Design and Analysis of Cross-Layer Contention Resolution Algorithms for Multi-Packet Reception Slotted ALOHA Systems

In this paper, we propose contention resolution algorithms for multi-packet reception slotted ALOHA systems with immediate- and delayed-first-transmission protocols, in which a base station broadcasts the retransmission probability for each slot to all mobile terminals. As a cross-layer approach, the base station estimates the system backlog by exploiting information on multiple access interference. Based on this information, the algorithm chooses the optimal retransmission probability to maximize the expectation of the system throughput conditioned on the number of retransmitting terminals. The performance of our algorithms and the system stability are evaluated by theoretical analysis and compared to simulations. Results show that our algorithm achieves around 68.3% throughput efficiency under ideal channel conditions.