Resource Block Allocation for Interference Mitigation in Heterogeneous Networks
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Solution Overview
Problem
Heterogeneous wireless networks experience interference at the edges of access node coverage areas due to frequency reuse, leading to reduced data throughput and spectral efficiency, with existing methods like ICIC and ABS schemes requiring excessive overhead or capacity loss.
Innovation Solution
Divide resource blocks into uniquely numbered sets and allocate them across access nodes, rotating the allocation based on different timestamps or starting numbers to minimize interference, allowing each potentially interfering sector to use a different resource block set.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If inter-cell interference coordination (ICIC) or almost blank subframes (ABS) are used to mitigate interference, then interference is reduced, but communication overhead increases and capacity is lost due to muting resource blocks
Solution Approach 1:
The patent segments the available resource blocks into multiple sets (first resource block set, second resource block set, etc.) and assigns different sets to different access nodes in a rotating manner. This segmentation allows interference mitigation without requiring repeated coordination communication, as the allocation pattern is predetermined and published once, eliminating the need for continuous ICIC signaling overhead.
Solution Approach 2:
The patent performs preliminary action by pre-defining the resource block set allocation pattern before actual data transmission occurs. The eNodeB publishes the allocation pattern in system information, and user equipment uses this pre-established pattern to determine which resource blocks to monitor. This eliminates the need for real-time coordination communication between access nodes during data transmission.
2Object-affected harmful factors
If inter-cell interference coordination (ICIC) or almost blank subframes (ABS) are used to mitigate interference, then interference is reduced, but data throughput decreases due to capacity loss
Solution Approach 1:
The patent divides resource blocks into multiple sets and assigns them to different access nodes in a rotating manner, ensuring that all resource blocks are utilized for data transmission. This eliminates the need to mute resource blocks as in ABS schemes, maintaining full capacity while reducing interference through the rotating allocation pattern.
Solution Approach 2:
The patent implements periodic action through the rotating allocation pattern where resource block sets are cycled among different access nodes over time. This periodic rotation allows interference mitigation without requiring resource blocks to be permanently muted, as each block is periodically assigned to different nodes, maintaining throughput while reducing ICI.
3Productivity
If frequencies are re-used by neighboring access nodes, then spectral efficiency is improved, but signal interference increases at coverage area edges
Solution Approach 1:
The patent applies local quality by assigning different resource block sets to different access nodes that are proximate to each other. This ensures that neighboring access nodes use different resource blocks in their overlapping coverage areas, reducing interference locally at the edges while maintaining frequency reuse benefits for spectral efficiency.
Data Source
AI summary
Devices, systems, and methods to reduce interference in heterogeneous networks having a plurality of access nodes, such as combinations of macro cells, micro cells, pico cells, femto cells, etc. are disclosed. Interference caused in sectors of two or more access nodes that face each other is minimized by dividing a total number of resource blocks into resource block sets that are uniquely numbered and allocated across each sector of each access node. The allocation is rotated based on a different time stamp or a different starting number, or may be a random sequence of sets per access node. These independent allocations for each access node generally distribute the interference across the system, and provide better interference reduction, resulting in an increase in system capacity per sector of each cell.