Terminal CQI Transmission Scheduling During DRX Transitions

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Solution Overview

Problem

In mobile communication systems, particularly in LTE, the sudden termination of active time during discontinuous reception (DRX) leads to inefficiencies in CSI/SRS transmission, causing potential double decoding and increased power consumption, which complicates terminal operation and increases costs.

Innovation Solution

The method involves scheduling CQI transmission on the Physical Uplink Control Channel (PUCCH) at a predetermined number of subframes after the active time termination, ensuring it does not overlap with HARQ feedback or PUSCH transmission, thereby preventing double decoding and optimizing processing capabilities.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the terminal transmits CQI during the transition period after sudden DRX state change, then the channel quality information can be reported, but it may cause double decoding at the eNB and increase processing complexity

Engineering Contradiction:
ImproveCSI transmission reliabilityVSAvoidterminal processing capability
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The terminal checks whether CQI transmission is scheduled before the DRX state change occurs. By performing this check in advance, the terminal can determine whether to transmit CQI during the transition period, avoiding unnecessary transmission and reducing processing complexity while ensuring reliable transmission when needed

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The invention dynamically adjusts CQI transmission behavior based on the DRX state change timing. The terminal adapts its transmission decisions according to whether the CQI transmission timing coincides with the DRX transition, optimizing the balance between transmission reliability and processing capability requirements

Inventive Principle:
Principle #15Dynamics

2Adaptability or versatility

If the terminal maintains processing capability during DRX transition, then CQI/SRS transmission can be supported, but power consumption increases

Engineering Contradiction:
Improveterminal operation flexibilityVSAvoidterminal power consumption
Core Design Contradiction:
Adaptability or versatilityVSUse of energy by moving object

Solution Approach 1:

The terminal performs partial processing by checking CQI transmission scheduling only when necessary (before DRX state change) rather than continuously maintaining full processing capability. This partial action approach reduces power consumption while still supporting CQI/SRS transmission when required by the network

Inventive Principle:
Principle #16Partial or excessive action

Solution Approach 2:

The invention implements periodic CQI transmission based on scheduled timing rather than continuous transmission. The terminal activates processing only at scheduled CQI transmission opportunities, allowing it to enter low-power states between periods, thus reducing overall power consumption while maintaining operational flexibility

Inventive Principle:
Principle #19Periodic action

3Reliability

If the eNB decodes PUSCH assuming both CQI and HARQ-ACK are transmitted, then no decoding error occurs, but transmission efficiency decreases due to redundant decoding

Engineering Contradiction:
Improvedecoding accuracyVSAvoidtransmission efficiency
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The eNB uses feedback information (DRX state change notification) to determine whether CQI transmission is scheduled. Based on this feedback, the eNB can make informed decisions about decoding strategies, avoiding redundant decoding operations while ensuring accurate decoding when CQI is actually transmitted, thus improving transmission efficiency without sacrificing reliability

Inventive Principle:
Principle #23Feedback

Data Source

PatentEP2768171B1Method and device for transmitting reverse control signal in mobile communication system
Publication Date: 2022.04.13 SAMSUNG ELECTRONICS CO LTD
  • EP2768171B1 patent drawingFigure 1
  • EP2768171B1 patent drawingFigure 2
  • EP2768171B1 patent drawingFigure 3

AI summary

The present invention pertains to a method and device for transmitting a control signal, and a method for a terminal to transmit a control signal according to one embodiment of the present invention can comprise: a step for sensing a forced termination in a first subframe during active time; and a step in which if the forced termination is sensed and if, in a second subframe among a pre-set number of subframes after the first subframe, Channel Quality Indicator (CQI) transmission via a Physical Uplink Control Channel (PUCCH) is set, and if neither one among Hybrid Automatic Repeat Request (HARQ) feedback transmission and Physical Uplink Shared Channel (PUSCH) transmission is set in the second subframe, the CQI transmission is executed via the PUCCH. The embodiment of the present invention enables power consumption by the terminal to be reduced.