Abstract
LTE’s extension for unlicensed spectrum called Licensed Assisted Access (LAA) is equipped with Listen-Before-Talk(LBT) designed similar with the backoff mechanism of Wi-Fi for coexistence. However, Wi-Fi’s backoff mechanism hasnot evolved from its old design for compatibility with legacy devices, thus LAA’s LBT is not efficient either in utilizingspectrum. If LAA operates with no Wi-Fi systems in proximity, it can run more efficient LBT. In this paper, we proposeNarrowband Clear Channel Assessment (NCCA) for narrowband transmission. In NCCA, an LAA node performs LBT ineither wide or each narrow bandwidth segment. This allows multiple LAA nodes to perform simultaneous transmissionsin orthogonal bandwidth segments in the same time slot. We design four variants of NCCA implementation and modeltheir performance using a mathematical model. The coexistence performance of NCCA with conventional wideband nodesand the accuracy of the model are shown via simulation.
| Translated title of the contribution | Narrowband Listen-Before-Talk under Coexistence with Wideband Systems in Unlicensed Spectrum |
|---|---|
| Original language | Korean |
| Pages (from-to) | 91-98 |
| Number of pages | 8 |
| Journal | 전기전자학회논문지 |
| Volume | 23 |
| Issue number | 1 |
| DOIs | |
| State | Published - 2019 |