Modified Orthogonal Matching Pursuit (MOMP)-based Multiuser Detector for Uplink Grant Free NOMA Systems

A multiuser detection (MUD) scheme, the modified orthogonal matching pursuit (MOMP)-based MUD is proposed for uplink grant free non-orthogonal multiple access (NOMA) systems. In the proposed MUD, the temporary correlation of active user sets between adjacent time slots is exploited in conjunction with the side information (the a-priori knowledge of the active user support set's estimate). The detections of user's activity and data are performed by the proposed MOMP-based MUD in a continuous time slots in divergence to how the traditional OMP-based MUD and some other MUDs considered in this paper perform similar detection in each time slot with assumption of invariant user's set activity within a frame. Computer simulation results show that the proposed MOMP-based MUD achieves better performance in comparison with the performances of the traditional OMP-based MUD and others.