Information Carrying Slotting Principles for Unsourced Coded Slotted Random Access

We investigate an unsourced coded slotted random access (RA) protocol which combines physical and MAC layer approaches. In contrast to the literature, we consider MAC-layer slotting which carries information. We distinguish three categories w.r.t. the amount of information carried by the slotting principle; non/partial/full information carrying setups. We model physical layer performance in a slot with a pilot sequence transmission selected based on information, combined with a finite block length code. For MAC-layer non/partial/full information carrying slotting, we use interference-free (IF) constant weight codes with different numbers of packet repetitions, and compare averaged per user block error rate performance with grant-free 5G NR 2-step RA. We observe that the full information carrying setup provides the best results for all slot repetition schemes, and in addition such schemes have the potential to significantly outperform 5G-NR RA. Also, partial information carrying schemes can provide a large portion of the gain over non-information carrying schemes for the same receiver complexity.