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.