A novel channel estimator for Zero-Tail DFT-spread-OFDM

Zero-tail Discrete Fourier Transform-spread-Orthogonal Frequency Division Multiplexing (ZT DFT-s-OFDM) waveform is considered as an attractive candidate for a 5th Generation (5G) radio access technology given its flexibility and spectral containment properties. However, high quality channel estimation in ZT DFT-s-OFDM is compromised by the necessity of accommodating a zero head/tail in the transmit signal. This zero-insertion affects negatively reference sequence properties such as cyclic zero-autocorrelation and flat frequency response. In this paper, we propose a novel channel estimator for ZT DFT-s-OFDM which circumvents such limitations by enabling the correlation of the received signal against the original sequence rather than its zero-padded version. Simulation results prove the benefits in terms of mean square error (MSE) of the proposed channel estimator with respect to existing solutions.