Femtocell Power Control Module for Interference Avoidance
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Solution Overview
Problem
Femtocell deployment in wireless communication networks often results in interference with macrocell networks, leading to coverage holes due to the inability to dynamically adjust transmit power without modifying existing network structures or entities, especially in shared frequency deployments.
Innovation Solution
A femtocell power control module that dynamically adjusts the transmit power of femtocell base stations based on uplink communication characteristics, such as interference levels and RACH message rates, to reduce downlink interference and maintain network quality without requiring modifications to the macrocell network or entities.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of stationary object
If femtocell base station transmits at high power to improve coverage, then femtocell coverage area is improved, but downlink interference to macrocell users increases causing coverage holes
Solution Approach 1:
The patent implements dynamic transmit power adjustment for the femtocell base station, transitioning from static high power transmission to adaptive power levels. The femtocell continuously monitors uplink interference indicators and adjusts its downlink transmit power accordingly, reducing power when macrocell users are detected and maintaining higher power when interference is minimal, thus resolving the contradiction between coverage area and interference generation
Solution Approach 2:
The patent establishes a feedback mechanism where the femtocell base station monitors uplink interference indicators (such as RACH message rates and interference levels) from macrocell users and uses this feedback to adjust its downlink transmit power. This closed-loop control enables the system to automatically adapt to changing conditions, reducing downlink interference while maintaining adequate coverage, thereby resolving the technical contradiction
2Device complexity
If static fixed power is used for femtocell transmission, then device complexity is reduced, but adaptability to different deployment scenarios is worsened
Solution Approach 1:
The patent implements a self-service power control mechanism where the femtocell base station autonomously monitors uplink interference indicators and adjusts its own downlink transmit power without requiring external control or complex coordination with macrocell base stations. This self-managing approach maintains relatively simple device complexity while achieving high adaptability to different deployment scenarios through automatic response to interference conditions
3Measurement precision
If MUE measurements are used to control HNB power, then power adaptation accuracy is improved, but network complexity increases due to information transfer requirements
Solution Approach 1:
The patent extracts the power control functionality from the macrocell network infrastructure and implements it directly at the femtocell base station. Instead of relying on complex information transfer between macrocell base stations and femtocells, the femtocell independently monitors uplink interference indicators and autonomously adjusts its power, thereby maintaining measurement precision while significantly reducing network complexity and information transfer requirements
Data Source
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AI summary
A femtocell power control module is operative to: obtain at least one uplink communication characteristic associated with the uplink signals transmitted by the at least one cellular communication device and received by the femtocell base station; estimate, from the obtained uplink communication characteristic, the power level of the downlink signals transmitted by the femtocell base station, as received by the at least one cellular communication device; if the estimated power level of the downlink signals transmitted by the femtocell base station as received by the at least one cellular communication device exceeds a predefined threshold power level, reduce the power level of the downlink signals transmitted by the femtocell base station to a reduced power level.