NR-U Channelization and LBT Sharing for 52.6 GHz Coexistence
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Solution Overview
Problem
Existing NR-U technologies struggle to efficiently manage channelization and listen-before-talk (LBT) in the frequency range from 52.6 GHz to 71 GHz due to mismatched channel bandwidths with other RATs like 802.11ad/ay, leading to interference and inefficient spectral utilization.
Innovation Solution
Implement channelization methods and guardband configurations that align or do not align with integer multiples of 802.11ad/ay channel bandwidths, along with LBT and COT sharing schemes, to facilitate coexistence and reduce interference.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If NR-U uses fixed 20 MHz LBT bandwidth to match 802.11 channels, then LBT compatibility is achieved, but spectral efficiency deteriorates in 52.6 GHz+ bands where wider channels are available
Solution Approach 1:
The patent implements dynamic LBT bandwidth selection where the LBT bandwidth is adjusted based on the activated BWP size. When a wider BWP is activated, the LBT bandwidth is increased proportionally (e.g., 40 MHz, 80 MHz, or 160 MHz) rather than being fixed at 20 MHz. This dynamic adaptation allows the system to maintain LBT compatibility while efficiently utilizing wider spectral resources available in the 52.6 GHz+ frequency range.
Solution Approach 2:
The patent changes the LBT bandwidth parameter from a fixed 20 MHz value to a variable parameter that can take multiple discrete values (20 MHz, 40 MHz, 80 MHz, 160 MHz) based on the activated BWP configuration. This parameter change enables the system to adapt to different spectral conditions and maximize spectral efficiency while maintaining compatibility with 802.11 LBT requirements.
2Productivity
If channel bandwidth is increased to utilize available spectrum, then spectral efficiency improves, but interference with other RATs worsens due to bandwidth mismatch
Solution Approach 1:
The patent segments the total channel bandwidth into multiple 20 MHz sub-channels for LBT purposes. When a wider BWP is activated (e.g., 80 MHz), the system performs LBT on multiple 20 MHz sub-channels rather than treating it as a single wide channel. This segmentation approach allows the system to utilize wider bandwidths for data transmission while maintaining compatibility with 802.11 LBT mechanisms that operate on 20 MHz channels, thereby reducing interference with other RATs.
Solution Approach 2:
The patent makes the LBT mechanism universal by making it adaptable to both narrow (20 MHz) and wide (40, 80, 160 MHz) bandwidth scenarios. The same LBT procedure can be applied regardless of the activated BWP size, allowing the system to maintain compatibility with 802.11 while efficiently utilizing wider spectral resources when available, thus serving multiple bandwidth requirements with a single flexible mechanism.
3Productivity
If LBT bandwidth is dynamically adjusted to match activated BWP, then spectral efficiency improves, but system complexity increases
Solution Approach 1:
The patent performs preliminary configuration of LBT parameters based on the activated BWP before actual LBT execution. The gNB configures the UE with appropriate LBT bandwidth settings in advance through RRC signaling or MAC CE, so that when data transmission occurs, the LBT bandwidth is already determined and matches the activated BWP size. This preliminary action simplifies the real-time operation by avoiding complex dynamic adjustments during active transmission.
4Adaptability or versatility
If multiple LBT bandwidths are supported, then adaptability to different BWPs improves, but measurement and detection difficulty worsens
Solution Approach 1:
The patent implements feedback mechanisms where the gNB informs the UE about the configured LBT bandwidth through RRC signaling or MAC CE commands. The UE receives explicit feedback about which LBT bandwidth to use based on the activated BWP, eliminating the need for the UE to independently detect or measure the appropriate LBT bandwidth. This feedback approach simplifies the detection process by providing direct information from the network about the expected LBT bandwidth configuration.
Data Source
AI summary
Methods, systems, and devices may assist in channelization and LBT for NR unlicensed band. This may apply to NR-U from 52.6 GHz to 71 GHz and above. In an example, a method may include configuring listen before talk (LBT) bandwidth (BW) and channel occupation time (COT) sharing schemes when co-exist other radio access technology's (RAT'S) channel BW for NR-U from 52.6 to 71 GHz and above; and when LBT or a resource block (RB) set BW is set to equal to each component carrier (CC) BW Nor transmission BW, performing LBT for each CC, primary cell (PCell), primary secondary cell (PSCell), or a scheduling secondary cell (SCell) can co-schedule LBT results for other CC.