Localized SRS Transmission for PAPR Reduction and Multiplexing

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Solution Overview

Problem

In wireless communication systems, especially in new radio access technologies, there is a need for efficient SRS transmission methods that minimize resource waste and peak-to-average power ratio (PAPR) issues, while allowing for flexible multiplexing of uplink channels to support enhanced mobile broadband, massive Machine Type Communications, and Ultra-Reliable and Low Latency Communications.

Innovation Solution

The method involves transmitting localized SRS and uplink control channels in specific symbols, with control information providing details on starting positions and bandwidths, and using patterns to prevent overlap between transmission bands, allowing for flexible SRS transmission based on received patterns from the base station.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If SRS is transmitted over wide bandwidth to improve channel estimation accuracy, then measurement precision is improved, but peak-to-average power ratio increases causing power amplifier inefficiency

Engineering Contradiction:
Improvechannel estimation accuracyVSAvoidpeak-to-average power ratio
Core Design Contradiction:
Measurement precisionVSUse of energy by moving object

Solution Approach 1:

The patent divides the wideband SRS transmission into multiple localized SRS transmissions across different subframes. Each localized SRS occupies a specific frequency subset, allowing the terminal to transmit SRS sequentially across the full bandwidth without simultaneous wideband transmission, thereby reducing PAPR while maintaining overall channel estimation coverage.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent implements periodic localized SRS transmission patterns where SRS is transmitted in a distributed manner across multiple subframes. This periodic distribution allows the terminal to use lower instantaneous power in each subframe while collectively covering the full bandwidth over time, reducing peak power requirements.

Inventive Principle:
Principle #19Periodic action

2Productivity

If multiple uplink channels are multiplexed in the same time-frequency resources to improve resource utilization, then productivity is improved, but interference between channels increases affecting reliability

Engineering Contradiction:
Improveresource utilizationVSAvoidchannel multiplexing interference
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The patent applies local quality by assigning different frequency subsets to different uplink channels within the same subframe. The localized SRS occupies specific resource blocks that are distinct from those used by other uplink channels, allowing spatial-frequency separation that reduces interference while maintaining high resource utilization through localized rather than wideband occupation.

Inventive Principle:
Principle #3Local quality

3Use of energy by moving object

If localized SRS transmission is used to reduce PAPR and improve power efficiency, then use of energy is improved, but the degree of freedom for multiplexing is reduced

Engineering Contradiction:
Improvepower efficiencyVSAvoidmultiplexing flexibility
Core Design Contradiction:
Use of energy by moving objectVSAdaptability or versatility

Solution Approach 1:

The patent introduces dynamic adaptability by allowing the network to configure different localized SRS transmission patterns based on traffic conditions and channel characteristics. The transmission pattern, frequency subset, and subframe selection can be dynamically adjusted through RRC signaling, enabling the system to optimize between power efficiency and multiplexing flexibility depending on operational requirements.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent creates a universal localized SRS framework that can serve multiple functions: channel estimation, beam management, and resource allocation feedback. The same localized SRS mechanism can be adapted for different uplink channel types and transmission scenarios, providing multi-functionality that maintains versatility while preserving power efficiency benefits.

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

Data Source

PatentEP3588884B1Method for transmitting SRS in wireless communication system and terminal for same
Publication Date: 2022.08.03 LG ELECTRONICS INC
  • EP3588884B1 patent drawingFigure 1
  • EP3588884B1 patent drawingFigure 2a
  • EP3588884B1 patent drawingFigure 2b

AI summary

A method for transmitting a sounding reference symbol (SRS) by a terminal in a wireless communication system can comprise the steps of: receiving, from a base station, control information comprising a first indicator for indicating localized SRS transmission; and transmitting a localized SRS in a particular symbol on the basis of the first indicator.