Unlicensed Spectrum Channel Occupancy Detection for Fair Access
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Solution Overview
Problem
In wireless communication systems, particularly in NR systems with massive MIMO, the interference in different beam directions varies significantly, making it challenging to determine channel occupancy across multiple carriers using Listen Before Talk (LBT) as the results only reflect channel occupancy in the specific beam direction, not others.
Innovation Solution
A method where a node performs energy detection in multiple sub-pools on different sub-bands to determine whether to transmit a radio signal, considering the correlation between beams used on each carrier, allowing for reduced detection time and appropriate backoff processes to ensure fairness in Unlicensed Spectrum access.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If LBT is performed on one carrier, then channel occupancy in that carrier's beam direction is determined, but channel occupancy in other beam directions remains unknown
Solution Approach 1:
The patent segments the channel detection process by performing separate LBT operations on different carriers, where each carrier's LBT result provides channel occupancy information for a specific beam direction. This segmentation allows the system to accumulate directional channel knowledge across multiple carriers rather than requiring a single omnidirectional detection.
Solution Approach 2:
The patent introduces a spatial dimension to channel occupancy detection by associating different beam directions with different carriers. Instead of detecting channel occupancy in a single dimension, the system performs detection across multiple spatial dimensions (beam directions), where each carrier's LBT result contributes to understanding channel state in its corresponding beam direction.
2Measurement precision
If beams on multiple carriers point in different directions, then beam-specific channel information is obtained, but LBT results cannot be shared across carriers
Solution Approach 1:
The patent applies local quality by making LBT behavior carrier-specific and beam-direction-specific. Each carrier performs LBT independently based on its own beam direction requirements, rather than using a uniform LBT approach across all carriers. This allows optimal channel access decisions tailored to each carrier's spatial characteristics.
Solution Approach 2:
The patent introduces dynamics by allowing the LBT process to adapt based on beam direction correlations. When beams on different carriers point in similar directions, the system can dynamically share LBT results between carriers, reducing redundant detections and improving access rates. When beam directions differ significantly, independent LBT is performed.
3Object-affected harmful factors
If LBT is performed independently on each carrier, then beam direction interference is avoided, but detection time increases
Solution Approach 1:
The patent applies preliminary action by performing LBT on one carrier first to determine channel occupancy in its beam direction. This preliminary detection result is then used to inform subsequent LBT operations on other carriers, potentially reducing the total detection time by avoiding redundant sensing in already-determined directions.
Solution Approach 2:
The patent implements feedback by using LBT results from one carrier to influence LBT decisions on other carriers. The channel occupancy information obtained from detecting one carrier's beam direction is fed back into the decision-making process for other carriers, allowing the system to adapt its detection strategy based on accumulated channel knowledge.
Data Source
AI summary
The present disclosure a method and a device in a UE and a base station used for wireless communications. A first node performs Q energy detection(s) on a first sub-band to obtain Q detection value(s); and determines based on the Q detection value(s) that a first radio signal is transmitted on the first sub-band at a first instant of time; performs P energy detection(s) on a second sub-band to obtain P detection value(s); and transmits or drops transmitting a second radio signal on the second sub-band at the first instant of time; each of the Q energy detection(s) is associated with a first antenna port group; when each of the P energy detection(s) is associated with the first antenna port group, the P is P1, otherwise the P is P2. The present disclosure is advantageous in ensuring fairness in the contention for spectrum occupancy in multicarrier-supporting Unlicensed Spectrum communications.