一种基于合约的认知网络协作频谱共享策略

A Contract-Based Cooperative Spectrum Sharing Approach in Cognitive Radio System

为解决基于合约制的多个主用户和多个次用户间的协作频谱共享问题,依据统计学的思想,提出了一种以主用户获得期望总效用最大化为目标的合约设计方法.主用户在为每个次用户设计合约时充分利用次用户接受的概率信息,得到统计意义上的期望效用,进而得到主用户期望总效用最大化的优化问题,通过理论推导化简优化问题并利用遗传算法求出次优解,即次优的合约集.数值仿真表明:通过引入统计信息成功解决了主、次用户的协作频谱共享问题,与DMA-UI算法相比,依靠统计学的方法可以使主用户在统计意义上获得更多的效用,进而提高了主用户的能效与谱效.

To solve the problem of contract-based cooperative spectrum sharing between multiple primary users and multiple secondary users, we put forward a contract design method based on statistical theory to maximize the total utility of primary users. Firstly, the primary users make full use of the accepting contract statistical information of secondary users to design a reasonable contract. Then, the primary users according to the statis- tical expected utility to obtain the optimization problem of maximizing theirs total expected utilities. Further- more, we simplify the problem in theory and exploit the genetic algorithm to derive the sub-optimal solution. The simulation results and analysis show the contract design method can solve the problem of contract-based cooperative spectrum sharing successfully. Compared with the DMA-UI, the approach we formulated can make primary users obtain a higher utility, and further improve the primary users＇ energy efficiency and spectrum efficiency.