FDD Leakage Estimation Using Training Resource Signaling

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Solution Overview

Problem

Simultaneous uplink and downlink transmissions in frequency division duplex systems result in leakage interference, where a portion of the downlink signal leaks into the uplink, degrading the signal-to-noise ratio.

Innovation Solution

A communication method and apparatus that estimates leakage propagation characteristics using training signals on designated resources to identify and mitigate the interference by determining and reducing the leaked signal.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If frequency division duplexers are used to enable simultaneous uplink and downlink transmissions, then communication efficiency is improved, but leakage interference occurs when downlink signals leak into uplink frequency bands

Engineering Contradiction:
Improvecommunication efficiencyVSAvoidleakage interference
Core Design Contradiction:
ProductivityVSObject-affected harmful factors

Solution Approach 1:

The system performs preliminary actions by sending training signals before actual uplink transmission to estimate the leakage propagation characteristic in advance. This allows the receiver to prepare compensation parameters beforehand, reducing the impact of leakage interference when actual communication occurs.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The system establishes a feedback mechanism where the receiver estimates the leakage propagation characteristic based on training signals and feeds back this information to the transmitter. The transmitter then uses this feedback to adjust and cancel leakage interference in subsequent uplink transmissions, creating a closed-loop control system.

Inventive Principle:
Principle #23Feedback

2Reliability

If training signals are sent on training resources to estimate leakage propagation characteristic, then leakage interference mitigation is improved, but training complexity increases

Engineering Contradiction:
Improveleakage interference mitigationVSAvoidtraining complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

Instead of performing complete leakage cancellation across all frequency bands and time resources, the system applies partial action by selecting specific training resources (time-frequency slots) to send training signals. This partial measurement approach reduces training complexity while still achieving sufficient leakage estimation accuracy for practical interference mitigation.

Inventive Principle:
Principle #16Partial or excessive action

Solution Approach 2:

The training signals serve multiple functions simultaneously: they act as downlink transmission signals for normal communication, reference signals for channel estimation, and training signals for leakage propagation characteristic estimation. This multi-functionality reduces the need for separate dedicated training resources, thereby lowering overall training complexity.

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

Data Source

PatentEP4708711A1Communication method and communication apparatus
Publication Date: 2026.03.11 HUAWEI TECH CO LTD
  • EP4708711A1 patent drawingFigure 1~3
  • EP4708711A1 patent drawingFigure 4(a)~5
  • EP4708711A1 patent drawingFigure 6

AI summary

Embodiments of this application provide a communication method and a communication apparatus. The method includes: receiving resource indication information, where the resource indication information is used to determine information about at least one training resource; receiving at least one training signal on the at least one training resource; and determining a leakage propagation characteristic based on the at least one training signal, where the leakage propagation characteristic is used to determine a signal that is leaked from a sending link to a receiving link. According to this application, a device (for example, a radio frequency device) that receives the resource indication information may distinguish between the training resource and a non-training resource based on the resource indication information, so that the device that receives the resource indication information can determine the leakage propagation characteristic based on the training signal whose transmission is performed on the training resource, and training complexity can be reduced.