ARIA-LAA: Alignment reference interval adaptation-based licensed-assisted access for LTE in unlicensed bands

In the Third Generation Partnership Project (3GPP) standardization for LTE services in the unlicensed band, i.e., aggregation of LTE on licensed and unlicensed spectrum, known as 'Licensed-Assisted Access using LTE' (LAA), carrier sensing via Listen-Before-Talk (LBT) procedure is a vital feature for fair sharing and friendly operation in the unlicensed spectrum. Meanwhile, along with the recent contribution to performance enhancement with the frequency reuse-1 for Licensed-Assisted Access using LTE (LAA) system, we propose a new scheme, referred to as alignment reference interval adaptation-based LAA (ARIA-LAA), by combining the advantages of each conventional scheme into a unified access framework. Our simulation results demonstrate that ARIA-LAA is a novel scheme of spectrum sharing with spatial reuse for LAA that can increase the overall system capacity while satisfying the fair-coexistence requirement. Its implementation is simple and robust as only a single design parameter is dynamically controlled and optimized for adaptation to the varying traffic load.