Research On Mode Selection And System Capacity For Device To Device Communication System

In recent years, the demand of conducting wireless communication anytime is increasing with the extremely rapid development of communication technology, so various kinds of new communication technologies emerge constantly. D2 D technology allows direct data transmission between users by the way through multiplexing cellular resources, and reduces the transmission power of terminals as well as increases the spectral efficiency of system, moreover, the D2 D communication technology is able to effectively improve the phenomenon of deficient spectrum resource in hybrid wireless communication networks.Although D2 D communication can product gain for the hybrid networks, at the same time,it faces difficult problems and rigorous challenges: Firstly,the direct transmission way between terminals will bring more mode selections. Secondly, the complexity of interference environment in cellular and D2 D hybrid networks will promote with the rising diversification of resource sharing mode. Therefore, effectively improving the D2 D multiplexing strategy, reducing interference of D2 D and cellular equipment, as well as enhancing communication capacity is urgently need to be solved in the hybrid D2 D and cellular networks.D2D technology multiplexs uplink resources using multiplexing mode or orthogonal mode in hybrid network. This article conducts the research from the following three aspects:! !Firstly, we take research on resource allocation, power control, interference coordination and mode selection. Secondly, we consider system capacity of the whole hybrid system, analysis the orthogonal and multiplexing mode, and gain optimal conditions. Lastly, we focus on the mode selection, and respectively study the case of including relay node or not, propose the mode selection scheme based on relative position information of D2 D users, then we study the system capacity of different modes and auxiliary relay condition, and the effectiveness of above-mentioned system capacity and mode selection optimization strategies is validated by numerical simulation.