Sub-band LBT for Carrier Aggregation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current multicarrier communication systems face challenges in efficient channel access and carrier aggregation, particularly in wide bandwidth systems, where existing technologies struggle to optimize channel access and resource allocation effectively.
Innovation Solution
The implementation of advanced radio access network architectures and protocols, including next-generation Node B (gNB) and evolved Node B (ng-eNB) nodes, which employ advanced modulation schemes and hybrid transmission mechanisms like OFDMA, CDMA, and OFDM/CDMA, to enable efficient channel access and carrier aggregation through dynamic resource allocation and beam management.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If Listen Before Talk (LBT) is performed on the entire carrier bandwidth, then channel access reliability is improved, but signaling overhead and processing complexity increase
Solution Approach 1:
The patent divides the carrier bandwidth into multiple sub-bands, where each sub-band is independently subjected to LBT procedures. This segmentation allows the system to maintain reliable channel access by performing LBT on multiple smaller units rather than one large bandwidth, while reducing overall signaling overhead because each sub-band requires separate but manageable signaling. The base station can selectively activate or deactivate sub-bands based on LBT outcomes without needing to signal the entire carrier bandwidth status.
2Productivity
If carrier aggregation is implemented to increase bandwidth, then data transmission capacity is improved, but channel access management complexity increases
Solution Approach 1:
The patent applies segmentation by dividing the aggregated carrier bandwidth into multiple sub-bands that can be independently managed. Each sub-band within the aggregated carriers undergoes separate LBT procedures, allowing the system to scale bandwidth through carrier aggregation while maintaining manageable channel access complexity through modular sub-band control.
Solution Approach 2:
The patent implements dynamic sub-band activation and deactivation based on LBT outcomes. The base station can dynamically adjust which sub-bands are active for data transmission depending on channel conditions and LBT results, enabling flexible adaptation to changing radio environments while managing channel access across aggregated carriers.
3Productivity
If sub-bands are dynamically activated based on LBT results, then spectral efficiency is improved, but processing speed requirements increase
Solution Approach 1:
The patent performs LBT procedures on sub-bands in advance before data transmission is needed. By conducting channel sensing and making activation decisions beforehand, the system prepares the sub-band configuration ahead of time, reducing the processing speed burden during actual data transmission while still achieving dynamic spectral efficiency optimization.
Data Source
AI summary
A wireless device receives a grant scheduling a transmission on sub-bands of a physical uplink shared channel of a cell. The sub-bands comprise a first sub-band and one or more other sub-bands. The wireless device performs, in response to the grant: a first type listen-before-talk (LBT) on the first sub-band; and a second type LBT on each of the one or more other sub-bands. Data is transmitted on a sub-band of the sub-bands, based on a determination that: the first type LBT indicates that the first sub-band is clear; and the second type LBT indicates that each of the one or more other sub-bands are clear.