The Frequency Offset Estimation and Tracking in MIMO-OFDM BASED 802.11n System

This article addresses the problem of estimation of the carrier frequency offset (CFO) and the residual CFO(or phase noise) compensation in the proposed MIMO-OFDM based IEEE802.11n system. Due to the training sequence in the preamble and the pilot design in the data field, we can estimate the CFO and mitigate the phase error conveniently. With the maximum CFO (40 ppm) requirement specified by the 802.11n Draft4.0 standard, simulation results show that the degradation is limited to within 3dB for the TGn channel model D and E in various modulation coding scheme (MCS). The results also show that the bit error rate and packet error rate can satisfy the requirement of the 802.11n D4.0.