Cell-Specific CRS Muting for efeMTC Interference and Power Efficiency

Solution Overview

Problem

Existing LTE networks face challenges in minimizing inter-cell interference and optimizing power consumption for low-complexity UEs in even further enhanced Machine Type Communication (efeMTC), particularly in bandwidth-reduced scenarios, which affects downlink throughput and connection stability.

Innovation Solution

Implementing cell-specific reference signal (CRS) muting techniques, including frequency and time domain muting, based on UE capability signaling to reduce unnecessary CRS transmissions, thereby optimizing network power usage and reducing inter-cell interference.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If CRS transmissions are continued in all frequency resources, then channel estimation accuracy is maintained, but inter-cell interference increases and power consumption rises

Engineering Contradiction:

Improvechannel estimation accuracyVSAvoidinter-cell interference

Core Design Contradiction:

Measurement precisionVSObject-affected harmful factors

Solution Approach 1:

The patent applies local quality by making CRS muting configuration UE-specific and bandwidth-part-specific. Different UEs receive different muting patterns based on their capability indications, allowing the system to optimize channel estimation locally for each UE while reducing overall interference. The network configures muting patterns that are tailored to individual UE requirements rather than applying uniform muting across all UEs.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The patent changes the parameter of CRS transmission by introducing muting patterns that selectively zero out CRS in specific resource elements. The muting pattern is dynamically configured based on UE capability indications, transforming the CRS transmission from a static full-bandwidth signal to a dynamically adjusted signal with selective muting, thereby reducing interference while maintaining necessary channel estimation capability.

Inventive Principle:

Principle #35Parameter changes

2Measurement precision

If CRS transmissions are continued in all frequency resources, then channel estimation accuracy is maintained, but network power consumption increases

Engineering Contradiction:

Improvechannel estimation accuracyVSAvoidnetwork power consumption

Core Design Contradiction:

Measurement precisionVSUse of energy by stationary object

Solution Approach 1:

The patent applies local quality by making CRS muting configuration UE-specific and bandwidth-part-specific. Different UEs receive different muting patterns based on their capability indications, allowing the system to optimize channel estimation locally for each UE while reducing overall interference. The network configures muting patterns that are tailored to individual UE requirements rather than applying uniform muting across all UEs.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The patent changes the parameter of CRS transmission by introducing muting patterns that selectively zero out CRS in specific resource elements. The muting pattern is dynamically configured based on UE capability indications, transforming the CRS transmission from a static full-bandwidth signal to a dynamically adjusted signal with selective muting, thereby reducing interference while maintaining necessary channel estimation capability.

Inventive Principle:

Principle #35Parameter changes

3Loss of energy

If CRS muting is applied in bandwidth-reduced scenarios, then power efficiency improves and interference reduces, but downlink throughput may be affected

Engineering Contradiction:

Improvepower efficiencyVSAvoiddownlink throughput

Core Design Contradiction:

Loss of energyVSProductivity

Solution Approach 1:

The patent applies dynamics by making the CRS muting configuration adaptive rather than static. The muting pattern is dynamically adjusted based on UE capability indications received from each UE. This allows the system to optimize the balance between power efficiency and throughput for each UE individually, applying muting only where and when it is beneficial while maintaining throughput where full CRS coverage is needed.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The patent segments the bandwidth into different parts with different muting configurations. By dividing the available bandwidth and applying different muting patterns to different bandwidth parts based on UE capability, the system can maintain high throughput in critical bandwidth regions while applying aggressive muting in less critical regions, thus balancing power efficiency and overall throughput.

Inventive Principle:

Principle #1Segmentation

Data Source

PatentEP4138334B1Design of cell specific reference signal (CRS) muting for even further enhanced machine type communication (efemtc)

Publication Date: 2025.07.23 APPLE INC

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AI summary

A network device such as an evolved NodeB (eNB) or next generation NodeB (gNB) can configure a set of user equipment (UE) for cell reference signal (CRS) muting in order to provide better channel quality and power efficiency in communications. Where an eNB mutes CRS transmissions that are not needed by any UE, an improvement in downlink throughput and reduce connection drop rate can be generated. A CRS muting capability can be determined based on a user equipment (UE) capability information. According to the CRS muting capability of a UE, CRS muting can be generated in a physical channel outside of a narrow band (NB) or a wide band (WB) plus / minus X physical resource blocks (PRBs), wherein X is a non-negative integer, based on the CRS muting capability.