关键词: 认知无线电, 能效, 跨层设计, 传输控制, 约束马尔可夫决策过程

Abstract: A cross-layer transmission control scheme based on Cognitive Radio（CR） for average power minimization under the constraints of collision with licensed user and buffer state is addressed.The scheme is formulated by Constrained Markov Decision Process（CMDP），which is solved by Linearly Programming（LP）.State aggregation is employed to solve the problem in the case that channel state information cannot be achieved in CR networks.To reduce the complexity of LP，state aggregation and action set reduction are utilized to cope with the curse of dimensionality.According to the simulation results，the scheme can afford average power minimization under constraints，and complexity reduced solution almost does not reduce performance of the scheme.

Key words: Cognitive Radio（CR）, energy-efficient, cross-layer design, transmission control, Constrained Markov Decision Process（CMDP）