CDMA Radio Link Management via Power Control Loop Feedback

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Solution Overview

Problem

In CDMA communication systems with combined cells, there is no reliable method to determine if a user terminal benefits from downlink power in specific cell portions, leading to unnecessary power transmission and interference.

Innovation Solution

A CDMA communication node arrangement with spatially separated antenna units and a central control unit that alters transmitting power in a dedicated channel to monitor the user terminal's power control loop responses, determining whether to continue, start, or stop communication based on the received feedback.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Area of stationary object

If downlink power is transmitted in all cell portions to all user terminals, then coverage is improved, but power consumption increases and interference is generated

Engineering Contradiction:
Improvecoverage areaVSAvoidpower consumption
Core Design Contradiction:
Area of stationary objectVSLoss of energy

Solution Approach 1:

The patent applies local quality by transmitting downlink power selectively in specific cell portions where user terminals can actually benefit, rather than uniformly across all cell portions. The control unit determines which cell portions require power transmission based on terminal location and signal conditions, thereby reducing overall power consumption while maintaining necessary coverage.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The system dynamically adjusts downlink power transmission by continuously monitoring terminal positions and signal conditions. The control unit makes real-time decisions about which antenna units should transmit power to which terminals, allowing the system to adapt to changing conditions and optimize power usage accordingly.

Inventive Principle:
Principle #15Dynamics

2Reliability

If downlink power is transmitted in all cell portions, then signal availability is improved, but inter/intra cell interference increases

Engineering Contradiction:
Improvesignal availabilityVSAvoidinterference
Core Design Contradiction:
ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The patent reduces interference by applying local quality - transmitting signals only in specific cell portions where terminals are located rather than across the entire cell. This localized transmission approach minimizes the number of active transmitters at any given time and location, thereby reducing both inter-cell and intra-cell interference while maintaining signal availability where needed.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The system extracts or removes unnecessary power transmissions from cell portions where no terminals are present or where signals would not be beneficial. By taking out these redundant transmissions, the system eliminates the associated interference while preserving signal availability in areas where terminals actually require service.

Inventive Principle:
Principle #2Taking out (Extraction)

3Loss of energy

If the system monitors power control loop commands to detect beneficial cell portions, then power efficiency is improved, but system complexity increases

Engineering Contradiction:
Improvepower efficiencyVSAvoidsystem complexity
Core Design Contradiction:
Loss of energyVSDevice complexity

Solution Approach 1:

The patent employs feedback by monitoring power control loop commands from user terminals to determine which cell portions are beneficial for power transmission. The control unit analyzes these feedback signals to make informed decisions about power allocation, achieving improved power efficiency through intelligent, feedback-driven control rather than simple heuristic rules.

Inventive Principle:
Principle #23Feedback

Data Source

PatentEP3231226B1Radio link management in a combined cell
Publication Date: 2019.02.20 TELEFONAKTIEBOLAGET LM ERICSSON (PUBL)
  • EP3231226B1 patent drawingFigure 1
  • EP3231226B1 patent drawingFigure 2~3
  • EP3231226B1 patent drawingFigure 4~5

AI summary

The present disclosure relates to a CDMA communication node arrangement comprising at least two spatially separated antenna units, at least one radio unit and at least one control unit. Each antenna unit has at least one corresponding coverage area and is connected to the central unit. The control unit is arranged to alter transmitting properties of at least a first antenna unit, to a user terminal, such that more or less power is transmitted by the first antenna unit in a dedicated channel. The control unit is arranged to monitor received inner power control loop commands when at least a second antenna unit is communicating with the user terminal, and to determine whether said first antenna unit should start or stop communicating with the user terminal, or continue as before, based on how the inner power control loop commands respond. The present disclosure also relates to a corresponding method.