UCI Multiplexing on PUSCH for TDD Overhead Reduction

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Solution Overview

Problem

In TDD wireless communication networks, the strict separation of HARQ feedback from user data introduces excessive overhead delay, which could otherwise be used to improve the effective user plane bitrate.

Innovation Solution

A radio network device transmits Uplink Control Information (UCI) on the same physical uplink channel as data, allowing for flexible allocation of frequency resources and encoding schemes to facilitate early decoding and reduce overhead.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If HARQ feedback is strictly separated from user data in TDD configurations, then control plane signaling is maintained, but excessive overhead delay is introduced into the communication

Engineering Contradiction:
Improvecontrol plane signalingVSAvoidoverhead delay
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The patent merges HARQ feedback (control plane signaling) with user data transmission by allowing UCI to be multiplexed onto the PUSCH. This combining approach eliminates the need for separate control channel transmissions, thereby reducing overhead delay while maintaining reliable control signaling through the integrated transmission mechanism.

Inventive Principle:
Principle #5Merging (Combining)

2Loss of time

If HARQ feedback is multiplexed on PUSCH, then overhead delay is reduced, but resource allocation complexity increases

Engineering Contradiction:
Improveoverhead delayVSAvoidresource allocation
Core Design Contradiction:
Loss of timeVSDevice complexity

Solution Approach 1:

The patent segments the PUSCH resources by allocating specific resource elements for UCI transmission within the data channel. This segmentation approach structures the resource allocation process, dividing control and data resources into distinct portions with specific allocation rules, thereby managing complexity through organized resource division rather than unstructured sharing.

Inventive Principle:
Principle #1Segmentation

3Productivity

If UCI and data are transmitted together on the same physical uplink channel, then effective user plane bitrate is improved, but encoding complexity increases

Engineering Contradiction:
Improveeffective user plane bitrateVSAvoidencoding
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The patent applies preliminary encoding and mapping operations to UCI before multiplexing with data on the PUSCH. By preparing the control information in advance with specific encoding schemes and resource mapping rules, the system simplifies the overall transmission process and reduces real-time encoding complexity while maintaining improved effective bitrate through efficient resource utilization.

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentEP3764583B1Scheduled UCI transmission scheme
Publication Date: 2025.05.21 TELEFONAKTIEBOLAGET LM ERICSSON (PUBL)
  • EP3764583B1 patent drawingFigure 1
  • EP3764583B1 patent drawingFigure 2
  • EP3764583B1 patent drawingFigure 3

AI summary

A radio network device is operative to transmit uplink data on a physical uplink shared channel aggregating two or more contiguous slots. The device is further operative to transmit, in addition to the uplink data, Uplink Control Information (UCI) in at least one of the aggregated slots. The UCI may comprise a HARQ ACK/NACK. The UCI is configured in response to Downlink Control Information (DCI) received from a serving network node. The DCI also includes a UL scheduling grant for the physical uplink channel. The UCI may be configured in the physical uplink channel transmission in a variety of ways. Various amounts of frequency resource (e.g., subcarriers) may be allocated to UCI. The subcarriers may be non-contiguous. In slot aggregation, the UCI subcarriers may frequency hop from slot to slot. The UCI may be encoded differently in different slots, to facilitate early decoding by a receiver (which may, for example immediately prepare a re-transmission in the case of a NACK).