Picocell Pilot Signal Power Adjustment for Leakage Control

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Picocell base stations often cause interference and excessive handover attempts due to pilot signal leakage outside buildings, leading to reduced data handling performance and resource constraints in wireless telecommunications networks, especially when deployed without proper centralized planning.

Innovation Solution

A method to dynamically adjust the pilot signal transmission power from a picocell base station based on feedback from user terminals, keeping the power above a minimum level (Pmin) when multiple authorized users are present and reducing it below Pmin when only one authorized user is active, to minimize interference and handover requests from unauthorized users.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Area of stationary object

If pilot signal transmission power is set as a predetermined fraction of maximum transmission power (e.g., 10%), then coverage and capacity of the base station are maximized, but significant leakage of pilot signals occurs outside the building causing interference to macrocell base stations and excessive handover attempts

Engineering Contradiction:
Improvecoverage areaVSAvoidpilot signal leakage
Core Design Contradiction:
Area of stationary objectVSObject-generated harmful factors

Solution Approach 1:

The patent applies dynamics by making the pilot signal transmission power adjustable rather than fixed. The base station dynamically adapts the pilot power level based on detected conditions (such as presence of unauthorized terminals or handover requests), transitioning between high power (for coverage) and low power (to prevent leakage), thereby resolving the contradiction between maximizing coverage and minimizing harmful signal leakage.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent changes the transmission power parameter from a static predetermined fraction to a variable parameter that can be adjusted based on operational conditions. By modifying the power level parameter dynamically, the system can provide adequate coverage when needed while reducing leakage to prevent interference and unwanted handovers, thus addressing both requirements simultaneously.

Inventive Principle:
Principle #35Parameter changes

2Object-generated harmful factors

If pilot signal transmission power is reduced to minimize leakage outside the building, then interference to macrocell base stations is reduced, but coverage within the building may be insufficient

Engineering Contradiction:
Improvepilot signal leakageVSAvoidcoverage area
Core Design Contradiction:
Object-generated harmful factorsVSArea of stationary object

Solution Approach 1:

The system dynamically adjusts pilot power levels based on detected conditions. When unauthorized terminals are detected or excessive handover requests are observed, the base station reduces power to minimize leakage. When coverage is needed, the base station increases power accordingly. This dynamic adaptation allows the system to optimize between coverage and leakage prevention in real-time.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent employs feedback mechanisms where the base station monitors conditions (such as terminal authentication status, handover request patterns, and signal reception quality) and uses this information to adjust pilot power levels. This feedback loop enables the system to maintain adequate coverage while preventing excessive leakage, resolving the contradiction between these two requirements.

Inventive Principle:
Principle #23Feedback

3Ease of manufacture

If picocell base stations are deployed without detailed centralized cell-planning, then deployment flexibility and ease of installation are improved, but inappropriate locations cause excessive handover attempts and reduced data handling performance

Engineering Contradiction:
Improvedeployment flexibilityVSAvoiddata handling performance
Core Design Contradiction:
Ease of manufactureVSProductivity

Solution Approach 1:

The patent applies self-service by enabling the picocell base station to automatically detect and respond to inappropriate deployment conditions. The base station monitors for unauthorized terminals and excessive handover requests, and autonomously adjusts its operation (reducing pilot power or blocking handovers) to prevent performance degradation. This self-regulating capability allows flexible deployment without centralized planning while maintaining data handling performance.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The system uses feedback from network conditions (handover requests, terminal authentication status, signal quality measurements) to automatically adjust picocell operation. This feedback mechanism allows picocells deployed without centralized planning to self-optimize their performance, preventing data handling degradation while maintaining deployment flexibility.

Inventive Principle:
Principle #23Feedback

4Adaptability or versatility

If the number of picocell base stations is increased within a network, then coverage flexibility and capacity are improved, but more network resources are required to handle handovers reducing quality of service

Engineering Contradiction:
Improvecoverage flexibilityVSAvoidnetwork resource consumption
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent makes handover handling dynamic by adjusting pilot power levels based on network conditions. When the number of active picocells is high and network resources are constrained, the system reduces pilot power to minimize unwanted handovers, thereby reducing network resource consumption while maintaining coverage flexibility for authorized users.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system changes operational parameters (pilot power level, handover acceptance criteria) based on network load and picocell density. By adjusting these parameters dynamically, the network can support more picocells with flexible coverage while managing resource consumption to maintain quality of service, resolving the contradiction between adaptability and complexity.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP2071738B1A picocell base station and method of adjusting transmission power of pilot signals therefrom
Publication Date: 2016.09.07 NOKIA OF AMERICA CORP
  • EP2071738B1 patent drawingFigure 1~2
  • EP2071738B1 patent drawingFigure 3~4
  • EP2071738B1 patent drawingFigure 5

AI summary

A method is provided of adjusting transmission power of pilot signals from a picocell base station for radio communications to a user terminal in radio connection with the picocell base station. The method comprises: the base station sending a signal at a first signal power; the user terminal measuring received signal level and sending an information signal indicating received signal level; and the base station adjusting its pilot signal power dependent upon said received signal level indicated in the information signal.