基于MIMO技术的IEEE802.11n协议研究与实现

发布时间：2018-11-19 08:25

【摘要】：随着人们对无线通信技术的依赖和需求越来越高,原本有限的频谱资源日益捉襟见肘,无线传输环境也变得越来越复杂。新的无线通信技术必须要有更快的传输速率、更大的网络容量以及更高的可靠性。MIMO(Multiple-Input Multiple-Output)技术作为一种通过采用多根发射、接收天线从而做到在无线信道中产生多条并行数据通道的技术,在不需要额外频段的情况下极大的提高了系统的传输速率和通信质量。新一代无线局域网标准IEEE802.11n协议在传统协议的基础上采用了MIMO技术,将传输速率由54Mb/s提升至300Mb/s。本文主要在MIMO技术分析的基础上深入研究了802.11n协议,设计了一个4*4MIMO的完整通信链路,并在WARP上搭建了一个基于真实的无线信道环境的验证平台。本文首先对IEEE802.11n协议的做了一个基本的介绍。阐述了802.11n协议的特点和优势,就802.11n协议的关键技术:向前纠错编码、短保护间隔、最大合并比和信道捆绑给出了详细的说明。在802.11n协议的基础上,分析了MIMO技术和OFDM技术的原理,并给出了MIMO+OFDM系统模型。其次,分析了802.11n协议中的三种MIMO技术:信道估计、空时编码和MIMO信号检测的原理。并对各技术中的不同算法进行了仿真分析,对比了在不同信噪比(SNR)情况下的误码率(BER)。基于IEEE802.11n协议,本文设计了一个4*4MIMO的完整通信链路,对整个系统模型进行了模块化划分。发射端的主要模块有调制、导频信号、空时编码、天线映射、快速傅里叶逆变换和加循环前缀,然后发送的信号经过无线信道到达接收端,接收端对接收到的信号进行逆向解码,主要分析的模块有MIMO检测和解调,并对整个链路在MATLAB上进行了仿真分析。本文在最后针对真实的无线信道环境,基于WARP搭建了一个实时通信协议的仿真平台,验证了前面设计的4*4MIMO系统性能,并进行了真实的视频传输。
[Abstract]:With the increasing dependence and demand on wireless communication technology, the original limited spectrum resources are increasingly stretched, and the wireless transmission environment is becoming more and more complex. New wireless communication technologies must have faster transmission rates, greater network capacity, and higher reliability. MIMO (Multiple-Input Multiple-Output) technology as a means of using multiple transmissions. The technology of receiving antennas to generate multiple parallel data channels in wireless channels greatly improves the transmission rate and communication quality of the system without requiring additional frequency bands. The new standard IEEE802.11n protocol of WLAN adopts MIMO technology on the basis of traditional protocol, which improves the transmission rate from 54Mb/s to 300MB / s. Based on the analysis of MIMO technology, this paper deeply studies 802.11n protocol, designs a complete communication link of 4*4MIMO, and builds a verification platform based on real wireless channel environment on WARP. This paper firstly introduces the IEEE802.11n protocol. The characteristics and advantages of 802.11n protocol are described. The key technologies of 802.11n protocol are described in detail, such as forward error correction coding, short protection interval, maximum combining ratio and channel binding. Based on 802.11n protocol, the principle of MIMO and OFDM is analyzed, and the MIMO OFDM system model is given. Secondly, the principles of channel estimation, space-time coding and MIMO signal detection are analyzed. The different algorithms of each technique are simulated and analyzed, and the bit error rate (BER).) under different SNR (SNR) is compared. Based on IEEE802.11n protocol, a complete communication link of 4*4MIMO is designed, and the whole system model is divided into modules. The main modules of the transmitter are modulation, pilot signal, space-time coding, antenna mapping, FFT and cyclic prefix, and then the transmitted signal reaches the receiver via the wireless channel. The receiver decodes the received signal in reverse, the main analysis module is MIMO detection and demodulation, and the whole link is simulated on MATLAB. Finally, aiming at the real wireless channel environment, a real-time communication protocol simulation platform based on WARP is built, which verifies the performance of the 4*4MIMO system designed before and carries out the real video transmission.
【学位授予单位】：国防科学技术大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TN919.3

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