A Game-Theoretic Approach for Exploiting Multiuser Diversity in Cooperative Slotted Aloha

Multiuser diversity gains can be achieved by assigning channels to users with better channel quality in multiuser systems. To avoid the extensive information exchange required for centralized approaches, we propose a distributed fair pricing strategy for a slotted Aloha system in which users act selfishly to improve their own utilities for both the collision model and the multipacket reception (MPR) model. Based on a game-theoretic framework, we show that multiuser diversity gains can be achieved by appropriately designing the Nash equilibrium thresholds for the selfish users to preserve the throughput and revenue achieved in the classical slotted Aloha systems. The network enforces fairness among different users by employing a pricing policy that favors equal access probabilities. Our simulation results show that significant multiuser diversity gains are achieved in terms of energy consumption and/or spectral efficiency.