  This article introduces a novel framework of multi-user detection (MUD) for
K-repetition grant-free non-orthogonal multiple access (K-GF-NOMA), called
$\alpha$ iterative interference cancellation diversity slotted aloha
($\alpha$-IIC-DSA). The proposed framework targets at a simple yet effective
decoding process where the AP can intelligently exploit the correlation among
signals received at different resource blocks (RBs) so as to generate required
multi-access interference (MAI) for realizing the signal-interference
cancellation (SIC) based MUD. By keeping all operation and hardware complexity
at the access point (AP), the proposed framework is applicable to the scenarios
with random and uncoordinated access by numerous miniature mMTC devices
(MTCDs). Numerical experiments are conducted to gain deep understanding on the
performance of launching the proposed framework for K-GF-NOMA.
