SRS Frequency Allocation via DCI for Flexible Uplink Sounding

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Solution Overview

Problem

The existing SRS configuration in wireless communications networks is static and inflexible, leading to issues such as interference, frequency-selective fading, and limited bandwidth adaptation, which affects uplink coverage and capacity.

Innovation Solution

Implementing dynamic frequency domain resource assignment (FDRA) through DCI signaling to enable flexible SRS transmission bandwidth and resource allocation, allowing for more efficient use of frequency resources and improved coverage.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If static SRS configuration is used, then device complexity is reduced, but adaptability and frequency resource efficiency deteriorate

Engineering Contradiction:

Improvefrequency resource adaptationVSAvoidconfiguration complexity

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent implements dynamic SRS frequency resource allocation by allowing the network node to flexibly configure the frequency domain start position and length of SRS resources through RRC signaling and DCI triggering. This enables the SRS configuration to adapt to varying channel conditions and traffic requirements, transforming the static configuration into a dynamic one that can respond to changing network conditions while maintaining manageable complexity through standardized signaling procedures.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The patent changes key parameters of SRS frequency resources including the start position (freqDomainPosition), length (nrofSRS), and bandwidth (srs-Bandwidth) to optimize channel sounding performance. By allowing these parameters to be dynamically adjusted based on channel conditions, traffic type, and network requirements, the system achieves better adaptability without requiring complete redesign of the SRS configuration mechanism.

Inventive Principle:

Principle #35Parameter changes

2Measurement precision

If wider SRS bandwidth is allocated, then measurement precision is improved, but interference and frequency-selective fading effects worsen

Engineering Contradiction:

Improvechannel estimation accuracyVSAvoidfrequency-selective fading

Core Design Contradiction:

Measurement precisionVSObject-affected harmful factors

Solution Approach 1:

The patent segments the uplink bandwidth into multiple SRS frequency resources that can be independently configured and activated. Instead of using a single wideband SRS resource that suffers from frequency-selective fading, the system divides the bandwidth into smaller segments that can be selectively sounded based on channel conditions. This segmentation allows the network to focus measurements on frequency regions with better channel quality while avoiding severe fading regions.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent applies local quality by allowing different SRS frequency resources to be configured with different properties such as start position, length, and comb offset. This enables the network to optimize channel sounding for specific frequency regions where the channel quality is better, rather than uniformly sounding all frequency resources. The network can selectively activate SRS resources in frequency regions that provide sufficient measurement precision without being affected by severe fading in other regions.

Inventive Principle:

Principle #3Local quality

3Productivity

If dynamic frequency allocation is implemented, then productivity and resource efficiency are improved, but device complexity increases

Engineering Contradiction:

Improveuplink capacityVSAvoidsignaling processing complexity

Core Design Contradiction:

ProductivityVSDevice complexity

Solution Approach 1:

The patent implements a universal SRS configuration mechanism that can serve multiple functions including channel sounding, beam management, and link adaptation. By designing the frequency resource allocation to be flexible yet standardized, the same configuration framework can support different SRS usage scenarios (periodic, semi-persistent, and aperiodic) and different frequency resource patterns, reducing the need for separate specialized mechanisms for each function.

Inventive Principle:

Principle #6Universality (Multi-functionality)

Solution Approach 2:

The patent introduces standardized RRC signaling and DCI triggering as intermediary layers that manage the complexity of dynamic frequency allocation. These intermediary signaling mechanisms provide a structured interface between the network node and the wireless device, allowing complex frequency resource configurations to be conveyed through standardized message formats and procedures. This intermediary layer shields the device from implementing complex allocation logic directly, instead following well-defined signaling protocols that simplify the implementation while enabling flexible resource allocation.

Inventive Principle:

Principle #24Intermediary (Mediator)

Data Source

PatentUS12557083B2Wireless device, network node, and methods performed thereby, for configuring frequency allocation of sounding reference signals

Publication Date: 2026.02.17 TELEFONAKTIEBOLAGET LM ERICSSON (PUBL)

AI summary

A method performed by a wireless device of configuring uplink sounding transmissions is provided. The method includes receiving, from a network node, downlink control information, DCI. The DCI triggering a SRS transmission and includes a configuration parameter for uplink sounding reference signal, SRS, transmissions for the wireless device. The DCI further includes frequency domain resource assignment, FDRA, that indicates the frequency allocation for the triggered SRS transmission. The method further includes generating a sounding reference signal based on the received DCI. Methods performed by a network node is also provided.