【摘要】：近年來,隨著無線通信技術(shù)的不斷進步與發(fā)展,移動數(shù)據(jù)業(yè)務(wù)迅速普及。有數(shù)據(jù)顯示超過60%的話音業(yè)務(wù)和80%的數(shù)據(jù)流量業(yè)務(wù)都發(fā)生在室內(nèi)場所,而傳統(tǒng)的Macrocell網(wǎng)絡(luò)雖然具有覆蓋范圍比較大的優(yōu)勢,但是卻在室內(nèi)場所等熱點區(qū)域覆蓋問題上具有明顯的不足。異構(gòu)網(wǎng)絡(luò)正是針對上述問題從網(wǎng)絡(luò)架構(gòu)方面提出的解決方案,通過引入Femtocell較好地提升了室內(nèi)用戶的服務(wù)質(zhì)量和頻譜資源利用率,但同時也產(chǎn)生了層間干擾和頻繁越區(qū)切換等問題,而這將會導(dǎo)致較高的系統(tǒng)掉話率,嚴(yán)重干擾Macrocell用戶(MUE)的正常通信。為此,本文采用協(xié)作通信技術(shù)尋求上述問題的解決方案,提升MUE上下行鏈路的通信質(zhì)量。論文主要研究內(nèi)容如下:首先,對Femtocell的引入原因和發(fā)展歷程進行簡單的闡述,并著重分析用戶接入Femtocell接入點(FAP)的三種接入模式和部署Femtocell的重要性;對放大轉(zhuǎn)發(fā)(AF)和譯碼轉(zhuǎn)發(fā)(DF)兩種協(xié)議通信協(xié)作進行詳細(xì)的分析比較,并從仿真結(jié)果得出DF協(xié)議的中斷概率性能優(yōu)于AF協(xié)議;同時,構(gòu)建Femtocell/Macrocell雙層異構(gòu)網(wǎng)絡(luò)上下行鏈路的系統(tǒng)模型,在該模型的基礎(chǔ)上分析MUE上下行鏈路。然后,對異構(gòu)網(wǎng)絡(luò)MUE的下行鏈路進行了研究。下行鏈路協(xié)作通常采用基站間協(xié)作方式,需要大量的共享信息,為避免這一問題,本文選用Femtocell用戶(FUE)作為中繼節(jié)點,提出了宏基站(MBS)與FUE的協(xié)作通信方式。同時,為了選擇出合適的中繼節(jié)點,提出了一種協(xié)作FUE的選擇算法。該算法借鑒了軟切換的思想,通過引入持續(xù)時間和設(shè)置信噪比門限值選擇合適中繼構(gòu)建中繼集合:中繼候選集和中繼入選集,繼而獲得性能穩(wěn)定且對MUE有益的中繼集合。理論分析和仿真結(jié)果表明基于FUE的協(xié)作方案確實提升了MUE下行鏈路誤比特率和系統(tǒng)吞吐量性能。最后,對異構(gòu)網(wǎng)絡(luò)MUE的上行鏈路進行了研究。由于邊緣MUE與MBS之間路徑損耗比較嚴(yán)重,導(dǎo)致邊緣MUE與MBS間的通信鏈路經(jīng)常中斷,為解決這一問題,本文選擇FAP充當(dāng)中繼節(jié)點,提出MUE與FAP的協(xié)作方案,并分析了DF和直接轉(zhuǎn)發(fā)兩種轉(zhuǎn)發(fā)方式下MUE性能。同時,在DF方式下還分析了兩種情形:一種是考慮FUE空閑;另一種則考慮FUE也在通信,然后對MUE上行鏈路性能進行仿真實現(xiàn),其結(jié)果表明采用FAP協(xié)作方案的MUE上行鏈路中斷概率和誤比特率性能要明顯優(yōu)于直接傳輸。
[Abstract]:In recent years, with the continuous progress and development of wireless communication technology, mobile data services are rapidly popularized. Some data show that more than 60% of voice services and 80% of data traffic occur in indoor places, while the traditional Macrocell network has the advantage of large coverage. However, there are obvious deficiencies in the coverage of hot spots such as indoor places. Isomeric network is to solve the above problems from the aspect of network architecture, through the introduction of Femtocell to improve the quality of service and spectrum resource utilization of indoor users. However, there are also some problems such as interlayer interference and frequent handoff, which will lead to a higher system drop rate and seriously interfere with the normal communication of Macrocell user (MUE). In order to improve the communication quality of MUE uplink and downlink, this paper uses cooperative communication technology to find solutions to the above problems. The main contents of this paper are as follows: firstly, the introduction reason and development course of Femtocell are briefly described, and the importance of three access modes of (FAP) and the importance of deploying Femtocell are analyzed. The communication cooperation between amplifying and forwarding (AF) and decoding forwarding (DF) is analyzed and compared in detail. From the simulation results, the outage probability performance of DF protocol is better than that of AF protocol, and the system model of Femtocell/Macrocell double-layer heterogeneous network is constructed. Based on this model, MUE uplink and downlink are analyzed. Then, the downlink of heterogeneous network MUE is studied. In order to avoid this problem, the Femtocell user (FUE) is chosen as the relay node, and a cooperative communication mode between (MBS) and FUE is proposed in this paper. At the same time, in order to select the appropriate relay nodes, a cooperative FUE selection algorithm is proposed. The algorithm draws lessons from the idea of soft handoff and selects the appropriate relay set by introducing duration and setting SNR threshold: relay candidate set and relay selected set, and then obtains the relay set which is stable in performance and beneficial to MUE. Theoretical analysis and simulation results show that the cooperative scheme based on FUE can improve the bit error rate (BER) and system throughput performance of MUE downlink. Finally, the uplink of heterogeneous network MUE is studied. Because of the serious path loss between the edge MUE and the MBS, the communication link between the edge MUE and the MBS is often interrupted. In order to solve this problem, this paper chooses FAP as the relay node and proposes a cooperative scheme between MUE and FAP. The performance of MUE under DF and direct forwarding is analyzed. At the same time, two cases are analyzed in DF mode: one is to consider FUE idle, the other is to consider that FUE is also communicating, and then emulate the performance of MUE uplink. The results show that the outage probability and bit error rate (BER) performance of MUE uplink using FAP cooperative scheme is better than that of direct transmission.
【學(xué)位授予單位】：蘭州交通大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2017
【分類號】：TN929.5

【參考文獻】

相關(guān)期刊論文 前10條

1 龔霞;陳華南;朱永慶;;多用戶協(xié)作網(wǎng)絡(luò)中的中繼和頻譜分配方案探討[J];移動通信;2017年03期

2 曹龍;趙杭生;鮑麗娜;張建照;;分層認(rèn)知無線電網(wǎng)絡(luò)中基于穩(wěn)定匹配的資源分配算法[J];電子與信息學(xué)報;2016年10期

3 張媛媛;王堅;;異構(gòu)無線網(wǎng)絡(luò)多網(wǎng)資源優(yōu)化管理研究[J];計算機科學(xué);2016年04期

4 米根鎖;馬碩梅;;基于速度觸發(fā)的提前切換算法在LTE-R中的應(yīng)用研究[J];電子與信息學(xué)報;2015年12期

5 吳熹;龍華;唐嘉麒;彭永杰;;采用分布式編碼的協(xié)作HARQ協(xié)議[J];計算機工程與應(yīng)用;2015年18期

6 郭強;朱若函;張曉萌;;基于遺傳禁忌算法優(yōu)化的模糊神經(jīng)網(wǎng)絡(luò)垂直切換算法[J];計算機應(yīng)用研究;2016年03期

7 劉靜靜;徐家品;;LTE-A系統(tǒng)中FSHO切換的優(yōu)化方案[J];計算機系統(tǒng)應(yīng)用;2015年05期

8 譚歆;劉瑞雪;李云;黃巍;;兩層異構(gòu)蜂窩網(wǎng)絡(luò)中femtocell和macrocell間的有效干擾管理[J];系統(tǒng)工程與電子技術(shù);2016年01期

9 左旭舟;夏瑋瑋;沈連豐;;LTE系統(tǒng)中femtocell的動態(tài)頻譜接入方法[J];通信學(xué)報;2015年01期

10 王夢冉;喬少杰;于珊珊;;蜂窩網(wǎng)中基于位置預(yù)測的切換算法[J];計算機科學(xué);2014年S2期

相關(guān)碩士學(xué)位論文 前2條

1 吳昊;Femtocell雙層網(wǎng)絡(luò)功率控制技術(shù)研究及仿真實現(xiàn)[D];北京郵電大學(xué);2015年

2 王喜東;Femtocell雙層網(wǎng)絡(luò)綠色自優(yōu)化技術(shù)研究[D];北京郵電大學(xué);2015年

，

本文編號：2254656