A novel decision-directed CFO blind tracking algorithm for OFDM system in multipath channels

In this paper, a novel decision-directed CFO (carrier frequency offset) blind tracking algorithm for an OFDM system in multipath channels, based on a time domain signal reconstructed by data after the decision and channel estimation, has been addressed, and the accurate CFO estimate result is derived. The improvement of performance due to using the new estimate result is illustrated. The tracking algorithm is analyzed carefully, and it is found that not only noise, but other three factors - channel estimate errors, carrier number and modulation schemes - also affect the estimate result and tracking range. Moreover, carrier number and modulation schemes are the dominant factors. This estimator has the advantage of high accuracy even on low Eb/N0 conditions, but its implementation is relatively simple.