Subframe Interlacing for Heterogeneous Network Interference
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Solution Overview
Problem
Wireless communication networks, particularly LTE systems, face challenges in managing interference and optimizing bandwidth utilization due to heterogeneous network characteristics, leading to coverage dead spots and undesirable user equipment cell association, especially with the increasing deployment of semiautonomous base stations like femtocells and picocells.
Innovation Solution
The method involves subframe partitioning and resource allocation between base stations, where a subframe partition configuration is stored and negotiated between base stations, allowing for semi-static or dynamic resource allocation, and includes unassigned resources, enabling time-division or frequency-division multiplexing to mitigate interference and optimize resource usage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of stationary object
If base stations are deployed in heterogeneous networks to expand coverage, then network coverage is improved, but inter-cell interference increases causing coverage dead spots and undesirable user equipment cell association
Solution Approach 1:
The patent segments the downlink subframes into different types (non-muting, first muting, second muting) and assigns them to different base station groups. This segmentation allows macro base stations and small base stations to transmit in different subframe patterns, reducing inter-cell interference while maintaining expanded network coverage.
Solution Approach 2:
The patent implements periodic muting patterns where base stations transmit in alternating subframe sequences. Macro base stations transmit in non-muting and first muting subframes while small base stations transmit in second muting subframes, creating a periodic transmission pattern that reduces interference and allows UEs to periodically associate with appropriate cells.
2Productivity
If semiautonomous base stations like femtocells and picocells are deployed to increase network capacity, then bandwidth utilization is improved, but interference with existing base stations increases
Solution Approach 1:
The patent applies different transmission characteristics to different base station types and locations. Macro base stations use one subframe pattern while small base stations (femtocells and picocells) use another pattern, allowing each to operate optimally in its local environment without causing excessive interference to others.
Solution Approach 2:
The patent introduces a coordinating entity that manages subframe allocation and muting patterns across heterogeneous base stations. This intermediary coordinates the transmission schedules of macro and small base stations, enabling high network capacity while minimizing interference through centralized resource management.
3Reliability
If deep penetration of physical channels is implemented to overcome coverage dead spots, then signal penetration is improved, but unwanted interference between nodes and equipment increases
Solution Approach 1:
The patent implements dynamic subframe allocation where muting patterns can be adjusted based on network conditions and UE associations. This allows the system to dynamically optimize signal penetration in coverage dead spots while adapting interference management strategies to current network states, reducing unwanted interference as UEs associate with appropriate cells.
Data Source
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AI summary
Methods and apparatus for providing wireless communications using subframe partitioning are disclosed. Two or more base stations may be allocated subframes in a radio frame. All or part of the subframe allocation may be provided to the associated user equipment (UEs), which may use it to determine signal metrics during assigned subframes for an associated base station.