MU-MIMO Base Station Pairing Gain Threshold Optimization

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

The system performance of Multi-User Multiple-Input Multiple-Output (MU-MIMO) technology is not significantly improved compared to Single User Multiple-Input Multiple-Output (SU-MIMO) due to interference between paired UEs and overheads of measurement pilots, limiting the potential gains in channel capacity and network coverage.

Innovation Solution

A method where a base station obtains precoding matrix indicators (PMIs) from UEs with ranks 1 and 2, pairs them to form a weighted PMI with a rank of 2, and performs data transmission using the same time-frequency resource if the pairing gain exceeds a threshold, adjusting Modulation and Coding Schemes (MCS) and scheduling priorities to improve transmission accuracy and resource usage.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If MU-MIMO technology is implemented with paired UEs using the same time-frequency resource, then channel capacity and network coverage are improved, but interference between paired UEs and measurement pilot overheads reduce system performance

Engineering Contradiction:
Improvechannel capacityVSAvoidsystem performance
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The base station performs preliminary actions by obtaining PMIs from multiple UEs before pairing, calculating pairing gains in advance, and selecting optimal UE pairs that meet threshold criteria. This preliminary selection process ensures that only UEs with compatible channel characteristics are paired, reducing interference and measurement pilot overhead while maintaining high channel capacity.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent changes key parameters including PMI (precoding matrix indicator) selection, pairing gain thresholds, and MCS (modulation and coding scheme) adjustments. By dynamically adjusting these parameters based on channel conditions and pairing gains, the system optimizes the balance between channel capacity improvement and interference reduction, thereby enhancing overall system performance.

Inventive Principle:
Principle #35Parameter changes

2Productivity

If UEs are paired for MU-MIMO transmission, then resource utilization improves, but transmission errors increase due to interference

Engineering Contradiction:
Improveresource utilizationVSAvoidtransmission accuracy
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The base station implements feedback mechanisms by obtaining PMI information from UEs and calculating pairing gains based on channel conditions. This feedback loop allows the system to continuously adjust UE pairing decisions and MCS selections to maintain high resource utilization while minimizing transmission errors through interference-aware pairing.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

Before actual data transmission, the base station performs preliminary pairing evaluations by calculating pairing gains and comparing them against thresholds. This preliminary action ensures that only UE pairs with acceptable interference levels are selected, thereby maintaining high resource utilization while preventing excessive transmission errors.

Inventive Principle:
Principle #10Preliminary action

3Reliability

If pairing gain threshold is set high to ensure quality, then transmission quality improves, but fewer UE pairs qualify for MU-MIMO

Engineering Contradiction:
Improvetransmission qualityVSAvoidnumber of paired UEs
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The system dynamically adjusts the pairing gain threshold based on overall system conditions, channel environments, and resource availability. This dynamic thresholding allows the base station to maintain high transmission quality when conditions permit while increasing the number of qualifying UE pairs when system load or channel conditions require more aggressive resource utilization.

Inventive Principle:
Principle #15Dynamics

Data Source

PatentEP3442287B1Multi-user multi-input multi-output (MU-MIMO) data transmission method and base station
Publication Date: 2020.09.02 HUAWEI TECH CO LTD
  • EP3442287B1 patent drawingFigure 1~2
  • EP3442287B1 patent drawingFigure 3~4
  • EP3442287B1 patent drawing

AI summary

Embodiments of this application provide a MU-MIMO data transmission method and a base station, to implement pairing scheduling on UE and improve resource usage. The method includes: obtaining, by a base station, a first precoding matrix indicator PMI of first user equipment UE, where a first rank of the first UE is 1; obtaining, by the base station, a second PMI of second UE, where a second rank of the second UE is 1, and a weighted value corresponding to the first PMI and a weighted value corresponding to the second PMI form a weighted value corresponding to a third PMI whose rank is 2; and separately performing, by the base station by using the third PMI and a same time-frequency resource, data transmission with the first UE and the second UE that are paired, where a pairing gain of the first UE and the second UE is greater than a preset threshold. In this way, the base station first determines that a gain of two UEs after they are paired is greater than a threshold, so as to ensure that a relatively large system gain can be generated after the two UEs are paired, and improve quality of data transmission between the base station and the two UEs.