MAC channel with states for pulse-based communication systems

We consider a two-user binary multiple access setup suitable for pulse based communications. The link from each user to the receiver is modeled by independent time-varying Z-channel. We consider the cross-over probabilities of the Z-channels as the state of the process. Each user has access only to its own state process and is unaware of the other user´s states. The receiver observes the superposition of the symbols from the links. Assuming a block fading state process, we propose adaptive communication schemes, which also ensure outage-free communication in any transmission block. Furthermore, the proposed strategies turn out to be throughput optimal for highly dispersive systems.