Low-Complexity Channel Estimation for ISDB-T Over Doubly-Selective Fading Channels

Orthogonal Frequency Division Multiplexing (OFDM) technique that has been adopted by ISDB-T system is an effective multi-carrier modulation technique due to its robustness for multi-path fading channels. Recently, in the case of the doubly selective fading channel that is usually caused by high-speed moving reception, a new method named Compressed Sensing (CS) has been proposed to estimate the channel state information (CSI) for OFDM system, which can improve the accuracy of estimate with less pilots. However, high computational complexity of CS makes it difficult to implement for practical applications. Although orthogonal matching pursuit has been proposed that can reduce the computational complexity of CS, the improvement is still not enough. In this paper, therefore, a new scheme of channel estimation by using modified orthogonal matching pursuit (MOMP) is proposed that can further reduce the computational complexity as well as keep accurate estimation performance, comparing with the conventional OMP scheme. The computer simulation demonstrates its effect on channel estimation for ISDB-T system.