R-PDCCH Interleaving with CSI-RS Resource Discounting

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Solution Overview

Problem

In wireless communication systems, particularly in LTE networks, the Relay Physical Downlink Control Channel (R-PDCCH) faces challenges due to limited resource elements (REs) availability in slots allocated for CSI-RS, leading to insufficient resources for effective control channel transmission.

Innovation Solution

The method involves determining the number of antenna ports for CSI-RS and allocating groups of resource elements in a transmission resource unit by disregarding CSI-RS and CSI-RS ports, allowing for efficient transmission of control information for relay nodes by optimizing resource allocation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If resource elements are allocated for CSI-RS in the first slot, then channel state information reference signal transmission is enabled, but the number of available resource elements for R-PDCCH becomes insufficient

Engineering Contradiction:
ImproveCSI-RS transmission reliabilityVSAvoidavailable resource elements for R-PDCCH
Core Design Contradiction:
ReliabilityVSQuantity of substance

Solution Approach 1:

The transmission resource unit is divided into multiple groups of resource elements, with each group assigned to different relay nodes. This segmentation allows efficient allocation of R-PDCCH resources while accounting for CSI-RS requirements, ensuring that sufficient resources remain for control channel transmission even when CSI-RS is present.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The method performs preliminary determination of the number of CSI-RS antenna ports and pre-calculates the resource element allocation for R-PDCCH groups before actual transmission. This advance planning ensures that resource elements are properly allocated and that sufficient resources are reserved for R-PDCCH regardless of CSI-RS configuration.

Inventive Principle:
Principle #10Preliminary action

2Measurement precision

If the number of CSI-RS antenna ports is increased, then channel state information accuracy improves, but the number of available resource elements for control information transmission decreases

Engineering Contradiction:
Improvechannel state information accuracyVSAvoidresource elements for control information
Core Design Contradiction:
Measurement precisionVSQuantity of substance

Solution Approach 1:

Different groups of resource elements are allocated to different relay nodes based on their specific needs and the actual number of CSI-RS antenna ports configured. This localized allocation approach allows the system to maintain high CSI-RS accuracy where needed while ensuring sufficient R-PDCCH resources for all relay nodes.

Inventive Principle:
Principle #3Local quality

3Ease of operation

If resource elements are discounted based on highest possible CSI-RS ports, then resource allocation simplicity increases, but actual resource utilization may decrease when fewer ports are used

Engineering Contradiction:
Improveresource allocation simplicityVSAvoidresource utilization efficiency
Core Design Contradiction:
Ease of operationVSProductivity

Solution Approach 1:

The system determines the actual number of CSI-RS antenna ports to be used and adjusts the resource element discounting accordingly. Rather than always discounting based on the maximum possible ports, the method dynamically adapts the discounting parameter to match the actual configuration, thereby improving resource utilization while maintaining allocation simplicity.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP2606600B1Interleaving for relay physical downlink control channel (r-pdcch)
Publication Date: 2018.06.06 QUALCOMM INC
  • EP2606600B1 patent drawingFigure 1~2
  • EP2606600B1 patent drawingFigure 3
  • EP2606600B1 patent drawingFigure 4

AI summary

Certain aspects of the present disclosure provide methods and apparatus for interleaving control information for one or more nodes. For certain aspects, the control information may comprise one or more Relay Physical Downlink Control Channels (R-PDCCHs) for one or more relay nodes. The interleaving may comprise interleaving Common Reference Signal (CRS)-based R-PDCCH, wherein the resource elements (REs) for CRS and/or Channel State Information Reference Signal (CSI-RS) may be discounted in a physical resource block (PRB).