Study On The Strategies Of Relay Selection In Cooperative Relay Networks With Smart Grid

The cooperative relay communication technology can increase wireless transmission rate and enlarge coverage area with less energy cost,which can become a key technology for improving the communication quality in the future wireless communication system.With the development of advanced information technology,the smart grid is expected to be the next generation electricity grid,so the relay neworks powered by smart grid has attracted much attention in the academic circles in recent years.However,most of the related studies on relay networks with smart grid consider relay nodes as “free” service supporters.In general,the relay nodes in the neworks may belong to different inities and authorities with their own interests.Especially,the relay nodes powered by the smart grid will have their own resource costs,which will become “selfish” in order to save their own costs.Thus it is necessary to study the incentive strategies of the relay networks powered by smart grid to promote the energy efficiency and performance of the wireless networks.In this thesis,we will use the game thory to formulate strategies to select the optimal relays and allocate wireless resources reasonably so as to ensure the networks performance and the utilization efficiency.The main contributions of this thesis involve the following aspects:Firstly,we propose a non-cooperative game strategy for the relay networks powered by smart grid.Using the statistic Channel State Information(CSI),we derive the outage capacity of relay networks and a closed-form solution of the optimal purchase power when the user selects each relay.Based on the pricing mechanism,a non-cooperative game strategy of relay networks with smart grid is proposed to select the optimal relay and optimal power allocation by modeling the user as a buyer and each relay powered by the smart grid as a seller.The simularion results verify the our proposed strategy can guarantee the utilites of user as well as relays.The results also illustrate that it may increase the energy efficiency of the netwroks.Secondly,a non-cooperative game strategy of single-user multiple input multiple output(MIMO)relay networks with finite-alphabet inputs is discussed.We propose an improved linear precoding design algorithm with low complexity.The proposd linear precoding design algorithm is incorporated into the non-cooperative game strategy of relay networks with smart grid and we can obtain the optimal relay as well as the prichase power.The simulation results show the proposed scheme with finite-alphabet inputs in this thesis provides significant performance gain over existing schemes with Gaussian inputs.The results also indicate the proposed non-cooperative game with the precoding algorithm can also improve the performance of networks.Finally,we study the multiuser MIMO relay networks powered by smart grid with finitealphabet inputs.By designing the linear precoding matrix with purchasing power,the utility function of each user relay will be maximized when selecting the candidate.Then the mutual preference matrixes between users and relays will be established.On this basis,we propose a many-to-many stable matching algorithm for relay networks.The simulation examples show the proposed stable matching algorithm can obtain a stable solution,which offers significant performance gain.