节点文献
OFDM无线局域网关键技术的FPGA实现
FPGA Implementation of the Key Techniques for OFDM WlANs
【作者】 魏振；
【导师】 任光亮；
【作者基本信息】 西安电子科技大学 ， 通信与信息系统， 2009， 硕士
【摘要】 无线局域网(WLAN)是未来移动通信系统的重要组成部分。由于摆脱了有线连接的束缚,无线局域网具有移动性好、成本低以及网络传输故障少等诸多优点,得到了越来越广泛的发展与应用。正交频分复用(OFDM)技术具有抗多径衰落,频谱利用率高等优点,特别适合于无线环境下的高速数据传输,是高速无线局域网的首选技术之一。从IEEE802.11a,IEEE802.11g到IEEE802.11n都是以OFDM为基础。随着OFDM技术的普及以及下一代通信技术对OFDM的青睐,研究与实现应用于无线局域网的OFDM关键技术具有一定的意义。本文首先介绍了WLAN的基本概念及相关协议标准和OFDM系统的工作原理,并描述了基于IEEE802.11a和IEEE802.11n标准的OFDM系统的数据帧结构以及系统参数。文中对OFDM传输系统的关键算法进行了详细的研究。然后以Xilinx公司的ISE10.1为软件平台,利用VHDL描述的方式,并以FPGA(现场可编程门阵列)芯片SPARTAN-3E为硬件平台,研究实现了适用于IEEE802.11a和IEEE802.11n的64点16bits复数块浮点结构的FFT模块,(2,1,7)卷积编码和维特比译码模块,以及分组检测和符号定时模块,并进行了仿真、综合、下载验证等工作。
【Abstract】 Wireless Local Area Network (WLAN) will become one of the important parts of mobile communication system in the future. Without wires, WLAN is of a good deal of merits, such as high mobility, low cost, little circuit troubles and so on. It is being developed and applied more and more widely. OFDM technology has many advantages, such as robustness against multipath fading and high bandwidth efficiency, which are suitable for the high-rate data transmission in wireless environments. Accordingly, OFDM is one of the preferred techniques in WLAN. IEEE802.11a,IEEE802.11g and IEEE802.11n are all based on OFDM. As OFDM becomes more and more widely applied in the next generation of telecommunication technology, the research and implementation of the key techniques of the OFDM for WLAN is valuable.Some basic conceptions of WLAN, the standards involved, and the principle of OFDM system are introduced. The OFDM frame structure and system parameters based on the IEEE 802.11a and IEEE 802.11n specifications are described. The key algorithms in the OFDM systems are analyzed. Then, with VHDL description, a 64-point block-floating point complex FFT module, a (2,1,7) convolutional encoder and Viterbi decoder module, and a packet detection and synchronization module are implemented on Xilinx ISE10.1 and SPARTAN-3E FPGA platform. All of them are suitable for IEEE802.11a and IEEE802.11n. The modules are simulated, synthesized, and downloaded.