Uplink Control Information Transmission in Multi-Carrier Systems

Solution Overview

Problem

In multi-carrier wireless communication systems, particularly in LTE-A, transmitting multiple uplink control information bits, such as ACK/NACK, across multiple carriers using conventional methods results in increased power consumption and peak-to-average power ratio (PAPR), reducing coverage due to inefficient power utilization and potential collisions with CQI transmission.

Innovation Solution

The method involves using PUCCH formats 2/2a/2b with channel coding and block spreading to transmit multiple ACK/NACK bits, allowing for efficient multiplexing and bundling while preserving the single-carrier property, and employing explicit channel selection to optimize resource allocation, thereby reducing power requirements and maintaining coverage.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of information

If multiple ACK/NACK bits are transmitted using conventional methods in multi-carrier system, then the control information can be transmitted across multiple carriers, but the power consumption and peak-to-average power ratio (PAPR) increase

Engineering Contradiction:

Improvecontrol information transmissionVSAvoidpower consumption

Core Design Contradiction:

Loss of informationVSUse of energy by moving object

Solution Approach 1:

The patent combines multiple ACK/NACK bits into a single uplink control information message that is transmitted through one uplink component carrier. Instead of transmitting separate control signals on multiple carriers, the invention aggregates the control information and sends it through a single carrier, thereby reducing power consumption and PAPR while maintaining the ability to convey acknowledgment status for multiple downlink carriers.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The patent enables a single uplink component carrier to perform multiple functions by transmitting aggregated control information for multiple downlink carriers. This uplink carrier universally handles ACK/NACK transmission for various downlink carriers, eliminating the need for separate dedicated control carriers and reducing overall system power requirements.

Inventive Principle:

Principle #6Universality (Multi-functionality)

2Loss of information

If multiple ACK/NACK bits are transmitted using conventional methods in multi-carrier system, then the control information can be transmitted across multiple carriers, but the peak-to-average power ratio (PAPR) increases

Engineering Contradiction:

Improvecontrol information transmissionVSAvoidpeak-to-average power ratio

Core Design Contradiction:

Loss of informationVSPower

Solution Approach 1:

The patent combines multiple ACK/NACK bits into a single uplink control information message that is transmitted through one uplink component carrier. Instead of transmitting separate control signals on multiple carriers, the invention aggregates the control information and sends it through a single carrier, thereby reducing power consumption and PAPR while maintaining the ability to convey acknowledgment status for multiple downlink carriers.

Inventive Principle:

Principle #5Merging (Combining)

3Loss of information

If multiple ACK/NACK bits are transmitted using conventional methods in multi-carrier system, then the control information can be transmitted across multiple carriers, but collisions with CQI transmission may occur

Engineering Contradiction:

Improvecontrol information transmissionVSAvoidtransmission collision

Core Design Contradiction:

Loss of informationVSReliability

Solution Approach 1:

The patent combines multiple ACK/NACK bits into a single uplink control information message that is transmitted through one uplink component carrier. Instead of transmitting separate control signals on multiple carriers, the invention aggregates the control information and sends it through a single carrier, thereby reducing power consumption and PAPR while maintaining the ability to convey acknowledgment status for multiple downlink carriers.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The patent resolves resource conflicts by separating control information types in the frequency dimension. CQI transmissions occur on specific downlink carriers while ACK/NACK transmissions occur on uplink carriers, creating a dimensional separation that eliminates collisions between these control signal types.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

Data Source

PatentEP2495900B1Uplink control information transmission method and apparatus in multi-carrier system

Publication Date: 2019.03.06 LG ELECTRONICS INC

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AI summary

A method for transmitting uplink control information of a user equipment in a multi-carrier system is provided. The method includes: transmitting each of acknowledgement/not-acknowledgement (ACK/NACK) for downlink data transmitted by a base station through multiple downlink component carriers; and transmitting channel state information indicating a state of a downlink channel to the base station, wherein each of the ACK/NACK and the channel state information are allocated to the same uplink control channel resource in a subframe, and if each of the ACK/NACK and the channel state information are reserved to be transmitted on the same subframe, each of the ACK/NACK only is transmitted. Accordingly, a user equipment can transmit uplink control information while preserving a single-carrier property of an uplink signal in a multi-carrier system using carrier aggregation.