Femto Node Transmit Power Self-Calibration
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Solution Overview
Problem
Femto cells in wireless communication systems cause interference due to ad-hoc deployment, affecting macro cellular networks and leading to coverage holes and reduced communication performance.
Innovation Solution
Adaptive power management for femto nodes based on received signal strength from macro access nodes and other femto nodes, allowing for dynamic adjustment of transmit power to mitigate interference and optimize coverage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If femto base stations are deployed to provide robust indoor wireless coverage, then coverage for indoor users is improved, but interference to macro cells and other femto cells increases
Solution Approach 1:
The patent implements dynamic transmit power adjustment for femto base stations based on real-time interference measurements. The system continuously monitors interference levels and automatically adjusts power levels to maintain indoor coverage while reducing harmful interference to macro cells and other femto cells.
Solution Approach 2:
The patent establishes a feedback mechanism where femto base stations receive interference information from macro cells and other femto cells, process this information to determine appropriate power levels, and adjust their transmit power accordingly. This closed-loop feedback system enables automatic interference management.
2Adaptability or versatility
If ad-hoc deployment of femto base stations is allowed to meet user needs, then deployment flexibility is improved, but interference management becomes difficult
Solution Approach 1:
The patent enables femto base stations to autonomously manage their own interference by automatically measuring interference levels, processing measurement information, and adjusting their transmit power without requiring manual configuration or complex external management systems.
Solution Approach 2:
The patent changes the transmit power parameter dynamically based on measured interference conditions. By automatically adjusting this key parameter, the system simplifies interference management while maintaining deployment flexibility.
3Area of stationary object
If transmit power is increased to improve coverage, then coverage area is expanded, but interference to other cells increases
Solution Approach 1:
The patent implements dynamic power adjustment where the transmit power level is continuously adapted based on real-time interference measurements and coverage requirements, allowing the system to expand coverage when needed while reducing interference when conditions change.
Solution Approach 2:
The patent dynamically changes the transmit power parameter to balance coverage requirements with interference reduction. By adjusting this parameter based on measured conditions, the system achieves optimal coverage without excessive interference.
Data Source
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AI summary
Transmit power (e.g., maximum transmit power) may be defined based on the maximum received signal strength allowed by a receiver and a total received signal strength from transmitting nodes at the receiver. Transmit power may be defined for an access node (e.g., a femto node) such that a corresponding outage created in a cell (e.g., a macro cell) is limited while still providing an acceptable level of coverage for access terminals associated with the access node. An access node may autonomously adjust its transmit power based on channel measurement and a defined coverage hole to mitigate interference and perform a self-calibration process.