發(fā)布時間：2018-03-31 11:57

  本文選題：全球移動通信系統(tǒng)　切入點：異構網(wǎng)　出處：《中國科學技術大學》2014年碩士論文

【摘要】：隨著移動互聯(lián)網(wǎng)和智能終端的發(fā)展以及UMTS系統(tǒng)的演進,高速下行鏈路分組接入(HSDPA)技術已經(jīng)成為增強UMTS系統(tǒng)鏈路性能的重要手段。異構網(wǎng)技術由于引入了低功率節(jié)點,如微微(Pico)基站、家庭(Femto)基站和中繼(Relay)基站等,達到降低宏基站負載、提升網(wǎng)絡容量和增強網(wǎng)絡覆蓋的目的。鑒于此,UMTS HSDPA系統(tǒng)中引入異構網(wǎng)技術來提高系統(tǒng)性能也是很有實際意義的。本論文重點研究了在UMTS系統(tǒng)中引入異構網(wǎng)技術后的下行信號干擾協(xié)調(diào)問題,主要是Macro-Pico異構網(wǎng)中Pico基站邊緣下行高干擾用戶的干擾協(xié)調(diào)問題。 論文首先對異構網(wǎng)技術進行了介紹,重點對異構網(wǎng)中的干擾類型進行了分類和總結,對基于LTE架構和UMTS系統(tǒng)的異構網(wǎng)的區(qū)別進行了分析,并介紹了異構網(wǎng)中的低功率節(jié)點覆蓋增強技術(RE)以及基于時域、頻域、空域和碼域的下行干擾協(xié)調(diào)技術,重點對幾乎空白子幀方案(ABS方案)進行了綜述。 其次,論文對傳統(tǒng)的ABS干擾協(xié)調(diào)方案中ABS子幀比例的確定方法進行了介紹,提出了一種改進的ABS子幀比例確定方法,并進行了仿真分析。之后論文對ABS方案和多流方案的適用情況進行了分析,提出了一種ABS方案和多流方案相結合的干擾協(xié)調(diào)方案,該方案將Pico基站邊緣高干擾用戶分類為ABS用戶和多流用戶,對不同的用戶采用不同的干擾協(xié)調(diào)方案。仿真結果表明了該方案在某些場景下比單獨使用ABS方案有優(yōu)勢。 針對傳統(tǒng)的ABS方案的缺點,論文提出了一種下行的空域干擾協(xié)調(diào)方案,即Macro基站在ABS子幀上并不是完全不發(fā)送數(shù)據(jù),而是采用基于有限碼本的預編碼進行數(shù)據(jù)傳輸,在減小Macro基站對Pico基站邊緣用戶的下行干擾的同時,使Macro基站用戶性能不受太大影響。我們對不采用干擾協(xié)調(diào)的情況(Norm)、采用ABS方案的情況以及采用所提方案(CS)的情況進行了仿真比對,結果表明,所提的方案在用戶平均吞吐率的性能上好于ABS方案,更接近于Norm方案；在最差5%用戶吞吐率性能上,所提方案優(yōu)于Norm方案,更接近于ABS方案,取得了較好的性能折中。這說明所提干擾協(xié)調(diào)方案能夠在讓Pico基站邊緣高干擾用戶性能提高的前提下,保證系統(tǒng)吞吐量。
[Abstract]:With the development of mobile Internet and intelligent terminals and the evolution of UMTS system, high-speed downlink packet access (HSDPA) technology has become an important means to enhance the link performance of UMTS systems. Such as pico base station, home Femto base station and relay Relay base station, so as to reduce the load of Acer station. The purpose of enhancing network capacity and network coverage is to increase network capacity. In view of the fact that heterogeneous network technology is introduced into UMTS HSDPA system to improve system performance, this paper focuses on the introduction of heterogeneous network technology in UMTS system. Downlink signal interference coordination problem, The main problem is the interference coordination problem of Pico base station edge downlink high interference users in Macro-Pico heterogeneous network. In this paper, the technology of heterogeneous network is introduced, and the types of interference in heterogeneous network are classified and summarized. The differences between heterogeneous network based on LTE architecture and UMTS system are analyzed. The low power node coverage enhancement technique in heterogeneous networks and the downlink interference coordination techniques based on time domain, frequency domain, spatial domain and code domain are also introduced, with emphasis on the almost blank sub-frame scheme (ABS scheme). Secondly, the paper introduces the method of determining the proportion of ABS subframes in the traditional ABS interference coordination scheme, and proposes an improved method for determining the ratio of ABS subframes. Then the application of ABS scheme and multi-stream scheme is analyzed, and a kind of interference coordination scheme combining ABS scheme and multi-stream scheme is proposed. The scheme classifies the Pico base station edge high-interference users into ABS users and multi-stream users, and adopts different interference coordination schemes for different users. The simulation results show that this scheme has advantages over using ABS alone in some scenarios. Aiming at the shortcomings of the traditional ABS scheme, this paper proposes a downlink spatial interference coordination scheme, that is, the Macro base station does not send data completely on the ABS subframe, but uses the precoding based on the finite codebook for data transmission. While reducing the downlink interference of the Macro base station to the edge users of the Pico base station, The user performance of Macro base station is not greatly affected. The simulation results show that the ABS scheme and the proposed scheme are compared with each other in the case of no interference coordination. The performance of the proposed scheme is better than that of the ABS scheme and is closer to that of the Norm scheme, and the proposed scheme is better than the Norm scheme and closer to the ABS scheme in the worst 5% user throughput performance. A good performance compromise is achieved, which shows that the proposed interference coordination scheme can ensure the system throughput while improving the performance of users with high interference at the edge of the Pico base station.
【學位授予單位】：中國科學技術大學
【學位級別】：碩士
【學位授予年份】：2014
【分類號】：TN972

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本文編號：1690636