Sounding Reference Signal Multiplexing in LTE Carrier Aggregation

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Solution Overview

Problem

Current radio communication systems, particularly in LTE and LTE-Advanced, face challenges in efficiently transmitting sounding reference signals from user equipment to base stations, especially in wideband systems that utilize carrier aggregation, where existing methods do not effectively manage the multiplexing of periodic and additional sounding reference signals.

Innovation Solution

The method involves multiplexing periodic and additional sounding reference signals using different repetition factors, subframe offset values, and time division multiplexing to efficiently allocate resources, ensuring effective transmission across various bandwidth configurations and duplex schemes.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If periodic and additional sounding reference signals are transmitted using the same resources, then resource allocation is simplified, but signal interference and transmission reliability deteriorate

Engineering Contradiction:
Improveresource allocation complexityVSAvoidsignal transmission reliability
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The patent segments the transmission resources for periodic and additional sounding reference signals by applying different repetition factors. Periodic signals use one repetition factor while additional signals use another, effectively dividing the resource space to avoid interference while maintaining manageable allocation complexity

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent introduces a new dimension for resource differentiation by using repetition factors as an additional resource dimension beyond time and frequency. This allows periodic and additional signals to be distinguished and separated in the repetition factor domain, resolving the contradiction between simple allocation and reliable transmission

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Productivity

If carrier aggregation is used to expand bandwidth, then system capacity increases, but maintaining single carrier properties becomes more difficult

Engineering Contradiction:
Improvesystem bandwidth capacityVSAvoidsingle carrier property stability
Core Design Contradiction:
ProductivityVSStability of the object's composition

Solution Approach 1:

The patent applies different repetition factor configurations to different signal types (periodic vs. additional) within the carrier aggregation framework. This local differentiation allows each signal to maintain its required properties while operating within the aggregated bandwidth, preserving single carrier properties where needed

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The patent changes the repetition factor parameter differently for periodic and additional sounding reference signals. By adjusting this parameter locally for different signal types, the system can support wideband carrier aggregation while maintaining the stability of single carrier properties for specific signal transmissions

Inventive Principle:
Principle #35Parameter changes

3Productivity

If multiple sounding reference signals are multiplexed in the same time-frequency resources, then resource efficiency improves, but signal detection accuracy deteriorates

Engineering Contradiction:
Improveresource utilization efficiencyVSAvoidsignal detection accuracy
Core Design Contradiction:
ProductivityVSMeasurement precision

Solution Approach 1:

The patent dynamically assigns different repetition factors to periodic and additional sounding reference signals based on their respective requirements. This dynamic parameter assignment enables efficient resource multiplexing while maintaining sufficient detection accuracy by adapting the repetition pattern to each signal type's characteristics

Inventive Principle:
Principle #15Dynamics

Data Source

PatentEP2432292B1Method and apparatus for transmitting sounding reference signal in radio communication system
Publication Date: 2019.07.10 LG ELECTRONICS INC
  • EP2432292B1 patent drawingFigure 1
  • EP2432292B1 patent drawingFigure 2(a)~2(b)
  • EP2432292B1 patent drawingFigure 3

AI summary

Disclosed is a method for transmitting a sounding reference signal from to a base station in a radio communication system. More specifically, the method comprises the steps of: transmitting a periodic sounding reference signal to a base station; receiving a transmission instruction for an additional sounding reference signal from the base station; multiplexing said periodic sounding reference signal and said additional sounding reference signal along a frequency axis or a time axis; and transmitting said multiplexed periodic sounding reference signal and said additional sounding reference signal to said base station. Said multiplexing step is characterized by multiplexing said periodic sounding reference signal and said additional sounding reference signal along a frequency axis or a time axis.