Low-Complexity DFT-Based Channel Estimation with Leakage Nulling for OFDM Systems

In this letter, a low-complexity but near-optimal DFT-based channel estimator with leakage nulling is proposed for OFDM systems using virtual subcarriers. The proposed estimator is composed of a time-domain (TD) index set estimation considering the leakage effect followed by a low-complexity TD post-processing to suppress the leakage. The performance and complexity of the proposed channel estimator are analyzed and verified by computer simulation. Simulation results show that the proposed estimator outperforms conventional estimators and provides near-optimal performance while keeping the low complexity comparable to the simple DFT-based channel estimator.