Joint estimation of carrier and sampling frequency offsets using OFDM WLAN preamble

The estimation of carrier and sampling frequency offsets is considered, for IEEE 802.11a-based OFDM wireless LAN (WLAN) systems, based on the guard interval and two long symbols (GI2L) in the preamble of an OFDM WLAN packet. The model of the measurement of the GI2L is developed, in the presence of both carrier and sampling frequency offsets. Based on this model, a method is proposed, based on the GI2L. Improved performance, measured by estimation error and bit error rate, is achieved by the proposed method, as compared with some relevant existing methods.