AbstractIn this article, the recently developed Kaczmarz successive interference cancellation (KSIC) detector is generalized to the nonlinear case; specifically, a projected SIC detection scheme is developed using the projected Kaczmarz iterative method. This novel detector enjoys improved performance with minimal additional computational complexity. The new detector is first presented and then its convergence analysis is detailed. After that, the computational complexity analysis of this detector is conducted and compared to that of the KSIC detector. Finally, extensive numerical simulations are conducted in different scenarios. Simulation results show that the proposed projected Kaczmarz SIC detector can achieve lower BER and can support more users in the system compared to the KSIC detector.