Dynamic Guard Period Adjustment for Far-End Interference in TDD Networks

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Solution Overview

Problem

Far-end interference in TDD wireless networks causes significant performance issues due to signal propagation delays exceeding guard periods, leading to widespread interference that existing methods can only partially mitigate within 200km and not in real-time.

Innovation Solution

The method involves determining far-end interference through dedicated reference signals and adjusting the guard period (GP) length based on distance information of the interference source, either by configuring time slot formats at the interfered or interfering stations, or by reporting detection results to a centralized control unit for dynamic adjustments.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If the Guard Period (GP) length is increased to cover far-end interference propagation delay, then uplink interference is reduced, but downlink throughput is significantly reduced due to longer GP occupying more time resources

Engineering Contradiction:
Improveuplink interferenceVSAvoiddownlink throughput
Core Design Contradiction:
Object-affected harmful factorsVSProductivity

Solution Approach 1:

The patent implements dynamic adjustment of GP length based on detected interference distance. The GP length is not fixed but adapts to the actual interference scenario: when far-end interference is detected at distance D, the GP is extended to exactly cover the propagation delay for that distance. This dynamic approach allows the system to minimize GP extension rather than using a conservative fixed long GP, thereby reducing downlink throughput loss while still protecting against the detected interference.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent changes the GP length parameter based on the detected interference source distance. By measuring the distance to the far-end base station and calculating the corresponding propagation delay, the system adjusts the GP length parameter to match the actual interference coverage requirement. This parameter adaptation allows precise matching of GP duration to interference characteristics, avoiding both insufficient coverage and excessive extension.

Inventive Principle:
Principle #35Parameter changes

2Reliability

If the GP length is fixed to cover the maximum possible interference distance, then all far-end interference is circumvented, but the system cannot adapt to varying interference conditions and suffers continuous throughput loss even when interference is absent or distant

Engineering Contradiction:
Improveinterference circumvention coverageVSAvoiddownlink throughput
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The system continuously monitors for far-end interference and dynamically adjusts GP length based on real-time detection results. When interference is detected at a certain distance, the GP is extended appropriately. When interference is not detected or is detected at a shorter distance, the GP is reduced or maintained at a baseline level. This dynamic behavior allows the system to adapt to varying interference conditions rather than maintaining a fixed conservative GP length.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system performs self-adjustment of GP length based on its own interference detection capabilities. The base station autonomously detects far-end interference, calculates the interference distance, and adjusts its own GP configuration without requiring external control. This self-service mechanism enables the system to automatically optimize its performance based on actual operating conditions.

Inventive Principle:
Principle #25Self-service

3Measurement precision

If existing interference detection methods are used, then interference within 200km can be detected, but detection and circumvention are not real-time and cannot handle ultra-long distance propagation

Engineering Contradiction:
Improveinterference detection rangeVSAvoiddetection and response time
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The patent uses preliminary actions by deploying dedicated reference signal sequences that are specifically designed for far-end interference detection. These reference signals are transmitted continuously or periodically in advance, allowing the system to detect interference sources at ultra-long distances before they cause significant disruption. The reference signals enable early warning and proactive GP adjustment, reducing the time from interference occurrence to system response.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent replaces traditional mechanical or fixed-threshold detection methods with a signal-processing-based detection mechanism using dedicated reference sequences. Instead of relying on general signal strength monitoring with fixed thresholds, the system uses correlation-based detection of specific reference signal patterns, enabling more sensitive and accurate detection of far-end interference at ultra-long distances with faster response time.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Data Source

PatentEP3905750B1Method, interfered station and interfering station for circumventing far-end interference
Publication Date: 2024.08.14 DATANG MOBILE COMM EQUIP CO LTD
  • EP3905750B1 patent drawingFigure 1
  • EP3905750B1 patent drawingFigure 2~3
  • EP3905750B1 patent drawingFigure 4~5

AI summary

Disclosed in the present application are a method, system and device for circumventing far-end interference, which are used to better circumvent far-end interference by means of flexibly adjusting a GP length. The method for circumventing far-end interference provided by the present application comprises: an interference-receiving station preliminarily determining that there is far-end interference according to far-end interference features, and sending a first dedicated reference signal sequence to an interfering station; the interfering station determining that there is far-end interference according to the first dedicated reference signal sequence, and sending a second dedicated reference signal sequence to the interference-receiving station; the interference-receiving station finally determining that there is far-end interference according to the second dedicated reference signal sequence; and the interference-receiving station and the interfering station circumventing the far-end interference by means of adjusting the GP length.