Coordinated Beam Forming Scheduling for Inter-Cell Interference
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Solution Overview
Problem
In communication systems, particularly OFDM cellular networks like LTE and WiMax, inter-cell interference poses a significant challenge, especially in small cell scenarios where signals from adjacent cells interfere with each other, affecting signal quality and throughput.
Innovation Solution
The implementation of Coordinated Beam Forming (CBF) techniques, which involve active coordination among cells to schedule user equipment (UE) and manage beam forming decisions to minimize interference, using a scheduling controller that dynamically determines scheduling orders and feedback mechanisms to optimize channel state information sharing and precoder design.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If frequency reuse-1 system is used to improve spectrum efficiency, then spectrum efficiency is improved, but inter-cell interference increases
Solution Approach 1:
The patent combines coordinated beam forming (CBF) and multi-user MIMO (MU-MIMO) techniques into a unified system. CBF merges channel state information from multiple cells to form coordinated beams, while MU-MIMO merges multiple user streams from the same base station, achieving both interference mitigation and high spectrum efficiency simultaneously
Solution Approach 2:
The patent applies different transmission strategies to different spatial regions. Beam forming creates directional beams with high gain toward intended users while providing low gain toward adjacent cells, creating local quality variations in signal strength and interference levels across different spatial locations
2Object-affected harmful factors
If coordinated beam forming is implemented to reduce inter-cell interference, then inter-cell interference is reduced, but system complexity increases
Solution Approach 1:
The patent segments the interference mitigation problem into manageable parts: (1) CBF handles inter-cell interference through coordinated beam forming across cells, (2) MU-MIMO handles intra-cell multiplexing through spatial separation of users. This segmentation allows each technique to be optimized independently while working together as a unified system
Solution Approach 2:
The patent implements feedback mechanisms where user equipment reports channel state information to base stations, and base stations exchange coordination information within cell clusters. This feedback enables dynamic adaptation of beam forming weights and scheduling decisions to current channel conditions, optimizing interference mitigation while managing system complexity through information-driven control
3Productivity
If cell size is reduced to increase network capacity, then network capacity is increased, but inter-cell interference increases
Solution Approach 1:
The patent employs dynamic beam forming weights and scheduling decisions that adapt to changing channel conditions and traffic patterns. The coordinated beam forming continuously adjusts beam directions and gains based on real-time channel state information, enabling the system to dynamically mitigate interference as cells are added or traffic varies, maintaining high network capacity regardless of cell size
Data Source
AI summary
In one embodiment, a method for wireless communication includes receiving cell information for a cluster of cells to be coordinated. A first cluster scheduling order used for the cluster of cells is retrieved. The first cluster scheduling order represents a sequence in which the cluster of cells were scheduled in a previous schedule. A second cluster scheduling order is generated. The second cluster scheduling order determines a sequence in which the cluster of cells are scheduled in an upcoming schedule. The second cluster scheduling order is decided based on the first cluster scheduling order and/or the cell information. The second cluster scheduling order is transmitted to the cluster of cells.