Design of Physical Layer Network Coded LDPC Code for a Multiple-Access Relaying System

In this letter we propose a novel physical layer network coded LDPC code structure, named PNC-LDPC code, for a non-orthogonal multiple access relay channel. An iterative detection-and-decoding receiver is designed to tackle the multi-user interference at the destination. Based on the code structure and the iterative receiver, we optimize the PNC-LDPC code profile to approach the system achievable rate by utilizing the extrinsic mutual information transfer (EXIT) chart. Simulations show that the performance of our PNC-LDPC code outperforms other conventional network coding based LDPC codes.