Abstract
The immediate availability of Uplink (UL) time-frequency resources for transmission of new data is a key factor in reducing latency and improving UL throughput in cellular systems. This is particularly important for unlicensed spectrum operation where access to the channel is subject to Listen-Before-Talk (LBT), and scheduling UL transmissions with a preceding Downlink (DL) transmission as in Long-Term Evolution (LTE) can be inefficient. Therefore, this work proposes and studies autonomous UL transmissions (AUL) for LTE-based systems in unlicensed spectrum, where UL transmissions are allowed without requiring a prior scheduling request or an explicit scheduling grant from the Evolved Node B (eNB). The implications of AUL transmissions for the design of hybrid automatic repeat request (HARQ) and link adaptation mechanisms are investigated. Detailed performance evaluations in the 5 GHz unlicensed band show that dynamic switching between scheduled and autonomous UL transmissions offers the best throughput performance, while also coexisting fairly with co-channel Wi-Fi networks.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
