Interference Control via Power Region Division in Heterogeneous Networks

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Solution Overview

Problem

In heterogeneous networks, the interference between the Physical Downlink Control Channel (PDCCH) of a macro base station and the Physical Downlink Shared Channel (PDSCH) of a small base station due to different numerologies and transmission powers is not effectively addressed by existing cross-carrier scheduling methods, leading to reduced spectrum utilization and service disruptions.

Innovation Solution

The method involves dividing the control region of a time domain transmission unit into two power regions, with higher transmission power used for channels with poor quality and lower transmission power for channels with good quality, and transmitting this information to terminals via signaling, allowing them to demodulate PDCCH correctly while minimizing interference.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If the macro base station uses high transmission power on CC1, then the coverage and signal strength are improved, but strong interference is generated to the PDCCH and PDSCH of the small base station on CC1

Engineering Contradiction:
Improvesignal strengthVSAvoidinterference
Core Design Contradiction:
StrengthVSObject-generated harmful factors

Solution Approach 1:

The control region of the macro base station is segmented into a first power region and a second power region. The first power region uses high transmission power for channels with poor quality, while the second power region uses low transmission power for channels with good quality, thereby reducing interference to small base stations while maintaining coverage for edge users.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Different transmission powers are applied to different regions within the control channel. The first power region is specifically designed with high power to cover users with poor channel quality, while the second power region uses low power to minimize interference, creating localized quality optimization without affecting the entire control region uniformly.

Inventive Principle:
Principle #3Local quality

2Reliability

If cross-carrier scheduling is used to solve PDCCH interference, then PDCCH reliability is improved, but PDSCH interference from macro base station to small base station cannot be resolved

Engineering Contradiction:
ImprovePDCCH reliabilityVSAvoidPDSCH interference
Core Design Contradiction:
ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The transmission power in the control region is made dynamic and adaptable. The base station dynamically adjusts transmission power between the first and second power regions based on channel quality conditions, allowing the system to adaptively resolve both PDCCH and PDSCH interference issues without being constrained by fixed cross-carrier scheduling configurations.

Inventive Principle:
Principle #15Dynamics

3Adaptability or versatility

If different numerologies are used for macro and small base stations on the same carrier, then spectrum flexibility is improved, but control region length mismatch causes increased interference

Engineering Contradiction:
Improvespectrum flexibilityVSAvoidinterference
Core Design Contradiction:
Adaptability or versatilityVSObject-generated harmful factors

Solution Approach 1:

The invention changes the transmission power parameter within the control region based on channel quality and numerology differences. By adjusting power levels in different regions, the system accommodates different numerologies (subcarrier spacings and slot lengths) between macro and small base stations while minimizing the interference caused by control region length mismatches.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP3661273B1Method and device for controlling interference
Publication Date: 2022.01.26 BEIJING XIAOMI MOBILE SOFTWARE CO LTD
  • EP3661273B1 patent drawingFigure 1~2B
  • EP3661273B1 patent drawingFigure 3~5
  • EP3661273B1 patent drawingFigure 6A~6B

AI summary

The present disclosure provides a method and a device for controlling interference, the method comprising: dividing a control region in a time domain transmission unit, to obtain a first power region and a second power region, the transmission power of the first power region being higher than that of the second power region; dividing all current channels, to obtain a first channel group and a second channel group; transmitting data carried by all the channels included in the second channel group by means of the first power region, and transmitting data carried by all the channels included in the first channel group by means of the second power region. The present disclosure may greatly reduce interference to a PDSCH of a small cell from a PDCCH of a macro base station when the macro base station and the small cell use different parameter sets on the same carrier in a heterogeneous network, without reducing the spectrum utilization rates of the macro base station and the small cell.