Research On User Scheduling And Resource Allocation Scheme Of Power Line Communication System Based On NOMA

With the rapid development of modern communication technology,the traditional power line carrier communication technology has the defects of limited application range and limited transmission rate,which is difficult to meet the requirements of user business development.At present,power line carrier communication is developing towards highspeed,wide connection and large capacity,and has changed from high-voltage transmission line to low-voltage distribution network for carrier communication.Although OFDM technology has been applied in power line carrier communication to improve system capacity and anti-interference performance,there are still some problems such as low spectrum utilization.NOMA is a multiple access technology that changes the power domain from single user occupation to multi-user sharing,and can improve the system spectral efficiency and the number of terminal access.Therefore,the application of NOMA technology in power line communication system is of great significance.This paper focuses on the user scheduling and resource allocation in the power line communication system based on NOMA,and designs the channel user grouping and power allocation scheme to expand the system capacity and improve the energy efficiency of the system.The main work of this paper is as follows:Firstly,this paper summarizes the development status of low-voltage power line carrier communication at home and abroad,expounds the basic principle and technical characteristics of NOMA technology,analyzes the transmission characteristics and noise characteristics of low-voltage power line channel,and establishes the channel model of low-voltage power line communication.Secondly,in order to maximize the system capacity,two user packet allocation schemes based on channel state sorting pairing and channel allocation based on matching are designed.According to the user grouping,two user power allocation schemes based on user weighting and system and rate maximization under the minimum rate constraint of a single user are designed.The two user grouping schemes and two power allocation schemes are combined for MATLAB simulation.The simulation results show that after the channel user grouping is determined by using the channel state sorting pairing and channel allocation schemes,the power allocation schemes used under the two constraints of weighting condition and minimum rate of single user verify the performance of the designed scheme.Finally,a low complexity suboptimal scheme is designed to maximize the system energy efficiency.The scheme includes the matching process between subchannels and users and the determination of power allocation factor between multiplexing users on subchannels.On this basis,a power allocation scheme between subchannels is designed.Because the optimization objective function is non convex,the DC programming scheme is used to transform the original non convex problem into a convex optimization problem,which is solved by iteration.The simulation results show that compared with the OFDMA mode in the traditional power line communication system,this scheme effectively improves the energy efficiency of the power line communication system based on NOMA.