Graph-Based Channel-Aware Secure-Coding for Cooperative Communication

This work considers the 5G new radio (5G-NR) frame structure through the 3GPP channel model in Rural-Macro (RMa) scenario. A graph-based channel-coding scheme to ensure data-security to the intended user/destination in a MIMO-cooperative communication network in presence of an external passive eavesdropper is proposed. For this purpose, two graphs: $\mathcal{G}_{M}(\mathrm{V}_{M},\ \mathcal{E}_{M},\ \mathrm{W}_{M})$, $\mathcal{G}_{E}(\mathrm{V}_{E},\ \mathcal{E}_{E},\ \mathrm{W}_{E})$ corresponding to the source-relay-destination, source-relay-eavesdropper are considered in MIMO-channels environment respectively. The channel coding scheme, based on the inverse graph Fourier transformation (IGFT) of the $\mathcal{G}_{M}$, is proposed to create increased bit/symbol errors at the eavesdropper along with the MIMO-diversity gain at the main user. The GFT of $\mathcal{G}_{M}$ based postcoder is used at the destination to detect the transmitted symbols whereas GFT of $\mathcal{G}_{E}$ with/without postcoder at the eavesdropper is used to estimates the signal. Physical layer security (PLS) scheme based on the difference of BERs between destination and the eavesdropper is proposed.