Downlink Precoding Codebook Partitioning for Inter-Cell Interference
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Solution Overview
Problem
Inter-cell interference in wireless communication networks constrains throughput, particularly for cell-edge devices using the same frequency band, leading to low signal-to-interference-and-noise ratios.
Innovation Solution
Implementing a codebook partitioner to divide codebooks into subsets based on channel estimation, with a processor identifying and sending feedback information to base stations to select precoding matrices that minimize interference below a threshold, and coordinating between base stations to avoid interference.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If multiple base stations use the same frequency band to serve their respective user equipments, then network coverage and service capacity are improved, but inter-cell interference increases and throughput is constrained
Solution Approach 1:
The patent changes the parameter of codebook selection by dividing the codebook into preferred and restricted sets based on interference thresholds. Base stations dynamically select precoding matrices from the preferred set that guarantee interference remains below a threshold level, thereby resolving the contradiction between maintaining network throughput and reducing inter-cell interference.
Solution Approach 2:
The patent implements a feedback mechanism where user equipments report recommended and restricted codebook information to their serving base stations. This feedback enables base stations to adjust their precoding selections to avoid causing excessive interference to neighboring cells, thus maintaining both throughput and interference control.
2Device complexity
If base stations use standardized codebook for precoding transmission, then implementation complexity is reduced, but interference control capability is limited
Solution Approach 1:
The patent segments the standardized codebook into two distinct sets: a preferred set containing precoding matrices that cause interference below a threshold, and a restricted set containing others. This segmentation allows base stations to operate with reduced complexity by selecting only from the preferred set, while effectively controlling interference without requiring a completely new codebook design.
3Area of stationary object
If cell-edge devices are served in proximity to other user equipments, then network coverage is extended, but signal-to-interference-and-noise ratio decreases
Solution Approach 1:
The patent applies preliminary action by having user equipments pre-calculate and report recommended codebook information before actual data transmission. This allows base stations to select precoding matrices in advance that are guaranteed to keep interference below thresholds, thereby protecting cell-edge devices from excessive interference and maintaining reliable signal-to-interference-and-noise ratios while extending coverage.
Data Source
Figure 1A~1B
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AI summary
A system and method for inter-cell interference avoidance. A device capable of performing channel estimation is configured to divide a codebook into two sets. A first set of said two sets corresponds to codebook information that will cause an interference in a received signal to be less than a threshold. The device further is configured to send feedback information corresponding to the first or second set, or both. A base station is configured to select a precoding vector or matrix based, in part, on a portion of the feedback information.