Synchronization And Channel Estimating Technique Research And Implementation Based On OFDM Communication System

Synchronization and Channel Estimating is the most critical part in OFDM communication system.Some module such as carrier synchronization is important,which even determines the quality of signal reception directly in wireless communication.In this paper,frame finding,carrier synchronization,symbol synchronization and channel estimating is mentioned.Based on fundamental technique and algorithm of these modules,and new algorithm is come up in carrier synchronization.In recent years,researchers come up lots of algorithm in whether fr-equency domain or time domain.Some algorithm are related to modulation,equalization or coding.However,White Gaussian Noise(WGN)still influences the quality of these methods.In this paper,a new algorithm based on weighted mean filter is presented.This interframe algorithm takes full advantage of the information of CFO estimate result in latest frames and reduces the effect of WGN further.To guarantee this algorithm robust in unstable wireless environment,it employs self-adaptive weighted mean filter in which the weighted value is chosen by achieving minimum mean square error(MMSE).It solves the problem of traditional algorithm such as the "floor effect".This algorithm renders excellent performance and achieves nearly one tenth of variance of traditional method.A simple method of implementation is also raised which use less multipliers.Finally,the whole system is simplified and it is implemented on the FPGA platform,the transmitter and receiver are on different board and they are connected by Ethernet port.The throughput is all above 93Mbps and the performance loss is 0.3dB in average.The complexity and resources is reasonable and meets the need of project.