Blind iterative channel estimation and LDPC decoding for OFDM systems

This paper aims at designing a novel blind iterative receiver for LDPC coded OFDM systems, where pilot symbols for estimating the channel are not inserted in the transmitter. Incorporating the differential QPSK scheme and LDPC decoder, we show that the decision-directed channel estimator can produce the channel information to improve performance of the LDPC decoder. The resulting blind iterative receiver can resolve the drawbacks of differential detection, an improved channel estimate and BER performance in the frequency selective channel, while keeping bandwidth efficiency. Simulation results verify performance of our scheme.