新一代无线局域网中多用户波束赋形技术研究

发布时间：2017-12-27 17:38

本文关键词：新一代无线局域网中多用户波束赋形技术研究　出处：《南京邮电大学》2015年硕士论文　论文类型：学位论文

【摘要】：新一代无线局域网(WL AN)标准IEEE 802.11ac首次采用多用户MIMO技术,并利用波束赋形技术对发送信号进行预编码来抑制用户间的干扰,使得同一时频资源下系统可以支持多个用户通信。然而由于基站天线数目的限制,系统支持的用户数目有限,系统需通过用户选择算法选择用户进行波束赋形。本文基于(无线局域网)多用户波束赋形算法,针对系统中用户总数大于基站所支持用户数目时的用户选择算法展开研究。本文首先研究了无线局网中MIMO的分集与复用技术,分析了Alamouti空时编码方案,并对比分析了几种V-BLAST系统检测方法；研究了无线局域网MIMO信道特性,介绍了IEEE802.11ac的TGac信道；分析了单用户MIM O以及多用户MIM O的系统容量。然后,研究了IEEE 802.11ac中的单用户和多用户波束赋形技术。详细分析了单用户下的奇异值分解算法(SVD),多用户下迫零波束赋形(ZF)、块对角化波束赋形(BD)以及迫零脏纸编码(ZFDPC),并对其性能进行了仿真。最后,本文对IEEE 802.11ac的MIMO用户选择算法进行了深入研究。首先研究了多用户MIMO下的用户选择算法,包括半正交用户选择算法、最小化伪逆矩阵范数算法、比例公平算法、贪婪用户选择算法；其次,研究了一种基于串行迫零的低复杂度贪婪用户选择算法(SZF-LcGUS),该算法利用用户信道的相关性来减小算法复杂度,同时保证系统的高吞吐率,但无法保证用户的公平性；在此基础上本文提出了一种具有公平性的贪婪用户选择的改进算法,将比例公平算法与SZF-LcGUS算法相结合。仿真结果表明,该算法既能获得较高的系统吞吐量,又能保证用户的公平性。
[Abstract]:The new generation of wireless LAN (WL AN) standard IEEE 802.11ac uses multi-user MIMO technology for the first time, and uses beamforming technology to pretransmit the transmitted signal to suppress interference between users, enabling the system to support multiple user communication under the same frequency resources. However, because of the limitation of the number of base station antennas, the number of users supported by the system is limited, and the user selection algorithm is required to select the user's beamforming through the user selection algorithm. Based on (wireless LAN) multiuser beamforming algorithm, this paper studies the user selection algorithm when the total number of users is larger than the number of users supported by the base station. This paper studies the diversity and multiplexing of MIMO wireless local network, analyzes the Alamouti space-time encoding scheme, and comparative analysis of several detection methods of V-BLAST system; wireless LAN MIMO channel characteristic, introduced the TGac IEEE802.11ac channel; analysis of the single user MIM O and multi user MIM O system capacity. Then, the single user and multiuser beamforming technology in IEEE 802.11ac is studied. The singular value decomposition algorithm (SVD) under the single user is analyzed in detail, the zero forcing beamforming (ZF), the block diagonalization beamforming (BD) and the zero forcing dirty paper coding (ZFDPC) under multi-user are carried out, and its performance is simulated. Finally, this paper makes an in-depth study on the MIMO user selection algorithm of IEEE 802.11ac. Firstly, multi user MIMO user selection algorithm, including semi orthogonal user selection algorithm and pseudo inverse matrix norm minimization algorithm, proportional fairness algorithm, the greedy user selection algorithm; secondly, on a low complexity greedy user serial selection algorithm based on zero forcing (SZF-LcGUS), the algorithm uses the correlation of user channel to reduce the complexity of the algorithm, at the same time ensure high system throughput, but cannot guarantee the fairness of the user; on this basis, this paper presents an improved algorithm with fairness of the greedy user selection, the proportional fair algorithm combined with the SZF-LcGUS algorithm. The simulation results show that the algorithm can not only obtain higher system throughput, but also guarantee the fairness of the user.
【学位授予单位】：南京邮电大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TN925.93

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