This paper proposes a high-throughput short reference differential chaos shift keying cooperative communication system with the aid of code index modulation,referred to as CIM-SR-DCSK-CC system.In the proposed CIM-SR-...This paper proposes a high-throughput short reference differential chaos shift keying cooperative communication system with the aid of code index modulation,referred to as CIM-SR-DCSK-CC system.In the proposed CIM-SR-DCSK-CC system,the source transmits information bits to both the relay and destination in the first time slot,while the relay not only forwards the source information bits but also sends new information bits to the destination in the second time slot.To be specific,the relay employs an N-order Walsh code to carry additional log_(2)N information bits,which are superimposed onto the SRDCSK signal carrying the decoded source information bits.Subsequently,the superimposed signal carrying both the source and relay information bits is transmitted to the destination.Moreover,the theoretical bit error rate(BER)expressions of the proposed CIMSR-DCSK-CC system are derived over additive white Gaussian noise(AWGN)and multipath Rayleigh fading channels.Compared with the conventional DCSKCC system and SR-DCSK-CC system,the proposed CIM-SR-DCSK-CC system can significantly improve the throughput without deteriorating any BER performance.As a consequence,the proposed system is very promising for the applications of the 6G-enabled lowpower and high-rate communication.展开更多
In relay-assisted cooperative communication,relay nodes help forwarding the information of a source node in case of link failure between the source and a destination.Although user cooperation improves the overall effi...In relay-assisted cooperative communication,relay nodes help forwarding the information of a source node in case of link failure between the source and a destination.Although user cooperation improves the overall efficiency of the network,it requires incentive to stimulate potential relay nodes to assist the source by forwarding its data to the destination.Moreover,the potential relays are better informed than the source about their channel conditions to destination,which results in asymmetric information between the source and the relays.In this paper,we study the problem of lack of forwarding incentive in cooperative communication when channel state information of relays is private information and not known by the source.To tackle this problem,we apply the principle of contract theory to a cooperative wireless system.Source first designs incentive compatible and individually rational contract,consisting of a set of power-credit pairs.Then it broadcasts contract items to nearby nodes.Once the source node receives reply messages from the volunteer relays,it chooses one or more relays based on its requirements and communication starts.Simulation results show how credit assignment works in order to stimulate relays to cooperate and prevents relays from cheating behavior.展开更多
To facilitate the demand for a higher spectrum and power efficiency arising from the next generation mobile communication system, the introduction of relay-aided cooperative communication into the existing cellular in...To facilitate the demand for a higher spectrum and power efficiency arising from the next generation mobile communication system, the introduction of relay-aided cooperative communication into the existing cellular infrastructure is considered as the most practical improvement under high rate and coverage. In comparison with the legacy cellular network, relay-aided cooperative communication network enjoys relative advantages over coverage efficiency, operation cost and transmission capacity. Transmission in relay-aided cooperative system falls into three types: the three-terminal transmission model, two-hop multi-relay parallel transmission model, and multi-hop multi-relay transmission model. For the extensive perspective of relay-aided cooperative communication in application, a profound research has been carried out in communication standards such as Worldwide Interoperability for Microwave Access (WiMAX) and Wireless World Initiative New Radio (WINNER).展开更多
With the requirements of users enhanced for wireless communication, the cooperative communication will become a development trend in future. In this paper, a model based on complex networks with both preferential atta...With the requirements of users enhanced for wireless communication, the cooperative communication will become a development trend in future. In this paper, a model based on complex networks with both preferential attachment is researched to solve an actual network CCN （Cooperative Communication Network）. Firstly, the evolution of CCN is given by four steps with different probabilities. At the same time, the rate equations of nodes degree are presented to analyze the evolution of CCN. Secondly, the degree distribution is analyzed by calculating the rate equation and numerical simulation. Finally, the robustness of CCN is studied by numerical simulation with random attack and intentional attack to analyze the effects of degree distribution and average path length. The results of this paper are more significant for building CCN to programme the resource of communication.展开更多
To achieve the better system performance for cooperative communication in non-orthogonal cognitive radio vehicular adhoc networks(CR-VANETs),this paper investigates the power allocation considering the interference to...To achieve the better system performance for cooperative communication in non-orthogonal cognitive radio vehicular adhoc networks(CR-VANETs),this paper investigates the power allocation considering the interference to the main system in a controllable range.We propose a three-slot one-way vehicle system model where the mobile vehicle nodes complete information interaction with the assistance of other independent nodes by borrowing the unused radio spectrum with the primary networks.The end-to-end SNR relationship in overlay and underlay cognitive communication system mode are analyzed by using two forwarding protocol,namely,decode-and-forward(DF)protocol and amplify-and-forward(AF)protocol,respectively.The system outage probability is derived and the optimal power allocation factor is obtained via seeking the minimum value of the approximation of system outage probability.The analytical results have been confirmed by means of Monte Carlo simulations.Simulation results show that the proposed system performance in terms of outage under the optimal power allocation is superior to that under the average power allocation,and is also better than that under other power allocation systems.展开更多
Cooperative communication and cognitive radio have become hot topics in recent research of communication networks, attracting a widespread attention. Cooperative communication technique can enhance the transmission ca...Cooperative communication and cognitive radio have become hot topics in recent research of communication networks, attracting a widespread attention. Cooperative communication technique can enhance the transmission capacity of a communication system, while cognitive radio technique can improve the spectrum utilization ratio. As a result, the combination of the two techniques will have a significant impact on the future wireless mobile communication system. This lecture comes in four parts. This part introduces the key technologies for cooperative communications, and the basic concept and key technologies of Cognitive Radio (CR).展开更多
For the multipath fading on electromagnetic waves of wireless communication in the confined areas,the rectangular tunnel cooperative communication system was established based on the multimode channel model and the ch...For the multipath fading on electromagnetic waves of wireless communication in the confined areas,the rectangular tunnel cooperative communication system was established based on the multimode channel model and the channel capacity formula derivation was obtained.On the optimal criterion of the channel capacity,the power allocation methods of both amplifying and forwarding(AF) and decoding and forwarding(DF) cooperative communication systems were proposed in the limitation of the total power to maximize the channel capacity.The mode selection methods of single input single output(SISO) and single input multiple output(SIMO) models in the rectangular tunnel,through which the higher channel capacity can be obtained,were put forward as well.The theoretical analysis and simulation comparison show that,channel capacity of the wireless communication system in the rectangular tunnel can be effectively enhanced through the cooperative technology;channel capacity of the rectangular tunnel under complicated conditions is maximized through the proposed power allocation methods,and the optimal cooperative mode of the channel capacity can be chosen according to the cooperative mode selection methods given in the paper.展开更多
Cooperative communication and cognitive radio have become hot topics in recent researches of communication networks,attracting a widespread attention.Cooperative communication technique can enhance the transmission ca...Cooperative communication and cognitive radio have become hot topics in recent researches of communication networks,attracting a widespread attention.Cooperative communication technique can enhance the transmission capacity of a communication system,while cognitive radio technique can improve the spectrum utilization ratio.As a result,the combination of the two techniques will have significant impact on the future wireless mobile communication system.This lecture comes in four parts.This part introduces the history of cooperative communication as well as several cooperation schemes.展开更多
Cooperative communication and cognitive radio have become hot topics in recent research of communication networks, attracting a widespread attention. Cooperative communication technique can enhance the transmission ca...Cooperative communication and cognitive radio have become hot topics in recent research of communication networks, attracting a widespread attention. Cooperative communication technique can enhance the transmission capacity of a communication system, while cognitive radio technique can improve the spectrum utilization ratio. As a result, the combination of the two techniques will have a significant impact on the future wireless mobile communication system. This lecture comes in four parts. This part analyzes the impacts of cooperative communication technology on modern wireless communication systems.展开更多
Cooperative communication and cognitive radio have become hot topics in recent research of communication networks, attracting a widespread attention. Cooperative communication technique can enhance the transmission ca...Cooperative communication and cognitive radio have become hot topics in recent research of communication networks, attracting a widespread attention. Cooperative communication technique can enhance the transmission capacity of a communication system, while cognitive radio technique can improve the spectrum utilization ratio. As a result, the combination of the two techniques will have a significant impact on the future wireless mobile communication system. This lecture comes in four parts. This part analyzes the impacts of cooperative communication technology on modern wireless communication systems.展开更多
With the low cost and low hardware complex considerations,cooperative systems are a tendency in the future communications.This work considers the secure cooperative communications systems.For a practical situation in ...With the low cost and low hardware complex considerations,cooperative systems are a tendency in the future communications.This work considers the secure cooperative communications systems.For a practical situation in the system,the scenario includes multiple source stations,multiple relay stations,multiple destination stations,and eavesdroppers.To analyze the optimal relay selection in the system,we begin with the performance analysis for a single source station and a single destination station.By applying two cooperative models,the amplify-andforward（AF） mode and decode-and-forward（DF）mode,the secrecy capacity is derived.Then,we apply the derived results to the considered environment to find the optimal relay assignment.By the way,the relay selection can be obtained by the exhaustive search algorithm.However,there are a lot of steps needed if the number of source stations is large.Hence,applying the characters of the cooperative modes in the relay selection,the pre-selection step is proposed with a mathematical derivation.It could be used for the practical situation without a long-time calculation.展开更多
A mobile satellite indoor signal is proposed to model perfor mance of cooperative communication protocols and maximal ra tio combining.Cooperative diversity can improve the reliability of satellite system and increase...A mobile satellite indoor signal is proposed to model perfor mance of cooperative communication protocols and maximal ra tio combining.Cooperative diversity can improve the reliability of satellite system and increase data speed or expand cell radi us by lessening the effects of fading.Performance is determined by measured bit error rates（BERs）in different types of coopera tive protocols and indoor systems（e.g.GSM and WCDMA net works）.The effect of performance on cooperative terminals lo cated at different distances from an indoor cellular system is al so discussed.The proposed schemes provide higher signal-tonoise ratio（SNR）-around 1.6 dB and 2.6 dB gap at BER 10-2for amplify-and-forward（AF）and decode-and-forward（DF）cooperative protocols,respectively,when the cooperative termi nal is located 10 m from the WCDMA indoor system.Coopera tive protocols improve effective power utilization and,hence,improve performance and cell coverage of the mobile satellite network.展开更多
With the rapid development and application of energy harvesting technology,it has become a prominent research area due to its significant benefits in terms of green environmental protection,convenience,and high safety...With the rapid development and application of energy harvesting technology,it has become a prominent research area due to its significant benefits in terms of green environmental protection,convenience,and high safety and efficiency.However,the uneven energy collection and consumption among IoT devices at varying distances may lead to resource imbalance within energy harvesting networks,thereby resulting in low energy transmission efficiency.To enhance the energy transmission efficiency of IoT devices in energy harvesting,this paper focuses on the utilization of collaborative communication,along with pricing-based incentive mechanisms and auction strategies.We propose a dynamic relay selection scheme,including a ladder pricing mechanism based on energy level and a Kuhn-Munkre Algorithm based on an auction theory employing a negotiation mechanism,to encourage more IoT devices to participate in the collaboration process.Simulation results demonstrate that the proposed algorithm outperforms traditional algorithms in terms of improving the energy efficiency of the system.展开更多
The properties of broadcast nature, high densities of deployment and severe resource limitations of sensor and mobile networks make wireless networks more vulnerable to various attacks, including modification of messa...The properties of broadcast nature, high densities of deployment and severe resource limitations of sensor and mobile networks make wireless networks more vulnerable to various attacks, including modification of messages, eavesdropping, network intrusion and malicious forwarding. Conventional cryptography-based security may consume significant overhead because of low-power devices, so current research shifts to the wireless physical layer for security enhancement. This paper is mainly focused on security issues and solutions for wireless communications at the physical layer. It first describes the RSSI-based and channel based wireless authentication methods respectively, and presents an overview of various secrecy capacity analyses of fading channel, MIMO channel and cooperative transmission, and then examines different misbehavior detection methods. Finally it draws conclusions and introduces the direction of our future work.展开更多
In this manuscript, a cooperative non-orthogonal multiple access based intelligent mobile edge computing(NOMA-MEC) communication system is constructed in detail. The nearby user is viewed as a decoding and forwarding ...In this manuscript, a cooperative non-orthogonal multiple access based intelligent mobile edge computing(NOMA-MEC) communication system is constructed in detail. The nearby user is viewed as a decoding and forwarding relay, which can assist a distant user in offloading tasks to the intelligent MEC server. Then, the closed-form expressions of offloading outage probability for a pair of users are derived in detail to evaluate the performance of the cooperative NOMA-MEC system. Furthermore, the approximate expressions of offloading outage probability are provided in the high signal-to-noise ratio region. Based on the asymptotic analyses, the diversity order of distant user and nearby user is n+m+1 and n+1, respectively. The system throughput and energy efficiency of cooperative NOMA-MEC are analyzed in delay-limited transmission mode. Numerical results show that 1) Cooperative NOMA-MEC is better than orthogonal multiple access(OMA) in terms of offload performance;2) The offload performance of cooperative NOMA-MEC system improves as the number of transmission task decreases;and 3) Cooperative NOMA-MEC performs better than OMA in energy efficiency.展开更多
Cognitive radio and cooperative communication can greatly improve the spectrum efficiency in wireless communications.We study a cognitive radio network where two secondary source terminals exchange their information w...Cognitive radio and cooperative communication can greatly improve the spectrum efficiency in wireless communications.We study a cognitive radio network where two secondary source terminals exchange their information with the assistance of a relay node under interference power constraints.In order to enhance the transmit rate and maintain fairness between two source terminals,a practical 2-phase analog network coding protocol is adopted and its optimal power allocation algorithm is proposed.Numerical results verify the superiority of the proposed algorithm over the conventional direct transmission protocol and 4-phase amplify-and-forward relay protocol.展开更多
Routing plays a critical role in data transmission for underwater acoustic sensor networks(UWSNs)in the internet of underwater things(IoUT).Traditional routing methods suffer from high end-toend delay,limited bandwidt...Routing plays a critical role in data transmission for underwater acoustic sensor networks(UWSNs)in the internet of underwater things(IoUT).Traditional routing methods suffer from high end-toend delay,limited bandwidth,and high energy consumption.With the development of artificial intelligence and machine learning algorithms,many researchers apply these new methods to improve the quality of routing.In this paper,we propose a Qlearning-based multi-hop cooperative routing protocol(QMCR)for UWSNs.Our protocol can automatically choose nodes with the maximum Q-value as forwarders based on distance information.Moreover,we combine cooperative communications with Q-learning algorithm to reduce network energy consumption and improve communication efficiency.Experimental results show that the running time of the QMCR is less than one-tenth of that of the artificial fish-swarm algorithm(AFSA),while the routing energy consumption is kept at the same level.Due to the extremely fast speed of the algorithm,the QMCR is a promising method of routing design for UWSNs,especially for the case that it suffers from the extreme dynamic underwater acoustic channels in the real ocean environment.展开更多
The coverage probability of both the cellular users and the Device-to-Device(D2D) users are analyzed. We assume that the cellular users are able to communication with the Base Station(BS) either by relying on the assi...The coverage probability of both the cellular users and the Device-to-Device(D2D) users are analyzed. We assume that the cellular users are able to communication with the Base Station(BS) either by relying on the assistance of Full-Duplex(FD) mode relays or via direct user-to-BS links with high-enough Signal-to-Interference-plus-Noise-Ratio(SINR). Note that the FD-mode devices are capable of simultaneously operating in two modes,i.e. the D2D mode and the cooperative relay mode,with the sum power consumption at these devices kept constant. The closedform expressions for coverage probability of both tier users are derived. After that,numerical analyses are provided,showing that the coverage probability of the both the cellular and the D2D users can be substantially influenced by a variety of parameters,including the power allocation factor of the relays,the density of users,and the self-interference imposed on the FD mode relays,etc. Furthermore,in the D2D enabled networks,it is shown that the FD relay aided transmission is beneficial to enhancing the coverage probability of the cellular users if the target SINR is lower than 5 d B.展开更多
An exact average symbol error rate analysis for the distributed dual-hop relay cooperative network with multiple relays in a Nakagami-m fading environment is presented.In the derivation of the moment generation functi...An exact average symbol error rate analysis for the distributed dual-hop relay cooperative network with multiple relays in a Nakagami-m fading environment is presented.In the derivation of the moment generation function of receiver Signal-to-Noise Ratio(SNR),the sectional integral method is used,instead of the cumulative density function method which is ordinarily used by the deduction of the outage probability of S-R-D link.The accurate symbol error rate of a dual-hop relay cooperative network is obtained with the closed-form Moment Genoration Function (MGF) expression.The correctness of the symbol error rate is verified through numerical simulations and is compared with other analytical methods.These deductions clearly show that the distributed cooperative diversity network presented has strong superiorities in overcoming severe fading and can achieve full diversity order.展开更多
In this paper, a three-dimensional(3D) geometry- based stochastic scattering model(GBSSM) for wideband multi-input multi-output(MIMO) vehicle-to-vehicle(V2V) relay-based cooperative fading channel based on geometrical...In this paper, a three-dimensional(3D) geometry- based stochastic scattering model(GBSSM) for wideband multi-input multi-output(MIMO) vehicle-to-vehicle(V2V) relay-based cooperative fading channel based on geometrical three-cylinder is proposed. Non-line-of-sight(NLOS) propagation condition is assumed in amplify-and-forward(AF) cooperative networks from the source mobile station(S) to the destination mobile station(D) via the mobile relay station(R). We extend the proposed narrowband model to wideband and also introduce the carrier frequency and bandwidth into the model. To avoid complicated procedure in deriving the analytical expressions of the channel parameters and functions, the channel is realized first. By using the realized channel matrix, the channel properties are further investigated.展开更多
基金supported in part by the NSF of China under Grant 62322106,62071131 and 62171135the Guangdong Basic and Applied Basic Research Foundation under Grant 2022B1515020086+2 种基金the NSF of Guangdong Province under Grant 2019A1515011465the International Collaborative Research Program of Guangdong Science and Technology Department under Grant 2022A0505050070the Industrial R&D Project of Haoyang Electronic Co.,Ltd.under Grant 2022440002001494.
文摘This paper proposes a high-throughput short reference differential chaos shift keying cooperative communication system with the aid of code index modulation,referred to as CIM-SR-DCSK-CC system.In the proposed CIM-SR-DCSK-CC system,the source transmits information bits to both the relay and destination in the first time slot,while the relay not only forwards the source information bits but also sends new information bits to the destination in the second time slot.To be specific,the relay employs an N-order Walsh code to carry additional log_(2)N information bits,which are superimposed onto the SRDCSK signal carrying the decoded source information bits.Subsequently,the superimposed signal carrying both the source and relay information bits is transmitted to the destination.Moreover,the theoretical bit error rate(BER)expressions of the proposed CIMSR-DCSK-CC system are derived over additive white Gaussian noise(AWGN)and multipath Rayleigh fading channels.Compared with the conventional DCSKCC system and SR-DCSK-CC system,the proposed CIM-SR-DCSK-CC system can significantly improve the throughput without deteriorating any BER performance.As a consequence,the proposed system is very promising for the applications of the 6G-enabled lowpower and high-rate communication.
文摘In relay-assisted cooperative communication,relay nodes help forwarding the information of a source node in case of link failure between the source and a destination.Although user cooperation improves the overall efficiency of the network,it requires incentive to stimulate potential relay nodes to assist the source by forwarding its data to the destination.Moreover,the potential relays are better informed than the source about their channel conditions to destination,which results in asymmetric information between the source and the relays.In this paper,we study the problem of lack of forwarding incentive in cooperative communication when channel state information of relays is private information and not known by the source.To tackle this problem,we apply the principle of contract theory to a cooperative wireless system.Source first designs incentive compatible and individually rational contract,consisting of a set of power-credit pairs.Then it broadcasts contract items to nearby nodes.Once the source node receives reply messages from the volunteer relays,it chooses one or more relays based on its requirements and communication starts.Simulation results show how credit assignment works in order to stimulate relays to cooperate and prevents relays from cheating behavior.
基金the National High-Tech Research and Development Plan of China("863"Program)under Grant No.2007AA01Z262National Natural Science Foundation of China under Grant Nos.60672093and60496310National Basic Research Program of China("973"Program)under Grant No.2007CB310603
文摘To facilitate the demand for a higher spectrum and power efficiency arising from the next generation mobile communication system, the introduction of relay-aided cooperative communication into the existing cellular infrastructure is considered as the most practical improvement under high rate and coverage. In comparison with the legacy cellular network, relay-aided cooperative communication network enjoys relative advantages over coverage efficiency, operation cost and transmission capacity. Transmission in relay-aided cooperative system falls into three types: the three-terminal transmission model, two-hop multi-relay parallel transmission model, and multi-hop multi-relay transmission model. For the extensive perspective of relay-aided cooperative communication in application, a profound research has been carried out in communication standards such as Worldwide Interoperability for Microwave Access (WiMAX) and Wireless World Initiative New Radio (WINNER).
基金Project supported by the Natural Science Foundation of Beijing(Grant No.4152035)the National Natural Science Foundation of China(Grant No.61272507)
文摘With the requirements of users enhanced for wireless communication, the cooperative communication will become a development trend in future. In this paper, a model based on complex networks with both preferential attachment is researched to solve an actual network CCN （Cooperative Communication Network）. Firstly, the evolution of CCN is given by four steps with different probabilities. At the same time, the rate equations of nodes degree are presented to analyze the evolution of CCN. Secondly, the degree distribution is analyzed by calculating the rate equation and numerical simulation. Finally, the robustness of CCN is studied by numerical simulation with random attack and intentional attack to analyze the effects of degree distribution and average path length. The results of this paper are more significant for building CCN to programme the resource of communication.
基金funded by the Six Talent Peaks Project in Jiangsu Province(No.KTHY-052)the National Natural Science Foundation of China(No.61971245)+1 种基金the Science and Technology program of Nantong(Contract No.JC2018048)the Key Lab of Advanced Optical Manufacturing Technologies of Jiangsu Province&Key Lab of Modern Optical Technologies of Education Ministry of China,Soochow University(No.KJS1858).
文摘To achieve the better system performance for cooperative communication in non-orthogonal cognitive radio vehicular adhoc networks(CR-VANETs),this paper investigates the power allocation considering the interference to the main system in a controllable range.We propose a three-slot one-way vehicle system model where the mobile vehicle nodes complete information interaction with the assistance of other independent nodes by borrowing the unused radio spectrum with the primary networks.The end-to-end SNR relationship in overlay and underlay cognitive communication system mode are analyzed by using two forwarding protocol,namely,decode-and-forward(DF)protocol and amplify-and-forward(AF)protocol,respectively.The system outage probability is derived and the optimal power allocation factor is obtained via seeking the minimum value of the approximation of system outage probability.The analytical results have been confirmed by means of Monte Carlo simulations.Simulation results show that the proposed system performance in terms of outage under the optimal power allocation is superior to that under the average power allocation,and is also better than that under other power allocation systems.
基金supported by the National Natural Science Foundation of China under Grant No.60872049the National High-Tech Research and Development Plan of China("863" Program)under Grant No.2007AA10Z235the Teaching and Research Finances for the Returned Overseas Chinese Scholars
文摘Cooperative communication and cognitive radio have become hot topics in recent research of communication networks, attracting a widespread attention. Cooperative communication technique can enhance the transmission capacity of a communication system, while cognitive radio technique can improve the spectrum utilization ratio. As a result, the combination of the two techniques will have a significant impact on the future wireless mobile communication system. This lecture comes in four parts. This part introduces the key technologies for cooperative communications, and the basic concept and key technologies of Cognitive Radio (CR).
基金financial supports provided by the National Natural Science Foundation of China (No.51274202)the Fundamental Research Funds for the Central Universities (No.2013RC11)+3 种基金the Science and Technology Achievements Transformation Project of Jiangsu Province (No.BA2012068)the Natural Science Foundation of Jiangsu Province (Nos.BK20130199 and BK20131124)Ceeusro Prospective Joint Research Project of Jiangsu Province (No.BY2014028-01)Great Cultivating Special Project at China University of Mining and Technology (No.2014ZDPY16)
文摘For the multipath fading on electromagnetic waves of wireless communication in the confined areas,the rectangular tunnel cooperative communication system was established based on the multimode channel model and the channel capacity formula derivation was obtained.On the optimal criterion of the channel capacity,the power allocation methods of both amplifying and forwarding(AF) and decoding and forwarding(DF) cooperative communication systems were proposed in the limitation of the total power to maximize the channel capacity.The mode selection methods of single input single output(SISO) and single input multiple output(SIMO) models in the rectangular tunnel,through which the higher channel capacity can be obtained,were put forward as well.The theoretical analysis and simulation comparison show that,channel capacity of the wireless communication system in the rectangular tunnel can be effectively enhanced through the cooperative technology;channel capacity of the rectangular tunnel under complicated conditions is maximized through the proposed power allocation methods,and the optimal cooperative mode of the channel capacity can be chosen according to the cooperative mode selection methods given in the paper.
基金supported by the National Natural Science Foundation of China under Grant No.60872049the National High-Tech Researchand Development Plan of China ("863" Program) under Grant No.2007AA10Z235the Teachingand Research Finances for the Returned Overseas Chinese Scholars.
文摘Cooperative communication and cognitive radio have become hot topics in recent researches of communication networks,attracting a widespread attention.Cooperative communication technique can enhance the transmission capacity of a communication system,while cognitive radio technique can improve the spectrum utilization ratio.As a result,the combination of the two techniques will have significant impact on the future wireless mobile communication system.This lecture comes in four parts.This part introduces the history of cooperative communication as well as several cooperation schemes.
基金supported by the National Natural Science Foundation of China under Grant No. 60872049 the National High-Tech Research and Development Plan of China ("863" Program) under Grant No. 2007AA10Z235the Teaching and Research Finances for the Returned Overseas Chinese Scholars.
文摘Cooperative communication and cognitive radio have become hot topics in recent research of communication networks, attracting a widespread attention. Cooperative communication technique can enhance the transmission capacity of a communication system, while cognitive radio technique can improve the spectrum utilization ratio. As a result, the combination of the two techniques will have a significant impact on the future wireless mobile communication system. This lecture comes in four parts. This part analyzes the impacts of cooperative communication technology on modern wireless communication systems.
基金supported by the National Natural Science Foundation of China under Grant No.60872049the National High-Tech Research and Development Plan of China ("863" Program)under Grant No.2007AA10Z235the Teaching and Research Finances for the Returned Overseas Chinese Scholars
文摘Cooperative communication and cognitive radio have become hot topics in recent research of communication networks, attracting a widespread attention. Cooperative communication technique can enhance the transmission capacity of a communication system, while cognitive radio technique can improve the spectrum utilization ratio. As a result, the combination of the two techniques will have a significant impact on the future wireless mobile communication system. This lecture comes in four parts. This part analyzes the impacts of cooperative communication technology on modern wireless communication systems.
文摘With the low cost and low hardware complex considerations,cooperative systems are a tendency in the future communications.This work considers the secure cooperative communications systems.For a practical situation in the system,the scenario includes multiple source stations,multiple relay stations,multiple destination stations,and eavesdroppers.To analyze the optimal relay selection in the system,we begin with the performance analysis for a single source station and a single destination station.By applying two cooperative models,the amplify-andforward（AF） mode and decode-and-forward（DF）mode,the secrecy capacity is derived.Then,we apply the derived results to the considered environment to find the optimal relay assignment.By the way,the relay selection can be obtained by the exhaustive search algorithm.However,there are a lot of steps needed if the number of source stations is large.Hence,applying the characters of the cooperative modes in the relay selection,the pre-selection step is proposed with a mathematical derivation.It could be used for the practical situation without a long-time calculation.
文摘A mobile satellite indoor signal is proposed to model perfor mance of cooperative communication protocols and maximal ra tio combining.Cooperative diversity can improve the reliability of satellite system and increase data speed or expand cell radi us by lessening the effects of fading.Performance is determined by measured bit error rates（BERs）in different types of coopera tive protocols and indoor systems（e.g.GSM and WCDMA net works）.The effect of performance on cooperative terminals lo cated at different distances from an indoor cellular system is al so discussed.The proposed schemes provide higher signal-tonoise ratio（SNR）-around 1.6 dB and 2.6 dB gap at BER 10-2for amplify-and-forward（AF）and decode-and-forward（DF）cooperative protocols,respectively,when the cooperative termi nal is located 10 m from the WCDMA indoor system.Coopera tive protocols improve effective power utilization and,hence,improve performance and cell coverage of the mobile satellite network.
基金funded by the Researchers Supporting Project Number RSPD2024R681,King Saud University,Riyadh,Saudi Arabia.
文摘With the rapid development and application of energy harvesting technology,it has become a prominent research area due to its significant benefits in terms of green environmental protection,convenience,and high safety and efficiency.However,the uneven energy collection and consumption among IoT devices at varying distances may lead to resource imbalance within energy harvesting networks,thereby resulting in low energy transmission efficiency.To enhance the energy transmission efficiency of IoT devices in energy harvesting,this paper focuses on the utilization of collaborative communication,along with pricing-based incentive mechanisms and auction strategies.We propose a dynamic relay selection scheme,including a ladder pricing mechanism based on energy level and a Kuhn-Munkre Algorithm based on an auction theory employing a negotiation mechanism,to encourage more IoT devices to participate in the collaboration process.Simulation results demonstrate that the proposed algorithm outperforms traditional algorithms in terms of improving the energy efficiency of the system.
基金supported in part by State Key Program of National Nature Science Foundation of China under Grant No.60932003National High Technical Research and Development Program of China (863 Program ) under Grant No.2007AA01Z452
文摘The properties of broadcast nature, high densities of deployment and severe resource limitations of sensor and mobile networks make wireless networks more vulnerable to various attacks, including modification of messages, eavesdropping, network intrusion and malicious forwarding. Conventional cryptography-based security may consume significant overhead because of low-power devices, so current research shifts to the wireless physical layer for security enhancement. This paper is mainly focused on security issues and solutions for wireless communications at the physical layer. It first describes the RSSI-based and channel based wireless authentication methods respectively, and presents an overview of various secrecy capacity analyses of fading channel, MIMO channel and cooperative transmission, and then examines different misbehavior detection methods. Finally it draws conclusions and introduces the direction of our future work.
基金supported in part by the Natural Science Foundation of Beijing Municipality under Grant 4204099,Grant 19L2022,Grant L182032,Grant L182039 and Grant KZ201911232046the Science and Technology Project of Beijing Municipal Education Commission under Grant KM202011232002 and Grant KM202011232003。
文摘In this manuscript, a cooperative non-orthogonal multiple access based intelligent mobile edge computing(NOMA-MEC) communication system is constructed in detail. The nearby user is viewed as a decoding and forwarding relay, which can assist a distant user in offloading tasks to the intelligent MEC server. Then, the closed-form expressions of offloading outage probability for a pair of users are derived in detail to evaluate the performance of the cooperative NOMA-MEC system. Furthermore, the approximate expressions of offloading outage probability are provided in the high signal-to-noise ratio region. Based on the asymptotic analyses, the diversity order of distant user and nearby user is n+m+1 and n+1, respectively. The system throughput and energy efficiency of cooperative NOMA-MEC are analyzed in delay-limited transmission mode. Numerical results show that 1) Cooperative NOMA-MEC is better than orthogonal multiple access(OMA) in terms of offload performance;2) The offload performance of cooperative NOMA-MEC system improves as the number of transmission task decreases;and 3) Cooperative NOMA-MEC performs better than OMA in energy efficiency.
基金Acknowledgements The work was supported by National Natural Science Foundation of China （Grant No.60972008）. The corresponding author is Jiang Wei.
文摘Cognitive radio and cooperative communication can greatly improve the spectrum efficiency in wireless communications.We study a cognitive radio network where two secondary source terminals exchange their information with the assistance of a relay node under interference power constraints.In order to enhance the transmit rate and maintain fairness between two source terminals,a practical 2-phase analog network coding protocol is adopted and its optimal power allocation algorithm is proposed.Numerical results verify the superiority of the proposed algorithm over the conventional direct transmission protocol and 4-phase amplify-and-forward relay protocol.
基金the National Key Research and Development Program of China under Grant No.2016YFC1400200in part by the Basic Research Program of Science and Technology of Shenzhen,China under Grant No.JCYJ20190809161805508+2 种基金in part by the Fundamental Research Funds for the Central Universities of China under Grant No.20720200092in part by the Xiamen University’s Honors Program for Undergraduates in Marine Sciences under Grant No.22320152201106in part by the National Natural Science Foundation of China under Grants No.41476026,41976178 and 61801139。
文摘Routing plays a critical role in data transmission for underwater acoustic sensor networks(UWSNs)in the internet of underwater things(IoUT).Traditional routing methods suffer from high end-toend delay,limited bandwidth,and high energy consumption.With the development of artificial intelligence and machine learning algorithms,many researchers apply these new methods to improve the quality of routing.In this paper,we propose a Qlearning-based multi-hop cooperative routing protocol(QMCR)for UWSNs.Our protocol can automatically choose nodes with the maximum Q-value as forwarders based on distance information.Moreover,we combine cooperative communications with Q-learning algorithm to reduce network energy consumption and improve communication efficiency.Experimental results show that the running time of the QMCR is less than one-tenth of that of the artificial fish-swarm algorithm(AFSA),while the routing energy consumption is kept at the same level.Due to the extremely fast speed of the algorithm,the QMCR is a promising method of routing design for UWSNs,especially for the case that it suffers from the extreme dynamic underwater acoustic channels in the real ocean environment.
基金supported by Key Project of the National Natural Science Foundation of China (Grant No.61431001)National Natural Science Foundation of China (Grant Nos.61501182,U1501253,61377024)+3 种基金Research Foundation of Education Department of Hunan Province (Grant No.15C0558)Startup Foundation for Doctors of Hunan University of Science and Technology (Grant No.E51539)Key Laboratory of Cognitive Radio and Information Processing,Ministry of Education (Guilin University of Electronic Technology)Foundation of Beijing Engineering and Technology Center for Convergence Networks and Ubiquitous Services
文摘The coverage probability of both the cellular users and the Device-to-Device(D2D) users are analyzed. We assume that the cellular users are able to communication with the Base Station(BS) either by relying on the assistance of Full-Duplex(FD) mode relays or via direct user-to-BS links with high-enough Signal-to-Interference-plus-Noise-Ratio(SINR). Note that the FD-mode devices are capable of simultaneously operating in two modes,i.e. the D2D mode and the cooperative relay mode,with the sum power consumption at these devices kept constant. The closedform expressions for coverage probability of both tier users are derived. After that,numerical analyses are provided,showing that the coverage probability of the both the cellular and the D2D users can be substantially influenced by a variety of parameters,including the power allocation factor of the relays,the density of users,and the self-interference imposed on the FD mode relays,etc. Furthermore,in the D2D enabled networks,it is shown that the FD relay aided transmission is beneficial to enhancing the coverage probability of the cellular users if the target SINR is lower than 5 d B.
基金supported by Important National Science ＆ Technology Specific Projects under Grant No.CX01011the Important National Science ＆ Technology Specific Projects under Grant No.4101002+2 种基金the National Natural Science Foundation of China under Grants No.61002014,No.60972017,No.60972018the Excellent Young Teachers Program of MOE,PRC under Grant No.2009110120028the Research Fund for the Doctoral Program of Higher Education under Grants No.20091101110019,No.20070007019
文摘An exact average symbol error rate analysis for the distributed dual-hop relay cooperative network with multiple relays in a Nakagami-m fading environment is presented.In the derivation of the moment generation function of receiver Signal-to-Noise Ratio(SNR),the sectional integral method is used,instead of the cumulative density function method which is ordinarily used by the deduction of the outage probability of S-R-D link.The accurate symbol error rate of a dual-hop relay cooperative network is obtained with the closed-form Moment Genoration Function (MGF) expression.The correctness of the symbol error rate is verified through numerical simulations and is compared with other analytical methods.These deductions clearly show that the distributed cooperative diversity network presented has strong superiorities in overcoming severe fading and can achieve full diversity order.
基金supported by the open research fund of National Mobile Communications Research Laboratory, Southeast University (No. 2016D09)National Nature Science Foundation of China (NSFC) under grant No. 61372051
文摘In this paper, a three-dimensional(3D) geometry- based stochastic scattering model(GBSSM) for wideband multi-input multi-output(MIMO) vehicle-to-vehicle(V2V) relay-based cooperative fading channel based on geometrical three-cylinder is proposed. Non-line-of-sight(NLOS) propagation condition is assumed in amplify-and-forward(AF) cooperative networks from the source mobile station(S) to the destination mobile station(D) via the mobile relay station(R). We extend the proposed narrowband model to wideband and also introduce the carrier frequency and bandwidth into the model. To avoid complicated procedure in deriving the analytical expressions of the channel parameters and functions, the channel is realized first. By using the realized channel matrix, the channel properties are further investigated.
