Uplink Power Control in Carrier Aggregation Systems

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Solution Overview

Problem

In wireless communication systems with carrier aggregation, there is no defined mechanism to allocate and control uplink transmit power across multiple component carriers, leading to challenges in managing competing power commands for PUCCH, PUSCH, and SRS when the total power exceeds the maximum transmit power of a component carrier or the user equipment.

Innovation Solution

A method that involves decoding transmit power control commands from downlink control channels, comparing them with the configured maximum transmit power of each component carrier, and adjusting the transmission of uplink channels accordingly to prevent exceeding the maximum power limits, prioritizing channels like PUCCH over PUSCH and SRS, and distributing power among component carriers based on priority and commanded power changes.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If carrier aggregation is used to aggregate multiple component carriers to support wider transmission bandwidths, then throughput is improved, but power management complexity increases and power allocation becomes undefined

Engineering Contradiction:
ImprovethroughputVSAvoidpower management complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The patent segments the power management problem by treating each component carrier separately. It divides the uplink channels into different categories (PUCCH, PUSCH, SRS) and assigns priority levels to each segment. The power allocation is performed in a segmented manner: first allocating power to PUCCH on the primary carrier, then to PUSCH channels, and finally to SRS, ensuring that each segment receives appropriate power while respecting the total power constraint.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent changes the power parameter dynamically based on channel priority and power availability. It introduces a priority-based power allocation mechanism where the transmit power for each channel is adjusted according to its priority level and the remaining power budget. This parameter change approach allows the system to adapt power distribution to varying channel conditions and quality requirements.

Inventive Principle:
Principle #35Parameter changes

2Reliability

If transmit power is increased to achieve desired quality of service, then data rate and error rate are improved, but interference to other users increases and battery life decreases

Engineering Contradiction:
Improvequality of serviceVSAvoidinterference to other users
Core Design Contradiction:
ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The patent dynamically adjusts transmit power parameters based on channel conditions and quality requirements. It uses closed-loop power control where the transmit power is continuously adapted according to feedback from the receiver, allowing the system to achieve the desired quality of service with minimum necessary power, thereby reducing interference to other users.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent applies different power allocation strategies to different uplink channels based on their specific quality requirements. PUCCH, which carries critical control information, receives higher priority and more robust power allocation compared to data channels like PUSCH. This local quality approach ensures that each channel receives appropriate power according to its specific quality-of-service requirements.

Inventive Principle:
Principle #3Local quality

3Area of stationary object

If power is allocated to multiple uplink channels on multiple component carriers, then channel coverage is improved, but the risk of exceeding maximum transmit power increases

Engineering Contradiction:
Improvechannel coverageVSAvoidpower limit compliance
Core Design Contradiction:
Area of stationary objectVSReliability

Solution Approach 1:

The patent performs preliminary power allocation calculations before actual transmission. It calculates the required power for each channel based on channel conditions and priority, then compares the total allocated power against the maximum transmit power limit. If the total exceeds the limit, the patent preemptively adjusts the power allocation according to channel priorities, ensuring that power limit compliance is maintained before transmission occurs.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent implements a feedback mechanism where the allocated power for each channel is monitored and adjusted based on the total power consumption. When the sum of power allocations approaches the maximum transmit power limit, the system provides feedback to reduce power allocation for lower-priority channels, ensuring that the total power remains within the configured maximum limit.

Inventive Principle:
Principle #23Feedback

Data Source

PatentEP2567580B1Uplink power control in aggregated carrier communication systems
Publication Date: 2016.11.09 QUALCOMM INC
  • EP2567580B1 patent drawingFigure 1
  • EP2567580B1 patent drawingFigure 2
  • EP2567580B1 patent drawingFigure 3

AI summary

A user equipment (UE) is configured for carrier aggregation in a wireless communication system. The UE decodes transmit power control commands from at least one downlink control channel for at least one uplink channel, where the at least one uplink channel is to be transmitted in a component carrier of a number of component carriers (401). The UE compares a commanded transmit power for the at least one uplink channel with a configured maximum transmit power of the component carrier (402) and transmits the at least one uplink channel in the component carrier (403).