Configured Uplink Starting Positions for Unlicensed Spectrum

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Solution Overview

Problem

In the New Radio (NR) standard, there is a challenge in detecting the start of a configured uplink transmission in unlicensed spectrum without significantly increasing the processing burden on the network node, especially since the gNB does not know when the UE will transmit on configured UL resources, leading to difficulties in verifying valid UL transmissions early and enhancing channel access granularity.

Innovation Solution

The solution involves configuring multiple starting points for configured UL transmissions via RRC, using a PUSCH starting position bitmap or PUSCH symbol indices, and employing front-loaded DMRS to mark the start of transmission, allowing UCI mapping to begin immediately after, with UCI coded symbols calculated independently of the actual PUSCH length, and adapting the transport block size based on listen-before-talk outcomes.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If the gNB waits to detect the start of configured UL transmission, then it can verify valid transmissions, but the processing time is insufficient and detection is delayed

Engineering Contradiction:

Improvedetection accuracy of UL transmission startVSAvoidprocessing time for demodulation/decoding

Core Design Contradiction:

Measurement precisionVSLoss of time

Solution Approach 1:

The gNB performs preliminary actions by preparing demodulation and decoding resources in advance based on the configured starting positions. The network node pre-configures multiple possible starting points for UL transmissions, allowing it to prepare processing resources beforehand rather than waiting until transmission actually begins, thus reducing processing time while maintaining detection accuracy.

Inventive Principle:

Principle #10Preliminary action

2Measurement precision

If the gNB monitors all possible UL transmission starting positions, then it can detect transmissions accurately, but the processing burden increases significantly

Engineering Contradiction:

Improvedetection accuracy of UL transmission startVSAvoidprocessing burden on network node

Core Design Contradiction:

Measurement precisionVSDevice complexity

Solution Approach 1:

The gNB segments the monitoring task by focusing only on specific configured starting positions rather than monitoring all possible positions. The network node divides the uplink time resources into discrete configured starting positions, and only monitors at these segmented points, reducing the overall processing burden while maintaining accurate detection capability at the relevant positions.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The gNB applies local quality by concentrating monitoring resources at the specific configured starting positions where UL transmissions are expected to occur. Rather than uniformly monitoring all time positions, the network node intensifies monitoring effort locally at the configured starting points, achieving accurate detection with reduced overall processing burden.

Inventive Principle:

Principle #3Local quality

3Device complexity

If single starting position is used for configured UL, then the configuration is simple, but channel access granularity is limited

Engineering Contradiction:

Improveconfiguration complexityVSAvoidchannel access granularity

Core Design Contradiction:

Device complexityVSAdaptability or versatility

Solution Approach 1:

The system transitions from a static single starting position to dynamic multiple starting positions. The network node configures multiple possible starting positions for UL transmissions, allowing the actual starting position to be dynamically selected based on channel access outcomes. This dynamic approach enhances channel access granularity while maintaining manageable configuration complexity through efficient representation methods.

Inventive Principle:

Principle #15Dynamics

4Adaptability or versatility

If multiple starting points are configured for UL transmissions, then channel access granularity is enhanced, but the processing burden on network node increases

Engineering Contradiction:

Improvechannel access granularityVSAvoidprocessing burden on network node

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The gNB performs partial monitoring by focusing only on the configured starting positions that are actually needed, rather than monitoring all possible starting positions. This partial action approach provides sufficient channel access granularity by monitoring at the necessary configured points without the excessive processing burden of comprehensive monitoring at all possible positions.

Inventive Principle:

Principle #16Partial or excessive action

Data Source

PatentUS12137448B2Configured uplink for unlicensed operation

Publication Date: 2024.11.05 TELEFONAKTIEBOLAGET LM ERICSSON (PUBL)

AI summary

A method performed by a wireless device (110) includes receiving a configuration for one or more data transmission starting positions for a configured uplink, UL, in unlicensed spectrum. The one or more data transmission starting positions include at least a first starting position. The method further includes performing an UL transmission at one of the one or more data transmission starting positions based on when the wireless device is able to access a channel. The UL transmission includes UL control information, UCI, multiplexed in a Physical Uplink Shared Channel, PUSCH. The UCI carries one or more parameters for unlicensed spectrum.