1 research outputs found
Contract-Based Cooperative Spectrum Sharing
Providing proper economic incentives is essential for the success of dynamic
spectrum sharing. Cooperative spectrum sharing is one effective way to achieve
this goal. In cooperative spectrum sharing, secondary users (SUs) relay
traffics for primary users (PUs), in exchange for dedicated transmission time
for the SUs' own communication needs. In this paper, we study the cooperative
spectrum sharing under incomplete information, where SUs' types (capturing
their heterogeneity in relay channel gains and evaluations of power
consumptions) are private information and not known by PUs. Inspired by the
contract theory, we model the network as a labor market. The single PU is the
employer who offers a contract to the SUs. The contract consists of a set of
contract items representing combinations of spectrum accessing time (i.e.,
reward) and relaying power (i.e., contribution). The SUs are employees, and
each of them selects the best contract item to maximize his payoff. We study
the optimal contract design for both weak and strong incomplete information
scenarios. First, we provide necessary and sufficient conditions for feasible
contracts in both scenarios. In the weak incomplete information scenario, we
further derive the optimal contract that achieves the same maximum PU's utility
as in the complete information benchmark. In the strong incomplete information
scenario, we propose a Decompose-and-Compare algorithm that achieves a
close-to-optimal contract. We future show that the PU's average utility loss
due to the suboptimal algorithm and the strong incomplete information are both
relatively small (less than 2% and 1:3%, respectively, in our numerical results
with two SU types).Comment: Part of this paper has appeared in IEEE DySPAN 2011, and this version
has been submitted to IEEE J-SA