认知Ad hoc网络中基于市场的三级频谱分配方案

分簇是Ad hoc网络规模较大时采用的主要结构，而频谱分配是Ad hoc网络的关键技术之一。该文针对认知无线电环境的分簇Ad hoc网络，提出了一种新的基于市场的频谱分配方案，该方案中簇首节点依据业务比例从频谱管理中心购买频谱，簇内采用基于供需市场理论的频谱分配算法。分析了簇内频谱市场的两种迭代定价算法额外需求迭代算法和连续松弛迭代算法以及簇首需求订购的过程。该方案能实现各簇收益的最大化，簇首基于需求的频谱购买相对于等量购买进一步提高了频谱效用。仿真结果表明这种频谱分配方案能有效提高系统频谱效用，额外需求迭代算法和连续松弛迭代算法均表现出良好的收敛性能。

A Three-Level Market-Based Scheme of Spectrum Allocation for Cognitive Ad hoc Networks

Clustering is the main framework of large scale Ad Hoc networks, and one of its key technologies is spectrum allocation. In this paper, a novel three-level market-based scheme of spectrum allocation is proposed for cognitive clustered Ad Hoc networks. In this scheme, cluster headers buy spectrum from spectrum administrator of primary service according to the estimation of their demands, and a market-based algorithm which stems from microeconomic theory is adopted in the spectrum allocation within each cluster. An analysis is given on the iterative pricing algorithms of Excess Demand-Based (EDB) and Successive Over-Relaxation (SOR) for in-cluster market as well as on the process of spectrum purchase based on demand executed by cluster headers. The simulation results show that cluster profit is maximized by adopting the market-based algorithm, and that a significantly utility improvement is achieved by demand-based purchase of cluster headers compared with equal purchase. As a result, the spectrum allocation scheme proposed in this paper can improve the system performance efficiently. The convergence of EDB and SOR iterative algorithms is also proved by simulation.