REG Bundle Mapping for LTE CRS Interference in NR CORESET
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Solution Overview
Problem
The coexistence of LTE and NR systems in the same spectrum is hindered by the continuous transmission of LTE CRS, which interferes with the NR system, leading to inaccurate channel estimation due to varying numbers of REs for NR PDCCH DMRSs across different REGs in a bundle.
Innovation Solution
A method is provided to determine a resource element group (REG) bundle by mapping it to an REG based on the distribution of LTE CRSs in a control resource set (CORESET), ensuring that the numbers of REs corresponding to NR PDCCH DMRSs are consistent across different REGs, thereby maintaining accurate channel estimation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If LTE CRS is continuously transmitted to maintain LTE system functionality, then LTE system reliability is improved, but NR system performance deteriorates due to interference and inaccurate channel estimation
Solution Approach 1:
The patent extracts the harmful LTE CRS signals from the frequency spectrum and identifies their exact resource element positions. By taking out knowledge of CRS locations, the system can exclude these interfering elements from NR PDCCH resource allocation, thereby resolving the interference issue while maintaining LTE continuity
Solution Approach 2:
The patent applies local quality by differentiating between resource elements occupied by LTE CRS and those available for NR PDCCH. The REG bundle mapping method ensures that only resource elements free from LTE CRS interference are assigned to NR PDCCH DMRS, creating localized clean regions for accurate channel estimation while allowing LTE to continue operating in CRS-occupied regions
2Device complexity
If REG bundle is mapped to REG sequentially in time and frequency domains, then mapping simplicity is improved, but channel estimation accuracy deteriorates due to varying numbers of REs for DMRS across different REGs
Solution Approach 1:
The patent introduces dynamic REG bundle mapping that adapts to the distribution pattern of LTE CRS. Instead of a fixed sequential mapping, the system dynamically adjusts the mapping strategy based on whether LTE CRS are present in the CORESET, ensuring consistent DMRS RE counts across REGs while maintaining implementation simplicity
Solution Approach 2:
The patent changes the mapping parameter from simple sequential ordering to CRS-aware ordering. By modifying the mapping approach to account for LTE CRS distribution patterns, the system achieves uniform DMRS RE allocation across REG bundles, directly improving channel estimation accuracy without significantly increasing system complexity
3Area of stationary object
If NR PDCCH DMRS is mapped to resource elements overlapping with LTE CRS positions, then spectrum utilization is improved, but signal interference increases causing estimation errors
Solution Approach 1:
The patent performs preliminary identification of LTE CRS positions before NR PDCCH resource allocation. By knowing in advance where LTE CRS are located, the system can pre-exclude these resource elements from NR PDCCH DMRS mapping, preventing interference before it occurs while maximizing usable spectrum
Solution Approach 2:
The patent uses the REG bundle as an intermediary structure that mediates between LTE CRS-occupied resources and NR PDCCH requirements. The REG bundle mapping mechanism allows the system to navigate around LTE CRS interference by redistributing DMRS resources within the bundle, enabling spectrum utilization while avoiding direct overlap with harmful signals
Data Source
AI summary
A method for determining a resource element group (REG) bundle, includes: determining a mapping mode from an (REG bundle to an REG according to distribution of long-term evolution cell-dedicated reference signals (LTE CRSs) in a control resource set (CORESET); and determining the REG bundle in the CORESET according to the mapping method.