小区间的干扰协调在LTE系统中的应用

发布时间：2018-11-23 17:43

【摘要】：随着无线通信的迅速发展,越来越多的人开始使用无线终端进行通信,这就使得频谱资源变得尤为珍贵。另外,下一代移动通信应该以最低的价格满足高质量服务为要求,比如高清晰的视频,高速度的网络等。但是,频谱资源得不到有效利用就无法满足这些需求。为了满足用户的需求,LTE采用OFDM技术,解决了小区内干扰,大大提升了系统的性能。LTE系统与传统的3G网络最大的不同,是采用了正交频分复用(Orthogonal Frequency Division Multiplexing,OFDM),OFDM可以使小区内用户使用的频率资源两两正交,克服了小区内干扰。同时,在小区间由于采用了同频复用的网络覆盖策略,导致了严重的小区间干扰。如何克服小区间干扰,是当下LTE系统研究的关键与热点。为了解决这个问题,3GPP提出了小区间干扰协调技术。传统的干扰协调方案大多数是从频率角度来对资源进行调度,使得边缘用户的频率相互正交,这样就能极大的减弱小区间的干扰。还有一部分干扰协调方案从时域角度对资源进行调度,使得小区边缘的相邻用户之间受到调用的时间相互正交,同样能减弱小区间的干扰。本论文在传统干扰协调方案的基础上,从频域与时域相结合的角度提出了两个干扰协调算法。1)一种基于时频二维的干扰协调方案RSFR:首先分析了传统频域干扰协调方案和时域干扰协调方案的优缺点,然后提出了一种时域和频域相结合的干扰协调方案,该方案允许边缘用户在整个频段上选择最好的资源块进行调度,有效提升了频率选择增益和系统吞吐量。2)一种基于时频二维的动态干扰协调方案DRSFR:首先分析了RSFR的优缺点,在RSFR方案的基础上,提出了一种基于时频二维的动态方案DRSFR,进一步解决了RSFR中边缘用户吞吐量不均匀的问题。为了对所提出的两个方案进行正确性和可行性的验证,本次论文在MATLAB系统级平台上对两个方案进行了仿真。仿真结果显示,RSFR方案和DRSFR方案可以有效提升频率选择增益,抑制了小区间的干扰,进一步提升了小区的整体性能。DRSFR方案相对于静态的RSFR方案而言,进一步解决了边缘用户吞吐量不均匀的问题,提升了系统的公平性。
[Abstract]:With the rapid development of wireless communication, more and more people begin to use wireless terminals to communicate. In addition, the next generation mobile communication should meet the requirements of high quality services at the lowest price, such as high definition video, high speed network and so on. However, the spectrum resources can not be used effectively to meet these needs. In order to meet the needs of users, LTE adopts OFDM technology to solve intra-cell interference and greatly improve the performance of the system. The greatest difference between the LTE system and the traditional 3G network is the use of orthogonal Frequency Division Multiplexing (Orthogonal Frequency Division Multiplexing,OFDM). OFDM can make the frequency resources used by the users in the cell to be two and two orthogonal, and overcome the interference in the cell. At the same time, due to the use of the same frequency multiplexing network coverage strategy in the cell, resulting in serious inter-cell interference. How to overcome inter-cell interference is the key and hotspot of current LTE system research. In order to solve this problem, 3GPP proposed the inter-cell interference coordination technique. Most of the traditional interference coordination schemes schedule resources from the frequency perspective, which makes the frequency of edge users orthogonal to each other, which can greatly reduce the interference of the cell. Another part of the interference coordination scheme schedules the resources from the time domain point of view, which makes the time between the adjacent users on the edge of the cell orthogonal to each other, and it can also reduce the interference of the cell. This thesis is based on the traditional interference coordination scheme. Two interference coordination algorithms are proposed from the point of view of the combination of frequency domain and time domain. 1) an interference coordination scheme based on time-frequency two-dimensional (RSFR:) is proposed. Firstly, the advantages and disadvantages of the traditional interference coordination scheme in frequency domain and time domain interference coordination scheme are analyzed. Then an interference coordination scheme combining time domain and frequency domain is proposed, which allows edge users to select the best resource blocks for scheduling in the whole frequency band. (2) A dynamic interference coordination scheme based on time-frequency two-dimensional (DRSFR:). Firstly, the advantages and disadvantages of RSFR are analyzed. On the basis of RSFR scheme, a dynamic scheme based on time-frequency 2-D (DRSFR,) is proposed. Furthermore, the problem of uneven throughput of edge users in RSFR is solved. In order to verify the correctness and feasibility of the proposed two schemes, this paper simulates the two schemes on the MATLAB platform. The simulation results show that the RSFR scheme and the DRSFR scheme can effectively enhance the frequency selection gain, suppress the interference between the cells, and further improve the overall performance of the cell. Compared with the static RSFR scheme, the DRSFR scheme is more effective than the static RSFR scheme. Furthermore, the problem of uneven throughput of edge users is solved, and the fairness of the system is improved.
【学位授予单位】：南京邮电大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：TN929.5

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