Robust Power Allocation and Outage Analysis for Secrecy in Independent Parallel Gaussian Channels
This work addresses secure data transmission in wireless networks with eavesdropper uncertainty, representing an incremental improvement in power allocation strategies for specific channel models.
The paper tackles the problem of secure communication over parallel Gaussian channels with uncertain eavesdropper channel state information by analyzing outage probabilities and proposing a robust power allocation scheme to minimize outage at a target secrecy rate, showing effectiveness compared to conventional methods.
This letter studies parallel independent Gaussian channels with uncertain eavesdropper channel state information (CSI). Firstly, we evaluate the probability of zero secrecy rate in this system for (i) given instantaneous channel conditions and (ii) a Rayleigh fading scenario. Secondly, when non-zero secrecy is achievable in the low SNR regime, we aim to solve a robust power allocation problem which minimizes the outage probability at a target secrecy rate. We bound the outage probability and obtain a linear fractional program that takes into account the uncertainty in eavesdropper CSI while allocating power on the parallel channels. Problem structure is exploited to solve this optimization problem efficiently. We find the proposed scheme effective for uncertain eavesdropper CSI in comparison with conventional power allocation schemes.