多播广播单频网无线资源管理策略研究

发布时间：2018-06-03 17:32

本文选题：MBSFN + 分集增益　；参考：《电子科技大学》2015年硕士论文

【摘要】：多播广播单频网(Multicast Broadcast Single Frequency Network,MBSFN)为第三代合作伙伴计划(The Third Generation Partner Project,3GPP)在演进多播组播多媒体服务(Evolved-Multimedia Broadcast and Multicast Service,E-MBMS)中引入的新的传输方式。MBSFN的各小区同时同频传输相同的业务的特性,使得MBSFN用户能够接收来自多个小区的分集增益,从而有效解决了多播组播多媒体服务(Multimedia Broadcast and Multicast Service,MBMS)中对无线资源利用不充分、业务接收不稳定以及盲区覆盖等问题,极大提高了频谱利用率和覆盖率。然而,MBSFN作为一种增强性的多播方式,虽然增强了多播业务的传输性能,但其在资源分配时依然受到信道质量差用户的限制,使得信道质量好的用户无法充分利用信道资源。在MBSFN中,所有的MBSFN小区使用相同的资源同时发送多播业务,如若根据信道质量最差用户来分配多播资源,MBSFN的统一资源分配特性会使得某些信道质量差用户影响到整个单频网的资源分配,从而多个小区的用户无法充分利用信道资源,甚至会对某些小区产生过高的负载,而影响该小区下其他用户的业务质量。针对该问题,本文设计了MBSFN下基于设备到设备(Device to Device,D2D)中继的协作多播策略。该策略利用D2D技术,让信道质量差用户通过D2D中继得到业务保证,从而在对MBSFN多播进行资源调度时可以不考虑信道质量差用户的限制,而充分利用多播信道资源。当有信道质量差用户的多播业务无法得到保障时,通过信道质量好用户中继多播数据来保障信道质量差用户多播业务的需求,从而最终达到充分利用多播信道资源,保障用户业务需求的目的。另外,根据MBSFN的传输特性及3GPP标准的规定,MBSFN下的Idle态用户也能接收多播业务,且当用户从MBSFN小区移动到一般小区时传统小区重选无法保证其业务连续性。因此,在MBSFN边缘的Idle态用户小区重选,需要考虑业务连续性的问题。其次,MBSFN分集增益的特性,使得小区的参考信号强度已不足以表征多播信道质量的好坏,一般小区重选方法已不足以保证其重选的有效性。因此,为了保证Idle态用户从MBSFN边缘移动到非MBSFN小区时的业务连续性,提高小区重选的性能,本文根据Idle态用户在MBSFN传输方式下的特殊性以及MBSFN的分集增益特点,设计了多播广播单频网边缘的小区重选策略。该策略使用多播广播单频网参考信号以及根据多播信道质量决定信道切换时刻,保证用户在MBSFN边缘重选时业务连续性,同时减少不必要的小区重选,充分利用多播资源,提高了小区重选效率。
[Abstract]:Multicast Broadcast Single Frequency Network (MBSFN) is the third generation partner program, the Third Generation Partner Project 3GPP, introduced in the evolving multicast multimedia service, Evolved-Multimedia Broadcast and Multicast Service E-MBMS.MBSFN 's cells transmit the same services at the same time as frequency. This enables MBSFN users to receive diversity gains from multiple cells, thus effectively solving the problems of inadequate utilization of wireless resources, unstable service reception and blind area coverage in multicast multimedia service (Multimedia Broadcast and Multicast Service MMS). The spectrum efficiency and coverage are greatly improved. However, as an enhanced multicast mode, MBSFN enhances the transmission performance of multicast services, but it is still limited by poor channel quality users in resource allocation, which makes the users with good channel quality unable to make full use of channel resources. In MBSFN, all MBSFN cells use the same resources to send multicast services at the same time, If multicast resources are allocated according to the worst users of the channel, the unified resource allocation characteristics of MBSFN will cause some poor channel users to affect the resource allocation of the whole single-frequency network, so that the users in multiple cells cannot make full use of the channel resources. It may even cause excessive load on some cells and affect the service quality of other users in the cell. To solve this problem, this paper designs a cooperative multicast strategy based on device to device D2D relay in MBSFN. In this strategy, D2D technology is used to ensure the service of the poor channel users through D2D relay, so that the resource scheduling of MBSFN multicast can make full use of the multicast channel resources without considering the limitations of the poor channel users. When the multicast service with poor channel quality can not be guaranteed, the demand of multicast service can be guaranteed by relaying multicast data to the users with good channel quality, so as to make full use of the multicast channel resources. The purpose of protecting the user's business needs. In addition, according to the transmission characteristics of MBSFN and the regulation of 3GPP standard, the Idle users under MBSFN can also receive multicast services, and the traditional cell reselection can not guarantee its business continuity when the user moves from the MBSFN cell to the general cell. Therefore, the problem of business continuity should be considered when the Idle user cell is reselected at the edge of MBSFN. Secondly, because of the characteristic of MBSFN diversity gain, the cell reference signal strength is not enough to characterize the quality of the multicast channel, and the general cell reselection method is not enough to ensure the effectiveness of the cell reselection. Therefore, in order to ensure the business continuity of Idle users moving from the edge of MBSFN to non-MBSFN cells and improve the performance of cell reselection, according to the particularity of Idle users in MBSFN transmission mode and the characteristics of MBSFN diversity gain, A cell reselection strategy for the edge of multicast single frequency network is designed. In this strategy, the multicast single frequency network reference signal is used and the channel switching time is determined according to the quality of the multicast channel, which ensures the business continuity during the MBSFN edge reselection, reduces unnecessary cell reselection, and makes full use of the multicast resources. The efficiency of cell gravity selection is improved.
【学位授予单位】：电子科技大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TN929.5

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