NR Beam Operation With Adaptive LBT for Hidden-Node Interference
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Solution Overview
Problem
Existing NR systems face challenges in frequencies above 52.6 GHz due to higher phase noise, larger propagation loss, lower power amplifier efficiency, and stringent regulatory requirements, along with issues in resource utilization and interference handling, particularly with hidden and exposed nodes.
Innovation Solution
A unified LBT adaptation scheme integrating multiple LBT methods is proposed, including omni-directional, directional, and receiver-assisted LBT, with adaptive switching mechanisms based on interference conditions, to optimize system performance and resource utilization.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If traditional LBT methods are used in frequencies above 52.6 GHz, then regulatory requirements may be met, but resource utilization deteriorates due to hidden and exposed node issues
Solution Approach 1:
The patent implements dynamic switching between different LBT methods (Category 2, Category 3, Category 4) based on real-time channel conditions and interference levels. The system adapts the LBT category and parameters dynamically rather than using a fixed approach, allowing optimization of resource utilization while maintaining regulatory compliance in mmWave frequencies above 52.6 GHz
Solution Approach 2:
The system changes LBT parameters such as contention window size, defer period, and energy detection thresholds based on channel conditions. By adjusting these parameters dynamically, the system resolves the contradiction between meeting regulatory requirements and maintaining high resource utilization in the presence of hidden and exposed nodes
2Productivity
If receiver assistance mode is used to improve resource utilization, then resource under-utilization is reduced, but system complexity increases
Solution Approach 1:
The receiver performs LBT and sends Ready-To-Receive (RTR) indications before the actual data transmission. This preliminary action allows the transmitter to proceed with transmission without performing full LBT, improving resource utilization while limiting complexity to specific receiver-assisted scenarios rather than universal implementation
Solution Approach 2:
The patent segments the LBT process into different parts: transmitter performs partial LBT, receiver performs independent LBT and sends RTR indication, and transmission proceeds based on RTR feedback. This segmentation allows receiver assistance to be applied selectively, improving resource utilization without requiring complete system redesign
3Reliability
If omni-directional LBT is used, then interference detection is comprehensive, but resource utilization deteriorates due to excessive interference avoidance
Solution Approach 1:
The patent employs asymmetric LBT approaches where different LBT strategies are used for different spatial directions or beam pairs. Omni-directional LBT is used when necessary for comprehensive interference detection, while directional LBT is used in other scenarios to improve resource utilization, creating an asymmetric but optimized overall approach
Data Source
AI summary
LBT adaptation, beam operation, and/or interference handling may be performed by wireless communication devices in NR above 52.6 GHZ. In an example, a wireless communications device may send information on a channel. The channel may comprise a Physical Downlink Control Channel (PDCCH), a Physical Downlink Shared Data Channel (PDSCH), or a Physical Random Access Channel (PRACH). The wireless communications device may receive, from a user equipment (UE), one or more ready to receives (RTRs). The wireless communications device may determine, based on a number of consecutive RTRs of the one or more RTRs, a listen before talk (LBT) mode. The LBT mode may be associated with staying or switching to a no receiver assistance mode or staying or switching to a receiver assistance mode.