On Channel Estimation for OFDM Based Two-Way Relay Networks

We consider the channel estimation issues for two-way relay network (TWRN) that employs orthogonal frequency division multiplexing (OFDM) modulation. We propose a two-phase training protocol for channel estimation, which is compatible with two-phase data transmission scheme associated with TWRN. It will be seen that channel estimation in TWRN is quite different from that in the traditional point-to-point system or even that in the one-way relay network (OWRN). The identifiability issue of the channel estimation, which particularly exists for TWRN, is studied. Simulation results corroborate the effectiveness of the proposed method.