【摘要】：隨著無線移動設備和服務的迅猛發(fā)展,電信運營商面臨著對更高數(shù)據(jù)速率、更大網(wǎng)絡容量、更高頻譜效率、更高能量效率以及新無線應用所需的更高移動性的持續(xù)增長的需求。4G網(wǎng)絡已經(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)絡技術(shù)應運而生。大規(guī)模MIMO技術(shù)已經(jīng)受到廣泛的關注和深入的研究,成為5G的關鍵技術(shù)之一。在采用頻率復用的多蜂窩小區(qū)環(huán)境下,由于導頻污染而產(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與預編碼技術(shù)進行研究。首先概述了5G通信技術(shù),分別介紹了5G特性、關鍵技術(shù)及挑戰(zhàn),并且對大規(guī)模MIMO技術(shù)的信道估計、預編碼和導頻污染等方面文獻進行了回顧。其次,針對MIMO-OFDM傳輸方案,研究了一種改進的、通過訓練序列中插入零導頻符號的信道估計導頻圖案。對該方的研究表明,所研究的導頻圖案既有利于減輕導頻污染的影響,又便于實現(xiàn)導頻復用。最后,我們對一種大規(guī)模MIMO下的匹配濾波器(MF)預編碼進行了仿真研究。通過對含有多個干擾小區(qū)(即含有導頻污染)的上行通信鏈路進行最小二乘法(LS)信道估計,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行線性預編碼。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.
【學位授予單位】：南京郵電大學
【學位級別】：碩士
【學位授予年份】：2017
【分類號】：TN919.3

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相關碩士學位論文 前1條

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本文編號：2218167