Common SRS Sequences for LTE NR Spectrum Sharing

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Solution Overview

Problem

Current spectrum sharing techniques between LTE and NR require separate SRS processes, leading to inefficient use of PRBs in the uplink shared spectrum, resulting in additional PRBs being reserved for over-the-air transmission.

Innovation Solution

Implementing a common set of SRS sequences for both LTE and NR wireless devices, allowing the reserved PRBs to be allocated to PUSCH and PUCCH instead, thereby optimizing resource usage.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If separate SRS processes are implemented for LTE and NR, then channel estimation functionality is maintained for both systems, but the number of PRBs reserved for sounding increases, reducing spectrum efficiency

Engineering Contradiction:
Improvechannel estimation functionalityVSAvoidnumber of PRBs reserved for sounding
Core Design Contradiction:
ReliabilityVSQuantity of substance

Solution Approach 1:

The patent merges the SRS processes of LTE and NR into a unified framework where a single SRS sequence can serve both systems. By combining the separate SRS transmissions into a shared resource pool, the patent reduces the total number of PRBs required while maintaining channel estimation functionality for both LTE and NR devices through coordinated resource allocation and sequence design.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The patent implements universal SRS sequences that can function for both LTE and NR channel estimation purposes. The SRS resources are designed with multi-functionality, allowing the same physical resource blocks to be utilized by both LTE and NR devices for sounding, thereby eliminating the need for dedicated separate PRB allocations for each system.

Inventive Principle:
Principle #6Universality (Multi-functionality)

2Adaptability or versatility

If separate SRS processes are implemented for LTE and NR, then each system can independently perform uplink channel-dependent scheduling, but resource utilization efficiency in the uplink shared spectrum decreases

Engineering Contradiction:
Improveindependent channel-dependent schedulingVSAvoidresource utilization efficiency
Core Design Contradiction:
Adaptability or versatilityVSProductivity

Solution Approach 1:

The patent introduces dynamic resource allocation mechanisms where SRS resources are flexibly assigned based on real-time network conditions, device types, and traffic demands. The system can dynamically switch between dedicated and shared SRS configurations, allowing adaptive optimization of resource utilization while maintaining the capability for independent channel-dependent scheduling when required.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent utilizes parameter changes in SRS configuration, including cyclic shifts, comb patterns, and resource block assignments, to enable multiple devices and systems to share the same physical resources. By varying these parameters, the system maintains independent scheduling capabilities for LTE and NR while achieving efficient resource utilization through shared PRB pools.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP4052403B1Sharing of sounding reference signals (SRS) resources between new radio and long term evolution
Publication Date: 2025.03.26 TELEFONAKTIEBOLAGET LM ERICSSON (PUBL)
  • EP4052403B1 patent drawingFigure 1
  • EP4052403B1 patent drawingFigure 2
  • EP4052403B1 patent drawingFigure 3~4

AI summary

A method, system and apparatus are disclosed. According to one or more embodiments, a network node (16) is provided. The network node includes processing circuitry (68) configured to: assign a plurality of wireless devices (22) respective sounding reference signal, SRS, sequences of a common set of SRS sequences where the common set of SRS sequences are shared among a first radio access technology, RAT, and a second RAT, and receive SRS sequences according to the assignment of the respective SRS sequences of the common set of SRS sequences.