Research And Implementation Of Time Domain Synchronization Technique In OFDM WLAN Systems

In this paper, we introduce the situation and future development of OFDM Wireless Local Area Network. The PHY parameters of two similar standards, IEEE 802.11a and HiperLAN/2 are analyzed. The time domain synchronization techniques of OFDM WLAN systems, including frame synchronization, carrier frequency offset estimation and symbol timing are discussed and the implementation of IEEE 802.11a system is given. As for IEEE 802.11a, a novel frame synchronization scheme using the permutational nature of the real and imaginary parts of the short training symbols is proposed, and an exponential weighted average method based on the filter principles is proposed to simplify the realization of symbol timing. Meanwhile, performance analysis of other time domain synchronization schemes are given and compared. The simulations of HiperLAN/2 system are also stated and a dual-peak detection frame synchronization method is given for broadcasting burst which could provide a wider range of carrier frequency offset estimation. Finally, the design schemes applied to FPGA are proposed taken IEEE 802.11a as an example. At the end, this paper makes a simulation of circuits with Quartus and FPGA-hardware into reality.