Structured Channel Rasters for LTE Wi-Fi Coexistence
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Solution Overview
Problem
In wireless communication networks, particularly when LTE operates in unlicensed spectrum like 5 GHz, the conventional channel rasters lead to a large search space and excessive consumption of EARFCNs, causing interference with Wi-Fi signals, which is undesirable.
Innovation Solution
The method involves determining a first channel raster for LTE that is aligned with a Wi-Fi channel raster in the unlicensed spectrum, using subsets of equally spaced carrier frequencies to reduce the search space and optimize EARFCN usage, thereby adapting wireless communication to coexist with WLAN signals.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a pre-configured channel raster is used for frequency scanning in unlicensed spectrum, then the frequency scanning can be performed systematically, but the search space becomes too large and excessive EARFCNs are consumed
Solution Approach 1:
The patent segments the unlicensed spectrum into multiple frequency ranges, each with its own channel raster configuration. Instead of using a single comprehensive channel raster that covers the entire unlicensed spectrum, the system divides the spectrum into smaller segments (e.g., different 5 GHz bands) and assigns appropriate channel rasters to each segment, thereby reducing the overall search space and EARFCN consumption while maintaining systematic frequency scanning capability
Solution Approach 2:
The patent changes the channel raster parameters (frequency spacing, offset values) based on the specific unlicensed spectrum band being scanned. By adapting the channel raster configuration to match Wi-Fi channel structures in different frequency ranges, the system optimizes the search space size and reduces the number of EARFCNs required, thereby improving frequency scanning efficiency without excessive resource consumption
2Adaptability or versatility
If LTE operates in unlicensed spectrum with a conventional channel raster, then LTE can provide wireless connectivity, but interference with Wi-Fi signals increases
Solution Approach 1:
The patent modifies the LTE channel raster parameters to align with Wi-Fi channel structures in the unlicensed spectrum. By adjusting frequency offsets and spacing to match common Wi-Fi channel configurations, the system enables LTE to operate in unlicensed spectrum while minimizing interference with Wi-Fi signals, thereby maintaining wireless connectivity provision while reducing harmful interference effects
Solution Approach 2:
The patent converts the potential harm of spectrum sharing interference into a benefit by aligning LTE channel raster with Wi-Fi channel structures. This alignment allows LTE to systematically avoid Wi-Fi frequencies or share them more efficiently, transforming the interference problem into an opportunity for coordinated spectrum usage that benefits both LTE and Wi-Fi operations
Data Source
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AI summary
Techniques for structured channel rasters for unlicensed spectrum are described. In an aspect, a first channel raster is identified, where the first channel raster is determined from a set of carrier frequencies and is used over an unlicensed or shared spectrum for a wireless wide area network (WWAN). The first channel raster is aligned with a second channel raster that is used over the unlicensed spectrum for a wireless local area network (WLAN). A frequency scanning may be performed by a user equipment (UE) or a network entity over the unlicensed spectrum for the WWAN using the first channel raster. In an aspect, the first channel raster is used over the unlicensed spectrum for the WWAN supported by the user equipment (UE) or the network entity.