Cyclic Redundancy Check for UCI in Carrier Aggregation

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Solution Overview

Problem

The reliability of transmitting uplink control information (UCI) in wireless communication systems, particularly in shared radio frequency spectrum bands, is compromised due to hidden node interference and resource allocation challenges, leading to suboptimal performance compared to dedicated spectrum bands.

Innovation Solution

Incorporating a cyclic redundancy check (CRC) for UCI transmission on control and data channels, especially in scenarios involving carrier aggregation and dual-connectivity modes, to enhance the reliability and error management of UCI, particularly for ACK/NAK information, by conditionally protecting it with a CRC based on payload size and channel configurations.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If UCI is transmitted on shared radio frequency spectrum bands, then data transmission capacity is enhanced, but transmission reliability deteriorates due to hidden node interference

Engineering Contradiction:

Improvedata transmission capacityVSAvoidtransmission reliability

Core Design Contradiction:

ProductivityVSReliability

Solution Approach 1:

A CRC (cyclic redundancy check) sequence is introduced as an intermediary error detection mechanism. The CRC sequence is attached to the UCI payload before transmission, enabling the receiver to detect transmission errors caused by hidden node interference in shared spectrum bands, thus resolving the reliability issue while maintaining the productivity benefits of shared spectrum usage

Inventive Principle:

Principle #24Intermediary (Mediator)

2Reliability

If CRC is always attached to UCI, then transmission reliability is improved, but overhead and resource efficiency deteriorate

Engineering Contradiction:

Improvetransmission reliabilityVSAvoidoverhead

Core Design Contradiction:

ReliabilityVSLoss of information

Solution Approach 1:

Instead of applying CRC to all UCI transmissions, the patent applies CRC selectively based on the UCI payload size. When the payload size exceeds a threshold (e.g., 11 bits), CRC is attached; when it is below the threshold, CRC is omitted. This partial application of error protection reduces overhead while maintaining reliability for larger, more critical payloads

Inventive Principle:

Principle #16Partial or excessive action

3Productivity

If multiple component carriers are used in parallel, then data transmission capacity is enhanced, but system complexity deteriorates

Engineering Contradiction:

Improvedata transmission capacityVSAvoidsystem complexity

Core Design Contradiction:

ProductivityVSDevice complexity

Solution Approach 1:

The patent implements a universal CRC attachment mechanism that works across multiple component carriers and different UCI types (ACK/NAK, CSI, SR). The same CRC generation and verification process is applied regardless of which component carrier or UCI type is involved, simplifying the complexity management in multi-carrier systems while maintaining enhanced data transmission capacity

Inventive Principle:

Principle #6Universality (Multi-functionality)

Data Source

PatentEP3304792B1Cyclic redundancy check for uplink control information on control and data channels

Publication Date: 2024.04.17 QUALCOMM INC

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AI summary

Methods, systems, and devices are described for wireless communication. One method includes identifying uplink control information (UCI) for a component carrier (CC) of a carrier aggregation (CA) configuration which may include a primary cell (PCell) and, in some aspects, a physical uplink control channel (PUCCH) enabled secondary cell (SCell); determining to include cyclic redundancy check (CRC) information for the UCI based at least in part on a UCI characteristic or an uplink control channel format; and transmitting an uplink channel comprising the UCI and the CRC information.