Optimal Power Allocation for Secrecy Fading Channels Under Spectrum-Sharing Constraints

TL;DR

This paper investigates optimal power allocation strategies for secondary users in spectrum-sharing channels with security constraints, considering fading environments and various CSI availability scenarios, to maximize secrecy capacity while respecting interference limits.

Contribution

It introduces new power allocation schemes for spectrum-sharing channels that account for security and interference constraints, including solutions with and without eavesdropper CSI.

Findings

Optimal power allocation under interference and security constraints.

Proposed suboptimal on/off power control method.

Secrecy capacity limits in fading spectrum-sharing channels.

Abstract

In the spectrum-sharing technology, a secondary user may utilize the primary user's licensed band as long as its interference to the primary user is below a tolerable value. In this paper, we consider a scenario in which a secondary user is operating in the presence of both a primary user and an eavesdropper. Hence, the secondary user has both interference limitations and security considerations. In such a scenario, we study the secrecy capacity limits of opportunistic spectrum-sharing channels in fading environments and investigate the optimal power allocation for the secondary user under average and peak received power constraints at the primary user with global channel side information (CSI). Also, in the absence of the eavesdropper's CSI, we study optimal power allocation under an average power constraint and propose a suboptimal on/off power control method.