Abstract: A channel estimation method based on multi-way array is proposed based on a two-way co-time co-fre-quency full-duplex (CCFD) relaying system． The method consists of three parts: self-interference cancellation，multi-way matrix modeling and channel estimation． At the sides of the two users，the proposed method simultane-ously transmits the designed pilot sequences to the relays，and the relays performs self-interference cancellation and then amplify and forward the received signals to two users． The proposed channel estimation method does not re-quire channel estimation and iteration at the relays，thus reduce the burden of the relays． Simulation results show that compared with the channel estimation methods of the existing Least Squares (LS)，Two-Stage Training (TST) and non-iterative P_KRF，the proposed method has higher channel estimation accuracy，and it can oper-ate under more flexible antenna configurations，which is more stable and more practical in the future application．

Key words: CCFD, two-way relay, multi-way array modeling, channel estimation, training sequen