On Preamble-based Grant-Free Transmission in Low Power Wide Area (LPWA) IoT Networks

Harini, G; Balasubramanya, Naveen Mysore; Rana, Mrinal

doi:10.1109/wf-iot48130.2020.9221437

Cited by 5 publications

(2 citation statements)

References 11 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Specifically, non-orthogonal preambles formed by the union of two orthogonal preamble sets have been proposed in [19] and [20], where the selection of preamble sets obeys predefined rules. Preambles consisting of fixed preambles and random sequences have been proposed in [21], where the random sequences have been used for data scrambling. Note that the preambles in [21] are carefully designed for two pre-defined categories of users, and there are one-to-one mapping relationships between fixed preambles and random sequences.…”

mentioning

confidence: 99%

“…Preambles consisting of fixed preambles and random sequences have been proposed in [21], where the random sequences have been used for data scrambling. Note that the preambles in [21] are carefully designed for two pre-defined categories of users, and there are one-to-one mapping relationships between fixed preambles and random sequences. The predefined rules and one-to-one mappings reduce the non-orthogonal interference, but also limit the preamble set size to some extent.…”

mentioning

confidence: 99%

See 1 more Smart Citation

Composite Preambles Based on Differential Phase Rotations for Grant-Free Random Access Systems

Wang

Juntti

et al. 2023

IEEE Internet Things J.

View full text Add to dashboard Cite

With the advantages of low signaling overhead and latency, grant-free random access (GFRA) becomes a promising technology for supporting massive machine-type communications (mMTC), but poses new challenges for active user detection (AUD) and channel estimation (CE), whose performance mainly depends on the preamble detection. In this paper, we design the composite preamble based on differential phase rotations by aggregating orthogonal Zadoff-Chu (ZC) sequences and multiple root ZC sequences with differential phase rotations to reduce the probability of preamble collisions, thereby improving the performance of AUD and CE. In particular, differential phase rotations extend the preamble set size so that users colliding in orthogonal sequences can be distinguished by phase rotations. In addition, it also reduces non-orthogonal interference and thus reduces CE errors. The preamble detection algorithm and CE scheme are proposed, along with the theoretical analysis of AUD and CE performance to verify the effectiveness of the designed preamble. In addition, the proposed preamble is extended to combine phase rotations with cyclic shifts to further enlarge the preamble set size with low non-orthogonality. Simulation results show that the proposed composite preamble outperforms existing preambles in terms of the probability of detection and CE accuracy.

show abstract

mentioning

confidence: 99%

mentioning

confidence: 99%