Research On Key Technologies Of Interference Coordination Based On Game Theory Among WBANs

As a new medical model,the Wireless Body Area Networks(WBANs)bring opportunities and hopes for the reform of the traditional medical industry.To avoid the intra-WBAN interference,Time Division Multiple Access(TDMA)or Frequency Division Multiple Access(FDMA)is adopted in each WBAN,which is referred to as TDMA-WBANs or FDMA-WBANs,respectively.However,due to the mobility and sociality of WBAN users and the limited resources,multiple WBANs may gather together to cause serious interference problems,which degrades the network performance.Especially for WBANs used for health monitoring,unreliable communication can even endanger the lives of users.Thus,this thesis studies the distributed network resources allocation schemes based on game theory to alleviate the interference among co-located WBANs.According to whether the users trust each other,two scenarios of cooperative coexistence and non-cooperative coexistence are studied.The innovations and contributions of this thesis are as follows:(1)To mitigate the interference among multiple TDMA-WBANs in the cooperative coexistence scenario,this paper proposes a power control scheme based on the bargaining game model(PCBG).The emergency index and the energy consumption factor are designed to respectively measure the urgency of the sensed data and the energy efficiency of the sensor.Moreover,to maximize the network Nash product,an optimization model is constructed and is equivalently transformed into a convex optimization model to obtain the Nash Bargaining Solution(NBS).The simulation results show that the proposed scheme alleviates the inter-WBAN interference.The reliability and timeliness of abnormal data and the energy efficiency of network are improved by adjusting sensors' transmission power according to the emergency index and the energy consumption factor.Compared with the power control schemes based on the traditional optimization models,the proposed PCBG scheme gives a good balance between the overall utility and the inter-WBAN fairness.Further,the PCBG scheme can achieve higher data transmission quality with lower power consumption by comparing with other power control schemes proposed in recent years.(2)To avoid the interference among multiple FDMA-WBANs in the cooperative coexistence scenario,this paper proposes an inter-WBAN capacity allocation scheme based on bargaining game model(CABG).Further,a power control scheme based on the Stackelberg game model(PCSG)is proposed.In the PCSG scheme,the coordinator control the transmission power of sensors by pricing under the condition that the network capacity is limited by the CABG scheme.Moreover,a non-uniform pricing algorithm and a uniform pricing algorithm are designed.Further,to obtain the Stackelberg Equilibrium(SE).the non-convex optimization pricing models are transformed into convex optimization models by adding constraints.And the priorities of the sensors are considered.The simulation results show that the CABG scheme avoids the inter-WBAN interference and ensures the data priorities while satisfying the minimum data rate requirement of each WBAN.Furthermore,compared with the traditional non-priority power control scheme,the PCSG scheme results in additional power consumption of about 34.61%,but it can meet the diversity demands of sensors for data transmission rates.Compared with the no pricing power control scheme,the PCSG scheme reduces the power consumption by 71.3%.(3)To alleviate the interference among multiple TDMA-WBANs in non-cooperative coexistence scenario,a power control scheme based on Stackelberg game and Bayesian game models(PCSBG)is proposed.On the one hand,in order to reduce the interference suffered by the coordinator and increase the data rates of sensors,a Stackelberg game model is established to describe the interaction between coordinators and sensors from adjacent WBANs.On the other hand,since the TDMA-WBANs in non-cooperative scenario can't fully grasp each other's time scheduling information,the relationship between sensors from neighboring WBANs is presented by the Bayesian game model.In addition,to guarantee the timeliness of the collected data,the scheme defines priority factor for each sensor and sets the sensors' wake-up probabilities,which is positively related to their priority factors.The simulation results show that the PCSBG scheme mitigates the inter-WBAN interference and converges to the equilibrium quickly.Moreover,the total data rate and the inter-WBAN fairness is balanced.Compared with the existing BGPC scheme,the PCSBG scheme improves the energy efficiency by designing the dynamic pricing function.In summary,this paper proposes several distributed interference coordination schemes based on game models to mitigate the inter-WBAN interference.According to the coexistence scenarios,the corresponding models are established and the algorithms are designed.The feasibility and effectiveness of the proposed schemes are verified by theoretical analysis and simulation results,which provides reference for the diverse applications of the WBANs.