Cooperative spectrum sharing with energy-save in cognitive radio networks

Cooperative spectrum sharing increases the spectrum efficiency and improves the performance of primary users (PUs) in cognitive radio domain. This paper proposes an energy-aware dynamic spectrum sharing framework, named Cooperative Spectrum Sharing with Energy-save(CSSE), which maximizes energy saving while ensures communication QoS (i.e. transmission rate) of primary transmitter (PT). In CSSE, the PT leverages a proper set of secondary transmitters (STs) as cooperative relays for its transmission and releases a proportion of bandwidth to the cooperative STs. Under the restriction of energy budget, each ST decides its power density allocation (including relaying power density and transmit power density for its own transmission) to maximize its transmission rate. Taking the users' selfishness and intellectuality into consideration, we formulate the above optimal problem as a Stackelberg game (SG) and prove that a Unique Nash Equilibrium (UNE) point exists among the non-cooperative STs. Theoretical analysis and simulation results show that the PU can obtain maximum benefit. Meanwhile, the relaying STs can get acceptable benefits under CSSE.