Frequency Selective Scheduling Joint Time-Frequency Optimization

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Solution Overview

Problem

Current radio resource scheduling methods in wireless cellular networks, such as LTE, often decouple time and frequency dimensions, leading to suboptimal assignments that do not maximize cell capacity and user throughput, especially in scenarios with complex radio propagation conditions and varying user demands.

Innovation Solution

A Frequency Selective Scheduling (FSS) method that jointly optimizes time and frequency resource assignments to users, allowing for simultaneous optimization of both dimensions to maximize cell capacity and user throughput while maintaining fairness among users, suitable for both downlink and uplink traffic.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If time and frequency dimensions are decoupled for scheduling, then scheduling algorithm complexity is reduced, but resource assignment optimality deteriorates

Engineering Contradiction:
Improvescheduling algorithm complexityVSAvoidresource assignment optimality
Core Design Contradiction:
Device complexityVSProductivity

Solution Approach 1:

The patent merges time and frequency dimension scheduling into a unified joint optimization framework. The base station performs simultaneous optimization of both time and frequency resource allocations by considering all dimensions together in the scheduling decision process, rather than treating them separately. This integration enables the system to achieve optimal resource assignments by evaluating the combined impact of time-frequency resource allocation on overall system performance.

Inventive Principle:
Principle #5Merging (Combining)

2Productivity

If frequency selective scheduling is implemented, then cell capacity and user throughput are maximized, but scheduling complexity increases

Engineering Contradiction:
Improvecell capacityVSAvoidscheduling complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The patent segments the frequency spectrum into multiple subbands and performs independent optimization for each subband. Instead of optimizing all frequency resources simultaneously as a single large problem, the system divides the frequency domain into manageable subbands and applies joint time-frequency optimization at the subband level. This segmentation reduces the overall computational complexity while still achieving frequency selective scheduling benefits for maximizing cell capacity and user throughput.

Inventive Principle:
Principle #1Segmentation

Data Source

PatentEP2676514B1Method and network entity for scheduling radio resources in mobile communication networks
Publication Date: 2018.05.09 TELEFONICA SA
  • EP2676514B1 patent drawingFigure 1
  • EP2676514B1 patent drawingFigure 2
  • EP2676514B1 patent drawingFigure 3

AI summary

A method and radio network entity for scheduling resources comprising: selecting the user for which the scheduling metric calculated based on CQI reports is a main maximum in a certain frequency subband and checking whether there is another subband in which the selected user has a calculated scheduling metric value higher than the main maximum. If so, secondary maxima of scheduling metrics for said user and others in another different subband are searched and compared with the previous calculated maximum. According to the result of this comparison, each user is assigned to at least one frequency subband, up to K subbands which can be adjacent or not depending upon the configuration of the network entity in uplink and downlink (e.g., supporting LTE). Scheduling of both time and frequency resources is optimized and simultaneously the throughput of users in a cell is maximized.