Dynamic Spectrum Allocation Based on Interference Threshold Modeling

Dynamic transmission power based dynamic spectrum allocation (DSA) schemes are extensively adopted in cognitive ratio (CR) networks due to their flexible spectrum access strategies to improve spectrum utility. However such DSAs suffer from high sensitivity to the environment change. Based on the protocol model of wireless communications, a notion of interference threshold (IT) is introduced into the DSA model such that the intricate interactions among CRs can be decoupled and CRs´ adaptations only affect the local area. With IT modeling, CRs´ strategy profile number turns into finite such that an exhaustive search based IT DSA (ES-IT DSA) scheme is feasible to enumerate all strategy profiles for finding the optimal one. To address the scalability issue in ES-IT-DSA, a suboptimal RGF-IT DSA is developed in virtue of restricted growth function theory. Simulation results concur that the IT based DSA algorithms can keep high spectrum utility while achieving simplicity.