Research And Design Of Relay Incentive Mechanism In Cooperative Communication

With the rapid development of wireless communication services,wireless communication systems will be targeted at higher data rates,better end-to-end performance and extended hotspot coverage.A large number of low-power nodes,relay and device-to-device(D2D)communication links will exist in traditional cellular systems,and collaboration between mobile devices will become more common.Compared to fixed relays,mobile devices have more flexible locations,a wider range of options,and a better adaptability to complex wireless transmission environments.However,when participating in the collaboration,mobile relay nodes consume the energy of equipment,if there is no reasonable reward,it will not be conducive to the establishment and maintenance of cooperative relationships between nodes.Therefore,to encourage mobile nodes to participate in collaboration actively,the design of good relay incentive mechanisms is of great significance,the main work of this paper is to design relay incentive schemes.Firstly,a relay incentive mechanism based on link imbalance(LIABLE)is proposed for cooperative downlink communication system.In order to encourage nodes to participate in cooperation,communication resource is offered as a reward to the relay node that participates in data cooperation.Unlike traditional bottleneck elimination methods in multi-hop end-to-end communication,the LIABLE attempts to make use of the bottleneck caused by link imbalance.Moreover,the location and size of bottleneck can be controlled on demand by adjusting relay's transmit power,so that the difference of data rates between two hops can be afforded to relay as reward.The proposed scheme can provide appropriate compensation to relay node on premise that the destination's transmission performance is guaranteed.In addition,enhancement of system spectral efficiency and relay node's energy efficiency can be realized.Secondly,In order to overcome the uncertainty of the reward with long-term relay incentive strategy and the degradation of resource utilization efficiency incurred by the short-term incentive scheme,a Cooperative Compound Relay Incentive mechanism(CCRI)is proposed for cooperative downlink communication system.By exploiting the bottleneck resulted from the imbalance of links' capability,the rate difference that the first hop exceeds the second is provided as an instant reward for the relay node's own data transmission.In addition,by taking into account the situations where the short-term reward is insufficient,excessive,or the bottleneck exists in the first hop in such a case the short-term incentive scheme becomes unavailable,a proportional fair based long-term incentive is employed as supplementary,with which the relay node's scheduling weight is further adjusted.So that the proposed scheme can provide rational reward to the relay and achieve improvements of system's spectral efficiency and lifetime,as well as relay's energy efficiency.Finally,with targeting at the limitations of the existing information relay incentive mechanisms when node's residual energy is low,a Cooperative Energy Relay Incentive mechanism(CERI)is proposed to jointly transmit energy and information based on the CCRI mechanism.While collaborating to forward the data required by the destination node,by exploiting the bottleneck resulted from the imbalance of links' capability,the energy transmission is provided as an instant energy reward for relay node.In addition,the long-term reward in CCRI is classified as information reward and energy reward acrroding to the node's residual energy.By providing energy reward to relay node,the proposed scheme can encourage the nodes whose residual energy is low to participate in cooperation.At the end of this paper,the research work of this paper is summarized and some possible directions for future study are given.