Performance Of Channel Estimation For (OFDM) System Based On Block-Type Pilot Arrangement In Rayleigh Fading Channel


Recently, the superimposed pilot channel estimation has been proposed for wireless communications, where the pilot symbol sequence is superimposed on a data symbol sequence and transmitted together, and thus it has higher spectral efficiency. The channel estimation for orthogonal frequency division multiplexing (OFDM) system based on pilot arrangement over frequency selective Rayleigh fading channel is presented. The estimation of the channel is based on least square (LS) and minimum mean square error (MMSE) estimators. In this work, two schemes of pilot arrangement are proposed; pilot aided form (3) and pilot aided form (1). The bit error rate (BER) performance of superimposed pilot channel estimation is compared with the two proposed schemes by simulation. The simulation results show that the superimposed pilot channel estimation outperforms pilot aided form (3), while pilot aided form (3) outperforms pilot aided form (1) under frequency selective fading channel for both MMSE and LS estimators.