基于ieee802.11a的無線局域網(wǎng)中正交頻分復用技術研究

1、南京航空航天大學碩士學位論文基于IEEE 802.11a的無線局域網(wǎng)中正交頻分復用技術研究姓名：閆崢申請學位級別：碩士專業(yè)：通信與信息系統(tǒng)指導教師：陳吉忠20061201基于 IEEE 802.11a 的無線局域網(wǎng)中 OFDM 技術研究 iiAbstract When the mobile communication has been developed to the third generation (3G), as the data

2、 flow increased and the needs of broad band multimedia service, the network needs broad band connected faculty. By using OFDM technology in WLAN, it has highly increased the transmission speed and achieved high bandwidth

3、 efficiency. OFDM technology has many advantages, such as defending the multipath fading and high bandwidth efficiency, which are suitable for the high-rate data transmission in wireless enviroment. This paper introduces

4、 some basic conception of WLAN, the protocol standards involved, and also the working principle and several key technologies of OFDM system. It describes the OFDM data frame format and the system simulation based on IEEE

5、 802.11a protocol detailedly. The paper focus on the research of channel estimation method in OFDM system. Firstly, it gives the classifiable explanation and deeply studied some typical channel estimation methods. Then o

6、n the basis of being familiar with the propagation characteristics of wireless channel, it proposes two channel estimation methods which separate the time-delay estimation to the amplitude estimation. The new methods dec

7、rease the number of pilot frequency, improve the bandwidth efficiency. The paper emulates the periodic channel estimation method and the adaptive channel estimation method with matlab. In the end, the comparison analyses