Research On Carrier Frequency Offset Estimation Algorithm For OFDMA Uplink

Orthogonal frequency division multiplexing(OFDM)receives a great attention for its high spectral efficiency and robustness against frequency selective fading channel.It has been used in digital video broadcasting(DVB),wireless local area networks(WLAN) and wireless metropolitan arae network(WMAN). Orthogonal frequency division multiple access(OFDMA) is a most common multi-user version of OFDM.It has been a promsiing technology of the4th generation(4G) wireless communication networks. OFDMA inherits from OFDM the weakness of being sensitive to synchronization errors,especialy to carrier frequency offsets(CFO).In OFDMA systems,CFO between the transmitter and receiver results in the loss of orthogonality among subcarriers and inter-carrier interference(ICI),which further introduces inter-user interference(IUI) and degrades the system performance.Hence,in this thesis,OFDM system has been briefly introduced,interference of OFDMA uplink caused by CFO was explained by analysis receive signal model.On this basis,the main work of this thesis can be summarized as the following:1.Classified summary CFO estimation schemes have been proposed of OFDMA uplink by structure-based and carrier allocation scheme-based at home and abroad,and then algorithms of some literatures have been briefly summarized.2.Two typical CFO estimation methods for OFDMA uplink with pilot-based and blind-based have been introduced,respectively.Based on the understanding that we implement the computer simulation of each method. To prove effectiveness of each approch,we compared results with the approch’s results. In order to get the application conditions of the method,and then we changed the initial conditions to simulation again. Finally the approch has been summaried.