Dynamic Downlink Power Control for WCDMA Load Adaptation

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Solution Overview

Problem

Existing downlink power control modes in WCDMA systems are static and do not adapt to changing network conditions, leading to inconsistent service performance as network load varies.

Innovation Solution

Implementing a method to dynamically adjust downlink power control based on the load condition of a cell, switching between fast and slow power control manners depending on the load level, with shorter time intervals for lighter loads and longer intervals for heavier loads to optimize signal quality and network capacity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If a static power control mode is adopted with fixed parameters configured by network management system, then the processing is simple, but the service performance cannot be ensured when network load changes

Engineering Contradiction:
Improveprocessing simplicityVSAvoidadaptability to network load changes
Core Design Contradiction:
Ease of operationVSAdaptability or versatility

Solution Approach 1:

The patent implements dynamic power control by allowing the RNC to adjust power control parameters (such as TPC command timing advance and power adjustment step size) based on real-time network load conditions. When load is high, the system increases timing advance and adjustment steps to compensate for interference; when load is low, it reduces them to maintain optimal performance. This transforms the static power control into a dynamic system that adapts to changing network conditions.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent changes key power control parameters dynamically based on network load. Specifically, it adjusts the timing advance value and power adjustment step size according to load measurements. The RNC monitors downlink quality metrics (such as BLER or SIR) and modifies power control parameters accordingly, enabling the system to maintain service performance across varying load conditions while keeping the overall framework relatively simple.

Inventive Principle:
Principle #35Parameter changes

2Reliability

If power control parameters are adjusted dynamically based on network load, then the service performance is maintained, but the processing complexity increases

Engineering Contradiction:
Improveservice performance consistencyVSAvoidprocessing complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent implements a feedback mechanism where the RNC monitors downlink quality metrics (such as Block Error Rate or Signal to Interference Ratio) and uses this feedback to adjust power control parameters. The mobile station sends quality reports to the RNC, which then modifies timing advance and power adjustment steps accordingly. This closed-loop feedback system maintains service performance consistency while keeping the complexity manageable through rule-based adjustments rather than complex optimization algorithms.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The patent pre-configures power control parameter adjustment rules and thresholds in the RNC before operation. Instead of calculating optimal parameters in real-time during load changes, the system has pre-defined adjustment strategies ready to be applied when specific conditions are met. This preliminary preparation reduces real-time processing complexity while still enabling dynamic adaptation to network conditions.

Inventive Principle:
Principle #10Preliminary action

3Reliability

If fast power control with short time interval is used when downlink load is light, then the quality of service is ensured, but the downlink interference increases when load is heavy

Engineering Contradiction:
Improvequality of serviceVSAvoiddownlink interference
Core Design Contradiction:
ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The patent dynamically adjusts the power control time interval (timing advance) based on downlink load conditions. When load is light, it uses shorter time intervals (faster power control) to quickly respond to channel variations and ensure service quality. When load increases, it extends the time interval to reduce the frequency of power adjustments, thereby reducing overall downlink interference and improving network capacity. This dynamic timing adjustment resolves the contradiction between fast response and interference reduction.

Inventive Principle:
Principle #15Dynamics

Data Source

PatentEP3060015B1Method and device for controlling downlink power
Publication Date: 2022.03.23 ZTE CORP
  • EP3060015B1 patent drawingFigure 1~2
  • EP3060015B1 patent drawingFigure 3~4

AI summary

Provided are a method and device for controlling downlink power. The method includes: according to a current downlink load condition of a cell, adopting a corresponding power control manner to control transmitting power of a Downlink Dedicated Physical Channel (DL_DPCH) of a base station. In the present disclosure, different power control manners are adopted according to the downlink load condition of a cell. When the downlink load is lighter, a mobile station receives a relatively better wireless signal; the adoption of a fast power control manner in which a shorter time interval is needed for a Transmitting power Control (TPC) command to take effect can ensure the quality of service well. When the downlink load is heavier, due to a downlink interface reason, the mobile station receives a relatively worse wireless signal; at this time, the adoption of a slow power control manner in which a longer time interval is needed for the TPC command to take effect can effectively reduce the downlink interference and meanwhile improve the network capacity.