Blind direct estimation of PSK symbols for zero padding OFDM in rapid channel variation cases

A totally blind ZP-OFDM receiver is derived in this letter. Unlike existing blind receivers that are based on the scheme that channels are estimated first and then equalizers (MMSE or ZF) are adopted to detect information symbols, our scheme is based on the symbol-block-by-symbol-block direct symbol estimation approach. The proposed receiver is also robust in rapid channel variation cases as long as channel responses remain almost constant during one symbol block. Simulation results show that the BER performance of our scheme and linear MMSE (and ZF) equalizers with perfect CSI are indistinguishable in SNR scenarios of interests, despite the fact that our scheme is totally blind.