The collision channel with recovery

We consider a simple conceptual model of random accessing to a receiver deploying multiuser detection techniques. The model is a simple extension of Massey and Mathys' collision channel without feedback in which a certain probability of recovery from collision is introduced. As the main result, we derive the slot-synchronized capacity region of this recovery channel and show that for sufficiently powerful multiuser detectors, maximal performance is achieved without any sophisticated transmission protocols. We also explore the effect of a simple fading model.