The Research On The Key Technology Of Cooperative Communication Based On Body Area Networks

In recent years, with the rapid development of intelligent hardware, man-machineinteraction and wearable devices and other cutting-edge technology, wireless bodyarea network （WBAN） as the cross field of the internet of things (IoT) and thestated technology above has received wide attention. WBAN have applied in medicalmonitoring, military, entertainment, aviation, sports and so on, containing a vastcommercial prospects and research value. However, there are many bottlenecks intheoretical research or technical implementation. In order to promote the developmentof WBAN a lot of problems need to be solved. Because WBAN have characteristicsof low power dissipation, miniaturization and mobility etc, this article embarks fromthe theoretical research aiming at two aspects of energy efficiency and reliability inorder to optimize the lifetime of WBAN.As the research progress of5G mobile communications, owing to the requirementsof achieving high data rate in a high bandwidth channel, MIMO technology has beenwidely concerned again. However, on account of that sensor nodes of WBAN haveonly single antenna, MIMO technology can’t achieve and cooperative communicationbecome a new method to solve the problem. Even though sensor nodes have onlysigle antenna, cooperative communication can achieve spatial diversity by sensornodes cooperation. Cooperative transmission mechanism can save energyconsumption of WBAN and improve the reliability of the system. In this paper, thekey technologies of cooperative communication based on WBAN are researched, themain research work is as follows:Firstly, the network model of WBAN and the channel statistical model have beenestablished in cooperative mechanism in order to optimize the lifetime of WBAN andimprove the reliability of system. The best transmission strategy and signal combiningmethod of WBAN have been studied in cooperative mechanism.Secondly, the existing efficiency index functions have been studied, including themaximum residual energy mode, the optimal channel mode, the max-min mode and DPLM mode to maximize the lifetime of WBAN as the goal. Under the premise oftrading off reliability, the power control mechanisms based on bit error rateconstraints have been studied in the direct transmission mode and the cooperativetransmission mode.Thirdly, energy efficient relay selection algorithms which are measured by theenergy efficiency index functions were proposed. Simulation experiments haverespectively been done though MATLAB software in frequency band of400MHz,2.4GHz and ultra wideband. The simulation results prove that relay selectionalgorithm of DPLM mode has the optimal network lifetime performance in mostapplication scenarios.Fourthly, distributed transmission scheduling algorithm is designed in cooperativemechanism. In WBAN, Physical layer, data link layer and MAC layer are mainlyprocessed in a distributed design. In the physical layer, under the constrains of biterror rate, a optimal power allocation strategy based on M-PSK modulation isproposed. In the data link layer, a distributed DPLM transmission protocol whichtakes channel state information and residual energy information into consideration isproposed. In the media access control layer, modified two hop media access controlprotocol based on IEEE802.15.6standard is used. The simulation results prove thatthe proposed distributed transmission scheduling algorithm under the premise ofensuring the network reliability maximizes the network lifetime performance.The main work of this paper provides a new method to solve the problems ofenergy efficiency and reliability in WBAN. The distributed transmission schedulingalgorithm proposed further optimize the lifetime performance of WBAN, which has acertain reference value to subsequent research of WBAN.