大規(guī)模MIMO系統(tǒng)信道估計方法的研究
發(fā)布時間：2018-12-12 00:57
【摘要】：大規(guī)模MIMO技術的眾多優(yōu)勢使其成為5G通信的關鍵技術之一。隨著天線的增多,信道矩陣維度越來越高,信道估計會更加復雜,這對信道估計算法提出了更高的要求�；趯ьl的信道估計方法較為簡單,但導頻污染會嚴重制約系統(tǒng)性能,因此研究低復雜度且能有效抗導頻污染的信道估計算法就顯得尤為重要。本文首先對無線信道衰落特性進行了簡單的介紹,介紹了點對點大規(guī)模MIMO系統(tǒng)和多用戶大規(guī)模MIMO系統(tǒng)模型。分析了無協(xié)作多小區(qū)大規(guī)模MIMO系統(tǒng)中存在的導頻污染現(xiàn)象,并理論分析了導頻污染產(chǎn)生的原因。接下來本文研究了三種基于導頻的信道估計方法,其中貝葉斯信道估計方法利用了信道的統(tǒng)計特征,如到達角(AOA)信息,有較好的抗導頻污染能力。最后通過仿真實驗對比其與LS估計的性能,實驗結(jié)果表明貝葉斯信道估計方法有著較好的抗導頻污染能力。半盲信道估計算法僅僅需要很少的導頻,這樣就避免了導頻污染。本文分析了基于EVD、SVD的半盲信道估計算法的原理,同時對算法的估計誤差進行了推導分析。接著推導出模糊矩陣迭代計算的關系式,利用FRRH子空間跟蹤算法減少了接收端信號自相關矩陣的信號子空間的計算量,然后給出了一種基于FRRH的半盲信道估計算法。通過仿真實驗對這三種半盲信道估計算法的性能進行比較分析。由仿真結(jié)果得出,基于FRRH信道估計算法在犧牲較少估計性能的重要前提下,大大減少了算法的復雜度,更加適用于實際的大規(guī)模MIMO系統(tǒng)。
[Abstract]:Large-scale MIMO technology has become one of the key technologies of 5 G communication due to its many advantages. With the increase of antenna, the dimension of channel matrix becomes higher and higher, and the channel estimation will become more complex, which puts forward higher requirements for channel estimation algorithm. The channel estimation method based on pilot frequency is relatively simple, but pilot pollution will seriously restrict the performance of the system. Therefore, it is very important to study the channel estimation algorithm with low complexity and effective resistance to pilot pollution. In this paper, the fading characteristics of wireless channel are introduced briefly, and the models of point-to-point large-scale MIMO system and multi-user large-scale MIMO system are introduced. The pilot pollution phenomenon in large scale MIMO system without collaboration is analyzed, and the causes of pilot pollution are analyzed theoretically. Then three pilot-based channel estimation methods are studied in this paper. The Bayesian channel estimation method makes use of the statistical characteristics of the channel such as the (AOA) information of the angle of arrival and has a good ability to resist pilot pollution. Finally, the performance of Bayesian channel estimation is compared with that of LS estimation. The experimental results show that the Bayesian channel estimation method has a good ability to resist pilot pollution. The semi-blind channel estimation algorithm requires only a few pilots, thus avoiding pilot pollution. In this paper, the principle of semi-blind channel estimation algorithm based on EVD,SVD is analyzed, and the estimation error of the algorithm is deduced and analyzed. Then the relation formula of iterative calculation of fuzzy matrix is derived, and the computation of signal subspace of autocorrelation matrix at the receiving end is reduced by using FRRH subspace tracking algorithm. Then a semi-blind channel estimation algorithm based on FRRH is presented. The performance of these three semi-blind channel estimation algorithms is compared and analyzed by simulation experiments. The simulation results show that the channel estimation algorithm based on FRRH greatly reduces the complexity of the algorithm at the expense of less estimation performance and is more suitable for large scale MIMO systems.
【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
本文編號：2373577
[Abstract]:Large-scale MIMO technology has become one of the key technologies of 5 G communication due to its many advantages. With the increase of antenna, the dimension of channel matrix becomes higher and higher, and the channel estimation will become more complex, which puts forward higher requirements for channel estimation algorithm. The channel estimation method based on pilot frequency is relatively simple, but pilot pollution will seriously restrict the performance of the system. Therefore, it is very important to study the channel estimation algorithm with low complexity and effective resistance to pilot pollution. In this paper, the fading characteristics of wireless channel are introduced briefly, and the models of point-to-point large-scale MIMO system and multi-user large-scale MIMO system are introduced. The pilot pollution phenomenon in large scale MIMO system without collaboration is analyzed, and the causes of pilot pollution are analyzed theoretically. Then three pilot-based channel estimation methods are studied in this paper. The Bayesian channel estimation method makes use of the statistical characteristics of the channel such as the (AOA) information of the angle of arrival and has a good ability to resist pilot pollution. Finally, the performance of Bayesian channel estimation is compared with that of LS estimation. The experimental results show that the Bayesian channel estimation method has a good ability to resist pilot pollution. The semi-blind channel estimation algorithm requires only a few pilots, thus avoiding pilot pollution. In this paper, the principle of semi-blind channel estimation algorithm based on EVD,SVD is analyzed, and the estimation error of the algorithm is deduced and analyzed. Then the relation formula of iterative calculation of fuzzy matrix is derived, and the computation of signal subspace of autocorrelation matrix at the receiving end is reduced by using FRRH subspace tracking algorithm. Then a semi-blind channel estimation algorithm based on FRRH is presented. The performance of these three semi-blind channel estimation algorithms is compared and analyzed by simulation experiments. The simulation results show that the channel estimation algorithm based on FRRH greatly reduces the complexity of the algorithm at the expense of less estimation performance and is more suitable for large scale MIMO systems.
【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
【參考文獻】
相關期刊論文 前1條
1 YAO Tianqi;LI Yong;;Pilot Contamination Reduction by Shifted Frame Structure in Massive MIMO TDD Wireless System[J];Wuhan University Journal of Natural Sciences;2015年03期
，本文編號：2373577
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