Weakest-Link Coalition: Further Investigation on Cooperative Interference-Aware Spectrum Sensing and Access

Interference-aware spectrum sensing extends conventional interference-agnostic sensing by exploring the fact that missed detection does not necessarily result in outage or intolerable interference on the primary user. While related work has motivated and demonstrated the benefits of interference-aware spectrum sensing for spectrum hole discovery, the inherent conflict of interests among the set of cooperative users with interference-aware spectrum detectors has not been properly formulated and addressed. In this paper, we aim to bridge the gap by considering a coalition-based model, where the set of secondary users is to be partitioned into multiple coalitions for cooperative spectrum sensing and access. The goal is to maximize the utility sum of all secondary users while observing the protection requirement of the primary user. Since the user with the largest interference probability in a coalition critically limits the detection performance of the coalition, there is a trade-off in determining the optimal coalition structure in the network. To proceed, we first formulate a joint threshold detection and coalition formation problem under the target cooperative model, and then explore important properties of the target problem. Our proposed algorithms based on polyblock approximation and search space partition can effectively solve the formulated problem with significant performance gains and complexity reduction against baseline approaches proposed in related work.