Research On D2D User Cooperation Algorithm

Device-to-Device communication, one of important parts of heterogeneous network, has great potential to handle problems in future complex and various heterogeneous networks by short-range communication among users directly, which dose not only help to enhance throughput, spectrum efficiency and energy efficiency but also have strong flexibility to adapt to various communication environments. Considering multiple D2 D users who form the cluster by self-organizing method, the cooperation schemes are proposed to solve the energy problem, relay selection problem and interference problem. The main research contenets are as follows:1.A pairing multi-user cooperation scheme is proposed for multiple D2 D users to solve users' energy problem. These multiple D2 D users use the orthogonal spectrums to form cluster by self-organizing method. Considering both the energy availability and signal to noise ratio(SNR) of each D2 D user, Kuhn-Munkres algorithm is introduced in cooperation scheme to solve relay selection problem so as to share data packets among multiple users by multi-hop relays. Based on the proposed cooperation scheme, the outrage probability of D2 D link is derived based on Shannon Equation considering both the link delay threshold and data rate. Combing the derived outrage probability, the relationships among the number of D2 D users, the length of data sequence, the number of data packets, the average link delay threshold, the average SNR, system efficiency of energy(EE) and the system efficiency of capacity(EC) are studied. The simulation results show that the proposed D2 D users cooperation scheme based on Kuhn-Munkres algorithm can not only help to offload energy consumption of the D2 D users but enhance the efficiency of energy(EE) and the efficiency of capacity(EC).2.An interference-limited multi-user cooperation scheme is proposed for multiple D2 D users to solve users' energy problem and interference problem. These multiple D2 D users use non-orthogonal spectrums to form cluster by self-organizing method. Considering link delay threshold, data rate and interference, the outrage probability of D2 D link is derived based on Shannon Equation. Multiple D2 D users are divided into different cooperative units. There is no interefence among different cooperative units so as to limit the interference of each D2 D user. Besides the energy availability and SNR of each D2 D user, the distance between D2 D users is considered when selecting the relaying D2 D users so as to enhance the signal to interference plus noise ratio(SINR) of D2 D receiving user. Combining the derived outrage probability, the relationships among average link delay threshold, system efficiency of energy and system efficiency of capacity are studied. The simulation results show that the interference-limited multiple D2 D user cooperation scheme can not only help to offload energy consumption and limit the interference of D2 D users, but enhance the efficiency of energy and efficiency of capacity.