Efficient pilot design scheme for OFDM-based full-duplex systems

In orthogonal frequency-division multiplexing (OFDM)-based full-duplex (FD) systems, the terminal is allowed to transmit and receive signals simultaneously in the same frequency band. This leads to new challenges to pilot for channel estimation. The conventional pilot design methods are no longer effective for such systems. In this study, the authors propose a new practical pilot design method for OFDM-based FD systems and its performance is analysed in terms of the self-interference cancellation capability. Unlike the existing OFDM-based FD pilot design schemes, which require the channel to be constant during multiple continuous OFDM symbols, the authors' proposed scheme can be implemented in the block fading channel (i.e. channels that vary from one OFDM symbol to another). Besides, the optimal pilot pattern of the proposed scheme is studied. Their simulation results demonstrate the efficiency of the proposed pilot design.