Low-Complexity Compressed Sensing-Based Channel Estimation With Virtual Oversampling for Digital Terrestrial Television Broadcasting

Abstract

This paper proposes a low-complexity compressed sensing (CS)-based time domain channel estimation with virtual oversampling for OFDM-based DTTB system. CS technique is first applied to sparse channel estimation in integrated services digital broadcasting-terrestrial (ISDB-T) system. Unfortunately, the CS-based time-domain channel estimation suffers from a performance degradation under the existence of fractional delay. Fractional delay is a common issue in time domain-based channel estimation due to sampling imperfection of channel delay time. Therefore, we propose virtual oversampling to deal with the fractional delay without increasing the signal bandwidth. Furthermore, exploiting the fact that the rate of change of path delay is slower than the path gain, a modified orthogonal matching pursuit is also proposed to reduce computational complexity. Numerical analyses of bit error rate and computational complexity are given to verify effectiveness of the proposed scheme.