In order to improve the Physical Layer Security(PLS)perspective,this paper aims to empower function of PLS by considering a backhaul Non-Orthogonal Multiple Access(NOMA)system in two practical situations.In the propos...In order to improve the Physical Layer Security(PLS)perspective,this paper aims to empower function of PLS by considering a backhaul Non-Orthogonal Multiple Access(NOMA)system in two practical situations.In the proposed schemes,the untrusted user intercepts information transmitted to the far user,or the external eavesdropper overhears confidential information sent to the far user in the context of NOMA technique.Unlike the conventional NOMA systems,this paper emphasizes the actual situations of the existence of actual illegal users and legitimate users,especially the reasonable use of relay selection architecture to improve the confidentiality performance.To evaluate the security properties of the proposed scheme,a comprehensive analysis of the Security Outage Probability(SOP)performance is first performed,and then the corresponding SOP asymptotic expressions are derived for real scenarios related to eavesdroppers and untrusted users.Numerical results are performed to verify the analysis in terms of the secure performance metric.展开更多
Heterogeneous networks(Het Nets)attracts a lot of attention due to its high capacity and large coverage for future communication networks.However,with the large-scale deployment of small cells,HetNets bears dramatical...Heterogeneous networks(Het Nets)attracts a lot of attention due to its high capacity and large coverage for future communication networks.However,with the large-scale deployment of small cells,HetNets bears dramatically increasing backhaul,which leads to a decrease of the outage performance.To improve the outage performance of Het Nets,we propose a wireless backhaul scheme for a two-layer HetNets,which automatically switches the three basic modes of orthogonal multiple access(OMA),nonorthogonal multiple access(NOMA)and cooperative non-orthogonal multiple access(CNOMA).First,we analyze the backhaul capacity and outage performance of these three basic modes.Then,we design the power allocation schemes based on minimizing outage probability for NOMA and CNOMA.Using the designed power allocation schemes,we propose a wireless backhaul scheme that switches the three modes according to the channel quality among different base stations(BSs).Moreover,the closed-form of the corresponding outage probability is derived.Compared with the three basic modes,the proposed wireless backhaul scheme can achieve the best outage performance and a higher backhaul capacity.Finally,all the analytical results are validated by simulations.展开更多
To reinforce the coverage and QoS(quality of service) of on-ground cellular communication system, unmanned aerial vehicles which are carrying small cells are deployed in some emergency and disaster areas. Although ASC...To reinforce the coverage and QoS(quality of service) of on-ground cellular communication system, unmanned aerial vehicles which are carrying small cells are deployed in some emergency and disaster areas. Although ASCs(aerial small cells) can provide a higher probability of LoS(line-of-sight) transmission, the wireless backhaul link will bring extra interference to the whole system if not well designed. Therefore, in this paper, we study the backhaul scheme for UAV-assist cellular network. We first analyze the interference environments of UAV-assist cellular network considering the IBOG(In-Band to On-Ground), OBOG(Out-of-Band to On-Ground) and IBTU(In-Band to Tethered-UAV) backhauling mode, and give the descriptions of the performance metrics for each mode. Then, the considered problem is formulated as an optimization of achievable rate. We derive the optimal solutions for the involved three backhauling modes for ASCs respectively, and closed-form optimal value for each mode is acquired with proof. We also give a pseudo-code form of our proposed optimal access/backhaul spectrum allocation algorithm. The simulation results indicate that the proposed scheme can deliver a significant gain, while IBTU performs best among proposed backhauling modes.展开更多
A novel user association model for heterogeneous network(Het Net) with dual connectivity(DC) and constrained backhaul is proposed in this paper, where not only the best combination of serving macro cell and small cell...A novel user association model for heterogeneous network(Het Net) with dual connectivity(DC) and constrained backhaul is proposed in this paper, where not only the best combination of serving macro cell and small cell for each user to associate is selected but also the optimal traffi c split between the macro cell and small cell is determined to enhance both radio resource effi ciency and backhaul capacity utilization. To solve this optimization problem, an intuitive algorithm based on iteratively solving two sub-problems is proposed. One sub-problem is a binary integer programming problem and a corresponding greedy algorithm is proposed, while the other sub-problem is a simple linear programming problem and can be easily solved. Numerical results show that the proposed model and algorithm can achieve better radio resource effi ciency and backhaul capacity utilization compared with user association in Het Net without DC, which validate the capacity enhancement potentials of radio resource coordination in Het Net with DC.展开更多
In this paper, we study the problem of resource allocation in small cell networks with distributed caching, that is, how to divide the spectrum resources for backhaul and access in order to improve network performance...In this paper, we study the problem of resource allocation in small cell networks with distributed caching, that is, how to divide the spectrum resources for backhaul and access in order to improve network performance. We formulate our concerned problem by using multi-dimensional Markov model. Our problem considers that each user may access multiple small cell base stations. We conduct simulation experiments to evaluate the performance of our proposed resource allocation scheme. Our simulation results show that the appropriate spectrum resource allocation is important to improve network performance.展开更多
Massive MIMO systems offer a high spatial resolution that can drastically increase the spectral and/or energy efficiency by employing a large number of antennas at the base station(BS).In a distributed massive MIMO sy...Massive MIMO systems offer a high spatial resolution that can drastically increase the spectral and/or energy efficiency by employing a large number of antennas at the base station(BS).In a distributed massive MIMO system,the capacity of fiber backhaul that links base station and remote radio heads is usually limited,which becomes a bottleneck for realizing the potential performance gain of both downlink and uplink.To solve this problem,we propose a joint antenna selection and user scheduling which is able to achieve a large portion of the potential gain provided by the massive MIMO array with only limited backhaul capacity.Three sub-optimal iterative algorithms with the objective of sumrate maximization are proposed for the joint optimization of antenna selection and user scheduling,either based on greedy fashion or Frobenius-norm criteria.Convergence and complexity analysis are presented for the algorithms.The provided Monte Carlo simulations show that,one of our algorithms achieves a good tradeoff between complexity and performance and thus is especially fit for massive MIMO systems.展开更多
In this paper,we consider a full-duplex(FD)millimeter wave(mmWave)multiuser integrated access and backhaul(IAB)system with massive MIMO,and the system asymptotic performance and interference cancellation schemes are i...In this paper,we consider a full-duplex(FD)millimeter wave(mmWave)multiuser integrated access and backhaul(IAB)system with massive MIMO,and the system asymptotic performance and interference cancellation schemes are investigated.First,the asymptotic performance of the IAB system with massive MIMO is analyzed.As the number of macro base station(MBS)and small base station(SBS)antennas approaches infinity,the FD selfinterference(SI),inter-tier interference and noise can be eliminated,which means that only multiuser interference remains in the system.Then,multiuser interference can be suppressed by the base band(BB)precoders.Since all interference and noise are suppressed,the spectral efficiency of the SBS and users are infinite in theory.Then,two interference suppression precoding schemes are proposed.A block diagonalization(BD)-based interference cancellation scheme is designed based on the channel characteristics and null space projection.The FD SI,intertier interference and multiuser interference are eliminated by BB precoders.Instead of eliminating interference completely,a signal to leakage and noise ratio(SLNR)-based precoding scheme is derived to suppress both interference and noise.By utilizing the Rayleigh-Ritz theorem,the SLNRs of the SBS and users are optimized.Simulation results show that all the interference can be effectively eliminated by the BD-based scheme at the cost of spectral efficiency performance loss,while the SLNR-based scheme can balance interference and noise and achieve higher spectral efficiency with comparatively low interference level.Therefore,the BD-based scheme is more suitable for interference elimination cases,and the SLNRbased scheme can improve the system performance in low interference scenarios.展开更多
The 5G cellular network aims at providing three major services:Massive machine-type communication(mMTC),ultra-reliable low-latency communications(URLLC),and enhanced-mobile-broadband(eMBB).Among these services,the URL...The 5G cellular network aims at providing three major services:Massive machine-type communication(mMTC),ultra-reliable low-latency communications(URLLC),and enhanced-mobile-broadband(eMBB).Among these services,the URLLC and eMBB require strict end-to-end latency of 1 ms while maintaining 99.999%reliability,and availability of extremely high data rates for the users,respectively.One of the critical challenges in meeting these requirements is to upgrade the existing optical fiber backhaul network interconnecting the base stations with a multigigabit capacity,low latency and very high reliability system.To address this issue,we have numerically analyzed 100 Gbit/s coherent optical orthogonal frequency division multiplexing(CO-OFDM)transmission performance over 400 km single-mode fiber(SMF)and 100 km of multi-mode fiber(MMF)links.The system is simulated over optically repeated and non-repeated SMF and MMF links.Coherent transmission is used,and the system is analyzed in a linear and non-linear regime.The system performance is quantified by bit error ratio(BER).Spectrally efficient and optimal transmission performance is achieved for 400 km SMF and 100 km MMF link.The results designate thatMMF links can be employed beyond short reach applications by using them in the existing SMF infrastructure for long haul transmission.In particular,the proposed CO-OFDM system can be efficiently employed in 5G backhaul network.The multi-gigabit capacity and lower BER of the proposed system makes it a suitable candidate especially for the eMBB and URLLC requirements for 5G backhaul network.展开更多
The Internet of things(IoT) as an important application of future communication networks puts a high premium on delay issues. Thus when Io T applications meet heterogeneous networks(HetNets) where macro cells are over...The Internet of things(IoT) as an important application of future communication networks puts a high premium on delay issues. Thus when Io T applications meet heterogeneous networks(HetNets) where macro cells are overlaid with small cells, some traditional problems need rethinking. In this paper, we investigate the delay-addressed association problem in two-tier Het Nets considering different backhaul technologies. Specifically, millimeter wave and fiber links are used to provide high-capacity backhaul for small cells. We first formulate the user association problem to minimize the total delay which depends on the probability of successful transmission, the number of user terminals(UTs), and the number of base stations(BSs). And then two algorithms for active mode and mixed mode are proposed to minimize the network delay. Simulation results show that algorithms based on mutual selection between UTs and BSs have better performance than those based on distance. And algorithms for mixed modes have less delay than those for active mode when the number of BSs is large enough, compared to the number of UTs.展开更多
With the development of self-interference(SI) cancelation technology, full-duplex(FD) communication becomes possible. FD communication can theoretically double the spectral efficiency. When the time slot(TS) resources...With the development of self-interference(SI) cancelation technology, full-duplex(FD) communication becomes possible. FD communication can theoretically double the spectral efficiency. When the time slot(TS) resources are limited and the number of flows is large, the scheduling mechanism of the flows becomes more important. Therefore, the effectiveness of FD scheduling mechanism for the flows is studied in millimeter wave wireless backhaul network with the limited TS resources. We proposed a full duplex concurrent scheduling algorithm based on coalition game(FDCG) to maximize the number of flows with their QoS requirements satisfied. We transformed the problem of maximizing the number of flows with their QoS requirements satisfied into the problem of maximizing sum rate of concurrently scheduled flows in each slot. We obtained the scheduled flows with maximum sum rate in first slot by using coalition game.And then with certain restrictions, the maximum sum rate of concurrently scheduled flows can also be achieved in subsequent time slots. The simulation results show that the proposed FDCG algorithm canachieve superior performance in terms of the number of flows that meet their QoS requirements and system throughput compared with other three algorithms.展开更多
In the scenario of downlink multicell processing with finite backhaul capacity in the case of two base stations and two mobile users, by regarding the channel as a multiple access diamond channel with two destinations...In the scenario of downlink multicell processing with finite backhaul capacity in the case of two base stations and two mobile users, by regarding the channel as a multiple access diamond channel with two destinations, an achievability scheme that sends correlated codewords through the multiple access channel with common data is proposed. By considering the superposition structure, fully correlated codewords can be supported by the proposed scheme, which can benefit the system throughput in the case of a relatively-large-capacity backhaul. First, an achievable region for the achievable theory is given and it is proved from the perspective of information theory. Then, in the Gaussian scenario, a simulation combining dirty-paper coding and power allocating is provided for the achievable region. Simulation results demonstrate that when the backhaul capacity is relatively large, the proposed scheme outperforms the existing achievability scheme without the superposition structure.展开更多
Ultra-dense networks （UDNs） are expected to be applied for the fifth generation wireless system （5G） to meet the requirements of very high throughput density and connections of a massive number of users. Consideri...Ultra-dense networks （UDNs） are expected to be applied for the fifth generation wireless system （5G） to meet the requirements of very high throughput density and connections of a massive number of users. Considering the large amount of small base stations （SBSs）, how to choose proper backhaul links is an important problem under investigation. In this paper, we propose a wireless backhaul algorithm to find an effective backhaul method for densely-deployed SBSs and to maximize energy efficiency of the system. We put forward adaptive backhaul methods of indirect and direct modes. The SBS can select the direct baekhaul which con- nects to the macro base station （MBS） directly, or the indirect backhaul which selects an idle SBS as a relay based on the backhaul channel condition. The algorithm also allocates network resources, including the power of SBSs and system bandwidth, to solve the serious interference problem in UDN. Finally, the simulation results show that the proposed wireless backhaul algorithm has desired performance to achieve higher energy efficiency with required data rate.展开更多
This paper investigates the performance of the W band millimeter wave (mmWave) backhaul network proposed by our EU TWEETHER project. We focus on the downlink transmission of the mmWave backhaul network, in which each ...This paper investigates the performance of the W band millimeter wave (mmWave) backhaul network proposed by our EU TWEETHER project. We focus on the downlink transmission of the mmWave backhaul network, in which each of the hubs serves a cluster of base stations (BSs). In the considered backhaul network, available frequency resources are first allocated to the downlink links with the consideration of fairness issue. In order to mitigate interference in the mmWave backhaul network, each hub operates the proposed algorithm, namely cooperation and power adaptation (CPA). Our simulation results show that, the backhaul network with mmWave capabilities can achieve a significant better throughput performance than the sub-6 GHz ultra high frequency (UHF) backhaul network. Furthermore, our simulations also reveal that the proposed CPA algorithm can efficiently combat interference in the backhaul network.展开更多
In this paper, we give an overview of mobile backhaul solutions and propose an MPLS-centered solution that takes intoaccount timing synchronization, OAM, and protection： We also propose an evolved protection bandwidt...In this paper, we give an overview of mobile backhaul solutions and propose an MPLS-centered solution that takes intoaccount timing synchronization, OAM, and protection： We also propose an evolved protection bandwidth allocation mechanism that makes the transport network as efficient as possible.展开更多
As next generation communication technologies emerge,new high data rate applications and high-definition large-screen video streaming have become very popular.As a result,network traffic has been increasing so much th...As next generation communication technologies emerge,new high data rate applications and high-definition large-screen video streaming have become very popular.As a result,network traffic has been increasing so much that existing backhaul networks soon will not be able to support all traffic demands.To support these needs in future 6G mobile systems,the establishment of an additional backhaul wireless network is considered essential.As one of the solutions,a wireless backhaul network based on an aerial platform has been proposed.In order to explore the potential of aerial platforms as wireless backhaul networks,in this paper,the categories for wireless backhaul networks based on aerial platforms are investigated.This paper includes a survey of the definitions and characteristics of low altitude platforms(LAPs)and high altitude platforms(HAPs),as well as channel models according to the atmosphere.For wireless backhaul network designs based on aerial platforms,altitude and platform selection options,deployment options,energy issues,and security based on target location and performance were considered in the analysis and investigation.展开更多
ZTE Corporation, a leading global provider of telecommunications equipment and network solutions, announced on November 23, 2010 that it has successfully completed the world＇s first large-scale commercial GPON-based ...ZTE Corporation, a leading global provider of telecommunications equipment and network solutions, announced on November 23, 2010 that it has successfully completed the world＇s first large-scale commercial GPON-based mobile backhaul network for TELKOM Indonesia, a full-service telecom operator in Indonesia. The project is the first such large-scale commercialization of GPON backhaul technology,展开更多
Wireless ultra-dense network （UDN） is one of the important technologies to solve the burst of throughput demand in the forthcoming fifth generation （SG） cellular networks. Reusing spectrum resource for the backhau...Wireless ultra-dense network （UDN） is one of the important technologies to solve the burst of throughput demand in the forthcoming fifth generation （SG） cellular networks. Reusing spectrum resource for the backhaul of small base stations （SBSs） is a hotspot research because of lower cost and rapid implementation with macro base stations （MBSs） in recent years. In heterogeneous UDN, the problem of spectrum allocation for wireless backhaul is investigated. In particular, two different spectrum resource reusing strategies for wireless backhaul are proposed in heterogeneous UDN with the limited bandwidth condition. Using a stochastic geometry-based heterogeneous UDN model, the success probabilities that mobile users communicate with SBSs or MBSs are derived under two different spectrum resource reusing strategies. In addition, the network throughput＇s analytical expressions and the optimal ratio of spectrum allocation are derived. Numeral results are provided to evaluate the performance of the proposed strategies at throughput. Thus, the effectiveness of the strategy that mobile users can only communicate with SBSs is validated.展开更多
With the intensive deployment of users and the drastic increase of traffic load, a millimeter wave （mmWave） backhaul network was widely investigated. A typical mmWave backhaul network consists of the macro base stat...With the intensive deployment of users and the drastic increase of traffic load, a millimeter wave （mmWave） backhaul network was widely investigated. A typical mmWave backhaul network consists of the macro base station （MBS） and the small base stations （SBSs）. How to efficiently associate users with the MBS and the SBSs for load balancing is a key issue in the network. By adding a virtual power bias to the SBSs, more users can access to the SBSs to share the load of the MBS. The bias values shall be set reasonably to guarantee the backhaul efficiency and the quality of service （QoS）. An improved Q-learning algorithm is proposed to effectively adjust the bias value for each SBS. In the proposed algorithm, each SBS becomes an agent with independent learning and can achieve the best behavior, namely the optimal bias value through a series of training. Besides, an improved behavior selection mechanism is adopted to improve the learning efficiency and accelerate the convergence of the algorithm. Finally, simulations conducted in the 60 GHz band demonstrate the superior performance of the proposed algorithm in backhaul efficiency and user outage probability.展开更多
文摘In order to improve the Physical Layer Security(PLS)perspective,this paper aims to empower function of PLS by considering a backhaul Non-Orthogonal Multiple Access(NOMA)system in two practical situations.In the proposed schemes,the untrusted user intercepts information transmitted to the far user,or the external eavesdropper overhears confidential information sent to the far user in the context of NOMA technique.Unlike the conventional NOMA systems,this paper emphasizes the actual situations of the existence of actual illegal users and legitimate users,especially the reasonable use of relay selection architecture to improve the confidentiality performance.To evaluate the security properties of the proposed scheme,a comprehensive analysis of the Security Outage Probability(SOP)performance is first performed,and then the corresponding SOP asymptotic expressions are derived for real scenarios related to eavesdroppers and untrusted users.Numerical results are performed to verify the analysis in terms of the secure performance metric.
基金supported in part by the National Science Foundation of China under Grant 61901185 and Grant 61971205。
文摘Heterogeneous networks(Het Nets)attracts a lot of attention due to its high capacity and large coverage for future communication networks.However,with the large-scale deployment of small cells,HetNets bears dramatically increasing backhaul,which leads to a decrease of the outage performance.To improve the outage performance of Het Nets,we propose a wireless backhaul scheme for a two-layer HetNets,which automatically switches the three basic modes of orthogonal multiple access(OMA),nonorthogonal multiple access(NOMA)and cooperative non-orthogonal multiple access(CNOMA).First,we analyze the backhaul capacity and outage performance of these three basic modes.Then,we design the power allocation schemes based on minimizing outage probability for NOMA and CNOMA.Using the designed power allocation schemes,we propose a wireless backhaul scheme that switches the three modes according to the channel quality among different base stations(BSs).Moreover,the closed-form of the corresponding outage probability is derived.Compared with the three basic modes,the proposed wireless backhaul scheme can achieve the best outage performance and a higher backhaul capacity.Finally,all the analytical results are validated by simulations.
基金supported in part by the National Natural Science Foundation of China under Grant 61631003in part by the National Science Fund for Distinguished Young Scholars under Grant 61525101
文摘To reinforce the coverage and QoS(quality of service) of on-ground cellular communication system, unmanned aerial vehicles which are carrying small cells are deployed in some emergency and disaster areas. Although ASCs(aerial small cells) can provide a higher probability of LoS(line-of-sight) transmission, the wireless backhaul link will bring extra interference to the whole system if not well designed. Therefore, in this paper, we study the backhaul scheme for UAV-assist cellular network. We first analyze the interference environments of UAV-assist cellular network considering the IBOG(In-Band to On-Ground), OBOG(Out-of-Band to On-Ground) and IBTU(In-Band to Tethered-UAV) backhauling mode, and give the descriptions of the performance metrics for each mode. Then, the considered problem is formulated as an optimization of achievable rate. We derive the optimal solutions for the involved three backhauling modes for ASCs respectively, and closed-form optimal value for each mode is acquired with proof. We also give a pseudo-code form of our proposed optimal access/backhaul spectrum allocation algorithm. The simulation results indicate that the proposed scheme can deliver a significant gain, while IBTU performs best among proposed backhauling modes.
基金supported by the National High Technical Research and Development Program of China(863 program)(No.2015AA01A705)
文摘A novel user association model for heterogeneous network(Het Net) with dual connectivity(DC) and constrained backhaul is proposed in this paper, where not only the best combination of serving macro cell and small cell for each user to associate is selected but also the optimal traffi c split between the macro cell and small cell is determined to enhance both radio resource effi ciency and backhaul capacity utilization. To solve this optimization problem, an intuitive algorithm based on iteratively solving two sub-problems is proposed. One sub-problem is a binary integer programming problem and a corresponding greedy algorithm is proposed, while the other sub-problem is a simple linear programming problem and can be easily solved. Numerical results show that the proposed model and algorithm can achieve better radio resource effi ciency and backhaul capacity utilization compared with user association in Het Net without DC, which validate the capacity enhancement potentials of radio resource coordination in Het Net with DC.
基金supported in part by the National Natural Science Foundation of China (Grants Nos. 61571351, and 61401326)the important national science & technology specific projects 2015ZX03002006-003Natural Science Basic Research Plan in Shaanxi Province of China (Program Nos. 2016JM6028 and 2016JQ6054)
文摘In this paper, we study the problem of resource allocation in small cell networks with distributed caching, that is, how to divide the spectrum resources for backhaul and access in order to improve network performance. We formulate our concerned problem by using multi-dimensional Markov model. Our problem considers that each user may access multiple small cell base stations. We conduct simulation experiments to evaluate the performance of our proposed resource allocation scheme. Our simulation results show that the appropriate spectrum resource allocation is important to improve network performance.
基金supported in part by National Natural Science Foundation of China No.61171080
文摘Massive MIMO systems offer a high spatial resolution that can drastically increase the spectral and/or energy efficiency by employing a large number of antennas at the base station(BS).In a distributed massive MIMO system,the capacity of fiber backhaul that links base station and remote radio heads is usually limited,which becomes a bottleneck for realizing the potential performance gain of both downlink and uplink.To solve this problem,we propose a joint antenna selection and user scheduling which is able to achieve a large portion of the potential gain provided by the massive MIMO array with only limited backhaul capacity.Three sub-optimal iterative algorithms with the objective of sumrate maximization are proposed for the joint optimization of antenna selection and user scheduling,either based on greedy fashion or Frobenius-norm criteria.Convergence and complexity analysis are presented for the algorithms.The provided Monte Carlo simulations show that,one of our algorithms achieves a good tradeoff between complexity and performance and thus is especially fit for massive MIMO systems.
基金supported by the National Natural Science Foundation of China (No.61831002 and 41861134010)
文摘In this paper,we consider a full-duplex(FD)millimeter wave(mmWave)multiuser integrated access and backhaul(IAB)system with massive MIMO,and the system asymptotic performance and interference cancellation schemes are investigated.First,the asymptotic performance of the IAB system with massive MIMO is analyzed.As the number of macro base station(MBS)and small base station(SBS)antennas approaches infinity,the FD selfinterference(SI),inter-tier interference and noise can be eliminated,which means that only multiuser interference remains in the system.Then,multiuser interference can be suppressed by the base band(BB)precoders.Since all interference and noise are suppressed,the spectral efficiency of the SBS and users are infinite in theory.Then,two interference suppression precoding schemes are proposed.A block diagonalization(BD)-based interference cancellation scheme is designed based on the channel characteristics and null space projection.The FD SI,intertier interference and multiuser interference are eliminated by BB precoders.Instead of eliminating interference completely,a signal to leakage and noise ratio(SLNR)-based precoding scheme is derived to suppress both interference and noise.By utilizing the Rayleigh-Ritz theorem,the SLNRs of the SBS and users are optimized.Simulation results show that all the interference can be effectively eliminated by the BD-based scheme at the cost of spectral efficiency performance loss,while the SLNR-based scheme can balance interference and noise and achieve higher spectral efficiency with comparatively low interference level.Therefore,the BD-based scheme is more suitable for interference elimination cases,and the SLNRbased scheme can improve the system performance in low interference scenarios.
基金supported by the National Research Foundation of Korea(NRF)grant funded by the Korean government(MSIT)(Nos.2019R1A4A1023746,2019R1F1A1060799)the Strengthening R&D Capability Program of Sejong University。
文摘The 5G cellular network aims at providing three major services:Massive machine-type communication(mMTC),ultra-reliable low-latency communications(URLLC),and enhanced-mobile-broadband(eMBB).Among these services,the URLLC and eMBB require strict end-to-end latency of 1 ms while maintaining 99.999%reliability,and availability of extremely high data rates for the users,respectively.One of the critical challenges in meeting these requirements is to upgrade the existing optical fiber backhaul network interconnecting the base stations with a multigigabit capacity,low latency and very high reliability system.To address this issue,we have numerically analyzed 100 Gbit/s coherent optical orthogonal frequency division multiplexing(CO-OFDM)transmission performance over 400 km single-mode fiber(SMF)and 100 km of multi-mode fiber(MMF)links.The system is simulated over optically repeated and non-repeated SMF and MMF links.Coherent transmission is used,and the system is analyzed in a linear and non-linear regime.The system performance is quantified by bit error ratio(BER).Spectrally efficient and optimal transmission performance is achieved for 400 km SMF and 100 km MMF link.The results designate thatMMF links can be employed beyond short reach applications by using them in the existing SMF infrastructure for long haul transmission.In particular,the proposed CO-OFDM system can be efficiently employed in 5G backhaul network.The multi-gigabit capacity and lower BER of the proposed system makes it a suitable candidate especially for the eMBB and URLLC requirements for 5G backhaul network.
基金supported by the National Natural Science Foundation of China (NSFC) under Grants 61427801 and 61671251the Natural Science Foundation Program through Jiangsu Province of China under Grant BK20150852+3 种基金the open research fund of National Mobile Communications Research Laboratory, Southeast University under Grant 2017D05China Postdoctoral Science Foundation under Grant 2016M590481Jiangsu Planned Projects for Postdoctoral Research Funds under Grant 1501018Asupported by NSFC under Grants 61531011 and 61625106
文摘The Internet of things(IoT) as an important application of future communication networks puts a high premium on delay issues. Thus when Io T applications meet heterogeneous networks(HetNets) where macro cells are overlaid with small cells, some traditional problems need rethinking. In this paper, we investigate the delay-addressed association problem in two-tier Het Nets considering different backhaul technologies. Specifically, millimeter wave and fiber links are used to provide high-capacity backhaul for small cells. We first formulate the user association problem to minimize the total delay which depends on the probability of successful transmission, the number of user terminals(UTs), and the number of base stations(BSs). And then two algorithms for active mode and mixed mode are proposed to minimize the network delay. Simulation results show that algorithms based on mutual selection between UTs and BSs have better performance than those based on distance. And algorithms for mixed modes have less delay than those for active mode when the number of BSs is large enough, compared to the number of UTs.
基金supported by the National Natural Science Foundation of China Grants 61725101 and 61801016the China Postdoctoral Science Foundation under Grant 2017M610040 and 2018T110041+2 种基金National key research and development program under Grant 2016YFE0200900the Beijing Natural Fund under Grant L172020Major projects of Beijing Municipal Science and Technology Commission under Grant No. Z181100003218010
文摘With the development of self-interference(SI) cancelation technology, full-duplex(FD) communication becomes possible. FD communication can theoretically double the spectral efficiency. When the time slot(TS) resources are limited and the number of flows is large, the scheduling mechanism of the flows becomes more important. Therefore, the effectiveness of FD scheduling mechanism for the flows is studied in millimeter wave wireless backhaul network with the limited TS resources. We proposed a full duplex concurrent scheduling algorithm based on coalition game(FDCG) to maximize the number of flows with their QoS requirements satisfied. We transformed the problem of maximizing the number of flows with their QoS requirements satisfied into the problem of maximizing sum rate of concurrently scheduled flows in each slot. We obtained the scheduled flows with maximum sum rate in first slot by using coalition game.And then with certain restrictions, the maximum sum rate of concurrently scheduled flows can also be achieved in subsequent time slots. The simulation results show that the proposed FDCG algorithm canachieve superior performance in terms of the number of flows that meet their QoS requirements and system throughput compared with other three algorithms.
基金The National Natural Science Foundation of China(No.61571123,61521061)the Research Fund of National Mobile Communications Research Laboratory of Southeast University(No.2017A03)Qing Lan Project
文摘In the scenario of downlink multicell processing with finite backhaul capacity in the case of two base stations and two mobile users, by regarding the channel as a multiple access diamond channel with two destinations, an achievability scheme that sends correlated codewords through the multiple access channel with common data is proposed. By considering the superposition structure, fully correlated codewords can be supported by the proposed scheme, which can benefit the system throughput in the case of a relatively-large-capacity backhaul. First, an achievable region for the achievable theory is given and it is proved from the perspective of information theory. Then, in the Gaussian scenario, a simulation combining dirty-paper coding and power allocating is provided for the achievable region. Simulation results demonstrate that when the backhaul capacity is relatively large, the proposed scheme outperforms the existing achievability scheme without the superposition structure.
基金jointly supported by the National Natural Science Foundation of China under Grant Nos.61771070 and 61671088the National Science and Technology Major Project under Grant No.2016ZX03001017
文摘Ultra-dense networks （UDNs） are expected to be applied for the fifth generation wireless system （5G） to meet the requirements of very high throughput density and connections of a massive number of users. Considering the large amount of small base stations （SBSs）, how to choose proper backhaul links is an important problem under investigation. In this paper, we propose a wireless backhaul algorithm to find an effective backhaul method for densely-deployed SBSs and to maximize energy efficiency of the system. We put forward adaptive backhaul methods of indirect and direct modes. The SBS can select the direct baekhaul which con- nects to the macro base station （MBS） directly, or the indirect backhaul which selects an idle SBS as a relay based on the backhaul channel condition. The algorithm also allocates network resources, including the power of SBSs and system bandwidth, to solve the serious interference problem in UDN. Finally, the simulation results show that the proposed wireless backhaul algorithm has desired performance to achieve higher energy efficiency with required data rate.
文摘This paper investigates the performance of the W band millimeter wave (mmWave) backhaul network proposed by our EU TWEETHER project. We focus on the downlink transmission of the mmWave backhaul network, in which each of the hubs serves a cluster of base stations (BSs). In the considered backhaul network, available frequency resources are first allocated to the downlink links with the consideration of fairness issue. In order to mitigate interference in the mmWave backhaul network, each hub operates the proposed algorithm, namely cooperation and power adaptation (CPA). Our simulation results show that, the backhaul network with mmWave capabilities can achieve a significant better throughput performance than the sub-6 GHz ultra high frequency (UHF) backhaul network. Furthermore, our simulations also reveal that the proposed CPA algorithm can efficiently combat interference in the backhaul network.
文摘In this paper, we give an overview of mobile backhaul solutions and propose an MPLS-centered solution that takes intoaccount timing synchronization, OAM, and protection： We also propose an evolved protection bandwidth allocation mechanism that makes the transport network as efficient as possible.
基金This work was supported by Institute for Information&communications Technology Promotion(IITP)grant funded by the Korea government(MSIT)(No.2019-0-00685Free space optical communication based vertical mobile network).
文摘As next generation communication technologies emerge,new high data rate applications and high-definition large-screen video streaming have become very popular.As a result,network traffic has been increasing so much that existing backhaul networks soon will not be able to support all traffic demands.To support these needs in future 6G mobile systems,the establishment of an additional backhaul wireless network is considered essential.As one of the solutions,a wireless backhaul network based on an aerial platform has been proposed.In order to explore the potential of aerial platforms as wireless backhaul networks,in this paper,the categories for wireless backhaul networks based on aerial platforms are investigated.This paper includes a survey of the definitions and characteristics of low altitude platforms(LAPs)and high altitude platforms(HAPs),as well as channel models according to the atmosphere.For wireless backhaul network designs based on aerial platforms,altitude and platform selection options,deployment options,energy issues,and security based on target location and performance were considered in the analysis and investigation.
文摘ZTE Corporation, a leading global provider of telecommunications equipment and network solutions, announced on November 23, 2010 that it has successfully completed the world＇s first large-scale commercial GPON-based mobile backhaul network for TELKOM Indonesia, a full-service telecom operator in Indonesia. The project is the first such large-scale commercialization of GPON backhaul technology,
基金supported by the Science and Technology Research Program of Chongqing Municipal Education Commission (KJ1704095)
文摘Wireless ultra-dense network （UDN） is one of the important technologies to solve the burst of throughput demand in the forthcoming fifth generation （SG） cellular networks. Reusing spectrum resource for the backhaul of small base stations （SBSs） is a hotspot research because of lower cost and rapid implementation with macro base stations （MBSs） in recent years. In heterogeneous UDN, the problem of spectrum allocation for wireless backhaul is investigated. In particular, two different spectrum resource reusing strategies for wireless backhaul are proposed in heterogeneous UDN with the limited bandwidth condition. Using a stochastic geometry-based heterogeneous UDN model, the success probabilities that mobile users communicate with SBSs or MBSs are derived under two different spectrum resource reusing strategies. In addition, the network throughput＇s analytical expressions and the optimal ratio of spectrum allocation are derived. Numeral results are provided to evaluate the performance of the proposed strategies at throughput. Thus, the effectiveness of the strategy that mobile users can only communicate with SBSs is validated.
基金supported by the State Major Science and Technique Project (MJ-2014-S-37)the 111 Project (B08038)
文摘With the intensive deployment of users and the drastic increase of traffic load, a millimeter wave （mmWave） backhaul network was widely investigated. A typical mmWave backhaul network consists of the macro base station （MBS） and the small base stations （SBSs）. How to efficiently associate users with the MBS and the SBSs for load balancing is a key issue in the network. By adding a virtual power bias to the SBSs, more users can access to the SBSs to share the load of the MBS. The bias values shall be set reasonably to guarantee the backhaul efficiency and the quality of service （QoS）. An improved Q-learning algorithm is proposed to effectively adjust the bias value for each SBS. In the proposed algorithm, each SBS becomes an agent with independent learning and can achieve the best behavior, namely the optimal bias value through a series of training. Besides, an improved behavior selection mechanism is adopted to improve the learning efficiency and accelerate the convergence of the algorithm. Finally, simulations conducted in the 60 GHz band demonstrate the superior performance of the proposed algorithm in backhaul efficiency and user outage probability.
