Performance Analysis Of NOMA System Based On User Collaboration And Forwarding Protocol

Non-orthogonal Multiple Access(NOMA)technology can meet the requirements of wide coverage and high transmission rate of wireless communication signals,and improve user service quality by combining with relaying.For this reason,this paper explores the combination of NOMA system and relaying protocol to improve the interruption performance of weak users and analysis the system throughput.The main work of this paper is as follows:First,this paper proposes a relaying scheme for the Hybrid Decode-Amplify-Forward(HDAF)protocol under a user collaborative NOMA system and improves the HDAF protocol by proposing an incremental Hybrid Decode-Amplify-Forward protocol to improve the interrupt performance of weak users.The consistency of the numerical results and Monte Carlo simulations verifies the correctness of the derived closed-form expressions and further shows that the scheme significantly improves the interrupt performance of weak users compared to existing schemes.In addition,collaborative user relay forwarding information is limited by energy,and the existing Energy Harvesting(EH)technology can easily collect energy from ambient Radio Frequency(RF)signals.For this reason,a full-duplex wireless communication powered relay system with EH technology is studied,in which energy is not only absorbed from RF signals but also recovered from the loop self-interference generated at the relay.In addition,the system performance is analysis under decode-and-forward,amplify-and-forward and HDAF protocols,respectively,and two cases of maximum ratio merging and selective merging are investigated at weak users,respectively.The consistency of their numerical results and Monte Carlo simulations verifies the correctness of the derived closed-form expressions and further shows that the proposed self-energy recovery schemes based on different forwarding protocols all have improved performance compared with the existing schemes,and the performance simulation comparison under different parameters is given to provide a theoretical reference for the selection of suitable parameters and schemes in real systems.