發(fā)布時(shí)間：2018-04-30 05:45

  本文選題：最大比傳輸 + 放大轉(zhuǎn)發(fā)��； 參考：《揚(yáng)州大學(xué)》2017年碩士論文

【摘要】：大規(guī)模MIMO(Multiple Input Multiple Output,MIMO)通過(guò)在基站配置幾十甚至幾百根天線,可以在同一信道上服務(wù)多個(gè)用戶,從而將系統(tǒng)容量提升10倍以上且將能源效率提升10-100倍。因此,大規(guī)模MIMO被學(xué)術(shù)界、工業(yè)界公認(rèn)為是5G的關(guān)鍵技術(shù)之一。在大規(guī)模MIMO系統(tǒng)中,信號(hào)傳輸具有精準(zhǔn)的方向,視距信號(hào)(Line of Sight,LoS)占據(jù)主導(dǎo)地位。萊斯(Ricean)分布能很好地刻畫(huà)存在LoS信號(hào)的信道衰落特性�；诖�,考慮Ricean衰落信道,針對(duì)多用戶MIMO系統(tǒng),本文展開(kāi)了一系列研究。首先,針對(duì)認(rèn)知多用戶小規(guī)模MIMO上行鏈路(即:N個(gè)單天線認(rèn)知用戶在同一信道上和配置M根天線的基站通信),考慮迫零波束成型(zero-forcing transmission,ZF)傳輸方案,利用非中心Wishart分布等數(shù)學(xué)知識(shí),本文獲得了其在兩種功率約束方案下的可達(dá)速率的閉合表達(dá)式。本文所考慮的兩種功率約束條件如下:即(1)單功率約束條件:Ps=Pmax,(2)雙功率約束條件:Ps=min(Ia/|gsn,P|2,Pmax),其中Pmax為認(rèn)知用戶n的最大發(fā)送功率,Ia為授權(quán)用戶所能容忍的最大干擾功率,gsn,P為認(rèn)知用戶n到授權(quán)用戶的信道衰落系數(shù),Ps為認(rèn)知用戶n的發(fā)射功率。數(shù)值與仿真結(jié)果驗(yàn)證了理論分析的正確性。本項(xiàng)研究成果可用于指導(dǎo)MIMO上行鏈路的設(shè)計(jì)與優(yōu)化。接著,針對(duì)多用戶大規(guī)模MIMO雙向放大前傳中繼網(wǎng)絡(luò),考慮最大比合并/最大比傳輸(maximum-ratio combining/maximum-ratio transmission,MRC/MRT),以及 ZF 兩種波束成型方案,本文獲得了當(dāng)中繼天線數(shù)目M →∞時(shí),系統(tǒng)可達(dá)速率漸進(jìn)結(jié)果的閉合表達(dá)式。特別地,我們考慮了四種典型功率分配方案,即:(1)PU=EU,PR=ER;(2)PU=EU/M,PR=ER;(3)PU=EU,PR=2NER/M;(4)PU = EU/M,PR = 2NER/M。其中PU為用戶的傳輸功率,PR表示中繼的總功率,EU,ER是固定值,N表示用戶對(duì)數(shù)。研究表明:在中繼天線數(shù)目M→∞時(shí),小尺度衰落、共道干擾被消除,可達(dá)速率趨向于一個(gè)定值。本項(xiàng)研究成果對(duì)于大規(guī)模MIMO中繼網(wǎng)絡(luò)的設(shè)計(jì)與性能優(yōu)化具有重要的指導(dǎo)意義。最后,本文研究了不完備CSI(channel state information,CSI)對(duì)多用戶大規(guī)模MIMO雙向放大前傳中繼網(wǎng)絡(luò)性能的影響,獲得了系統(tǒng)可達(dá)速率和能源效率的漸近表達(dá)式。研究表明:不完備CSI會(huì)降低用戶的接收信干燥比,從而降低系統(tǒng)性能;并且,我們發(fā)現(xiàn)當(dāng)中繼天線數(shù)目M→ ∞時(shí),在已知不完備CSI,并保證一定性能的前提下,用戶和中繼的發(fā)送功率最多都可以降低為原來(lái)的1/M。仿真結(jié)果與分析結(jié)果很好匹配,這部分研究成果為大規(guī)模MU-MIMO系統(tǒng)的性能方案的優(yōu)化與設(shè)計(jì)提供了很好的理論依據(jù)。
[Abstract]:By configuring dozens or even hundreds of antennas in the base station, large scale MIMO(Multiple Input Multiple output Mimo can serve multiple users on the same channel, thus increasing the system capacity by more than 10 times and energy efficiency by 10-100 times. Therefore, large-scale MIMO is recognized as one of the key technologies of 5 G by academia and industry. In large scale MIMO system, the signal transmission has the accurate direction, the line-of-sight signal line of SightLos is dominant. Rice Rican) distribution can well describe the fading characteristics of the channel with LoS signal. Considering the Ricean fading channel, a series of research on multi-user MIMO system is carried out in this paper. First of all, considering the zero-forcing beamforming zero-forcing transmission scheme for cognitive multi-user small-scale MIMO uplink (that is, one of N single-antenna cognitive users on the same channel and base station with M-antenna), using non-central Wishart distribution and other mathematical knowledge. In this paper, we obtain the closed expression of the reachable rate under two kinds of power constraint schemes. The two kinds of power constraints considered in this paper are as follows: 1) single power constraint: 1) single power constraint: Psn Pmax2) 2) double power constraint: Psminn Ia/ GsnN P2Pmax1, where Pmax is the maximum transmit power of the cognitive user n and Ia is the maximum interference power that the authorized user can tolerate, and the GsnP is the maximum interference power that the authorized user can tolerate. The channel fading coefficient of cognitive user n to authorized user is the transmit power of cognitive user n. Numerical and simulation results verify the correctness of the theoretical analysis. This study can be used to guide the design and optimization of MIMO uplink. Then, for the large scale multiuser MIMO bidirectional amplification forward relay network, the maximum ratio combining/maximum-ratio transmission maximum-ratio combining/maximum-ratio transmission MRT scheme and the ZF beamforming scheme are considered. The closed expression of the asymptotic result of system reachability rate. In particular, we consider four typical power distribution schemes, namely, 1 / 1 / 1 / 1 / 1 / 1 / 1 / 2 / 2 / respectively, and / or / or, respectively. Where pu is the transmission power of the user and PR indicates that the total power of the relay is a fixed value N to represent the subscriber logarithm. The results show that when the number of relaying antennas is M ~ 鈭，

本文編號(hào)：1823360