OFDM Sub-carrier Grouping for Contiguous Resource Allocation

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Solution Overview

Problem

Existing OFDM communication systems face inefficiencies in scheduling sub-carriers due to distributed allocations, which complicate signal generation and consume valuable link resources, especially in SC-FDMA transmitters, and current methods do not effectively manage interference and channel conditions for optimal data throughput.

Innovation Solution

The method involves channel-dependent interference-based scheduling, where sub-carriers are grouped based on interference levels and SINR profiles, allowing for efficient allocation and reduced signaling complexity by notifying mobile terminals of allocated sub-carrier groups rather than individual resource blocks, optimizing data throughput and resource usage.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If distributed sub-carrier allocations are used, then resource allocation flexibility is improved, but signal generation complexity and link resource consumption increase

Engineering Contradiction:
Improveresource allocation flexibilityVSAvoidsignal generation complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent merges distributed sub-carrier allocations into contiguous resource blocks for allocation, while maintaining the ability to represent distributed patterns through efficient signaling. This combines the flexibility of distributed allocation with the simplicity of contiguous resource management, reducing signal generation complexity while preserving allocation adaptability.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The patent segments the allocation representation into two parts: contiguous resource block assignments for efficiency and distributed sub-carrier patterns for flexibility. By segmenting the allocation structure, the system achieves both simplicity in resource block management and adaptability in sub-carrier distribution.

Inventive Principle:
Principle #1Segmentation

2Adaptability or versatility

If distributed sub-carrier allocations are used, then resource allocation flexibility is improved, but link resource consumption increases

Engineering Contradiction:
Improveresource allocation flexibilityVSAvoidlink resource consumption
Core Design Contradiction:
Adaptability or versatilityVSQuantity of substance

Solution Approach 1:

The patent merges the representation of distributed allocations into a compact form using contiguous resource block indicators. This reduces the signaling overhead and link resource consumption while maintaining the flexibility to allocate sub-carriers in distributed patterns across the frequency spectrum.

Inventive Principle:
Principle #5Merging (Combining)

3Manufacturing precision

If individual resource block allocations are notified to mobile terminals, then allocation precision is improved, but signaling complexity increases

Engineering Contradiction:
Improveallocation precisionVSAvoidsignaling complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent merges multiple individual resource block notifications into a single contiguous resource block assignment. This maintains precise allocation by specifying exact resource block boundaries while reducing signaling complexity by eliminating the need to notify each mobile terminal about every individual allocation separately.

Inventive Principle:
Principle #5Merging (Combining)

Data Source

PatentEP2204028B1Channel-dependent frequency-domain scheduling in an orthogonal frequency division multiplexing communications system
Publication Date: 2014.11.12 TELEFONAKTIEBOLAGET LM ERICSSON (PUBL)
  • EP2204028B1 patent drawingFigure 1~2B
  • EP2204028B1 patent drawingFigure 3
  • EP2204028B1 patent drawingFigure 4

AI summary

Methods and apparatus are disclosed for scheduling sub-carriers in an Orthogonal Frequency Division Multiplexing (OFDM) communication system. In an exemplary method, channel quality metric values (SINR) for each of a plurality of sub-channels are determined, in view of a selected mobile terminal. For each of two or more threshold levels (910) for the channel quality metric, sub-carrier groups (940) composed of sub-carriers corresponding to sub-channels having channel quality metric values superior to the threshold level are identified, and an estimated data throughput is calculated for each of the identified sub-carrier groups. One or more of the identified sub-carrier groups is allocated to the selected mobile terminal according to the estimated data throughputs.