| The rapid development of IoT technology brings considerable convenience to human life as well as demands for the development of 5G mobile communication technology in the future.As a part of 5G mobile communication standard,D2 D technology has made a breakthrough in improving transmitting data rate and spectrum efficiency of communication system and reducing transmission delay.Meanwhile,NOMA technology,as one of the research hotspots of 5G technology,has great potential in building an IoT network system architecture with a large number of connections and high spectral efficiency.Considering that the lifetime of IoT nodes is limited by the capacities of their batteries,in the MC-NOMA co-existing with D2 D hybrid system,we use spectrumpower trading technology to overcome the constraint of node's energy shortage.In particular,D2 D transmitter offloads traffic to MC-NOMA cellular system,where a base station communicates with a D2 D receiver directly.D2 D pair allow BS to utilize part of their bandwidth for cellular users and BS utilizes consume a certain power to serve the D2 D receiver.Our goal is to investigate the maximum transmission rate to the D2 D receiver via joint bandwidth and power allocation for guaranteeing the QoS of each NOMA user.This paper reveal that both the traded power and transmission rate of the MC-NOMA system are concave functions of allocated bandwidth.Subsequently,we solve the transmission rate maximization problem under a minimum QoS constraint.The concavity of the objective function allows us to characterize the optimal solution structure of joint bandwidth and power allocation and to derive an iterative algorithm for obtaining the optimal solution by utilizing monotonic optimization theory.What's more,this paper also reveal a low computing complexity suboptimal algorithm based on DC programming.Simulation results verify our theoretical findings and demonstrate the effectiveness of the proposed joint bandwidth and power optimization. |
PDF Full Text Request