Mode Selection and Resource Allocation Using Sumrate Maximization in D2D Communication

Abstract

From the past few years, there is massive increase in cell phone users and also in its applications. Because of limited bandwidth, it is necessary to develop the technique which can give higher spectral efficiency. One way to improve spectral efficiency is Device-to-Device (D2D) communication. In D2D communication, devices communicate directly with each other without involving the Base Station (BS). As the D2D communication reuses the block of cellular resources, it creates the interference and that is one of the major issues. Thesis addressing the shared resources of D2D communication and the cellular network communication considering that the control over the transmitting power and the radio resources of D2D links is given to cellular network. In this thesis, the main focus is on the mode selection and resource allocation using sum rate maximization. Three different modes are discussed in this thesis. An algorithm is developed to select the best mode by BS to maximize the sum rate for communication. Two cases are considered. In first case fixed transmit power is used and second case is greedy sum rate maximization under a maximum transmit power constraint. Performance metric for comparison is the rate ratio. The results show that for uplink, greedy sum rate maximization is 50.70% more efficient than fixed transmit power case for minimum distance between base station and D2D pair when D2D users are at minimum distance from each other and for maximum distance between BS and D2D users, it decreased to 49.29%. Also analysed that for maximum distance between two D2D users, greedy sum rate maximization and fixed transmit power case give same result for minimum distance between base station and D2D pair and for maximum distance between BS and D2D users, it is clearly seen that greedy sum rate maximization is 50% more efficient than fixed transmit power case.