Multi-Level Channel Valuations and Coalitional Subgames in Spatial Spectrum Reuse

To enable heterogeneous channel valuations in spatial spectrum reuse, user characteristics involving the supply and demand relationship need to be considered. In this paper, we design a channel transaction mechanism for non-symmetric networks and maximize the social welfare in consideration of multi-level channel valuations of the secondary users (SUs). Specifically, we group the SUs into allowable user crowds (AUCs) through a modified Bron-Kerbosch algorithm. We introduce a Vickrey-Clarke-Groves (VCG) auction, in which the participants are limited to the AUCs. To facilitate the bid formation, we transform the constrained VCG auction to a step-by-step decision process. In each step, the truthful bidding of an AUC is to reveal the accumulated channel valuation of the coalition. Meanwhile, the SUs in a coalition play a coalitional game with transferable utilities. We use the Shapley value to realize fair payoff distribution among the SUs in a coalition. Furthermore, we approach the optimal channel allocation via a greedy algorithm and batch allocation. In our simulation, we compare the low-complexity algorithms and demonstrate the efficiency of the channel transaction mechanism.