The Gaussian Multiple Access Wire-Tap Channel

Preprint
Publisher Website
Google Scholar
Abstract
We consider the Gaussian Multiple Access Wire-Tap Channel (GMAC-WT). In this scenario, multiple users communicate with an intended receiver in the presence of an intelligent and informed wire-tapper who receives a degraded version of the signal at the receiver. We define a suitable security measure for this multi-access environment. An outer bound for the rate region such that secrecy to some pre-determined degree can be maintained is derived. Using Gaussian codebooks, an achievable such secrecy region is also identified. Gaussian codewords are shown to achieve the sum capacity outer bound, and the achievable region coincides with the outer bound for Gaussian codewords, giving the capacity region when inputs are constrained to be Gaussian. Numerical results showing the new rate region are presented and compared with the capacity region of the Gaussian Multiple-Access Channel (GMAC) with no secrecy constraints. It is shown that the multiple-access nature of the channel can be utilized to reduce the rate lost due to the secrecy constraint for each user.

This publication has 0 references indexed in Scilit: