A QR Factorization Based Algorithm for Pilot Assisted Channel Estimation in OFDM Systems

This paper deals with the pilot assisted time-varying channel estimation in orthogonal frequency division multiplexing (OFDM) systems. Since the pilot sub-carrier correlations are rank deficient, an estimation scheme can be implemented by discarding the noise subspace components and filtering the subspace components. The subspace can be estimated by some subspace tracking (ST) algorithm. We propose to implement the subspace components filtering via a QR factorization based algorithm, which is suitable for operating in conjunction with the ST algorithm. The performance of the proposed schemes is verified by simulation in computer.