Interference Control via CRS Subtraction in Heterogeneous Networks
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Solution Overview
Problem
In heterogeneous wireless communication networks, intra-frequency interference between macro and lower power nodes affects the reliability of downlink and uplink channel transmissions, particularly due to the presence of cell reference signaling from neighboring cells, which complicates decoding of signaling and data on the physical downlink control and shared channels.
Innovation Solution
A method and device that measure and mitigate neighboring cell interference by identifying interfering cells based on signal strength differences and performing interference control through signal subtraction or discarding at specific cell reference signaling locations, using techniques such as parsing physical broadcast channels and obtaining cell reference signaling locations to reduce interference impact on user equipment.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If time division multiplexing inter-cell interference coordination is adopted with almost blank subframes, then transmission performance of victim UE is guaranteed, but cell reference signaling from ABS subframes still causes huge interference to decoding of signaling/data on PDCCH and PDSCH
Solution Approach 1:
The patent extracts and removes the harmful cell reference signaling (CRS) from the almost blank subframes of neighboring cells. By identifying and eliminating these interfering CRS signals, the system resolves the contradiction between maintaining transmission performance and removing harmful interference, allowing victim UEs to decode PDCCH and PDSCH reliably without CRS interference.
Solution Approach 2:
The patent converts the harmful CRS interference into a beneficial signal by having the UE treat the CRS from ABS subframes as a known interference pattern. The UE uses this information to perform interference cancellation, transforming the previously harmful CRS into a predictable signal that can be compensated for, thereby improving decoding reliability.
2Productivity
If spectrum multiplexing is performed on uplink and downlink spectrum resources for LPN and MeNB, then spectrum utilization efficiency is improved, but intra-channel interference is generated affecting channel transmission reliability
Solution Approach 1:
The patent applies local quality by treating different parts of the frequency spectrum differently. Specifically, it identifies and removes CRS signals from ABS subframes in neighboring cells while maintaining normal transmission in other subframes. This localized interference removal allows spectrum multiplexing to proceed efficiently without the harmful effects of CRS interference, resolving the contradiction between spectrum utilization and transmission reliability.
Data Source
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AI summary
The present invention relates to an interference control method and device. The interference control method includes: performing neighboring cell measurement, and selecting at least one neighboring cell whose signal transmission strength is larger than signal transmission strength of a serving cell from measured neighboring cells as an interfering cell; parsing a physical broadcast channel PBCH of the interfering cell to obtain the number of antenna ports of the interfering cell; obtaining a cell reference signaling CRS location of the interfering cell according to a physical cell identifier PCI and the number of antenna ports of the interfering cell; and performing interference control according to information of the CRS location. According to embodiments of the present invention, interference of a signal of a neighboring cell to a user equipment in a serving cell is reduced, the communication quality of the user equipment in the serving cell is improved, and some hotspot cells share service load better for a macro cell.