Dynamic SRS Waveform Selection in New Radio Uplink

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Solution Overview

Problem

Current wireless communication systems, particularly those using new radio (NR) technology, face challenges in efficiently transmitting sounding reference signals (SRS) due to limitations in waveform selection, which affects uplink channel quality measurement and resource utilization.

Innovation Solution

The system determines whether to use a discrete Fourier transform spread orthogonal frequency domain multiplexing (DFT-S-OFDM) or cyclic prefix orthogonal frequency domain multiplexing (CP-OFDM) waveform for SRS transmission, allowing for dynamic selection based on channel conditions and resource availability, enabling efficient frequency multiplexing with physical uplink shared channels.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If a single waveform type is used for SRS transmission, then device complexity is reduced, but adaptability to different channel conditions deteriorates

Engineering Contradiction:

Improvewaveform selection complexityVSAvoidadaptability to channel conditions

Core Design Contradiction:

Device complexityVSAdaptability or versatility

Solution Approach 1:

The patent implements dynamic waveform selection where the UE can switch between DFT-S-OFDM and CP-OFDM waveforms based on channel conditions and network configuration. The network dynamically indicates which waveform the UE should use for SRS transmission, allowing the system to adapt to varying channel characteristics without permanently increasing device complexity.

Inventive Principle:

Principle #15Dynamics

2Measurement precision

If DFT-S-OFDM waveform is used for SRS transmission, then uplink channel quality measurement is improved, but resource utilization efficiency deteriorates

Engineering Contradiction:

Improveuplink channel quality measurementVSAvoidresource utilization efficiency

Core Design Contradiction:

Measurement precisionVSProductivity

Solution Approach 1:

The patent changes the waveform parameter from a fixed type to a dynamically selectable type. By allowing switching between DFT-S-OFDM (better for channel measurement) and CP-OFDM (better for resource efficiency), the system can optimize the parameter based on current transmission requirements rather than being constrained by a single waveform type.

Inventive Principle:

Principle #35Parameter changes

3Productivity

If waveform selection is restricted to improve resource utilization, then resource utilization efficiency is improved, but uplink channel quality measurement capability deteriorates

Engineering Contradiction:

Improveresource utilization efficiencyVSAvoiduplink channel quality measurement

Core Design Contradiction:

ProductivityVSMeasurement precision

Solution Approach 1:

The patent makes the SRS transmission system universal by supporting multiple waveform types (both DFT-S-OFDM and CP-OFDM). This multi-functionality allows the same SRS mechanism to serve different purposes: DFT-S-OFDM for accurate channel quality measurement and CP-OFDM for efficient resource utilization, depending on what the network requires at any given time.

Inventive Principle:

Principle #6Universality (Multi-functionality)

Data Source

PatentUS11483107B2Transmitting sounding reference signals in new radio

Publication Date: 2022.10.25 QUALCOMM INC

AI summary

Certain aspects of the present disclosure relate to methods and apparatus for transmitting sounding reference signals (SRS) in communications systems operating according to new radio (NR) technologies. An exemplary method that a user equipment (UE) may perform includes determining whether to transmit a sounding reference signal (SRS) using a discrete Fourier transform (DFT) spread orthogonal frequency domain multiplexing (DFT-S-OFDM) waveform or a cyclic prefix orthogonal frequency domain multiplexing (CP-OFDM) waveform, and transmitting the SRS using the determined waveform.