in N-cadherin and Cx43 was via Smad3 activation,whereas knockdown of Smad3 signaling by using siRNA decreased the expressions of both N-cadherin and Cx43.Overall,these data indicate the direct interactions between N-cadherin and Cx43,and reveal the intervention of adhesion junction in functional gap junction in living osteoblasts.展开更多
With the increasing maritime activities and the rapidly developing maritime economy, the fifth-generation(5G) mobile communication system is expected to be deployed at the ocean. New technologies need to be explored t...With the increasing maritime activities and the rapidly developing maritime economy, the fifth-generation(5G) mobile communication system is expected to be deployed at the ocean. New technologies need to be explored to meet the requirements of ultra-reliable and low latency communications(URLLC) in the maritime communication network(MCN). Mobile edge computing(MEC) can achieve high energy efficiency in MCN at the cost of suffering from high control plane latency and low reliability. In terms of this issue, the mobile edge communications, computing, and caching(MEC3) technology is proposed to sink mobile computing, network control, and storage to the edge of the network. New methods that enable resource-efficient configurations and reduce redundant data transmissions can enable the reliable implementation of computing-intension and latency-sensitive applications. The key technologies of MEC3 to enable URLLC are analyzed and optimized in MCN. The best response-based offloading algorithm(BROA) is adopted to optimize task offloading. The simulation results show that the task latency can be decreased by 26.5’ ms, and the energy consumption in terminal users can be reduced to 66.6%.展开更多
Since 2000 mobile communications have undergoneextremely fast growth in Russia with a penetration ratefar surpassing China. In October 2007, Russian 3Gmobile communications networks were formallylaunched for commercia...Since 2000 mobile communications have undergoneextremely fast growth in Russia with a penetration ratefar surpassing China. In October 2007, Russian 3Gmobile communications networks were formallylaunched for commercial operation. This article attempts to bring forth some suggestions for China’s 3Gmobile communications development through a studyof the Russian mobile migration process from 2G to 3G.展开更多
Turbo code has been shown to have ability to achieve performance that is close to Shannon limit. It has been adopted by various commercial communication systems. Both universal mobile telecommunications system (UMTS) ...Turbo code has been shown to have ability to achieve performance that is close to Shannon limit. It has been adopted by various commercial communication systems. Both universal mobile telecommunications system (UMTS) TDD and FDD have also employed turbo code as the error correction coding scheme. It outperforms convolutional code in large block size, but because of its time delay, it is often only used in the non-real-time service. In this paper, we discuss the encoder and decoder structure of turbo code in B3G mobile communication System. In addition, various decoding techniques, such as the Log-MAP, Max-log-MAP and SOVA algorithm for non-real-time service are deduced and compared. The performance results of decoder and algorithms in different configurations are also shown.展开更多
Compared with the services in 3G, services in Beyond 3G (B3G) have some distinctive characteristics such as the packet data services being the majority, more service types, larger scale of services, higher peak transm...Compared with the services in 3G, services in Beyond 3G (B3G) have some distinctive characteristics such as the packet data services being the majority, more service types, larger scale of services, higher peak transmission rate, enlarged range of transmission rates, more spatial and temporal distribution differences, and more service transmission requests occurring in fast moving vehicles. In order to meet the requirements of B3G services, the B3G systems must have great improvement in network architecture, air interface scheme, radio resource allocation strategy, frequency bands, and Radio Frequency (RF) technology etc. Therefore, the research of the B3G systems should focus on the theory of generalized cellular communications networks, theory of the Multiple Input Multiple Output (MIMO) wireless transmission system, matching of radio resources to new-type air interfaces, new iterative detection and adaptive link methods, and new-type antenna and RF technologies.展开更多
A 3D fan-out packaging method for the integration of 5G communication RF microsystem and antenna is studied.First of all,through the double-sided wiring technology on the glass wafer,the fabrication of 5G antenna arra...A 3D fan-out packaging method for the integration of 5G communication RF microsystem and antenna is studied.First of all,through the double-sided wiring technology on the glass wafer,the fabrication of 5G antenna array is realized.Then the low power devices such as through silicon via(TSV)transfer chips,filters and antenna tuners are flip-welded on the glass wafer,and the glass wafer is reformed into a wafer permanently bonded with glass and resin by the injection molding process with resin material.Finally,the thinning resin surface leaks out of the TSV transfer chip,the rewiring is carried out on the resin surface,and then the power amplifier,low-noise amplifier,power management and other devices are flip-welded on the resin wafer surface.A ball grid array(BGA)is implanted to form the final package.The loss of the RF transmission line is measured by using the RF millimeter wave probe table.The results show that the RF transmission loss from the chip end to the antenna end in the fan-out package is very small,and it is only 0.26 dB/mm when working in 60 GHz.A slot coupling antenna is designed on the glass wafer.The antenna can operate at 60 GHz and the maximum gain can reach 6 dB within the working bandwidth.This demonstration successfully provides a feasible solution for the 3D fan-out integration of RF microsystem and antenna in 5G communications.展开更多
A LM-3C carrier rocket at 0:53 Beijing time on December 25 was launched from the Xichang Satellite Launch Center,putting the Communications Technology Test Satellite 3 into its orbit.The satellite was developed by SAS...A LM-3C carrier rocket at 0:53 Beijing time on December 25 was launched from the Xichang Satellite Launch Center,putting the Communications Technology Test Satellite 3 into its orbit.The satellite was developed by SAST for demonstrating related technologies.展开更多
ONDA Communication SpA于巴塞罗那举办的3GSM全球会中发表新款3G DVB-H手机,此款手机采用思亚诺(Siano Mobile Silicon)的多重标准移动电视接收芯片,并由ONDACommunication SpA与中国最大综合通信制造上市公司中兴通讯(ZTE)共同...ONDA Communication SpA于巴塞罗那举办的3GSM全球会中发表新款3G DVB-H手机,此款手机采用思亚诺(Siano Mobile Silicon)的多重标准移动电视接收芯片,并由ONDACommunication SpA与中国最大综合通信制造上市公司中兴通讯(ZTE)共同开发而成。展开更多
At 23:18 Beijing time on January 5,a LM-3B carrier rocket lifted off from the Xichang Satellite Launch Center,sending a communication technology test satellite into its preset orbit.This successful launch was a good s...At 23:18 Beijing time on January 5,a LM-3B carrier rocket lifted off from the Xichang Satellite Launch Center,sending a communication technology test satellite into its preset orbit.This successful launch was a good start for China’s launch missions in 2017.The Communications Technology Test Satellite 2 was developed by the Shanghai Academy of Spaceflight Technology.It is a next-generation telecom-展开更多
This paper studies a multi-unmanned aerial vehicle(UAV)enabled wireless communication system,where multiple UAVs are employed to communicate with a group of ground terminals(GTs)in the presence of potential jammers.We...This paper studies a multi-unmanned aerial vehicle(UAV)enabled wireless communication system,where multiple UAVs are employed to communicate with a group of ground terminals(GTs)in the presence of potential jammers.We aim to maximize the throughput overall GTs by jointly optimizing the UAVs’trajectory,the GTs’scheduling and power allocation.Unlike most prior studies,we consider the UAVs’turning and climbing angle constraints,the UAVs’three-dimensional(3D)trajectory constraints,minimum UAV-to-UAV(U2U)distance constraint,and the GTs’transmit power requirements.However,the formulated problem is a mixed-integer non-convex problem and is intractable to work it out with conventional optimization methods.To tackle this difficulty,we propose an efficient robust iterative algorithm to decompose the original problem be three sub-problems and acquire the suboptimal solution via utilizing the block coordinate descent(BCD)method,successive convex approximation(SCA)technique,and S-procedure.Extensive simulation results show that our proposed robust iterative algorithm offers a substantial gain in the system performance compared with the benchmark algorithms.展开更多
This paper conducts a research on modulation characteristics of blue light-emitting diodes (LEDs) used in a visible-light communication (VLC) system. Through analysis of the modulation characteristics of LEDs with dif...This paper conducts a research on modulation characteristics of blue light-emitting diodes (LEDs) used in a visible-light communication (VLC) system. Through analysis of the modulation characteristics of LEDs with different emitting sizes, we find that there is a similar linear relationship between LED’s 3dB bandwidth and the operation current density. This experiment also shows that high series resistance is one major issue that limits our LED's modulation speed. To further improve the LED bandwidth, the resistance can be reduced by optimizing device layout as well as reducing material bulk resistance. Clearly, this study provides an approach to increase the modulation bandwidth of GaN-based LEDs for VLC systems.展开更多
The dilemma of modern mobile communications technology is analyzed. Aiming at some problems in the 3G systems, a new network architecture is proposed on the principle of mobile information sharing grid (MIS-Grid). The...The dilemma of modern mobile communications technology is analyzed. Aiming at some problems in the 3G systems, a new network architecture is proposed on the principle of mobile information sharing grid (MIS-Grid). The essence of MIS-Grid is to transfer the hot wide band information with cheap unidirectional broadcasting channels and the personalized services with relatively expensive interactive networks.展开更多
Avalanche photodetectors(APDs) featuring an avalanche multiplication region are vital for reaching high sensitivity and responsivity in optical transceivers. Waveguide-coupled Ge-on-Si separate absorption, charge, and...Avalanche photodetectors(APDs) featuring an avalanche multiplication region are vital for reaching high sensitivity and responsivity in optical transceivers. Waveguide-coupled Ge-on-Si separate absorption, charge, and multiplication(SACM)APDs are popular due to their straightforward fabrication process, low optical propagation loss, and high detection sensitivity in optical communications. This paper introduces a lateral SACM Ge-on-Si APD on a silicon-on-insulator(SOI) wafer, featuring a 10 μm-long, 0.5 μm-wide Ge layer at 1310 nm on a standard 8-inch silicon photonics platform. The dark current measures approximately 38.6 μA at-21 V, indicating a breakdown voltage greater than-21 V for the device. The APDs exhibit a unitgain responsivity of 0.5 A/W at-10 V. At-15 V, their responsivity reaches 2.98 and 2.91 A/W with input powers of-10 and-25 dBm, respectively. The device's 3-dB bandwidth is 15 GHz with an input power of-15 dBm and a gain is 11.68. Experimental results show a peak in impedance at high bias voltages, attributed to inductor and capacitor(LC) circuit resonance, enhancing frequency response. Furthermore, 20 Gbps eye diagrams at-21 V and-9 dBm input power reveal signal to noise ratio(SNRs) of 5.30. This lateral SACM APD, compatible with the stand complementary metal oxide semiconductor(CMOS) process,shows that utilizing the peaking effect at low optical power increases bandwidth.展开更多
In this paper,we consider a new spectrum sharing scenario for a cognitive relay network,where a secondary unmanned aerial vehicle(UAV)relay receives information from the ground secondary base station(SBS)and transmits...In this paper,we consider a new spectrum sharing scenario for a cognitive relay network,where a secondary unmanned aerial vehicle(UAV)relay receives information from the ground secondary base station(SBS)and transmits information to the ground secondary user(SU),coexisting with the primary users(PUs)at the same wireless frequency band.We investigate the optimization of the UAV relay’s three-dimensional(3D)trajectory to improve the communication throughput performance of the secondary network subject to the interference constraints of the PUs.The information throughput maximization problem is studied by jointly optimizing the UAV relay’s 3D trajectory and the transmit power of the SBS and the UAV,subject to the constraints on the velocity and elevation of the UAV relay,the maximum and average transmit power,and the information causality,as well as a set of interference temperature(IT)constraints.An efficient algorithm is proposed to solve the admittedly challenging non-convex problem by using the path discretization technique,the successive convex approximation technique and the alternating optimization method.Finally,simulation results are provided to show that our proposed design outperforms other benchmark schemes in terms of the throughput。展开更多
This paper applies the perspective of business ecosystem to mobile communications industry,trying to help mobile network operators improve their strategies in the era of the third generation mobile communications(3G)....This paper applies the perspective of business ecosystem to mobile communications industry,trying to help mobile network operators improve their strategies in the era of the third generation mobile communications(3G).According to the definition of the business ecosystem,the ecosystem structure of mobile network operators is analyzed.As an important hub in the ecosystem,mobile network operators are advised to take a keystone strategy.The key points of the strategy are summarized.Finally,suggestions for Chinese mobile network operators are given based on the analysis.展开更多
The main function of the power communication business is to monitor,control and manage the power communication network to ensure normal and stable operation of the power communication network.Commu-nication services r...The main function of the power communication business is to monitor,control and manage the power communication network to ensure normal and stable operation of the power communication network.Commu-nication services related to dispatching data networks and the transmission of fault information or feeder automation have high requirements for delay.If processing time is prolonged,a power business cascade reaction may be triggered.In order to solve the above problems,this paper establishes an edge object-linked agent business deployment model for power communication network to unify the management of data collection,resource allocation and task scheduling within the system,realizes the virtualization of object-linked agent computing resources through Docker container technology,designs the target model of network latency and energy consumption,and introduces A3C algorithm in deep reinforcement learning,improves it according to scene characteristics,and sets corresponding optimization strategies.Mini-mize network delay and energy consumption;At the same time,to ensure that sensitive power business is handled in time,this paper designs the business dispatch model and task migration model,and solves the problem of server failure.Finally,the corresponding simulation program is designed to verify the feasibility and validity of this method,and to compare it with other existing mechanisms.展开更多
文摘Code converters are essential in digital nano communication;therefore,a low-complexity optimal QCA layout for a BCD to Excess-3 code converter has been proposed in this paper.A QCA clockphase-based design technique was adopted to investigate integration with other complicated circuits.Using a unique XOR gate,the recommended circuit’s cell complexity has been decreased.The findings produced using the QCADesigner-2.0.3,a reliable simulation tool,prove the effectiveness of the current structure over earlier designs by considering the number of cells deployed,the area occupied,and the latency as design metrics.In addition,the popular tool QCAPro was used to estimate the energy dissipation of the proposed design.The proposed technique reduces the occupied space by∼40%,improves cell complexity by∼20%,and reduces energy dissipation by∼1.8 times(atγ=1.5EK)compared to the current scalable designs.This paper also studied the suggested structure’s energy dissipation and compared it to existing works for a better performance evaluation.
文摘Gap junction(GJ)has been indicated to have an intimate correlation with adhesion junction.However,the direct interaction between them partially remains elusive.In the current study,we aimed to elucidate the role of N-cadherin,one of the core components in adhesion junction,in mediating connexin 43,one of the functional constituents in gap junction,via transforming growth factor-β1(TGF-β1)induction in osteoblasts.We first elucidated the expressions of N-cadherin induced by TGF-β1 and also confirmed the upregulation of Cx43,and the enhancement of functional gap junctional intercellular communication(GJIC)triggered by TGF-β1 in both primary osteoblasts and MC3T3 cell line.Colocalization analysis and Co-IP experimentation showed that N-cadherin interacts with Cx43 at the site of cell–cell contact.Knockdown of N-cadherin by siRNA interference decreased the Cx43 expression and abolished the promoting effect of TGF-β1 on Cx43.Functional GJICs in living primary osteoblasts and MC3T3 cell line were also reduced.TGF-β1-induced increase in N-cadherin and Cx43 was via Smad3 activation,whereas knockdown of Smad3 signaling by using siRNA decreased the expressions of both N-cadherin and Cx43.Overall,these data indicate the direct interactions between N-cadherin and Cx43,and reveal the intervention of adhesion junction in functional gap junction in living osteoblasts.
基金the National S&T Major Project (No. 2018ZX03001011)the National Key R&D Program(No.2018YFB1801102)+1 种基金the National Natural Science Foundation of China (No. 61671072)the Beijing Natural Science Foundation (No. L192025)
文摘With the increasing maritime activities and the rapidly developing maritime economy, the fifth-generation(5G) mobile communication system is expected to be deployed at the ocean. New technologies need to be explored to meet the requirements of ultra-reliable and low latency communications(URLLC) in the maritime communication network(MCN). Mobile edge computing(MEC) can achieve high energy efficiency in MCN at the cost of suffering from high control plane latency and low reliability. In terms of this issue, the mobile edge communications, computing, and caching(MEC3) technology is proposed to sink mobile computing, network control, and storage to the edge of the network. New methods that enable resource-efficient configurations and reduce redundant data transmissions can enable the reliable implementation of computing-intension and latency-sensitive applications. The key technologies of MEC3 to enable URLLC are analyzed and optimized in MCN. The best response-based offloading algorithm(BROA) is adopted to optimize task offloading. The simulation results show that the task latency can be decreased by 26.5’ ms, and the energy consumption in terminal users can be reduced to 66.6%.
文摘Since 2000 mobile communications have undergoneextremely fast growth in Russia with a penetration ratefar surpassing China. In October 2007, Russian 3Gmobile communications networks were formallylaunched for commercial operation. This article attempts to bring forth some suggestions for China’s 3Gmobile communications development through a studyof the Russian mobile migration process from 2G to 3G.
文摘Turbo code has been shown to have ability to achieve performance that is close to Shannon limit. It has been adopted by various commercial communication systems. Both universal mobile telecommunications system (UMTS) TDD and FDD have also employed turbo code as the error correction coding scheme. It outperforms convolutional code in large block size, but because of its time delay, it is often only used in the non-real-time service. In this paper, we discuss the encoder and decoder structure of turbo code in B3G mobile communication System. In addition, various decoding techniques, such as the Log-MAP, Max-log-MAP and SOVA algorithm for non-real-time service are deduced and compared. The performance results of decoder and algorithms in different configurations are also shown.
基金Program ofNational Nature Science Foundation of China(No. 60496311) Project of National "863"Plan ofChina (No. 2005AA121052)
文摘Compared with the services in 3G, services in Beyond 3G (B3G) have some distinctive characteristics such as the packet data services being the majority, more service types, larger scale of services, higher peak transmission rate, enlarged range of transmission rates, more spatial and temporal distribution differences, and more service transmission requests occurring in fast moving vehicles. In order to meet the requirements of B3G services, the B3G systems must have great improvement in network architecture, air interface scheme, radio resource allocation strategy, frequency bands, and Radio Frequency (RF) technology etc. Therefore, the research of the B3G systems should focus on the theory of generalized cellular communications networks, theory of the Multiple Input Multiple Output (MIMO) wireless transmission system, matching of radio resources to new-type air interfaces, new iterative detection and adaptive link methods, and new-type antenna and RF technologies.
文摘A 3D fan-out packaging method for the integration of 5G communication RF microsystem and antenna is studied.First of all,through the double-sided wiring technology on the glass wafer,the fabrication of 5G antenna array is realized.Then the low power devices such as through silicon via(TSV)transfer chips,filters and antenna tuners are flip-welded on the glass wafer,and the glass wafer is reformed into a wafer permanently bonded with glass and resin by the injection molding process with resin material.Finally,the thinning resin surface leaks out of the TSV transfer chip,the rewiring is carried out on the resin surface,and then the power amplifier,low-noise amplifier,power management and other devices are flip-welded on the resin wafer surface.A ball grid array(BGA)is implanted to form the final package.The loss of the RF transmission line is measured by using the RF millimeter wave probe table.The results show that the RF transmission loss from the chip end to the antenna end in the fan-out package is very small,and it is only 0.26 dB/mm when working in 60 GHz.A slot coupling antenna is designed on the glass wafer.The antenna can operate at 60 GHz and the maximum gain can reach 6 dB within the working bandwidth.This demonstration successfully provides a feasible solution for the 3D fan-out integration of RF microsystem and antenna in 5G communications.
文摘A LM-3C carrier rocket at 0:53 Beijing time on December 25 was launched from the Xichang Satellite Launch Center,putting the Communications Technology Test Satellite 3 into its orbit.The satellite was developed by SAST for demonstrating related technologies.
文摘ONDA Communication SpA于巴塞罗那举办的3GSM全球会中发表新款3G DVB-H手机,此款手机采用思亚诺(Siano Mobile Silicon)的多重标准移动电视接收芯片,并由ONDACommunication SpA与中国最大综合通信制造上市公司中兴通讯(ZTE)共同开发而成。
文摘At 23:18 Beijing time on January 5,a LM-3B carrier rocket lifted off from the Xichang Satellite Launch Center,sending a communication technology test satellite into its preset orbit.This successful launch was a good start for China’s launch missions in 2017.The Communications Technology Test Satellite 2 was developed by the Shanghai Academy of Spaceflight Technology.It is a next-generation telecom-
文摘This paper studies a multi-unmanned aerial vehicle(UAV)enabled wireless communication system,where multiple UAVs are employed to communicate with a group of ground terminals(GTs)in the presence of potential jammers.We aim to maximize the throughput overall GTs by jointly optimizing the UAVs’trajectory,the GTs’scheduling and power allocation.Unlike most prior studies,we consider the UAVs’turning and climbing angle constraints,the UAVs’three-dimensional(3D)trajectory constraints,minimum UAV-to-UAV(U2U)distance constraint,and the GTs’transmit power requirements.However,the formulated problem is a mixed-integer non-convex problem and is intractable to work it out with conventional optimization methods.To tackle this difficulty,we propose an efficient robust iterative algorithm to decompose the original problem be three sub-problems and acquire the suboptimal solution via utilizing the block coordinate descent(BCD)method,successive convex approximation(SCA)technique,and S-procedure.Extensive simulation results show that our proposed robust iterative algorithm offers a substantial gain in the system performance compared with the benchmark algorithms.
文摘This paper conducts a research on modulation characteristics of blue light-emitting diodes (LEDs) used in a visible-light communication (VLC) system. Through analysis of the modulation characteristics of LEDs with different emitting sizes, we find that there is a similar linear relationship between LED’s 3dB bandwidth and the operation current density. This experiment also shows that high series resistance is one major issue that limits our LED's modulation speed. To further improve the LED bandwidth, the resistance can be reduced by optimizing device layout as well as reducing material bulk resistance. Clearly, this study provides an approach to increase the modulation bandwidth of GaN-based LEDs for VLC systems.
基金Supported by the Foundation of National 863 Programme of China (No.2002AA121063) and the National Natural Science Foundation of China (No.60272014)
文摘The dilemma of modern mobile communications technology is analyzed. Aiming at some problems in the 3G systems, a new network architecture is proposed on the principle of mobile information sharing grid (MIS-Grid). The essence of MIS-Grid is to transfer the hot wide band information with cheap unidirectional broadcasting channels and the personalized services with relatively expensive interactive networks.
文摘Avalanche photodetectors(APDs) featuring an avalanche multiplication region are vital for reaching high sensitivity and responsivity in optical transceivers. Waveguide-coupled Ge-on-Si separate absorption, charge, and multiplication(SACM)APDs are popular due to their straightforward fabrication process, low optical propagation loss, and high detection sensitivity in optical communications. This paper introduces a lateral SACM Ge-on-Si APD on a silicon-on-insulator(SOI) wafer, featuring a 10 μm-long, 0.5 μm-wide Ge layer at 1310 nm on a standard 8-inch silicon photonics platform. The dark current measures approximately 38.6 μA at-21 V, indicating a breakdown voltage greater than-21 V for the device. The APDs exhibit a unitgain responsivity of 0.5 A/W at-10 V. At-15 V, their responsivity reaches 2.98 and 2.91 A/W with input powers of-10 and-25 dBm, respectively. The device's 3-dB bandwidth is 15 GHz with an input power of-15 dBm and a gain is 11.68. Experimental results show a peak in impedance at high bias voltages, attributed to inductor and capacitor(LC) circuit resonance, enhancing frequency response. Furthermore, 20 Gbps eye diagrams at-21 V and-9 dBm input power reveal signal to noise ratio(SNRs) of 5.30. This lateral SACM APD, compatible with the stand complementary metal oxide semiconductor(CMOS) process,shows that utilizing the peaking effect at low optical power increases bandwidth.
基金This work was supported by the National Key Research and Development Project under Grant 2020YFB1807602,Natural Science Foundation of China under Grant 62071223,62031012,61701214 and 61661028by the National Key Scientific Instrument and Equipment Development Project under Grant No.61827801+1 种基金the Open Project of the Shaanxi Key Laboratory of Information Communication Network and Security under Grant ICNS201701the Excellent Youth Foundation of Jiangxi Province under Grant 2018ACB21012 and in part by the Young Elite Scientist Sponsorship Program by CAST.
文摘In this paper,we consider a new spectrum sharing scenario for a cognitive relay network,where a secondary unmanned aerial vehicle(UAV)relay receives information from the ground secondary base station(SBS)and transmits information to the ground secondary user(SU),coexisting with the primary users(PUs)at the same wireless frequency band.We investigate the optimization of the UAV relay’s three-dimensional(3D)trajectory to improve the communication throughput performance of the secondary network subject to the interference constraints of the PUs.The information throughput maximization problem is studied by jointly optimizing the UAV relay’s 3D trajectory and the transmit power of the SBS and the UAV,subject to the constraints on the velocity and elevation of the UAV relay,the maximum and average transmit power,and the information causality,as well as a set of interference temperature(IT)constraints.An efficient algorithm is proposed to solve the admittedly challenging non-convex problem by using the path discretization technique,the successive convex approximation technique and the alternating optimization method.Finally,simulation results are provided to show that our proposed design outperforms other benchmark schemes in terms of the throughput。
文摘This paper applies the perspective of business ecosystem to mobile communications industry,trying to help mobile network operators improve their strategies in the era of the third generation mobile communications(3G).According to the definition of the business ecosystem,the ecosystem structure of mobile network operators is analyzed.As an important hub in the ecosystem,mobile network operators are advised to take a keystone strategy.The key points of the strategy are summarized.Finally,suggestions for Chinese mobile network operators are given based on the analysis.
基金funded by the“Research on Digitization and Intelligent Application of Low-Voltage Power Distribution Equipment”[SGSDDK00PDJS2000375]。
文摘The main function of the power communication business is to monitor,control and manage the power communication network to ensure normal and stable operation of the power communication network.Commu-nication services related to dispatching data networks and the transmission of fault information or feeder automation have high requirements for delay.If processing time is prolonged,a power business cascade reaction may be triggered.In order to solve the above problems,this paper establishes an edge object-linked agent business deployment model for power communication network to unify the management of data collection,resource allocation and task scheduling within the system,realizes the virtualization of object-linked agent computing resources through Docker container technology,designs the target model of network latency and energy consumption,and introduces A3C algorithm in deep reinforcement learning,improves it according to scene characteristics,and sets corresponding optimization strategies.Mini-mize network delay and energy consumption;At the same time,to ensure that sensitive power business is handled in time,this paper designs the business dispatch model and task migration model,and solves the problem of server failure.Finally,the corresponding simulation program is designed to verify the feasibility and validity of this method,and to compare it with other existing mechanisms.