gNB BWP Availability Signaling for Unlicensed Spectrum
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Solution Overview
Problem
In the 5G-NR system, there is no effective way for the gNB to inform the UE which bandwidth parts (BWPs) or sub-bands pass the clear channel assessment (CCA) check in the unlicensed spectrum, leading to inefficient bandwidth allocation.
Innovation Solution
The gNB configures multiple BWPs or sub-bands for the UE and performs a listen before talk (LBT) operation on each, transmitting a downlink control signal with assistance information indicating the availability of each sub-band or BWP, allowing the UE to determine which bands are available for transmission.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the gNB performs LBT operation on multiple BWPs or sub-bands, then spectrum utilization is improved, but the complexity of informing the UE about available bands increases
Solution Approach 1:
The patent segments the large bandwidth into multiple BWPs or sub-bands, allowing the gNB to perform LBT operations on individual segments and inform the UE about available segments through assistance information. This segmentation enables efficient spectrum utilization while managing complexity through structured information transmission.
Solution Approach 2:
The patent introduces assistance information as an intermediary element that carries LBT result indicators from the gNB to the UE. This intermediary mechanism efficiently communicates which BWPs or sub-bands are available for transmission without requiring complex direct negotiation or repeated LBT operations by the UE.
2Reliability
If the gNB transmits DL signal for bandwidth allocation after LBT, then successful allocation is improved, but transmission delay increases due to LBT waiting time
Solution Approach 1:
The gNB performs LBT operations in advance on multiple BWPs or sub-bands and prepares assistance information indicating which bands are available. This preliminary action allows the UE to quickly determine available bands without waiting for repeated LBT operations, reducing allocation delay while maintaining high success rates.
Solution Approach 2:
The patent implements a feedback mechanism where the gNB transmits assistance information about LBT results to the UE, enabling the UE to make informed transmission decisions. This feedback loop reduces unnecessary waiting and retransmissions, improving both reliability and timing efficiency.
3Productivity
If the UE performs transmission in unavailable sub-bands, then spectrum utilization is improved, but transmission reliability deteriorates due to interference
Solution Approach 1:
The UE uses the assistance information provided by the gNB to autonomously determine which sub-bands or BWPs are available for transmission. This self-service approach enables the UE to make intelligent transmission decisions based on current channel conditions, ensuring high spectrum utilization while avoiding interference in unavailable bands.
Data Source
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AI summary
A method of handling communication for a communication device (20) of a wireless communication system (10), wherein the communication device (20) is configured with a plurality of frequency bands (SB1-SB5, BWP1-BWP5), includes the step of: receiving a downlink, DL hereafter, control signal from a network of the wireless communication system (10) via a first frequency band (SB1, BWP1) among the plurality of frequency bands (SB1-SB5, BWP1-BWP5), wherein the DL control signal indicates whether at least one of the plurality of frequency bands (SB1-SB5, BWP1-BWP5) is available or not available.