Wireless Cell Interference Mitigation with Timing-Aware LLR Weighting
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Solution Overview
Problem
Inter-cell interference between terrestrial (TN) and non-terrestrial (NTN) cells is challenging due to differences in propagation delays and system bandwidths, making existing interference cancellation techniques difficult to apply effectively.
Innovation Solution
A method and device that utilize data blank information and cell-specific reference signal (CRS) blank information to identify and mitigate inter-cell interference by adjusting resource allocations and LLR weights based on timing offsets and CRS blank subframes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If existing interference cancellation techniques (ICIC, eICIC, FeICIC) are applied to reduce inter-cell interference, then interference reduction is achieved, but timing synchronization becomes difficult due to different propagation delays between TN cell and NTN cell
Solution Approach 1:
The patent applies preliminary action by having the NTN cell transmit a preamble signal before the actual data transmission. This preamble allows the TN cell to detect and measure the timing offset and propagation delay characteristics in advance, enabling the TN cell to adjust its reception timing and mitigate interference before the main data transmission occurs. This resolves the timing synchronization issue by performing timing adjustment preparation beforehand.
Solution Approach 2:
The patent changes the parameter of transmission timing by introducing a configurable preamble transmission timing offset. This allows flexible adjustment of when the preamble is transmitted relative to the data signal, enabling optimization of interference mitigation for different propagation delay conditions. The system can adapt the timing parameters to accommodate varying TN-NTN cell propagation delays.
2Object-affected harmful factors
If existing interference cancellation techniques are applied to reduce inter-cell interference, then interference reduction is achieved, but application becomes difficult due to different system bandwidths between TN cell and NTN cell
Solution Approach 1:
The patent segments the interference mitigation approach by treating different bandwidth conditions separately. The system identifies whether the TN cell and NTN cell have the same or different system bandwidths, and applies corresponding mitigation strategies: for same bandwidth, standard ICIC applies; for different bandwidths, the patent uses resource element level identification and weighting based on the overlapping resource regions. This segmentation allows the system to handle bandwidth differences without requiring complete redesign of the interference cancellation mechanism.
Solution Approach 2:
The patent applies local quality by focusing interference mitigation on specific resource elements rather than treating the entire bandwidth uniformly. The system identifies which resource elements overlap between TN and NTN cells based on their respective bandwidth configurations, and applies interference cancellation only to those local overlapping regions. This allows different bandwidth systems to coexist by targeting interference only where it occurs.
3Area of stationary object
If satellite coverage area is increased to provide wider coverage, then coverage area is improved, but vulnerability to interference signals increases due to weaker signal strengths
Solution Approach 1:
The patent applies preliminary action by having the NTN cell transmit a preamble signal before data transmission. This preamble serves as an early warning and timing reference that allows the TN cell to prepare interference mitigation strategies in advance. The preamble transmission enables the system to identify interference conditions beforehand and adjust reception parameters before the main data signal arrives, thereby protecting against interference while maintaining wide coverage.
Solution Approach 2:
The patent introduces the preamble signal as an intermediary element between the NTN cell transmission and the data reception process. This preamble acts as a mediator that carries timing and interference information, allowing the TN cell to process and prepare for interference mitigation without directly interfering with the main data transmission. The preamble serves as an intermediate step that enables coordinated interference management across different cells.
Data Source
AI summary
Provided is a method of operating an electronic device, the method including receiving data blank information from a serving cell, identifying at least one first subframe and at least one second subframe based on a timing offset and the data blank information, resource allocations between the serving cell and an interference cell overlapping in the at least one first subframe, and the resource allocations not overlapping in the at least one second subframe, increasing a first weight for a first log likelihood ratio (LLR) corresponding to the at least one first subframe, decreasing a second weight for a second LLR corresponding to the at least one second subframe, and calculating a third LLR based on the first LLR and the second LLR.