A Novel Hybrid AF/DF Cooperative Communication Scheme for Power Domain NOMA

Future wireless communication demand high data rates, low latency, high accuracy, better quality of service and much more. These demands raise challenges in wireless communication system because signal is traveling through medium where signal quality is degraded by random fades, diffraction, noise and other performance reducing phenomenon. To meet the demands, we need technological advancements, so we can alleviate these challenges. NOMA is emerging technique of 5G that ensures better performance than traditional multiple access techniques. In a typical NOMA system, users individually communicate with base station and treat any other user signal as noise. Here the important point is that NOMA strong users have information of all weak users. In this paper, we propose a novel hybrid cooperative communication scheme for multiuser power domain NOMA based on amplify-and-forward (AF) and decode-and-forward (DF) over strong user to improve performance of weak user in cellular system. We exploited the key feature of NOMA that states that strong user has prior knowledge of weak user with bad channel condition. Strong user is used as relay to improve performance of weak user via cooperative communication. BER Curves analysis proved that performance of weak user laying over the edge in cellular system can be improved via cooperative communication.