| Nowadays, the wide application of networks, for instance, Internet, is developing fast in the direction of integrated broadband multimedia, which consists of data, voice, image and so on. Broadband Wireless Access (BWA) technology has become a hot spot of the market because of its many advantages. All kinds of advanced technologies in microwave and wireless communications are introduced to BWA and many lands of BWA technologies are coming out.BWA system must have the ability to support near-LOS and non-LOS (NLOS) because of wireless environment where multipath may be significant. The multicarrier transmission known as OFDM has recently received considerable attentiom for its robustness to multipath selective fading and high bandwidth efficiency. Its basic idea is to divide a given channel into many parallel subchannels or subcarriers, so that multiple symbols are in parrllel. Though the whole channel appears as frequency-selective fading channel, the subchannels appear as orthogonal, plat fading channels.With the development of IP technology, the "burst mode" transmission techniques have recently received considerable attention. This thesis cares about design and implementation of OFDM receiver based on "burst mode". IEEE 802.11a WLAN is the first burst system using OFDM and realizing the wireless broadband IP transmission., therefore it has great value in designing OFDM receiver based on "burst mode".The chapters are arranged as following: Chapter 1 introduces the basic principles of OFDM and its application in BWA. Chapter 2 takes consideration of WLAN channel model and channel estimation. The quantitative analysis of synchronization error is given then. Chapter 3 as one kernel part of the thesis, studies different synchronization algorithms such as Frame Synchronization, Symbol Timing Synchronization and Carrier Synchronization. Chapter 4 as another kernel part, focuses on FPGA implementation of OFDM receiver. Many different testing results are given finally. |
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