Sparse channel estimation for OFDM systems based on pilot signals and MUSIC algorithm

A method of estimating the channel transfer function is presented for orthogonal frequency division multiplexing (OFDM) systems over sparse channels. The proposed method is based on the observation that the wireless channel can be parameterized as a combination of paths, each characterized by a delay and a complex amplitude. The amplitude of each path shows fast temporal variation due to the mobility of terminals while the delay is almost constant. This method employs multiple signal classification (MUSIC) algorithm to estimate non-sample-spaced path delays and amplitudes of OFDM symbols. Simulations show that this method outperforms the direct zeros-padding discrete fourier transformation (DFT) estimator by 2-3dB in signal-to-noise ratio (SNR).