Secrecy Capacity in Large Cooperative Networks in Presence of Eavesdroppers with Unknown Locations

TL;DR

This paper investigates the secrecy capacity of large cooperative wireless networks with unknown eavesdropper locations, proposing a power-efficient scheme that achieves unbounded secure rates as user density increases.

Contribution

It introduces a realistic model considering unknown eavesdropper locations and fading effects, and proposes stochastic virtual beamforming to enhance secrecy capacity.

Findings

Unbounded secure rate achievable with increasing user density.

Tolerable eavesdropper density becomes unbounded as user density grows.

Scheme works under realistic assumptions with fading and path loss.

Abstract

In this paper, an extended large wireless network under the secrecy constraint is considered. In contrast to works which use idealized assumptions, a more realistic network situation with unknown eavesdroppers locations is investigated: the legitimate users only know their own Channel State Information (CSI), not the eavesdroppers CSI. Also, the network is analyzed by taking in to account the effects of both fading and path loss. Under these assumptions, a power efficient cooperative scheme, named \emph{stochastic virtual beamforming}, is proposed. Applying this scheme, an unbounded secure rate with any desired outage level is achieved, provided that the density of the legitimate users tends to infinity. In addition, by tending the legitimate users density to the infinity, the tolerable density of eavesdroppers will become unbounded too.