Capacity analysis of an OFDM-based two-way relaying AF-PNC-PLC systems

A major challenge for researchers in Smart Grid, is how to supply robust and efficient communication since PLC channel is a fading channel whose characteristics vary considerably over long distances and at high frequencies. To overcome these constraints Cooperative communication and Network coding have been demonstrated to be effective. Consequently in this paper, we consider a two-way relaying network in which orthogonal frequency division multiplexing (OFDM) is employed for the source 1-to-source 2, the source 1-to-relay and the relay-to-source 2 links where the relay node performs Amplify and Forward (AF) protocol. We consider a conventional bi directional relaying schema (AF-PLC) and we compare it to a schema in which we include Physical Network Coding (AF-PNC-PLC) for different number of time slots dedicated to exchange data messages between two source nodes S
₁
and S
₂
with the assistance of the relay node R. We also evaluate the channel capacity for OFDM-based two-way relaying AF-PLC and AF-PNC-PLC systems without/with cooperative diversity. Moreover, we provide a solution based on sub-carrier pairing technique to further improve the channel capacity.