【作者】 杨波；

【导师】 唐友喜；

【作者基本信息】 电子科技大学 ， 通信与信息系统， 2011， 博士

【摘要】 分布式天线技术能够极大地提高无线通信系统的频谱效率,因此被看作是第四代移动通信系统的一个显著特征。无线资源管理(radio resource management, RRM)在分布式天线系统(distributed antenna system, DAS)中具有重要作用,直接影响系统性能。由于采用了分布式天线,传统的以基站为中心的小区被以用户为中心的虚拟小区所取代,并且带来了空间/天线资源的分配问题。这使得正交频分复用(orthogonal frequency division multiplexing, OFDM)资源分配也变得更加复杂。因此,本文针对基于分布式天线的无线资源管理技术展开研究,主要包括天线选择、接入控制以及OFDM资源分配等。首先,针对CDMA分布式天线系统上行链路,提出了基于发射功率最小化的天线动态选择算法。通过在接收比特信干噪比与接收机复杂度之间进行折中,动态地选择用户的虚拟小区天线,在保证用户业务质量的前提下最小化移动终端平均发射功率。其次,针对TDD-CDMA分布式天线系统上行链路,提出了基于干扰功率预测的接入控制算法。利用CDMA系统中的干扰功率预测方法,推导了基于分布式天线的上行链路负载因子,建立了干扰功率预测的数学模型,并在此基础上给出了接入控制算法。接着,针对多用户OFDM分布式天线系统下行链路,提出了基于图论方法的资源分配算法。根据单小区OFDM蜂窝系统最优资源分配策略,构造了一个定向图,将资源分配问题转化为网络流中的线性最优分布问题,并给出了相应的算法,在保证用户要求的最小子载波数目前提下最大化系统速率容量。最后,针对多用户OFDM分布式天线系统下行链路,提出了基于共享准则的资源分配算法。在第一种算法中,子载波可通过不同分布式天线分配给多个用户。然后,通过控制同信道干扰造成的速率恶化对该算法进行了改进,以便在速率容量和用户公平性之间进行折中。本文为基于分布式天线的无线资源管理研究提供了一些方法,并充实了现有的无线资源管理算法。所提出的算法具有一定的理论和实用价值。更多还原

【Abstract】 Distributed antenna technology can enhance dramatically spectrum efficiency of wireless communication systems and be viewed as a remarkable feature of the fourth generation mobile communication system. Radio resource management (RRM) plays a vital role in distributed antenna system (DAS) and directly affects the performance of the system.Due to distributed antennas, the traditional base-station-centered cell is replaced with the user-centered virtual cell (VC) and the space/antenna resource allocation problem is introduced. It makes the OFDM resource allocation problem more complex. Therefore, some RRM techniques based on distributed antenna, including antenna selection, admission control and OFDM resource allocation, are explored in this dissertation.First, an antenna dynamic selection algorithm is proposed based on the transmit power minimization for the uplink in CDMA distributed antenna system. By making a tradeoff between received bit signal-to-interference plus noise ratio and complexity of receiver, we select dynamically the antennas in VC so that the average transmit power of mobile terminals could be minimized under guaranteeing quality of service of users.Second, we provide an admission control algorithm based on interference power estimation for the uplink in TDD-CDMA distributed antenna system. Using interference power estimation method in CDMA system, we derive the uplink load factor based on distributed antennas and establish a mathematical model to estimate the interference power. Then the admission control algorithm is based on this model.Next, a resource allocation algorithm is presented based on graph theory method for the downlink in multi-user OFDM distributed antenna system. According to the optimal resource allocation strategy in the single cell OFDM cellular system, we construct a directed graph and transform the resource allocation problem into a linear optimal distribution problem in network flows. Then the resource allocation algorithm is given to maximize system rate capacity under guaranteeing the minimum number of subcarriers for each user.Finally, resource allocation algorithms are proposed based on shared criterion for the downlink in multi-user OFDM distributed antenna system. In the first algorithm, each subcarrier may be allocated to multiple users through different distributed antenna. Then, by imposing limitation on rate deterioration due to co-channel interference, we improve this algorithm so as to make a tradeoff between the rate capacity and user fairness.In this dissertation, we provide some methods for the research on RRM based on distributed antennas and make a supplement to the existing RRM algorithms. The proposed algorithms are of some values to theory and practice.更多还原