A Channel Estimation Method Based on Sample-Shift of Time-Domain Signal for OFDM Systems

A channel estimation method based on sample-shift of time-domain signal is proposed for OFDM systems. Through artificial cyclic sample-shift of time-domain signal, the equivalent coherent bandwidth of OFDM systems can be broadened. Hence, the channel estimation errors, caused by the simple linear interpolation in frequency-domain, can be reduced due to the increase of correlation between neighboring pilot sub-carriers. The theoretical analysis and simulation results show that equivalent channel coherent bandwidth can be broadened effectively and the channel estimation performance can be improved by sample-shift significantly, especially over high SNR range. When the value of cyclic sample-shift is given as the sampling-interval normalized RMS of channel, the near optimal performance can be achieved.