A dynamic bandwidth and power allocation scheme for cooperative D2D communications

In future mobile networks, the device-to-device (D2D) communication is considered as an efficient technique emerging direct and high-speed data transmission among devices (e.g. mobile social network services and machine type communications). Due to spectrum reuse among devices, the D2D however also brings in more interference, which will cause degradation in network performances. Therefore the concept of cooperative D2D communication is recently proposed to this issue and efficient radio resource allocations are further required. In this context, this paper focused on the bandwidth and power allocation problem for cooperative D2D communication and proposed a dynamic allocation scheme according to the channel status information (CSI) and data rate requirement. The goal is to minimize the total transmission power consumption in a cooperative D2D network with M transmitting devices(TDs) under respective data rate constraints of N receiving devices(RDs). Based on the KKT (Karush-Kuhn-Tucker) conditions of this problem, the dynamic allocation scheme is designed both for the cooperative diversity and multiplex modes. This scheme gives closed-form solutions for bandwidth and power allocation in cooperative diversity mode, and reduces the computational complexity of allocation in cooperative multiplex mode.