Uplink Grant Dropping for Intermodulation Mitigation
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Solution Overview
Problem
Carrier aggregation in wireless communication systems often leads to intermodulation interference with radio frequency spectrum bands, particularly affecting global navigation satellite systems, causing inaccurate positioning and signal errors.
Innovation Solution
A method for user equipment to selectively drop uplink grants based on the number of subframes and resource block allocations, determining whether these cause intermodulation interference, and marking or storing this information to mitigate interference in specific frequency bands.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If carrier aggregation is used to increase data transmission capacity, then productivity is improved, but intermodulation interference is generated that affects GNSS signal accuracy
Solution Approach 1:
The patent extracts and removes harmful uplink grants that cause intermodulation interference. The UE autonomously identifies and drops specific uplink grants (either on PCell or SCell) that would generate intermodulation products falling within GNSS frequency bands, thereby eliminating the source of interference while maintaining necessary uplink transmissions on other carriers.
Solution Approach 2:
The patent changes the transmission parameter by selectively dropping uplink grants based on frequency band analysis. The UE determines whether to transmit or drop uplink data by evaluating whether the uplink frequency would create intermodulation products in GNSS bands, dynamically adjusting transmission parameters to avoid interference.
2Productivity
If uplink grants are transmitted on multiple cells simultaneously, then data transmission efficiency is improved, but intermodulation interference with RF spectrum bands occurs
Solution Approach 1:
The patent converts the harmful effect of intermodulation into a beneficial filtering mechanism. By identifying which uplink grants would create intermodulation products in GNSS bands and selectively dropping those specific grants, the system uses the intermodulation calculation itself as a criterion for intelligent transmission scheduling, turning a potential harm into a basis for optimized resource allocation.
Solution Approach 2:
The patent introduces an intermediary decision-making process between receiving uplink grants and transmitting data. The UE performs intermediate analysis by calculating intermodulation products and comparing them against GNSS frequency bands, using this intermediate evaluation to determine whether to proceed with transmission or drop the grant, thereby mediating between transmission efficiency and interference avoidance.
3Productivity
If resource block allocation is increased to improve data rate, then productivity is improved, but interference to GNSS signals increases
Solution Approach 1:
The patent applies local quality by making transmission decisions specific to individual resource blocks and their corresponding frequency locations. Rather than uniformly restricting all uplink transmissions, the UE evaluates each uplink grant's frequency location and resource block allocation individually, dropping only those specific grants that would create intermodulation products in GNSS bands while allowing other transmissions to proceed.
Data Source
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AI summary
Aspects of the present disclosure generally relate to wireless communications. In some aspects, a device may receive a first uplink grant for a first cell that uses a first component carrier, and may receive a second uplink grant for a second cell that uses a second component carrier. The device may determine at least one of: a number of subframes for which uplink data is transmitted on both the first cell and the second cell during a time period, or a resource block allocation associated with the first cell and the second cell. The device may drop at least one of the first uplink grant or the second uplink grant based at least in part on at least one of: a determination that the number of subframes satisfies a threshold number of subframes, or a determination that the resource block allocation satisfies a condition.