5g通信系統(tǒng)中massivemimo-fbmc技術(shù)的結(jié)合概述(完整版)
【正文】 er candidates in 5G, since the FBMC has much lower outofband radiation than the OFDM.This article reviews existing related work and identifies the main challenges in the key 5G area at the intersection of waveform design (especially for FBMC) and largescale multiple antenna systems, also known as Massive MIMO. The property of selfequalization is then introduced for FBMCbased Massive MIMO, which can reduce the number of subcarriers required by the system. It is also shown that the blind channel tracking property of FBMC can be used to address pilot contamination one of the main limiting factors of Massive MIMO systems. Nevertheless, the implications of FBMC on errorrate performance, putational plexity, and linearity requirements in largescale MIMO systems with potentially hundreds of antennas at the base station are still unclear. More research works correspond to the massive MIMOFBMC system are needed in the future.Key Words: massive MIMO。傳統(tǒng)的OFDM雖然能達(dá)到很小的復(fù)雜度和非常高的帶寬效率，但在應(yīng)用到更復(fù)雜的動態(tài)或多用戶網(wǎng)絡(luò)中時，卻存在難以實現(xiàn)嚴(yán)格同步（移動環(huán)境下的多普勒效應(yīng)）和非連續(xù)頻帶的傳輸（譜泄漏嚴(yán)重）兩大主要問題，而濾波器組多載波（Filter Bank Multicarrier，F(xiàn)BMC）技術(shù)通過使用時頻聚焦性良好的濾波器解決了上述問題[4]。 Massive MIMO的引入假設(shè)在一個傳統(tǒng)MIMO系統(tǒng)下，基站天線數(shù)和用戶天線數(shù)分別為M、K，則基站處的接收信號向量可以表示為 (21)其中，表示均值為0、方差為1的獨立同分布加性高斯白噪聲（AWGN）。對于多用戶MIMO而言，如果多用戶分集增益可以被提取出來，信道矩陣秩的減少并不能造成太大危害。如何將導(dǎo)頻污染的影響降低到最小，或者采用何種檢測方式可以降低系統(tǒng)的導(dǎo)頻污染，需要進(jìn)一步深入研究。(3) 偏移正交振幅調(diào)制OFDM（Offset Quadrature Amplitude ModulationOFDM，OQAMOFDM）[9]：在OQAMOFDM中，輸入的是OQAM調(diào)制符號，即QAM符號的實部與虛部在時間上錯開半個符號周期。令，從文獻(xiàn)[10]中可知的值僅和p，q的大小相關(guān)，并且當(dāng)使用的原型函數(shù)有良好的時頻聚焦特性時，的值隨著，的增大而逐漸趨近于0。在瑞利信道模型下[14]，massive MIMO系統(tǒng)的信道硬化效應(yīng)可以表示為： (31)其中K表示上行用戶數(shù)，分別表示用戶信道和大尺度衰落因子，該式表明每個用戶信道的歐式范數(shù)近似等于其大尺度衰落因子，據(jù)此便可消除快衰落的影響，從而簡化了調(diào)度策略的復(fù)雜度。基于此，文獻(xiàn)[17]中作者將FSE技術(shù)應(yīng)用到massive MIMOFBMC中，從而有效提升了系統(tǒng)的均衡效果，這也使得該系統(tǒng)允許更高的比特率和更寬的子載波帶寬。CMT是FBMC的一種實現(xiàn)結(jié)構(gòu)，其不相干盲均衡性質(zhì)可以直接用于massive MIMOFBMC系統(tǒng)的信道均衡。未來massive MIMO與FBMC的結(jié)合可以很好的解決日益緊張的頻譜資源問題，是未來移動通信中極具競爭力的技術(shù)。e, JP. Javaudin, R. Legouable, A. Skrzypczak and P. Siohan, “Channel estimation methods for preamblebased OQAM/OFDM modulations,” European Wireless Conference, , .[11] I. Estella, A. PascualIserte, and M. Payaro, OFDM and FBMC performance parison for multistream MIMO systems, in Future Network and Mobile Summit, 2010, june 2010, pp. 18.[12] M. Payaro?, A. PascualIserte, and M. Na?jar, Performance parison between fbmc and ofdm in mimo systems under channel uncertainty, Proc. IEEE European Wireless (EW 2010), 1215 April 2010. Lucca (Italy).[13] P. Amini , R. Kempter and B. FarhangBoroujeny , A parison of alternative filterbank multicarrier methods in cognitive radios , Software Defined Radio Technical Conf. (SDR) , 2006[14] K. Zheng, S. Ou, and X. Yin, “Massive MIMO channel models: A survey,” Hindawi Int. J. Antennas Propag., vol. 2014, pp. 8480711–84807110, Jun. 2014.[15] A. Farhang, N.
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