An improved channel impulse response estimation for OFDM system with virtual subcarriers

We introduce a novel channel impulse response (CIR) estimation method to improve performance of conventional frequency-domain pilot and time-domain processing (FPTP) algorithm. In practical OFDM system with virtual subcarriers, the conventional FPTP algorithm can effectively reduce CIR estimation error caused by band-limitation effect but it has a limit on reducing the error if the first estimation error of CIR with maximum power is large. In order to overcome the problem, the proposed method estimates the CIR using a modified pilot sequence not to induce the correlation error in contrast with the conventional cancellation processing. Simulation results show that the proposed method outperforms the CEC method of the conventional FPTP algorithm.