Frequency offset and channel estimation in OFDM systems by blind adaptive filter

LTE is a step toward the 4th generation (4G) of radio technologies. OFDM is used in LTE system for the downlink to meet the LTE requirement for spectrum flexibility and enable cost-efficient solutions for very wide carriers with high peak rates. But OFDM systems is very sensitive to carrier frequency offset, and carrier frequency offset with even a small fraction of subcarrier spacing will degrade the performance of OFDM receiver greatly. This frequency offset results in inter-carrier interference (ICI) and. This paper proposed a method for frequency offset and channel estimation using adaptive filter is to reduce ICI effects and another adaptive filter to estimate frequency offset. The frequency offset is used to estimate the channel. This method can improve the efficiency of system, and can track the change of frequency offset. The simulated results show that this scheme can reduce ICI effects significantly and the frequency offset can be tracked effectually.