认知无线电跨层传输的建模与仿真

将认知无线电(CR)中的跨层传输建模为约束马尔可夫决策过程(MDP),考虑了频谱可用性的变化规律、上层数据的到达过程和信道衰落,提出一种满足掉包率约束的前提下最小化平均功率消耗的方案。采用拉格朗日乘子法对此过程求解,并用2种简化的方法,即状态聚合和行动集缩来解决因状态空间、行动集规模过大引起的收敛速度慢的问题。计算机仿真结果表明,简化方法对该方案的性能影响很小,且该方案的平均功耗最低。

Modeling and Simulation of Cross-layer Transmission Based on MDP in Cognitive Radio Networks

Cross-layer transmission in cognitive radio is modeled by constrained Markov Decision Process （MDP）. Considering the change rule of frequency spectrum availability, the arrival process of upper-layer data and channel fading, a scheme of minimizing average power consumption in cognitive radio networks under the constraint of packet drop probability is proposed. Lagrangian multiplier approach is used to solve the MDP, and two simplified methods are used to solve the problem of low convergence rate. Computer simulation result shows that the simplified methods have little impact on the performance of this scheme, and the scheme has the minimum average power consumption.