Device-to-device(D2D)communication is considered as a major challenge in the long term evolution(LTE)network wherein devices directly communicate with each other.One of the key challenges in D2D sidelink is reliable a...Device-to-device(D2D)communication is considered as a major challenge in the long term evolution(LTE)network wherein devices directly communicate with each other.One of the key challenges in D2D sidelink is reliable and reduced-complexity synchronization.To address this issue,a computationally efficient sequential detection scheme for integer carrier frequency offset and sidelink identity is proposed in the LTE-D2D system.To perform the frequency offset detection without retrieving the sidelink identity,the conjugate relation between two primary sidelink synchronization sequences is exploited,which facilitates the detection tasks of frequency offset and sidelink identity to be decoupled.It is demonstrated from simulation results that the inherent property of the sidelink synchronization sequences is effectively used for joint detection of frequency offset and sidelink identity with significantly reduced complexity,compared to existing estimation schemes.展开更多
第五代(5th Generation,5G)无线通信系统除了支持蜂窝通信,还支持侧行链路(Sidelink,SL)通信,即两个用户设备(User Equipment,UE)之间可以直接通信,而不需要经过基站中转,有利于降低传输时延、提升资源利用率。在现有的SL分布式系统中,...第五代(5th Generation,5G)无线通信系统除了支持蜂窝通信,还支持侧行链路(Sidelink,SL)通信,即两个用户设备(User Equipment,UE)之间可以直接通信,而不需要经过基站中转,有利于降低传输时延、提升资源利用率。在现有的SL分布式系统中,主要通过简单的能量测量进行干扰规避,资源复用准则欠佳,导致中高用户密度场景下吞吐受限。为此,提出了一种基于分布式功率控制的SL高谱效传输机制。各发送UE基于目标链路的信道状态信息(Channel State Information,CSI)和其他干扰链路的CSI进行功率优化,以实现局部范围内多个通信链路的和吞吐最大化;进一步,设计了广播式的CSI测量上报机制能实现多链路的分布式功率控制和资源选择。仿真结果表明,所提方案相比于现有的SL分布式资源分配机制,在中高用户密度下可获得30%~100%的吞吐增益;此外,所提方案相比于现有WiFi的载波侦听多址(Carrier Sense Multiple Access,CSMA)分布式信道接入机制,在中高用户密度下可获得50%~200%的吞吐增益。展开更多
The use of unmanned aircraft systems(UAS)for critical public service missions by public organizations,local governments,and social users is expanding.Robust radio transmission by unmanned aerial vehicles(UAVs)is indis...The use of unmanned aircraft systems(UAS)for critical public service missions by public organizations,local governments,and social users is expanding.Robust radio transmission by unmanned aerial vehicles(UAVs)is indispensable in these applications.One of the standards suitable for UAV wireless communications is local 5G.However,to introduce local 5G into a UAS,several problems specific to UASes must be solved.Challenges include the deterioration of the signal-to-noise ratio due to topography and obstacles,the uncertainty of the communication environment due to the movement of multiple UAVs,and the limitation of the frequency bandwidth.To address these problems and to introduce local 5G into the UAS,we propose a novel communication scheduling method.The method incorporates transmission modes with diversity.Our evaluations shows that total data volumes increase by 1.9~3 times with the proposed scheduling method compared with transmission without diversity or efficient scheduling.展开更多
基金This research was supported by Basic Science Research Program through the National Research Foundation of Korea(NRF)funded by the Ministry of Education(NRF-2018R1D1A1B07048819).
文摘Device-to-device(D2D)communication is considered as a major challenge in the long term evolution(LTE)network wherein devices directly communicate with each other.One of the key challenges in D2D sidelink is reliable and reduced-complexity synchronization.To address this issue,a computationally efficient sequential detection scheme for integer carrier frequency offset and sidelink identity is proposed in the LTE-D2D system.To perform the frequency offset detection without retrieving the sidelink identity,the conjugate relation between two primary sidelink synchronization sequences is exploited,which facilitates the detection tasks of frequency offset and sidelink identity to be decoupled.It is demonstrated from simulation results that the inherent property of the sidelink synchronization sequences is effectively used for joint detection of frequency offset and sidelink identity with significantly reduced complexity,compared to existing estimation schemes.
文摘第五代(5th Generation,5G)无线通信系统除了支持蜂窝通信,还支持侧行链路(Sidelink,SL)通信,即两个用户设备(User Equipment,UE)之间可以直接通信,而不需要经过基站中转,有利于降低传输时延、提升资源利用率。在现有的SL分布式系统中,主要通过简单的能量测量进行干扰规避,资源复用准则欠佳,导致中高用户密度场景下吞吐受限。为此,提出了一种基于分布式功率控制的SL高谱效传输机制。各发送UE基于目标链路的信道状态信息(Channel State Information,CSI)和其他干扰链路的CSI进行功率优化,以实现局部范围内多个通信链路的和吞吐最大化;进一步,设计了广播式的CSI测量上报机制能实现多链路的分布式功率控制和资源选择。仿真结果表明,所提方案相比于现有的SL分布式资源分配机制,在中高用户密度下可获得30%~100%的吞吐增益;此外,所提方案相比于现有WiFi的载波侦听多址(Carrier Sense Multiple Access,CSMA)分布式信道接入机制,在中高用户密度下可获得50%~200%的吞吐增益。
基金Part of this work was conducted under a national project,Research and Development of Communication Network Technology for Ef☀-cient Use of Frequency in Unmanned Aircraft Systems,which was supported by the Ministry of Internal Affairs and Communications(MIC),Japan,and this project was supported by the KDDI Foundation,Japan.The associate editor coordinating the review of this paper and approving it for publication was L.Bai.
文摘The use of unmanned aircraft systems(UAS)for critical public service missions by public organizations,local governments,and social users is expanding.Robust radio transmission by unmanned aerial vehicles(UAVs)is indispensable in these applications.One of the standards suitable for UAV wireless communications is local 5G.However,to introduce local 5G into a UAS,several problems specific to UASes must be solved.Challenges include the deterioration of the signal-to-noise ratio due to topography and obstacles,the uncertainty of the communication environment due to the movement of multiple UAVs,and the limitation of the frequency bandwidth.To address these problems and to introduce local 5G into the UAS,we propose a novel communication scheduling method.The method incorporates transmission modes with diversity.Our evaluations shows that total data volumes increase by 1.9~3 times with the proposed scheduling method compared with transmission without diversity or efficient scheduling.
