Switching Signal Decoding Order in Uplink NOMA System With Imperfect SIC

Abstract

The decoding order of successive interference cancelation (SIC) is a key issue in SIC implementation for non-orthogonal multiple access (NOMA) systems. This letter focuses on the dynamic SIC decoding order and proposes a switching SIC scheme, which dynamically determines the SIC order according to the ratio of the instantaneous received power to target data rate of each user. The outage performance is theoretically analyzed for our proposed scheme under the imperfect SIC conditions. Both the analysis and simulation demonstrate the effectiveness of our proposed scheme. It avoids searching possible SIC orders but achieves almost the same outage performance as the ideal exhaustive-search-SIC that considers all possible SIC orders to decode a signal.