Single-Carrier Frequency-Division Multiple Access Transmission with Physical Layer Network Coding over ISI Channels

We consider a two-way relaying approach employing physical layer network coding in a single-carrier frequencydivision multiple access (SC-FDMA) based transmission system. At the relay node, we use linear equalization and decisionfeedback equalization, respectively, in order to mitigate the distortion introduced by the radio channel.We introduce transmit filtering schemes that generate identical overall channel impulse responses for both source nodes, while achieving the maximum signal-to-noise ratio for either the zero-forcing or the minimum mean-squared error criterion. The performance of our optimized filtering scheme is compared against that of a suboptimum benchmark filtering approach which also creates identical channel impulse responses to enable linear equalization and decisionfeedback equalization at the relay.