Achieving positive rate with undetectable communication Over MIMO rayleigh channels

In this paper we consider the problem of achieving a positive error-free communications rate while guaranteeing that the sum of the detector´s probabilities of detection errors is arbitrarily close to one. Building on our previous work, we present approximations to the privacy rate over Multiple Input-Multiple Output (MIMO) Rayleigh fading channels when a detector employs a radiometer detector and has uncertainty about his noise variance. We conclude by presenting realizable privacy rates for several practical scenarios.