On BER for Low Complexity Non-SIC NOMA with M-User

In non-orthogonal multiple access (NOMA), one of factors for implementation complexity is successive interference cancellation (SIC), which is essential for each user to operate at quality of service (QoS). In this letter, we consider the NOMA scheme with M-user, without the SIC complexity. First, we derive the closed-form BER expression. Then it is shown that the non-SIC NOMA BER is comparable to the SIC NOMA BER. This can be possible, with two reasons; one is the power allocation of the user fairness, and the other is the optimal maximum-likelihood (ML) detection