Doubly selective channel estimation for amplify-and-forward two-way relay networks

Doubly selective channel estimation is considered for a two-way relay network (TWRN) that comprises two source terminals and an amplify-and-forward (AF) relay. The channel is depicted by complex exponential basis expansion model (CE-BEM). It is found that estimating all channel parameters require long training sequence and thus reduce the transmission efficiency. Therefore, estimation algorithm is proposed to estimate some combined channels, and the corresponding Cramer-Rao bound (CRB) is derived. Based on these estimates, detection of the information symbols can be realized at the source nodes. Finally, simulations are provided to corroborate the proposed studies.