【摘要】：隨著高性能處理器和嵌入式操作系統(tǒng)等技術(shù)的迅速發(fā)展,靈活輕便的智能設(shè)備開始融入到人們的生活中,廣泛應(yīng)用于各種場合,并逐漸改變著人們的生活方式。在過去的幾十年里,人與人、人與物、物與物信息交互的需求從來沒有像現(xiàn)在這樣迫切。隨著信息交互數(shù)據(jù)量的快速增長,當(dāng)前移動通信網(wǎng)絡(luò)逐漸無法滿足用戶的需求。在潛在市場的巨大需求下,第五代移動通信技術(shù)(5G)引起了研究者的廣泛興趣。5G關(guān)鍵技術(shù)包括網(wǎng)絡(luò)關(guān)鍵技術(shù)和無線關(guān)鍵技術(shù)。其中,在無線關(guān)鍵技術(shù)里面,大規(guī)模MIMO(Massive MIMO)和全雙工(Full-Duplex)技術(shù)逐漸成為學(xué)者們的研究熱點。大規(guī)模MIMO和全雙工技術(shù)都可以提高頻譜效率。通過部署大規(guī)模天線陣列,可以有效提升移動通信網(wǎng)絡(luò)的系統(tǒng)容量及抑制干擾和噪聲的能力。從本質(zhì)上看,這主要是由于大量獨立的天線提供了更多空間自由度或者并行子信道,同時天線陣列形成更窄更強(qiáng)的波束,提高了天線的發(fā)射和接收增益。研究結(jié)果表明,大規(guī)模MIMO的頻譜效率隨天線數(shù)量的增加而以對數(shù)規(guī)律增長。當(dāng)天線數(shù)目比較多時,采用簡單的線性波束賦形方法,比如MRT/MRC和ZFR/ZFT,就可以獲得非常好的效果。由于天線連接獨立的接收和發(fā)射單元,當(dāng)其中一個或幾個射頻鏈路出現(xiàn)故障時,系統(tǒng)的性能只會略微下降,不會導(dǎo)致業(yè)務(wù)的全部中斷。因此,相比單天線SISO及普通MIMO系統(tǒng),大規(guī)模MIMO可以大幅提升系統(tǒng)可靠性。全雙工技術(shù)采用的是同時同頻雙向傳輸模式,實現(xiàn)雙向通信。由于無線收發(fā)機(jī)在接收信號的同時會受到自身發(fā)送信號的干擾,在全雙工技術(shù)中,如何抑制自干擾,是實現(xiàn)正常通信的關(guān)鍵。一般情況下,全雙工無線收發(fā)機(jī)的發(fā)射天線和接收天線之間會通過物理隔離方法減輕自干擾的影響。雖然物理隔離可以大幅降低干擾,但相對于來自遠(yuǎn)端無線設(shè)備的有用信號來說,自干擾仍然過大。不過,由于干擾來自于本身,從本質(zhì)上講自干擾信號是已知的,采用模擬或數(shù)字干擾抵消方法可以進(jìn)一步抑制自干擾的影響。通過一系列的處理,全雙工系統(tǒng)的頻譜效率會明顯高于傳統(tǒng)的TDD和FDD半雙工系統(tǒng)。本文主要研究了全雙工大規(guī)模MIMO系統(tǒng)。首先討論了共享天線全雙工大規(guī)模MIMO系統(tǒng)的頻譜效率,然后研究了通過信道估計獲得不完全信道狀態(tài)信息情況下的系統(tǒng)自干擾的處理方法,并對混合天線全雙工大規(guī)模MIMO系統(tǒng)做了討論,最后研究了共享天線的全雙工中繼模型,分析了系統(tǒng)中用戶的功率分配問題。論文的主要研究成果有以下幾個方面:1.提出了一種共享天線(Shared-Antenna)全雙工多用戶大規(guī)模MIMO系統(tǒng),該系統(tǒng)同時具有大規(guī)模MIMO和全雙工系統(tǒng)的優(yōu)點,即較高的頻譜效率和上下行信道的互易性,同時降低了大規(guī)模MIMO系統(tǒng)的射頻單元硬件成本。在采用MRC/MRT和ZFR/ZRT等線性信號處理方法的基礎(chǔ)上,證明了即使該系統(tǒng)中上下行信道狀態(tài)完全相關(guān),仍然可以通過增加基站天線數(shù)量來抑制全雙工系統(tǒng)中的自干擾。不同于分離式(Separate-Antenna)全雙工大規(guī)模MIMO系統(tǒng),共享式全雙工大規(guī)模MIMO系統(tǒng)的自干擾抑制能力與陣列中天線數(shù)的平方根成正比。推導(dǎo)了該系統(tǒng)上下行鏈路可達(dá)速率的下界,該下界十分接近蒙特卡洛仿真結(jié)果。比較了該系統(tǒng)和TDD半雙工系統(tǒng)的性能,當(dāng)天線數(shù)目足夠大時,共享天線全雙工大規(guī)模MIMO系統(tǒng)的性能明顯優(yōu)于半雙工系統(tǒng)。(上述創(chuàng)新點對應(yīng)論文的第二章和發(fā)表論文列表中的2)2.研究了共享天線全雙工大規(guī)模MIMO系統(tǒng)上行鏈路的頻譜效率。不同于分離式全雙工大規(guī)模MIMO系統(tǒng),該模型中假設(shè)自干擾信道中存在直接鏈路(LOS)。證明了在采用線性信號處理方法抑制自干擾的同時,萊斯自干擾信道會轉(zhuǎn)變?yōu)槿鹄诺馈Ｌ岢隽艘环N上行鏈路可達(dá)速率的近似分析方法,獲得了上行鏈路的非常簡潔的閉合表達(dá)式,并且該方法只依賴于信道狀態(tài)的分布信息(CDI),而不是瞬時信息。該近似值非常接近于蒙特卡洛仿真結(jié)果。(上述創(chuàng)新點對應(yīng)論文的第三章和發(fā)表論文列表中的5)3.在信道狀態(tài)信息(CSI)估計不完全的情況下,研究了共享天線全雙工大規(guī)模MIMO系統(tǒng)上行鏈路的頻譜效率和能量效率。證明了在獲取到不完全CSI的情況下,基站側(cè)的自干擾仍然可以采用線性處理方法進(jìn)行抑制。設(shè)計了一種自干擾抵消方法,通過對自干擾等效信道的預(yù)先估計,在獲取到干擾信道的狀態(tài)信息后從總干擾中減去該干擾信號,再通過大規(guī)模天線線性方法處理殘余干擾,大幅降低了自干擾的強(qiáng)度。基于該方法,系統(tǒng)可以獲得比LALP方法高36 dB的自干擾抑制能力。在對干擾信道進(jìn)行估計時,提出了一種自干擾信道預(yù)編碼方法,大幅減小信道估計的計算量。推導(dǎo)了不完全CSI情況下的上行鏈路可達(dá)速率的下界,該下界非常接近于蒙特卡洛仿真結(jié)果。在此基礎(chǔ)上,還分析了基于信道估計時間長度和用戶發(fā)射功率的最優(yōu)頻譜效率和能量效率。(上述創(chuàng)新點對應(yīng)論文的第四章和發(fā)表論文列表中的3)4.提出了一種共享式和分離式天線混合的全雙工大規(guī)模MIMO系統(tǒng),在采用MRC/MRT和ZFR/ZRT等線性信號處理方法的基礎(chǔ)上,分別推導(dǎo)了該系統(tǒng)上下行鏈路可達(dá)速率的上界和下界。該模型允許用戶工作在全雙工模式和TDD半雙工模式。由于下行鏈路容易受到用戶自身和用戶之間發(fā)射信號的影響,自干擾會隨著系統(tǒng)負(fù)載的變化而發(fā)生改變,在系統(tǒng)負(fù)載較輕和過載時,討論了用戶雙工模式的選擇對系統(tǒng)頻譜效率的影響。(上述創(chuàng)新點對應(yīng)論文的第五章和發(fā)表論文列表中的4)5.提出了一種雙向全雙工大規(guī)模MIMO中繼系統(tǒng)模型。不同于已有的分離天線陣列中繼系統(tǒng),該系統(tǒng)采用一副共享式天線陣列。該模型采用信號放大轉(zhuǎn)發(fā)(AF)方式和MRC/MRT及ZFR/ZFT線性信號處理方法。證明了該類系統(tǒng)中環(huán)路自干擾(LI)可以看做類似于獨立同分布的加性零均值高斯白噪聲。推導(dǎo)了基站發(fā)射功率和信噪比的漸近表達(dá)式。當(dāng)天線數(shù)目足夠大時,推導(dǎo)出了簡潔的閉合形式的可達(dá)速率表達(dá)式。在此基礎(chǔ)上,采用拉格朗日乘子法解決了相同大尺度衰落情形下的用戶發(fā)射功率分配問題。對于任意大尺度衰落情形,采用遺傳算法(GA)優(yōu)化了用戶的功率分配,在用戶的總功率約束下,實現(xiàn)了頻譜效率和能量效率的最大化。(上述創(chuàng)新點對應(yīng)論文的第六章和發(fā)表論文列表中的1)
[Abstract]:With the rapid development of high performance processors and embedded operating systems, flexible and portable intelligent devices have been integrated into people's lives, widely used in various occasions, and gradually changing people's lifestyle. With the rapid growth of the amount of information exchange data, the current mobile communication network is gradually unable to meet the needs of users. Under the huge demand of the potential market, the fifth generation mobile communication technology (5G) has aroused widespread interest of researchers. The key technologies of 5G include network key technologies and wireless key technologies. Massive MIMO (Massive MIMO) and Full-Duplex (Full-Duplex) technologies have gradually become a research hotspot of scholars. Both large-scale MIMO and full-duplex technologies can improve spectral efficiency. By deploying large-scale antenna arrays, the system capacity of mobile communication networks can be effectively improved and the ability to suppress interference and noise can be effectively improved. The results show that the spectral efficiency of large-scale MIMO increases logarithmically with the increase of the number of antennas. Simple linear beamforming methods, such as MRT/MRC and ZFR/ZFT, can achieve very good results. Since the antenna is connected to a separate receiving and transmitting unit, when one or more RF links fail, the performance of the system will only slightly degrade and the service will not be completely interrupted. The full duplex technology uses the same frequency two-way transmission mode to realize the two-way communication. Because the wireless transceiver receives the signal at the same time will be interfered by its own transmission signal, in the full duplex technology, how to suppress the self-interference is the gateway to achieve normal communication. Key. In general, the effect of self-interference is mitigated by physical isolation between the transmit antenna and the receive antenna of a full-duplex transceiver. Although physical isolation can significantly reduce interference, self-interference is still too large for useful signals from remote wireless devices. However, since the interference comes from itself, it is essential In this paper, the full-duplex large-scale MIMO system is studied. First, the shared antenna full-duplex MIMO system is discussed. The spectrum efficiency of duplex large-scale MIMO system is studied. Then the method of system self-interference processing under the condition of incomplete channel state information obtained by channel estimation is studied. The full-duplex large-scale MIMO system with hybrid antenna is discussed. Finally, the full-duplex relay model of shared antenna is studied and the power distribution of users in the system is analyzed. The main research results of this paper are as follows: 1. A Shared-Antenna full-duplex multi-user large-scale MIMO system is proposed. The system has the advantages of both large-scale MIMO and full-duplex systems, i.e. high spectral efficiency and reciprocity of uplink and downlink channels, while reducing the transmission of large-scale MIMO systems. Based on the linear signal processing methods such as MRC/MRT and ZFR/ZRT, it is proved that the self-interference in full-duplex MIMO systems can be suppressed by increasing the number of base station antennas, even if the uplink and downlink channel states are completely correlated. The self-interference rejection ability of the full-duplex large-scale MIMO system is directly proportional to the square root of the antenna number in the array. The lower bound of the system's uplink and downlink reachable rate is derived, which is very close to the Monte Carlo simulation results. The performance of the system and the TDD half-duplex system is compared. When the antenna number is large enough, the shared antenna is all-duplex. The performance of industrial large-scale MIMO systems is significantly better than that of semi-duplex systems. (The innovations mentioned above correspond to Chapter 2 and List 2 of published papers.) 2. The spectrum efficiency of the uplink of full-duplex large-scale MIMO systems with shared antennas is studied. Link-to-Link (LOS). It is proved that Rice's self-interference channel can be transformed into Rayleigh channel when linear signal processing is used to suppress self-interference. An approximate analysis method of uplink reachable rate is proposed. A very concise closed-form expression of uplink is obtained, and the method only relies on the distribution information of channel state. This approximation is very close to the Monte Carlo simulation results. (The above innovation points correspond to Chapter 3 of the paper and 5 of the published papers list.) 3. In the case of incomplete channel state information (CSI) estimation, the spectrum efficiency and energy efficiency of the uplink of a fully duplex large-scale MIMO system with shared antenna are studied. It is clear that the self-interference on the base station side can still be suppressed by linear processing when the incomplete CSI is acquired. A self-interference cancellation method is designed. By pre-estimation of the self-interference equivalent channel, the interference signal is subtracted from the total interference signal after the state information of the interference channel is obtained, and then the interference signal is subtracted from the total interference signal by a large-scale antenna. Based on this method, the system can obtain 36 dB higher self-interference suppression ability than the LALP method. When estimating the interference channel, a self-interference channel precoding method is proposed, which greatly reduces the computational complexity of channel estimation. The lower bound of the reachable rate of the uplink is very close to the Monte Carlo simulation results. On this basis, the optimal spectral efficiency and energy efficiency based on the estimated time length of the channel and the transmit power of the user are analyzed. Based on the linear signal processing methods such as MRC/MRT and ZFR/ZRT, the upper and lower bounds of the achievable rate of the system's uplink and downlink are derived respectively. The model allows users to work in full-duplex mode and TDD half-duplex mode. When the system load is light and overloaded, the influence of the choice of the duplex mode on the spectrum efficiency of the system is discussed. (The above innovations correspond to the fifth chapter of the paper and the fourth in the list of published papers.) Different from the existing separate antenna array relay system, the system uses a shared antenna array. The model uses signal amplification and forwarding (AF) mode and linear signal processing methods of MRC/MRT and ZFR/ZFT. It is proved that the loop self-interference (LI) in such systems can be regarded as an additive zero similar to the independent identical distribution. The asymptotic expressions of the base station transmit power and signal-to-noise ratio are derived. When the number of antennas is large enough, a concise closed form of reachability rate expression is derived. On this basis, the Lagrange multiplier method is used to solve the problem of user transmit power allocation under the same large-scale fading. In the case of scale fading, a genetic algorithm (GA) is used to optimize the power allocation of the user and maximize the spectrum efficiency and energy efficiency under the constraint of the total power of the user.
【學(xué)位授予單位】：山東大學(xué)
【學(xué)位級別】：博士
【學(xué)位授予年份】：2017
【分類號】：TN919.3

【參考文獻(xiàn)】

相關(guān)期刊論文 前3條

1 張平;陶運錚;張治;;5G若干關(guān)鍵技術(shù)評述[J];通信學(xué)報;2016年07期

2 逄型棟;洪偉;楊天楊;李林盛;;應(yīng)用于第五代無線通信大規(guī)模MIM0的有源多波束天線系統(tǒng)(英文)[J];中國通信;2014年11期

3 尤肖虎;潘志文;高西奇;曹淑敏;鄔賀銓;;5G移動通信發(fā)展趨勢與若干關(guān)鍵技術(shù)[J];中國科學(xué):信息科學(xué);2014年05期

，

本文編號：2205224