【摘要】：隨著無線移動設(shè)備和服務(wù)的迅猛發(fā)展,電信運(yùn)營商面臨著對更高數(shù)據(jù)速率、更大網(wǎng)絡(luò)容量、更高頻譜效率、更高能量效率以及新無線應(yīng)用所需的更高移動性的持續(xù)增長的需求。4G網(wǎng)絡(luò)已經(jīng)接近了數(shù)據(jù)速率的理論極限,難以滿足上述挑戰(zhàn),未來第五代(5G)網(wǎng)絡(luò)技術(shù)應(yīng)運(yùn)而生。大規(guī)模MIMO技術(shù)已經(jīng)受到廣泛的關(guān)注和深入的研究,成為5G的關(guān)鍵技術(shù)之一。在采用頻率復(fù)用的多蜂窩小區(qū)環(huán)境下,由于導(dǎo)頻污染而產(chǎn)生的上行信道狀態(tài)信息(CSI)的誤差將影響預(yù)編碼器的性能,這明顯地限制了大規(guī)模MIMO系統(tǒng)的總速率。此外通過增長天線數(shù)量來減小干擾的方法,在導(dǎo)頻污染引起的小區(qū)間干擾和小區(qū)內(nèi)干擾失效。因此,導(dǎo)頻污染是大規(guī)模MIMO系統(tǒng)的基本挑戰(zhàn)。本文主要對信道估計(jì)與預(yù)編碼技術(shù)進(jìn)行研究。首先概述了5G通信技術(shù),分別介紹了5G特性、關(guān)鍵技術(shù)及挑戰(zhàn),并且對大規(guī)模MIMO技術(shù)的信道估計(jì)、預(yù)編碼和導(dǎo)頻污染等方面文獻(xiàn)進(jìn)行了回顧。其次,針對MIMO-OFDM傳輸方案,研究了一種改進(jìn)的、通過訓(xùn)練序列中插入零導(dǎo)頻符號的信道估計(jì)導(dǎo)頻圖案。對該方的研究表明,所研究的導(dǎo)頻圖案既有利于減輕導(dǎo)頻污染的影響,又便于實(shí)現(xiàn)導(dǎo)頻復(fù)用。最后,我們對一種大規(guī)模MIMO下的匹配濾波器(MF)預(yù)編碼進(jìn)行了仿真研究。通過對含有多個干擾小區(qū)(即含有導(dǎo)頻污染)的上行通信鏈路進(jìn)行最小二乘法(LS)信道估計(jì),從而得到上行信道的信道矩陣;下行利用已知的信道矩陣進(jìn)行線性預(yù)編碼。這里評估了下行的誤比特率(BER)。分析和仿真結(jié)果表明,在下行發(fā)射天線與接收天線比大于10以上時,在基站(BS)端采用簡單的線性預(yù)編碼也可滿足一定的誤碼性能。
[Abstract]:With the rapid development of wireless mobile devices and services, telecom operators are facing higher data rate, larger network capacity and higher spectrum efficiency. The growing demand for higher energy efficiency and higher mobility for new wireless applications. 4G networks have come close to the theoretical limits of data rates and are difficult to meet the above challenges. The fifth generation (5G) network technology emerges as the times require in the future. Large-scale MIMO technology has received extensive attention and in-depth research, and has become one of the key technologies of 5 G. The error of uplink channel state information (CSI) caused by pilot pollution will affect the performance of the precoder in the multi-cell environment with frequency multiplexing, which obviously limits the total rate of large-scale MIMO system. In addition, by increasing the number of antennas to reduce the interference, the inter-cell interference caused by pilot pollution and intra-cell interference failure. Therefore, pilot pollution is a basic challenge for large scale MIMO systems. In this paper, channel estimation and precoding techniques are studied. Firstly, the 5G communication technology is summarized, and the 5G characteristics, key technologies and challenges are introduced, and the literatures on channel estimation, precoding and pilot pollution of large-scale MIMO are reviewed. Secondly, for the MIMO-OFDM transmission scheme, an improved channel estimation pilot pattern based on the insertion of zero pilot symbols in the training sequence is studied. The results show that the pilot pattern can not only reduce the influence of pilot pollution, but also facilitate the realization of pilot multiplexing. Finally, we simulate the (MF) precoding of a large scale MIMO filter. The channel matrix of uplink channel is obtained by least square (LS) channel estimation for uplink communication links with multiple interference cells (that is, with pilot pollution), and linear precoding is performed by using known channel matrix in downlink. BER (BER). For downlink is evaluated here The analysis and simulation results show that when the ratio of the downlink transmit antenna to the receiving antenna is more than 10, the simple linear precoding at the (BS) end of the base station can also satisfy the performance of error code.
【學(xué)位授予單位】：南京郵電大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2017
【分類號】：TN919.3

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相關(guān)碩士學(xué)位論文 前1條

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本文編號：2218167