PDSCH Demodulation in CSI-RS Resources for MTC Coverage

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Solution Overview

Problem

Current wireless communication systems face challenges in enhancing coverage, particularly for machine type communication (MTC) in scenarios where traditional methods are inefficient, leading to suboptimal signal transmission and reception.

Innovation Solution

The method involves a UE receiving a physical downlink control channel (PDCCH) and a physical downlink shared channel (PDSCH) in a subframe with CSI-RS resources, with demodulation assumptions adjusted based on predetermined conditions, such as reception of information indicating PDSCH non-transmission or repeated transmission, to optimize signal processing and resource utilization.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If PDSCH is transmitted in CSI-RS resources, then resource utilization is improved, but demodulation accuracy deteriorates due to signal interference

Engineering Contradiction:
Improveresource utilizationVSAvoiddemodulation accuracy
Core Design Contradiction:
ProductivityVSMeasurement precision

Solution Approach 1:

The patent implements dynamic adaptation by allowing the UE to switch between two demodulation assumptions based on received indication information. When CSI-RS is transmitted, the UE assumes PDSCH is not transmitted in those resources; when CSI-RS is not transmitted, the UE assumes PDSCH can be transmitted. This dynamic switching resolves the contradiction by adapting the demodulation behavior to actual transmission conditions.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent changes the demodulation parameter (assumption about PDSCH transmission in CSI-RS resources) based on the transmission state of CSI-RS. By receiving indication information from the network, the UE adjusts its demodulation assumption parameter to match the actual resource allocation state, thereby maintaining demodulation accuracy while enabling flexible resource utilization.

Inventive Principle:
Principle #35Parameter changes

2Reliability

If coverage enhancement is implemented for MTC, then signal reception is improved, but system overhead increases

Engineering Contradiction:
Improvesignal receptionVSAvoidsystem overhead
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent enables the UE to self-determine the appropriate demodulation assumption by processing received indication information autonomously. The UE independently decides whether to assume PDSCH transmission in CSI-RS resources based on the indication, without requiring complex network-side coordination or additional overhead signaling for each demodulation decision. This self-service mechanism improves signal reception while minimizing system overhead.

Inventive Principle:
Principle #25Self-service

3Reliability

If repeated transmission is used for MTC coverage enhancement, then coverage is improved, but power consumption increases

Engineering Contradiction:
ImprovecoverageVSAvoidpower consumption
Core Design Contradiction:
ReliabilityVSUse of energy by moving object

Solution Approach 1:

The patent applies partial action by using repeated transmission only when necessary for coverage enhancement, rather than continuously. The UE dynamically adjusts its demodulation assumption based on received indications, enabling repeated transmission to be applied selectively in coverage-limited scenarios while avoiding unnecessary repetitions in good coverage conditions, thereby reducing overall power consumption while maintaining coverage improvement where needed.

Inventive Principle:
Principle #16Partial or excessive action

Data Source

PatentEP2999140B1Method for transmitting signal for improving coverage and apparatus for same
Publication Date: 2021.08.11 LG ELECTRONICS INC
  • EP2999140B1 patent drawingFigure 1
  • EP2999140B1 patent drawingFigure 2(a)~2(b)
  • EP2999140B1 patent drawingFigure 3

AI summary

The present invention relates to a wireless communication system. In particular, the present invention relates to a method and an apparatus for receiving data, by a terminal, in a wireless communication system, the method comprising the steps of: receiving a PDCCH; receiving a PDSCH corresponding to the PDCCH in a subframe including CSI-RS resource available in a cell; and demodulating the PDSCH. If a predetermined condition is satisfied, demodulation of the PDSCH is performed on the assumption that the PDSCH is not transmitted in the CSI-RS resource available in the cell, and if the predetermined condition is not satisfied, the demodulation of the PDSCH is performed on the assumption that the PDSCH can be transmitted in the CSI-RS resources available in the cell.