In limited feedback-based CloudRAN(C-RAN) systems,the inter-cluster and intra-cluster interference together with the quantification error can seriously deteriorates the system spectral efficiency.We,in this paper,prop...In limited feedback-based CloudRAN(C-RAN) systems,the inter-cluster and intra-cluster interference together with the quantification error can seriously deteriorates the system spectral efficiency.We,in this paper,propose an efficient three-phase framework and corresponding algorithms for dealing with this problem.Firstly,a greedy scheduling algorithm based on the lower bound of the ergodic rate is performed for generating an elementary cluster in the first phase.And then the elementary cluster is divided into many small clusters according to the following proposed algorithms based on the short term instantaneous information in the second phase.In the end,based on the limited feedback two zero-forcing(ZF) precoding strategies are adopted for reducing the intra-cluster interference in the third phase.The provided Monte Carlo simulations show the effectiveness of our proposed algorithms in the respect of system spectral efficiency and average user rate.展开更多
This paper investigates the device-to-device(D2D) communication underlaying cellular network assisted by a two-way decode-and-forward relay node. We assume the base station(BS) is equipped with M-antenna and serves it...This paper investigates the device-to-device(D2D) communication underlaying cellular network assisted by a two-way decode-and-forward relay node. We assume the base station(BS) is equipped with M-antenna and serves its own cellular user while the D2D users communicate via a two-way decode-and-forward relay node. Both beamforming(BF) and interference cancellation(IC) strategies at the BS are considered to improve the performance for the cellular link and D2D link, respectively. We first analyze the received signal-to-interference-plus-noise for the cellular link under BF and IC strategies and then derive the exact closed-form expressions for the cellular link. Asymmetric and symmetric cases are discussed for various locations of each user. Finally, the approximations for high signal-to-noise regime are also presented. Numerical results demonstrate the accuracy of the analytical and asymptotic results.展开更多
In 3G networks upgraded with high speed packet access(HSPA) technology,the high access bandwidth and advanced mobile devices make it applicable to share large files among mobile users by peer-to-peer applications.To r...In 3G networks upgraded with high speed packet access(HSPA) technology,the high access bandwidth and advanced mobile devices make it applicable to share large files among mobile users by peer-to-peer applications.To receive files as quickly as possible is essential for mobile users in file sharing applications,since they are subject to unstable signal strength and battery failures.While many researches present peer-to-peer file sharing architectures in mobile environments,few works focus on decreasing the time spent in disseminating files among users.In this paper,we present an efficient peer-to-peer file sharing design for HSPA networks called efficient file sharing(EFS) for 3G networks.EFS can decrease the dissemination time by efficiently utilizing the upstream-bandwidth of mobile nodes.It uses an adaptive rearrangement of a node's concurrent uploading transfers,which causes the count of the node's concurrent uploading transfers to lower while ensuring that the node's upstream-bandwidth can be efficiently utilized.Our simulations show that,EFS achieves much less dissemination time than other protocols including Bullet Prime and a direct implementation of BitTorrent for mobile environments.展开更多
基金supported by the National Natural Science Foundation of China(NSFC) under Grant(No. 61461136001)
文摘In limited feedback-based CloudRAN(C-RAN) systems,the inter-cluster and intra-cluster interference together with the quantification error can seriously deteriorates the system spectral efficiency.We,in this paper,propose an efficient three-phase framework and corresponding algorithms for dealing with this problem.Firstly,a greedy scheduling algorithm based on the lower bound of the ergodic rate is performed for generating an elementary cluster in the first phase.And then the elementary cluster is divided into many small clusters according to the following proposed algorithms based on the short term instantaneous information in the second phase.In the end,based on the limited feedback two zero-forcing(ZF) precoding strategies are adopted for reducing the intra-cluster interference in the third phase.The provided Monte Carlo simulations show the effectiveness of our proposed algorithms in the respect of system spectral efficiency and average user rate.
基金supported by the National Science Foundation for Distinguished Young Scholars of China(No.61701201)the Natural Science Foundation of Jiangsu Province(No.BK20170758,BK20170757)+1 种基金the Natural Science Foundation for colleges and universities of Jiangsu Province(No.17KJB510011)Project of Key Laboratory of Wireless Communications of Jiangsu Province
文摘This paper investigates the device-to-device(D2D) communication underlaying cellular network assisted by a two-way decode-and-forward relay node. We assume the base station(BS) is equipped with M-antenna and serves its own cellular user while the D2D users communicate via a two-way decode-and-forward relay node. Both beamforming(BF) and interference cancellation(IC) strategies at the BS are considered to improve the performance for the cellular link and D2D link, respectively. We first analyze the received signal-to-interference-plus-noise for the cellular link under BF and IC strategies and then derive the exact closed-form expressions for the cellular link. Asymmetric and symmetric cases are discussed for various locations of each user. Finally, the approximations for high signal-to-noise regime are also presented. Numerical results demonstrate the accuracy of the analytical and asymptotic results.
基金the National High Technology Research and Development Program (863) of China (No.2007AA01Z457)the Science and Technology Youth Qi-ming-xing Program of Shanghai (No.07QA14033)
文摘In 3G networks upgraded with high speed packet access(HSPA) technology,the high access bandwidth and advanced mobile devices make it applicable to share large files among mobile users by peer-to-peer applications.To receive files as quickly as possible is essential for mobile users in file sharing applications,since they are subject to unstable signal strength and battery failures.While many researches present peer-to-peer file sharing architectures in mobile environments,few works focus on decreasing the time spent in disseminating files among users.In this paper,we present an efficient peer-to-peer file sharing design for HSPA networks called efficient file sharing(EFS) for 3G networks.EFS can decrease the dissemination time by efficiently utilizing the upstream-bandwidth of mobile nodes.It uses an adaptive rearrangement of a node's concurrent uploading transfers,which causes the count of the node's concurrent uploading transfers to lower while ensuring that the node's upstream-bandwidth can be efficiently utilized.Our simulations show that,EFS achieves much less dissemination time than other protocols including Bullet Prime and a direct implementation of BitTorrent for mobile environments.
