Inter-band Carrier Aggregation Power Control for IMD Management

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Solution Overview

Problem

Current technologies lack effective means to reliably control intermodulation distortion in inter-band multi-carrier capable devices, leading to desensitization issues during carrier aggregation, which affects coverage and transmission performance.

Innovation Solution

A method and apparatus for acquiring output power restriction values for cumulative output power in inter-band multi-carrier devices, enabling switching between carrier combination and single carrier transmission modes to manage intermodulation distortion, using combination-specific and band-specific power restriction values.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If carrier aggregation is used to improve transmission performance and coverage, then data rate and reliability are improved, but intermodulation distortion causes desensitization and performance degradation

Engineering Contradiction:

Improvedata rateVSAvoidintermodulation distortion

Core Design Contradiction:

ProductivityVSObject-affected harmful factors

Solution Approach 1:

The patent changes the power parameter by introducing combination-specific power restrictions that adjust the transmit power levels based on the specific band combination being used. This prevents intermodulation distortion by ensuring that the cumulative power across aggregated carriers does not exceed thresholds that would generate harmful IMD products, while still allowing carrier aggregation to function for improved data rates.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent implements a feedback mechanism where the device determines whether intermodulation distortion is occurring based on measurements and comparisons with predefined thresholds. When IMD is detected or predicted to occur, the system provides feedback to adjust power allocation or switch transmission modes, creating a closed-loop control system that dynamically manages the trade-off between carrier aggregation benefits and IMD avoidance.

Inventive Principle:

Principle #23Feedback

2Object-affected harmful factors

If power restriction is applied to reduce intermodulation distortion, then desensitization is avoided, but coverage and transmission performance deteriorate

Engineering Contradiction:

ImprovedesensitizationVSAvoidcoverage

Core Design Contradiction:

Object-affected harmful factorsVSReliability

Solution Approach 1:

The patent applies local quality by implementing power restrictions that are specific to each band combination rather than applying a uniform restriction across all carriers. Each band combination receives tailored power management based on its specific intermodulation risk profile, allowing optimal power allocation that avoids desensitization in vulnerable combinations while maintaining full power and coverage in combinations that are less susceptible to IMD.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The patent segments the power control mechanism into combination-specific power restrictions that are independently configured for different band combinations. This segmentation allows the system to apply restrictive power management only where necessary to prevent desensitization, while other band combinations can operate with more aggressive power settings to maintain coverage and reliability.

Inventive Principle:

Principle #1Segmentation

3Device complexity

If band-specific power restriction values are used for each carrier, then individual carrier power is controlled, but cumulative intermodulation distortion is not effectively managed

Engineering Contradiction:

Improvepower control granularityVSAvoidcumulative intermodulation distortion

Core Design Contradiction:

Device complexityVSObject-affected harmful factors

Solution Approach 1:

The patent merges the individual band-specific power restrictions into a cumulative combination-specific power restriction framework. Rather than treating each band independently, the system combines the power considerations across all aggregated carriers and applies a unified power restriction that accounts for the cumulative intermodulation effect. This ensures that the total power across the aggregation does not generate harmful IMD products, even if individual band restrictions are properly set.

Inventive Principle:

Principle #5Merging (Combining)

Data Source

PatentUS8462724B1Transmission mode control for inter-band multi-carrier capable devices

Publication Date: 2013.06.11 XIAOMI H K

AI summary

There are provided measures for enabling transmission mode control for inter-hand multi-carrier capable devices, such as inter-band carrier aggregation capable devices. Such measure may exemplarily include acquiring at least one output power restriction value for a cumulative output power for a combination of at least two uplink carriers of a terminal device. The two uplink carriers operate on different bands, at the terminal device, and perform transmission mode control in terms of switching between an uplink carrier combination transmission mode and a single uplink carrier transmission mode using the acquired at least one output power restriction value at the terminal device.