Study On Jointly Power Allocation And Relay Selection Strategy For Underwater Acoustic Cooperative Communication Networks

The underwater acoustic communication technology become more popular with the absence of terrestrial resources and the increasing exploitation of Marine resources.Due to the unique features of underwater environment,such as limited bandwidth,time-space-frequency and multipath and so on,underwater acoustic communication faces great challenges.The wireless cooperative communication is a effective solution to improve the system capacity,expand the transmission range and enhance the reliability of signal transmission for underwater acoustic communication,which has been widely studied.Though the problem was solved in some degree,underwater acoustic cooperative communication still face the problems of limited bandwidth and energy etc.Thus,it is crucial to solve the problem of resources allocation for underwater acoustic cooperative communication.As we all know,the schemes of traditional RF cooperative communication can't be applied to underwater directly.Therefore,for different underwater communication scenarios,how to design reasonable resource allocation scheme in the underwater environment with limited energy so as to improve the performance of the network is the main content of this paper.Firstly,analyzed the basic knowledge of underwater acoustic communication environment,including the feature of underwater acoustic channel and the characteristics of the speed of sound for underwater environment and so on.Meanwhile,in this paper,the knowledge was introduced for cooperative communication.which establishes the theoretical basis for this paper.Secondly,in allusion to the issues of short time to live,the uncertain of channel information and the poor communication service in the case of multi-user single-relay for underwater environment,a power allocation scheme of consider the residual energy of the node is put forward in this paper.In this scheme,the residual energy,service quality and channel information uncertainty are considered synthetically.Simulation results show that the proposed scheme can reduce network energy consumption,prolong the life of nodes and improve the overall performance of the system.Finally,the scheme of joint relay selection and power allocation was discussed for the case of single-user multi-relay.For the issue of relay selection,the scheme of multi-relay selection was produced based on the transition probability,which require less information to select the set of relay.Next,the issue of multi-node power allocation was built a game model.In addition,the robust theory was introduced to counter the negative effects brought by the uncertainty of underwater acoustic channel state information,which making the proposed algorithm more adaptive.