Joint Power Control and Resource Allocation for D2D Communications underlaying Cellular Networks

Abstract

Device to device (D2D) communication in underlay mode is the most desirable since it improves bandwidth utilization by sharing the radio resources of existing cellular users with D2D pairs. The D2D pairs are able to interact by reusing the relevant resource blocks of the existing cellular network, thereby enhancing system capacity and spectrum efficiency. Sharing resources with D2D pairs may, however, result in co-channel interference in the cellular network, which could impair the principal users. Moreover appropriate power control scheme will improve the co-channel interference as well as system capacity.

In this thesis, a joint power and resource allocation algorithm is proposed with an aim to reduce system interference and maximize system capacity in order to optimize the trade-off between primary cellular users and D2D users. First we convert the problem into a bipartite graph where each node is expanded into multiple instance. After that an algorithm is proposed to solve the bipartite graph problem. For two different optimization problem appropriate weight is selected. The numerical analysis demonstrates that the proposed technique can determine the appropriate transmission power level for cellular UE and D2D pairs for given constraints. In addition, their performance is superior than that of contemporary algorithms.