Advanced receiver design for AF-FD cooperative schemes

This work investigates an amplify-and-forward full-duplex (AF-FD) relaying system that employs an intentional delay at the relay to enhance communication reliability in the presence of residual self-interference errors. The artificial delay emulates a convolutional coding structure, thereby introducing a diversity gain. The interference resulting from simultaneous transmissions by the source and relay is constructively leveraged to design an optimal detection algorithm, which is implemented using a Viterbi algorithm. To mitigate the complexity and latency associated with buffering the entire received frame, a sub-optimal detector with reduced delay is also developed. In addition, a joint maximum-likelihood estimator is proposed for the simultaneous recovery of both the channel coefficients and the artificially introduced delay. Furthermore, analytical performance expressions are derived to characterize the error probability of the proposed detectors and to serve as tight lower bounds under ideal detection conditions. Simulation results confirm the effectiveness of the proposed detectors and estimators, demonstrating superior performance over conventional methods.