Channel estimation for OFDM systems based on selective superimposed Pilot sequences

A novel data-aided channel estimation for OFDM systems based on selective superimposed pilot sequences is proposed in this paper, where the receiver correlates the received signal sequence with the pilot symbol sequence, and obtains the channel estimation. However, the pilot sequence is superimposed on a data sequence and transmitted together, and thus it has a high spectral efficiency. The selective pilot sequence owns low correlation with data sequence to reduce the interference. In the case of Pilot=1 and L=31, BER of the proposed channel estimation is improved about 2%. With the increase of L and pilot, BER gets lower. So by taking advantage of the correlation between pilot sequences themselves, the proposed algorithm can achieve the good channel estimation.