Uplink Control Information Reporting Using CAZAC Codes

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Solution Overview

Problem

Conventional methods for reporting uplink control information in next-generation mobile communication systems are inefficient, particularly for acknowledgment information, which requires high quality but is limited to a single bit, making it difficult to obtain coding gain and requiring resource allocation through downlink L1/L2 control signals.

Innovation Solution

A user apparatus uses a single carrier scheme to efficiently report uplink control information by employing CAZAC codes and block spread codes, allowing for orthogonal transmission of control signals, thereby reducing the need for frequent resource allocation and enhancing the quality of acknowledgment information transmission.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If acknowledgment information is transmitted using a single bit, then the transmission overhead is reduced, but the reliability and quality of transmission deteriorates

Engineering Contradiction:
Improvenumber of bits for acknowledgment informationVSAvoidquality of acknowledgment information transmission
Core Design Contradiction:
Quantity of substanceVSReliability

Solution Approach 1:

The patent changes the parameter of acknowledgment information from a single bit to multiple bits by introducing virtual acknowledgments. This allows the system to maintain the simplicity of single-bit transmission while achieving the reliability of multi-bit transmission through codebook-based selection and implicit signaling mechanisms.

Inventive Principle:
Principle #35Parameter changes

2Adaptability or versatility

If downlink L1/L2 control signals are used to allocate resources for uplink control information, then resource allocation flexibility is improved, but signaling overhead and processing complexity increase

Engineering Contradiction:
Improveresource allocation flexibilityVSAvoidsignaling overhead
Core Design Contradiction:
Adaptability or versatilityVSLoss of information

Solution Approach 1:

The patent extracts the resource allocation information from downlink L1/L2 control signals and embeds it directly in the uplink control information transmission. By using the physical uplink control channel resources and codebook structures already allocated, the system eliminates the need for separate resource allocation signaling, thereby reducing overhead while maintaining flexibility.

Inventive Principle:
Principle #2Taking out (Extraction)

3Reliability

If frequent resource allocation is performed for uplink control information, then transmission quality is improved, but system efficiency and throughput deteriorate

Engineering Contradiction:
Improvetransmission quality of control informationVSAvoiddata throughput
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The patent performs preliminary action by pre-configuring codebooks and resource structures for uplink control information transmission. The base station and user equipment prepare the acknowledgment codebooks and resource mappings in advance, allowing multiple acknowledgments to be transmitted using pre-allocated resources without requiring frequent re-allocation, thus maintaining high transmission quality while improving system efficiency.

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentEP2129158B1User device, system, and method in mobile communication system
Publication Date: 2016.10.12 NTT DOCOMO INC
  • EP2129158B1 patent drawingFigure 1
  • EP2129158B1 patent drawingFigure 2
  • EP2129158B1 patent drawingFigure 3

AI summary

A user apparatus transmits an uplink control signal to a base station apparatus using a single carrier scheme. The user apparatus includes: a unit configured to receive a downlink control signal and a downlink data signal; a unit configured to prepare acknowledgement information indicating positive acknowledgement or negative acknowledgement for the downlink data signal; a unit configured to prepare the uplink control signal including the acknowledgement information; a unit configured to transmit the uplink control signal using different resources which are different from resources that can be used for an uplink data signal; and a storage unit configured to store predetermined correspondence relationship which uniquely associates resources of the downlink control signal or the downlink data signal with resources used for the uplink control signal.