Bandwidth Efficient Channel Estimation using Super-imposed Pilots for OFDM systems

This paper explores channel estimation using superimposed pilots for OFDM systems. The pilots are added linearly to the modulated symbol at a fraction of the total transmit power, making the method spectrally efficient. We present a series of receivers in which complexity is traded for performance; in particular, a receiver that achieves the theoretically lowest BER but has high complexity and a low complexity receiver that shows near optimal performance. We show by simulations that the performance of the receiver is independent of the channel’s Doppler frequency and delay spread. We also analytically compute a bound for the bit error rate performance of the proposed receiver.