Energy-efficient power allocation for non-orthogonal multiple access with imperfect successive interference cancellation

As a promising technology for 5G, non-orthogonal multiple access (NOMA) has attracted much attention from academia and industry due to its superior spectral efficiency and user fairness, but the error propagation in successive interference cancellation decoding (SIC) might seriously restrict its performance. In this paper, we propose to utilize power allocation to mitigate the impact of imperfect SIC for a multiuser downlink NOMA system. In particular, we formulate a non-convex fractional programming problem with maximizing the system energy efficiency subject to a minimum data rate constraint for each user. To solve the intractable problem, we develop an iterative algorithm with a fast convergence speed. Simulation results validate that the proposed scheme can effectively alleviate the impact of imperfect SIC and achieve an obvious performance gain over two conventional baseline schemes.