MIMO系统中多小区间干扰抑制技术研究
发布时间：2018-08-25 14:32
【摘要】：多输入多输出（Multiple-Input Multiple Output, MIMO）技术能够利用多径效应，在不需要增加频谱资源以及发送功率的情况下能大幅度提高系统信道容量，从而提高频谱效率。MIMO技术正是具有这一优势，从而成为新一代无线通信系统的关键技术之一。然而，，当MIMO技术运用于多小区系统时，由于各小区的频谱复用因子为1，所以处在小区边缘的用户就会因为远离本小区基站而受到严重的相邻小区同频干扰，以至于边缘用户无法正常通信。小区间的同频干扰严重地影响了整个系统的性能，系统成为一个干扰受限的系统。因此，抑制小区间的同频干扰成为多小区MIMO系统十分重要的问题。 本文首先论述了MIMO技术的研究背景、意义、国内外研究现状并介绍了MIMO系统的基本概念。接着讨论了无线通信系统的信道模型，并阐述了单用户MIMO系统、单小区多用户MIMO系统以及多小区MIMO系统的信道模型，并给出了各系统信道模型下的接收信号表达式。利用MIMO技术能够大幅度提高系统的频谱利用率，因此本文也对MIMO系统的信道容量做了较详细的讨论，分析了不同系统信道的容量并对系统信道容量做了仿真比较。在讨论MIMO系统中多小区间干扰抑制时，本文首先介绍了单用户MIMO系统多种检测技术以及单小区多用户MIMO系统基于发送端预编码技术，并对它们的性能做了仿真对比。然后过渡到多小区MIMO系统，对多小区MIMO系统干扰抑制的传统方法做了研究，并对单小区模式下以及多小区联合处理模式下的多区间干扰抑制方法做了对比，分析了二者的优劣所在。由于单小区模式下系统的误码率性能较差，而多小区联合处理模式系统复杂度较高，所以这两种方法都不是很好的多小区干扰抑制方案。 文章重点研究了一种主动式干扰抑制方法，该方法是从干扰生成的角度考虑，将本基站产生的干扰进行主动抑制，当所有小区都采用主动式干扰抑制方法时，整个系统性能得到最佳。与单小区模式相比，主动式干扰抑制方法能够大大提高系统的误码率性能，与传统的多小区联合迫零模式相比，主动式干扰抑制方法具有较低的系统复杂度，且保持了系统的误码率性能。主动式干扰抑制方法有两种实现方案，一种是将干扰信道矩阵的所有子空间进行迫零来消除基站产生的干扰，称为主动式迫零预编码；另一种是将干扰信道矩阵最大奇异值所对应的子信道进行迫零，称之为最大特征干扰子信道预编码，与主动式迫零预编码相比，其提高了基站发送信息的天线自由度。如果不增加所要发送的有效信息数据流的数目，则基站发送天线数目大大减少。
[Abstract]:Multi-input-multiple-output (Multiple-Input Multiple Output, MIMO) technology can greatly improve the channel capacity without increasing spectrum resource and transmission power by using multipath effect. Therefore, it becomes one of the key technologies of the new generation wireless communication system. However, when the MIMO technology is applied to the multi-cell system, because the spectrum multiplexing factor of each cell is 1, the users on the edge of the cell will be seriously interfered by the same frequency of the adjacent cell because they are far from the base station of the cell. So that edge users can not communicate properly. The performance of the whole system is seriously affected by the co-frequency interference of the cell, and the system becomes an interference-limited system. Therefore, it is very important to suppress the co-frequency interference in multi-cell MIMO systems. This paper first discusses the research background and significance of MIMO technology, the current research situation at home and abroad, and introduces the basic concept of MIMO system. Then the channel model of wireless communication system is discussed, and the channel models of single-user MIMO system, single-cell multi-user MIMO system and multi-cell MIMO system are discussed, and the expressions of received signals under each system channel model are given. The spectral efficiency of the system can be greatly improved by using MIMO technology. Therefore, the channel capacity of MIMO system is discussed in detail, and the channel capacity of different systems is analyzed and compared by simulation. In the discussion of multi-cell interference suppression in MIMO system, this paper first introduces several detection techniques of single-user MIMO system and single-cell multi-user MIMO system based on sending-end precoding technology, and makes a simulation comparison of their performance. Then, the traditional methods of interference suppression in multi-cell MIMO system are studied, and the methods of multi-cell interference suppression in single-cell mode and multi-cell joint processing mode are compared. The advantages and disadvantages of the two are analyzed. Because the BER performance of the system in single-cell mode is poor and the complexity of multi-cell joint processing mode is high, neither of these two methods is a good multi-cell interference suppression scheme. In this paper, an active interference suppression method is studied. The method is to suppress the interference generated by the base station from the point of view of interference generation. When all the cells adopt the active interference suppression method, The performance of the whole system is optimized. Compared with single cell mode, active interference suppression method can greatly improve the BER performance of the system. Compared with the traditional multi-cell combined zero-forcing mode, the active interference suppression method has lower system complexity. The BER performance of the system is maintained. There are two schemes for active interference suppression. One is to eliminate the interference generated by the base station by forcing all subspaces of the interference channel matrix, which is called active zero-forcing precoding. The other is to force the subchannel corresponding to the maximum singular value of the interference channel matrix, which is called the maximum characteristic interference sub-channel precoding. Compared with the active zero-forcing precoding, it improves the antenna degree of freedom for the base station to transmit information. If the number of valid information streams to be transmitted is not increased, the number of transmit antennas in the base station is greatly reduced.
【学位授予单位】：重庆大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TN919.3
本文编号：2203166
[Abstract]:Multi-input-multiple-output (Multiple-Input Multiple Output, MIMO) technology can greatly improve the channel capacity without increasing spectrum resource and transmission power by using multipath effect. Therefore, it becomes one of the key technologies of the new generation wireless communication system. However, when the MIMO technology is applied to the multi-cell system, because the spectrum multiplexing factor of each cell is 1, the users on the edge of the cell will be seriously interfered by the same frequency of the adjacent cell because they are far from the base station of the cell. So that edge users can not communicate properly. The performance of the whole system is seriously affected by the co-frequency interference of the cell, and the system becomes an interference-limited system. Therefore, it is very important to suppress the co-frequency interference in multi-cell MIMO systems. This paper first discusses the research background and significance of MIMO technology, the current research situation at home and abroad, and introduces the basic concept of MIMO system. Then the channel model of wireless communication system is discussed, and the channel models of single-user MIMO system, single-cell multi-user MIMO system and multi-cell MIMO system are discussed, and the expressions of received signals under each system channel model are given. The spectral efficiency of the system can be greatly improved by using MIMO technology. Therefore, the channel capacity of MIMO system is discussed in detail, and the channel capacity of different systems is analyzed and compared by simulation. In the discussion of multi-cell interference suppression in MIMO system, this paper first introduces several detection techniques of single-user MIMO system and single-cell multi-user MIMO system based on sending-end precoding technology, and makes a simulation comparison of their performance. Then, the traditional methods of interference suppression in multi-cell MIMO system are studied, and the methods of multi-cell interference suppression in single-cell mode and multi-cell joint processing mode are compared. The advantages and disadvantages of the two are analyzed. Because the BER performance of the system in single-cell mode is poor and the complexity of multi-cell joint processing mode is high, neither of these two methods is a good multi-cell interference suppression scheme. In this paper, an active interference suppression method is studied. The method is to suppress the interference generated by the base station from the point of view of interference generation. When all the cells adopt the active interference suppression method, The performance of the whole system is optimized. Compared with single cell mode, active interference suppression method can greatly improve the BER performance of the system. Compared with the traditional multi-cell combined zero-forcing mode, the active interference suppression method has lower system complexity. The BER performance of the system is maintained. There are two schemes for active interference suppression. One is to eliminate the interference generated by the base station by forcing all subspaces of the interference channel matrix, which is called active zero-forcing precoding. The other is to force the subchannel corresponding to the maximum singular value of the interference channel matrix, which is called the maximum characteristic interference sub-channel precoding. Compared with the active zero-forcing precoding, it improves the antenna degree of freedom for the base station to transmit information. If the number of valid information streams to be transmitted is not increased, the number of transmit antennas in the base station is greatly reduced.
【学位授予单位】：重庆大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TN919.3
【参考文献】
相关期刊论文 前2条
1 陈斌;胡宏林;张小东;卜智勇;;未来移动通信系统中的小区间干扰协调技术[J];电信科学;2006年06期
2 刘乃金;邱玲;朱近康;;多小区MIMO系统中的一种主动式干扰抑制方案[J];数据采集与处理;2008年06期
相关博士学位论文 前1条
1 王阶;MIMO系统中的定向干扰抑制研究[D];电子科技大学;2010年
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