Relay-based secret key generation in LTE-A

Relay nodes (RNs), which are low-power nodes that provide enhanced coverage and capacity at low cost are an integral part of the Long Term Evolution Advanced (LTE-A) standard. In order to boost throughput, cooperative multiple input multiple output (co-op MIMO) techniques are proposed wherein RNs close to end users are recruited to operate as virtual antenna arrays (VAA). In this paper, we exploit the co-op MIMO structure to design and implement a physical layer (PHY-layer) security scheme for LTE-A networks. Specifically, we consider two relay-based co-op MIMO architectures and propose novel secret key generation (SKG) schemes for those cases. Information theoretic results regarding secret key generation rate (SKGR) are presented. Results indicate that relay-based co-op MIMO schemes, traditionally used to enhance LTE-A network throughput and coverage, can also increase SKGR. Our work demonstrates the viability of SKG technique as a potential PHY-layer security scheme for LTE-A networks.