Channel Estimation Using Frequency-domain Superimposed Pilot Time-Domain Correlation Method for OFDM Systems

This paper proposes a new channel estimation method based on frequency-domain superimposed pilot time-domain correlation (FSPTC) for orthogonal frequency division multiplexing (OFDM) systems. In this scheme, pilots are directly added on information symbols in frequency-domain at the transmitter without consuming extra bandwidth. At the receiver, we acquire the coarse estimation of channel and information symbols through the correlation between the known pilots and the received signals. More accurate estimation is obtained by iterative operations, which eliminate the effect of unknown information symbols on pilot correlation. The effect of parameters-total number of sub-carriers, the pilot period and the pilot power ratio-on estimation performance is discussed in theory and simulation. The simulation results show that the system performance of our proposed scheme is approximate to the performance under the situation of ideal channel state information (CSI).