多用户MIMO通信系统中盲干扰对齐算法研究

发布时间：2019-01-02 17:34

【摘要】：盲干扰对齐（Blind Interference Alignment，简称BIA）是一种改良于干扰对齐算法的基于MIMO技术下的干扰抑制算法，其将信道分为已压缩的干扰子空间和干扰与期望信号混合的子空间，然后消除干扰对期望信号的影响。其抑制干扰的效果十分显著，且应用前提与干扰对齐算法相比也较为宽松，但算法本身没有抗噪声能力，鲁棒性较差，从而在噪声的干扰下不仅信号传输受影响，更使其发生干扰泄漏，导致抑制干扰的能力下降；同时在某些特定应用环境，BIA仍有进一步提高单个用户接收信号容量和抗深度衰落的潜力。本文先对信道噪声对BIA算法的影响展开分析，并对其抗噪声进行研究；然后拟提出一种基于BIA的改良算法，以提高某些系统下的用户接收信号容量和抗深度衰落的能力。首先，本文针对BIA算法的核心对齐块受到信道噪声的影响进行定量分析，给出对齐块不同部分受到噪声影响后自由度受到的损失。然后，针对该问题分别从对齐块本身所具有的性质及联合其他抗噪声技术信道编码两个角度提出两种改良方案，并进行仿真。对比误比特率，比较两种方案的优缺点。其次，针对MIMO技术下的广播信道（Broadcast Channel，简称BC），本文建立一种对BIA的改良算法，即对于发射端来说其可知若干接收端的信道状态，这将使得运用该算法的其他接收端不再将干扰信号消除掉，而是获取出来，将干扰信号当成期望信号看待，从而增加了这部分接收端的信息量，提高了传输效率；并在MIMO技术的支持下该算法可使接收端降低信道的深度衰落引起的突发性错误和噪声引起的随机性错误。本文针对这一部分的研究给出发射端已知一个接收端信道状态和已知两个接收端信道状态的两种不同算法，比较了这两种算法和传统的BIA算法在MIMO BC信道下的误比特率，，并同上一部分的仿真结果作对比。综上，本文对BIA算法的抗噪声性进行分析并给出有效的抗噪声方案，使其具有更实际的应用，并对MIMO BC信道下的BIA算法进行改良，在进一步挖掘了其接收信号性能的同时使算法本身具有抗噪声性。
[Abstract]:Blind interference alignment (Blind Interference Alignment, (BIA) is an improved interference suppression algorithm based on MIMO technology, which divides the channel into compressed interference subspace and interference and desired signal subspace. The influence of interference on the desired signal is then eliminated. The effect of suppressing interference is very significant, and the application premise is also relatively loose compared with the interference alignment algorithm, but the algorithm itself has no anti-noise ability and poor robustness, so not only the signal transmission is affected under the noise interference. Moreover, it causes interference leakage, which leads to the decrease of the ability to suppress interference. At the same time, in some specific application environments, BIA still has the potential to further improve the received signal capacity of a single user and resist deep fading. In this paper, the influence of channel noise on BIA algorithm is analyzed, and its anti-noise is studied, and then an improved algorithm based on BIA is proposed to improve the signal capacity and the ability to resist deep fading in some systems. Firstly, the core alignment block of BIA algorithm is quantitatively analyzed by channel noise, and the loss of degrees of freedom caused by noise in different parts of alignment block is given. Then, two improved schemes are proposed to solve the problem from two aspects: the property of the alignment block itself and the channel coding with other anti-noise techniques, and the simulation is carried out. Compare the bit error rate and compare the advantages and disadvantages of the two schemes. Secondly, for the broadcast channel (Broadcast Channel, under MIMO technology, this paper presents an improved algorithm for BIA, that is, for the transmitter, it can know the channel state of several receivers. This will make other receivers using the algorithm not to eliminate the interference signal, but to obtain the interference signal as a desired signal, thus increasing the amount of information in this part of the receiver, and improving the transmission efficiency; With the support of MIMO technology, the algorithm can reduce the sudden error caused by the deep fading of the channel and the random error caused by the noise. In this paper, two different algorithms of known channel state of one receiver and two known channel states of two receivers are given, and the bit-error rates of these two algorithms and the traditional BIA algorithm in MIMO BC channel are compared. The simulation results in the same part are compared. In summary, this paper analyzes the anti-noise performance of BIA algorithm and gives an effective anti-noise scheme, which makes it more practical, and improves the BIA algorithm in MIMO BC channel. The performance of the received signal is further excavated and the algorithm itself is anti-noise.
【学位授予单位】：哈尔滨工业大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TN919.3

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