【摘要】：目前,新的移動(dòng)通信系統(tǒng)在寬帶化的過程中,所支持的數(shù)據(jù)數(shù)率不斷提升,所能夠提供的業(yè)務(wù)類型不斷擴(kuò)展。在業(yè)務(wù)量激增的情況下,小區(qū)內(nèi)的業(yè)務(wù)分布會(huì)更加不均勻,在一些用戶分布比較集中的地方會(huì)形成數(shù)據(jù)業(yè)務(wù)熱點(diǎn)區(qū)域。傳統(tǒng)的網(wǎng)絡(luò)拓?fù)浣Y(jié)構(gòu)一方面很可能會(huì)導(dǎo)致處于小區(qū)邊緣的熱點(diǎn)區(qū)域內(nèi)用戶的接收SINR較低、QoS嚴(yán)重下降；另一方面也不利于提升系統(tǒng)的頻譜效率。針對(duì)此問題,3GPP在LTE-A標(biāo)準(zhǔn)中引入了異構(gòu)網(wǎng)絡(luò)的概念。在LTE-A異構(gòu)網(wǎng)絡(luò)中,針對(duì)上述熱點(diǎn)區(qū)域,將采用Pico和Femto等低功率節(jié)點(diǎn)進(jìn)行小范圍同頻覆蓋從而提升這些區(qū)域內(nèi)用戶的QoS。但與此同時(shí),同頻組網(wǎng)會(huì)在微小區(qū)和宏小區(qū)之間引入嚴(yán)重的小區(qū)間干擾。異構(gòu)網(wǎng)絡(luò)復(fù)雜的拓?fù)浣Y(jié)構(gòu)和干擾場(chǎng)景使得傳統(tǒng)的小區(qū)間干擾協(xié)調(diào)(ICIC, Inter-Cell Interference Coordination)技術(shù)難以適用。因此,必須有針對(duì)性的提出增強(qiáng)型ICIC (eICIC, enhanced ICIC)技術(shù)。 目前主要的eICIC技術(shù)包括：小區(qū)范圍擴(kuò)展、時(shí)域eICIC以及一些新技術(shù)輔助的eICIC。小區(qū)范圍擴(kuò)展是指通過設(shè)置一定的小區(qū)選擇偏置值讓更多用戶接入到微小區(qū),從而實(shí)現(xiàn)宏小區(qū)和微小區(qū)之間的負(fù)載均衡；時(shí)域eICIC是指讓宏小區(qū)在物理層下行信道上空出一些幾乎空白子幀(ABS)來為受干擾較為嚴(yán)重的微小區(qū)用戶提供一些時(shí)域調(diào)度資源,從而減小下行干擾；其他一些eICIC技術(shù)主要以功率控制或載波聚合為基礎(chǔ)來解決異構(gòu)網(wǎng)絡(luò)的小區(qū)間干擾問題。 本文提出了一種LTE-A異構(gòu)網(wǎng)絡(luò)時(shí)域eICIC優(yōu)化方案。該方案基于LTE網(wǎng)絡(luò)架構(gòu),在不影響原有的宏小區(qū)之間資源分配方案的前提下,針對(duì)引入Pico小區(qū)之后的異構(gòu)場(chǎng)景,有效地解決了重疊小區(qū)之間的下行干擾問題。該方案采用了小區(qū)范圍擴(kuò)展技術(shù)和時(shí)域eICIC技術(shù),通過將兩種技術(shù)相結(jié)合,建立合理的數(shù)學(xué)模型,求解出最佳的小區(qū)范圍擴(kuò)展偏置值和宏小區(qū)ABS配置比例。與靜態(tài)時(shí)域eICIC技術(shù)相比,該方案很大程度上提升了受干擾用戶的接收SINR和Pico小區(qū)的吞吐率。 另一方面,就Femto小區(qū)而言,由于其采用了封閉用戶組(CSG)的接入限制,沒有接入權(quán)限的用戶在非�？拷麱emto小區(qū)時(shí)會(huì)受到其強(qiáng)烈的下行干擾。為了解決宏小區(qū)、Pico和Femto小區(qū)共存場(chǎng)景下的小區(qū)間干擾問題,本文分析了時(shí)域eICIC用于Femto小區(qū)存在的場(chǎng)景時(shí)所面臨的問題,并在Macro小區(qū)和Pico小區(qū)同頻異構(gòu)組網(wǎng)場(chǎng)景下時(shí)域eICIC方案的基礎(chǔ)上針對(duì)這些問題進(jìn)行了進(jìn)一步的方案優(yōu)化。經(jīng)系統(tǒng)級(jí)仿真驗(yàn)證,優(yōu)化方案在保證不同小區(qū)之間用戶公平性的條件下可以較大程度地提升宏小區(qū)和Pico小區(qū)的吞吐率
[Abstract]:At present, the new mobile communication system in the process of broadband, the number of supported data rate is increasing, and the types of services that can be provided continue to expand. In the case of traffic surge, the distribution of services in the cell will be more uneven, in some places where the user distribution is more concentrated, data service hot spots will be formed. On the one hand, the traditional network topology may lead to a serious decline in the received SINR of users in the hot area on the edge of the cell; on the other hand, it is not conducive to improving the spectral efficiency of the system. In order to solve this problem, 3GPP introduces the concept of heterogeneous network in LTE-A standard. In LTE-A heterogeneous networks, low power nodes, such as Pico and Femto, will be used to cover the same frequency in small range in order to improve the QoS of users in these areas. But at the same time, the same frequency network will introduce severe inter-cell interference between microcell and macro cell. The complex topology and interference scene of heterogeneous networks make the traditional ICIC (Inter-Cell interference Coordination) technology difficult to apply. Therefore, the enhanced ICIC (eICIC, enhanced ICIC) technology must be proposed. At present, the main technologies of eICIC include: cell range expansion, time domain eICIC and some new technology assisted eICs. The extension of cell scope refers to the load balancing between macro cell and micro cell by setting certain cell selection bias value to enable more users to access to microcell. Time domain eICIC is to let macro cell produce some almost blank sub-frames (ABS) over the downlink channel of physical layer to provide some time domain scheduling resources for the users with serious interference, so as to reduce the downlink interference. Some other eICIC technologies are mainly based on power control or carrier convergence to solve the problem of inter-cell interference in heterogeneous networks. This paper presents a time domain eICIC optimization scheme for LTE-A heterogeneous networks. This scheme is based on the LTE network architecture, and without affecting the original resource allocation scheme between macro cells, the downlink interference between overlapped cells is effectively solved for the heterogeneous scene after the introduction of Pico cells. By combining the two techniques, a reasonable mathematical model is established to solve the optimal cell range expansion bias value and the ratio of macro cell ABS configuration. The proposed scheme adopts the cell scope expansion technology and the time domain eICIC technology. Compared with the static time domain eICIC technology, the proposed scheme greatly improves the receiver throughput of SINR and Pico cells. On the other hand, as far as the Femto cell is concerned, because of the access restriction of the closed subscriber group (CSG), the users without access rights will be subjected to strong downlink interference when they are very close to the Femto cell. In order to solve the problem of intercellular interference in the coexistence of Pico and Femto cells, this paper analyzes the problems of time domain eICIC used in the scene of Femto cell. On the basis of the time domain eICIC scheme of Macro cell and Pico cell in the same frequency heterogeneous network scenario, the scheme optimization is carried out to solve these problems. System level simulation shows that the optimized scheme can greatly improve the throughput of macro and Pico cells under the condition of ensuring the fairness of users between different cells.
【學(xué)位授予單位】：西南交通大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2014
【分類號(hào)】：TN929.5

【共引文獻(xiàn)】

相關(guān)博士學(xué)位論文 前1條

1 張海君;IMT-Advanced異構(gòu)無線網(wǎng)絡(luò)中資源管理策略研究[D];北京郵電大學(xué);2013年

相關(guān)碩士學(xué)位論文 前1條

1 杜亮;Nanocell系統(tǒng)接入控制和資源管理若干技術(shù)的研究[D];廈門大學(xué);2014年

，

本文編號(hào)：2130681