A Multi-User Detector with Adaptive Iterative times in Scrambled Coded Multiple Access (SCMA) Systems

This paper proposes a Modified Chip-By-Chip (M-CBC) algorithm for iterative multi-user detector in Scrambled Coded Multiple Access (SCMA) systems. In the traditional SCMA system receiver, the number of iterative times is fixed and the best performance can only achieve by setting a larger iterative time, which results the system in poor flexibility. The M-CBC algorithm can adapt the number of iterations according to the convergence threshold calculated by the soft information of decoder. It solves the problem of how to set the iterative times and the simulation results show that the algorithm in this paper reduces the complexity of the receiver without losing system performance.