Dynamic TDD Subframe Structure for Interference Management

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Solution Overview

Problem

Current wireless communication systems face inefficiencies in capturing interference between DL-centric and UL-centric TDD subframes, leading to inaccurate interference measurement and reduced communication efficiency due to misalignment of reference signals.

Innovation Solution

The proposed solution involves aligning the UE-specific reference signal (UERS) with the demodulation reference signal (DMRS) of the UL-centric TDD subframe, allowing for more accurate interference capture and enabling inter-link MU-MIMO by assigning orthogonal ports, thereby enhancing the structure of TDD subframes to improve interference management.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If reference signals are transmitted in DL-centric and UL-centric TDD subframes without alignment, then interference measurement accuracy deteriorates, but maintaining separate reference signal structures provides flexibility in subframe configuration

Engineering Contradiction:
Improveinterference measurement accuracyVSAvoidreference signal structure complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent merges the functions of UE-specific reference signals and demodulation reference signals by aligning them in time and frequency resources. This combination allows a single reference signal structure to serve both purposes: enabling accurate interference measurement while maintaining subframe configuration flexibility, thereby resolving the contradiction between measurement precision and device complexity

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The patent introduces an intermediary mechanism where the aligned reference signal acts as a mediator between DL-centric and UL-centric subframes. By positioning the reference signal to capture interference from both subframe types, it enables accurate interference measurement without requiring separate complex reference signal structures for each subframe type

Inventive Principle:
Principle #24Intermediary (Mediator)

2Adaptability or versatility

If TDD subframes use fixed structure without dynamic adjustment, then implementation simplicity is maintained, but adaptability to different interference scenarios deteriorates

Engineering Contradiction:
Improvesubframe structure adaptabilityVSAvoidsubframe structure complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent applies dynamics by making the reference signal structure adaptable rather than fixed. The reference signal can be dynamically positioned and configured based on the specific TDD subframe type and interference conditions, allowing the system to adapt to different scenarios while maintaining a relatively simple overall structure through standardized alignment rules

Inventive Principle:
Principle #15Dynamics

3Measurement precision

If reference signals are aligned between DL-centric and UL-centric subframes, then interference capture accuracy improves, but flexibility in independent reference signal configuration deteriorates

Engineering Contradiction:
Improveinterference capture accuracyVSAvoidreference signal configuration flexibility
Core Design Contradiction:
Measurement precisionVSAdaptability or versatility

Solution Approach 1:

The patent makes the aligned reference signal universal by designing it to serve multiple functions simultaneously. The same reference signal structure is used for both interference measurement and demodulation purposes across different TDD subframe types, achieving accurate interference capture while maintaining configuration flexibility through a unified rather than specialized approach

Inventive Principle:
Principle #6Universality (Multi-functionality)

Data Source

PatentEP3522440B1Dynamic subframe structure
Publication Date: 2020.10.14 QUALCOMM INC
  • EP3522440B1 patent drawingFigure 1
  • EP3522440B1 patent drawingFigure 2
  • EP3522440B1 patent drawingFigure 3

AI summary

Various aspects provide for receiving signaling including information configured to indicate whether to adjust a structure of a time-division duplex (TDD) subframe. Such adjusting may include adjusting a time or subcarrier allocated for a control channel, data, and/or a reference signal, such as a user equipment (UE)-specific reference signal (UERS). The UERS may be time-aligned with a demodulation reference signal (DMRS) of another TDD subframe. The UERS may be utilized for inter-link multi-user multiple-input multiple-output (MU-MIMO) when the UERS is orthogonal to the DMRS. Various other aspects provide for communicating one or more pilot or null tones in a data portion of a first TDD subframe. The one or more pilot or null tones may be used to capture interference from a second TDD subframe communicated by another apparatus. The first TDD subframe may be communicated at least partially concurrent with the second TDD subframe.