基于MATLAB的MIMO系统预编码性能仿真教程

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摘要在现今的移动通信系统中，被极多的国际通信标准采纳为基础性关键技术的一种方法是多输入多输出的技术(Multiple-Input Multiple-Output，MIMO)。无线传输的技术是应用多项发射以及多次接收天线来进行。应用MIMO技术的情形下，就算是系统带宽和传输功率没有增加，仍然是能够显著的增长无线信道容量，它的增长往往是成倍得，譬如4G LTE技术。通过使用MIMO信道而增加的空间复用增益可以改善传输效率，其带来的空间分集增益也可以增加传输的可靠度。这两种增益的提高分别可以通过改变收发天线数来实现。

提高通信质量是需要MIMO技术在接收端和发送端配置很多的天线，然后使信号经过多个接收和发送端。本篇主要探索的是空间复用MIMO系统的线性预编码及信号检测方法。在发射端通过对传输信号进行预编码操作，不仅可以有效抑制干扰，还可以简化接收机数据解调的计算复杂度。同时对线性信号检测与预编码技术方法进行了分别的详细说明。想要验明一下MIMO系统预编码的性能，借助MATLAB这个软件进行验证确定仿真。结果表明，在其他的前提一样的情形下，以最小均方误差为基准的MMSE算法比简单的线性检测算法ZF算法，所得误差更小，噪比的变大而减小导致系统传输得可靠程度会跟着变化。

关键词：MIMO 信号检测 预编码 MATLAB

ABSTRACTIn mobile communication system, multi input multi output technology (Multiple-Output Multiple-Input, MIMO) is a technology that uses multiple transmit and multiple receive antennas for wireless transmission. MIMO technology can not increase the system bandwidth and transmission power, and exponentially improve the capacity of wireless channel, which has been adopted by many international communication standards as the basic key technologies, such as LTE 4G system. This technology can achieve the transmission efficiency and transmission reliability by changing the number of transmit and receive antennas, that is, the spatial multiplexing gain and the spatial diversity gain of MIMO channel are used to improve the transmission efficiency.MIMO technology need to configure multiple antennas at the receiver and transmitter, and then make the signal through a number of receiving and sending end, in order to improve the quality of communication. This paper mainly studies the spatial multiplexing MIMO system precoding and signal detection technology. At the transmitter, it can not only effectively suppress the interference, but also simplify the computation complexity of the receiver data demodulation. In this paper, the linear signal detection and pre coding technology are introduced and discussed in detail. In order to verify the performance of the MIMO system, the simula