Dynamic Rank Adjustment for MIMO Sub-band Scheduling

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

In wireless communication systems, maintaining a constant rank across sub-bands within a slot can lead to inefficient utilization of downlink resources due to bursty traffic patterns, as it fails to dynamically adjust resource allocation based on varying user data traffic demands.

Innovation Solution

Implementing a method where the scheduling entity dynamically changes the rank assigned to each UE across sub-bands of a slot based on the amount of scheduled user data traffic, allowing for flexible allocation of data streams in each sub-band to optimize resource utilization.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If the rank is maintained constant across all sub-bands within a slot, then the system complexity is reduced and control signaling is simplified, but the downlink resource utilization efficiency deteriorates due to inability to adapt to bursty traffic patterns

Engineering Contradiction:
Improvecontrol signaling complexityVSAvoiddownlink resource utilization efficiency
Core Design Contradiction:
Device complexityVSProductivity

Solution Approach 1:

The patent applies dynamics by enabling the rank to change between sub-bands within a slot based on traffic conditions. The base station dynamically adjusts the rank for different sub-bands according to the amount of user data traffic, allowing the system to adapt to bursty traffic patterns while maintaining simplified control signaling through the preservation of rank within each sub-band.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent segments the slot into multiple sub-bands and allows independent rank configuration for each sub-band. This segmentation enables differentiated resource allocation where each sub-band can have its own rank value optimized for the local traffic conditions, improving overall resource utilization without requiring complex cross-sub-band coordination.

Inventive Principle:
Principle #1Segmentation

2Productivity

If the rank is dynamically changed between sub-bands based on traffic demand, then the downlink resource utilization efficiency is improved, but the control signaling complexity increases

Engineering Contradiction:
Improvedownlink resource utilization efficiencyVSAvoidcontrol signaling complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The patent merges the rank indication with the downlink assignment control signaling. By combining the rank information with the existing downlink assignment messages that are already sent to UEs, the system conveys rank changes without requiring separate control channels or additional signaling overhead, thus improving resource utilization while avoiding increased control complexity.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The patent enables the UE to autonomously determine its rank for each sub-band based on pre-configured parameters and local traffic conditions. The UE uses the received configuration information to self-adjust its transmission parameters, eliminating the need for explicit base station control signals for each rank change and reducing control signaling complexity.

Inventive Principle:
Principle #25Self-service

3Productivity

If multiple data streams are allocated to a UE in each sub-band, then the data throughput is increased, but the interference to other UEs and the resource allocation complexity increase

Engineering Contradiction:
Improvedata throughputVSAvoidresource allocation complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The patent applies local quality by allocating different numbers of data streams (different ranks) to different sub-bands based on local traffic conditions. Each sub-band receives a customized rank assignment optimized for its specific traffic demand, allowing high throughput where needed while reducing allocation complexity in sub-bands with lower traffic requirements.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The patent changes the rank parameter dynamically between sub-bands according to traffic conditions. By adjusting this key parameter, the system can increase data throughput in sub-bands with high traffic demand while reducing the number of active data streams in sub-bands with lower demand, thereby managing interference and allocation complexity through parameter adaptation.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP3488652B1Enhanced control channel for DL sub-band scheduling
Publication Date: 2023.08.16 QUALCOMM INC
  • EP3488652B1 patent drawingFigure 1
  • EP3488652B1 patent drawingFigure 2
  • EP3488652B1 patent drawingFigure 3

AI summary

Aspects of the present disclosure provide a scheduling entity for facilitating Multiple Input Multiple Output (MIMO) wireless communication by dynamically assigning ranks to scheduled entities for each sub-band of a slot. In some examples, the rank assigned to a particular scheduled entity may be increased or decreased between sub-bands of the slot based on the amount of scheduled user data traffic for that particular scheduled entity relative to the amount of scheduled user data traffic for other scheduled entities. The scheduling entity further schedules resources within the sub-bands of the slot based on the assigned ranks and transmits an enhanced control channel providing scheduling information indicating the scheduled resources to the scheduled entities.