Research On D2D Relay Communication Technology In Plateau And Mountainous Areas

D2D technology can increase the coverage of the network,so D2 D technology can be applied to communication networks with poor signal coverage in mountainous regions of the plateau;When some users on the edge of the community can not directly access the base station under the influence of the mountain environment in the plateau,the introduction of D2 D relay technology into the cellular can effectively solve the problem that the mountain environment in the plateau leads to the edge coverage of the community.When the edge of the cell or the environment is unable to communicate directly with the base station,it can use the D2 D relay communication method to finally establish a complete communication link with the base station to achieve network coverage of the entire plateau mountainous area and provide communication support for residents living in the mountains.It is of great practical significance to promote the development and progress of the whole society.In this paper,D2 D relay communication based on plateau mountain area is studied.Because of the complex terrain environment,wireless signal will cause signal attenuation and delay when it is transmitted in complex environment.Therefore,the wireless communication channel in mountainous environment is studied in this paper.Through the establishment of system model and channel simulation,the influence of different environment and moving speed on signal attenuation is obtained,so as to master the communication status of wireless channel.Then,the two modes of D2 D relay forwarding,AF and DF forwarding,were modeled and simulated under the channel scene in the plateau mountains.The theoretical error rate,the actual error rate and the interrupt probability of the two forwarding modes are obtained,and the reasons for the interruption probability and the error rate are analyzed.The principle and method of D2 D relay communication and relay forwarding are thoroughly understood.Finally,the relay selection is further studied.Considering the communication channel of D2 D in plateau mountainous area and the special scene requirement,two relay selection algorithms are proposed: the maximum signal-to-noise ratio relay selection algorithm based on channel prediction(MS)and the combined energyefficiency relay selection algorithm(CES).MS algorithm uses existing MMSE algorithm to predict the channel coefficients,then calculates the signal-to-noise ratio through the channel coefficients,and finally chooses the optimal relay by the size of the signal-to-noise ratio.CES algorithm combines the energy efficiency of the system and selects the relay link with the highest energy efficiency for transmission.Finally,using MATLAB software,the proposed algorithm is simulated and analyzed with the interruption probability of the system as an index to verify the reliability of the proposed relay selection algorithm.