Blind adaptive scheme for joint frequency offset and channel estimation in OFDM systems

Abstract

OFDM systems are very sensitive to frequency offset. This frequency offset results in inter-carrier interference (ICI) and, as a result, the performance of the OFDM system degrades drastically. In this paper, a blind adaptive method for joint frequency offset and channel estimation is proposed to reduce ICI effects and estimate frequency offset and channel. Adaptive technique is used to suppress these ICI effects. The channel impulse response (CIR) affected by frequency offset is tracked by a channel tracker in frequency domain. The result of the tracker is used to estimate the frequency offset and the channel. Then the frequency offset estimate is feedback to compensate the receipt signal. A blind estimation method is used, in consequence the efficiency and security of system are not reduced. The simulated results show that this scheme can reduce ICI effects significantly and the frequency and channel can be estimated effectually.