Practical OFDM channel estimation method with Kalman filter theory

This paper proposes the practical OFDM channel estimation method with only Kalman filter theory. The method aims to achieve robust OFDM channel estimation from the canonical state space models with (i) a state equation composed of the channel gain and (ii) an observation equation composed of the pilot signal, the channel gain, and the additive noise. The remarkable features of this method are that (1) the channel gain estimation accuracy does not depend on the parameter of the AR system, (2) the maximum Doppler frequency is unknown, and (3) the proposed method can estimate the channel gain by low computational complexity, while many conventional methods based on the Kalman filter theory usually perform the channel gain estimation using the parameter estimation algorithm of the AR (auto-regressive) system and the Kalman filter algorithm. Numerical examples show the effectiveness of the proposed method.