本文選題：大規(guī)模MIMO + 導(dǎo)頻污染��； 參考：《電子科技大學(xué)》2017年碩士論文

【摘要】：多輸入多輸出(Multiple-Input Multiple-Output,MIMO)是一種多天線技術(shù),它可以在基站和用戶之間傳輸多個(gè)數(shù)據(jù)流,在長(zhǎng)期演進(jìn)技術(shù)(Long Term Evolution,LTE)中,時(shí)分多址和頻分多址模式都可以采用單用戶MIMO來提高頻譜效率。為了滿足新一代移動(dòng)通信(International Mobile Telecommunication,IMT)的要求,LTEAdvanced引入一種多用戶MIMO技術(shù),最大可支持8?8根收發(fā)天線,相比于單用戶MIMO,它能夠獲得更大的空間增益、更大的系統(tǒng)平均吞吐率、小區(qū)覆蓋程度和移動(dòng)通信系統(tǒng)的穩(wěn)定性。然而,隨著無線移動(dòng)設(shè)備和服務(wù)的發(fā)展,第四代移動(dòng)通信系統(tǒng)(the 4th Generation mobile communication technology,4G)仍然無法滿足應(yīng)用需求,比如稀缺的頻譜資源和較高的能源消耗。研究者們針對(duì)新的無線設(shè)備所帶來的更高的數(shù)據(jù)速率和移動(dòng)性要求開始了第五代移動(dòng)通信系統(tǒng)(the 4th Generation mobile communication technology,5G)的研究,并且預(yù)期在2020年開始商用。所以說,5G時(shí)代就要來臨了。大規(guī)模MIMO相對(duì)于4G技術(shù)能夠提高數(shù)個(gè)量級(jí)的頻譜效率,可以利用較大數(shù)量的天線來為數(shù)個(gè)用戶在同一時(shí)頻資源上提供多路信息傳輸,可以利用定向天線技術(shù)集中向特定的方向發(fā)送能量來最小化小區(qū)內(nèi)和小區(qū)間的干擾。因而大規(guī)模MIMO成為5G研究的一個(gè)極具前途的技術(shù)。在大規(guī)模MIMO系統(tǒng)中,一些理論研究和仿真分析也指出了大規(guī)模MIMO存在的限制,其中使用時(shí)分雙工(Time Division Duplexing,TDD)模式時(shí)一個(gè)最重要的限制因素就是導(dǎo)頻污染問題,在一些文獻(xiàn)中已經(jīng)提出了很多在多小區(qū)蜂窩系統(tǒng)中抑制導(dǎo)頻污染的研究和方法。本文中,我們分析了在TDD的大規(guī)模MIMO蜂窩小區(qū)中導(dǎo)頻污染產(chǎn)生的原因并提出了幾種抑制導(dǎo)頻污染的方法。首先,簡(jiǎn)要的給出了TDD大規(guī)模MIMO蜂窩小區(qū)系統(tǒng)的模型,并基于此模型討論了導(dǎo)頻污染產(chǎn)生的原因和上下行鏈路數(shù)據(jù)收發(fā)的模式,仿真了在使用正交導(dǎo)頻序列和非正交導(dǎo)頻序列情況下的系統(tǒng)平均吞吐率。另外介紹了不同的信道估計(jì)、信道檢測(cè)和預(yù)編碼方式,著重分析了大規(guī)模MIMO系統(tǒng)中上下行鏈路使用匹配濾波、迫零和最小均方誤差方式的系統(tǒng)容量性能,結(jié)果顯示當(dāng)天線數(shù)趨向于無限多時(shí),匹配濾波方式的性能可以逼近最小均方誤差方式。其次,為了抑制導(dǎo)頻污染,本文提出一種聯(lián)合時(shí)移和小區(qū)空間劃分的導(dǎo)頻序列分配方法(Time Shifted-Cell Sectorization Pilot Assignment,TS-CSPA),該方法通過從時(shí)域和空間域兩個(gè)角度降低導(dǎo)頻復(fù)用程度來抑制導(dǎo)頻污染。文中推導(dǎo)了系統(tǒng)使用該方案時(shí)的等效信干比和用戶可達(dá)速率。仿真結(jié)果表明提出的方法能有效的抑制大規(guī)模MIMO系統(tǒng)的導(dǎo)頻污染,相比于其他幾種抑制方法能夠在系統(tǒng)性能上獲得一定程度的提升。最后,本文提出了基于用戶位置信息的導(dǎo)頻序列分配方案。所提方案根據(jù)用戶與基站間的距離以及其在小區(qū)基站為極點(diǎn)的極坐標(biāo)系下的極角大小,對(duì)用戶進(jìn)行分層或排序并依次分配導(dǎo)頻。該方案通過避免用戶復(fù)用的導(dǎo)頻序列距離過近,從而達(dá)到降低導(dǎo)頻污染、提高信道條件較差的用戶的可達(dá)和速率的目的。仿真結(jié)果表明,所提方案不僅能夠降低系統(tǒng)的導(dǎo)頻污染,還能有效縮小不同用戶間的性能差距,提高了系統(tǒng)的公平性。
[Abstract]:Multiple-Input Multiple-Output (MIMO) is a multi antenna technology, which can transmit multiple data streams between the base station and the user. In the Long Term Evolution (LTE), the time division multiple access and frequency division multiple access mode can use single user MIMO to improve the spectrum efficiency. In order to satisfy the new generation of mobile communication network, it can satisfy the new generation of mobile communication. As required by International Mobile Telecommunication (IMT), LTEAdvanced introduces a multiuser MIMO technology to support a maximum of 8? 8 transceiver antennas. Compared to single user MIMO, it can gain greater spatial gain, greater system average throughput, cell cover degree and stability of mobile communication systems. The development of mobile devices and services, the fourth generation mobile communication system (the 4th Generation mobile communication technology, 4G) still cannot meet application requirements, such as scarce spectrum resources and high energy consumption. Researchers have begun the fifth generation of higher data rate and mobility requirements for new wireless devices. The research of the 4th Generation mobile communication technology (5G), and is expected to start commercially in 2020. So it says the era of 5G is coming. Large scale MIMO can improve the spectral efficiency of several orders of magnitude relative to 4G technology, and can use a large number of antennas for several users on the same time frequency resource. Providing multi-channel information transmission, we can use directional antenna technology to send energy in a particular direction to minimize interference between cell and cell. Therefore, large-scale MIMO has become a promising technology in 5G research. In large-scale MIMO systems, some theoretical research and simulation analysis also point out the limitations of large-scale MIMO. One of the most important limiting factors for the use of time division duplex (Time Division Duplexing, TDD) is the pilot pollution problem. In some literature, a number of research and methods to suppress pilot pollution in multi cell cellular systems have been proposed. In this paper, we analyzed the pilot pollution production in a large MIMO cellular cell in TDD. Several methods to suppress pilot pollution are proposed. First, a model of TDD large scale MIMO cellular cell system is given briefly. Based on this model, the cause of pilot pollution and the mode of sending and receiving data for uplink and downlink are discussed. The system is simulated in the case of using orthogonal pilot sequence and non orthogonal pilot sequence. In addition, different channel estimation, channel detection and precoding are introduced. The capacity performance of the system with matched filtering, zero forcing and minimum mean square error in the upper and lower links in large scale MIMO systems is analyzed. The results show that the performance of the matched filtering method can be approximated when the antenna number tends to be less than the limit. Secondly, in order to suppress pilot pollution, a pilot sequence allocation method (Time Shifted-Cell Sectorization Pilot Assignment, TS-CSPA) is proposed in order to suppress pilot pollution (Sectorization Pilot Assignment, TS-CSPA). This method reduces pilot pollution by lowering the pilot multiplexing degree from the time domain and space domain. The simulation results show that the proposed method can effectively suppress pilot pollution of large scale MIMO system, and can improve the system performance to a certain extent compared with several other suppression methods. Finally, the pilot sequence based on user location information is proposed. The proposed scheme is based on the distance between the user and the base station and the size of the polar angle in the polar coordinates of the cell base station. The proposed scheme is stratified or ordered and assigned the pilot in turn. This scheme can reduce pilot pollution and improve the channel condition by avoiding the distance of the pilot sequence of the user reused. The simulation results show that the proposed scheme can not only reduce the pilot pollution of the system, but also effectively reduce the performance gap between different users, and improve the fairness of the system.
【學(xué)位授予單位】：電子科技大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2017
【分類號(hào)】：TN919.3

【參考文獻(xiàn)】

相關(guān)期刊論文 前3條

1 方昕;張建鋒;曹海燕;劉超;潘鵬;;大規(guī)模MIMO系統(tǒng)中動(dòng)態(tài)導(dǎo)頻分配[J];電子與信息學(xué)報(bào);2016年08期

2 胡丞;宋榮方;;大規(guī)模MIMO系統(tǒng)中基于EVD半盲信道估計(jì)的導(dǎo)頻污染研究[J];南京郵電大學(xué)學(xué)報(bào)(自然科學(xué)版);2016年01期

3 何強(qiáng);張秀軍;肖立民;周世東;;大規(guī)模MIMO系統(tǒng)中多小區(qū)導(dǎo)頻重用對(duì)上行可達(dá)速率的影響[J];清華大學(xué)學(xué)報(bào)(自然科學(xué)版);2015年05期

，

本文編號(hào)：2057786