Superimposed Pilots Aided Joint CFO and Channel Estimation for ZP-OFDM Modulated Two-Way Relay Networks
Existing works on joint Carrier Frequency Offset (CFO) and channel estimation in Two-Way Relay Networks (TWRN) only deal with the convoluted channel parameters and the mixed CFO values. In this paper, the authors design a superimposed pilot based training strategy from the relay node such that the individual frequency and channel parameters can be obtained at the source terminals. They consider the Amplify-and-Forward (AF) relaying scheme and discussed over the Zero-Padding (ZP) based Orthogonal Frequency Division Multiplexing (OFDM) modulation in order to cope with the frequency selective fading channels. They build up the system model and propose the joint estimation method. Then, an iterative process is proposed to further improve the estimation accuracy.