DCI Transmission Method Optimizing PDCCH Coverage

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Solution Overview

Problem

The New Radio (NR) system faces challenges with high code rates in Downlink Control Information (DCI) transmission, leading to insufficient coverage of the Physical Downlink Control Channel (PDCCH), which affects the scheduling of Remaining Minimum System Information (RMSI) and Paging information.

Innovation Solution

A method and device for DCI transmission that determine a DCI format including a time domain resource allocation field, an aggregation transmission indication field, and modulation order indications, optimizing the resource allocation and modulation scheme to reduce the code rate and enhance PDCCH coverage.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If DCI format 1_0 is used to schedule RMSI/OSI/paging information with aggregation level 4 or 8, then the scheduling function is achieved, but the code rate becomes too large and PDCCH coverage is insufficient

Engineering Contradiction:
ImprovePDCCH coverageVSAvoidcode rate
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The patent changes the code rate parameter from 0.074/0.052 (DCI format 1_0) to 0.065 (MIB code rate) by optimizing resource allocation. It increases the number of available REs through better resource configuration and reduces DMRS overhead from 1/4 to 1/3 occupation, thereby achieving a lower code rate and improved PDCCH coverage while maintaining scheduling capability.

Inventive Principle:
Principle #35Parameter changes

2Reliability

If more resources are allocated to PDCCH to reduce code rate, then coverage is improved, but the available resources for data transmission are reduced

Engineering Contradiction:
ImprovePDCCH coverageVSAvoidavailable REs for data transmission
Core Design Contradiction:
ReliabilityVSQuantity of substance

Solution Approach 1:

The patent implements dynamic resource allocation where the number of OFDM symbols for PDCCH can be flexibly configured (2, 4, or 7 symbols) based on coverage requirements. It also dynamically adjusts the initial BWP bandwidth (24, 48, or 96 RBs) to balance PDCCH resource allocation with data transmission needs, allowing the system to adapt resource distribution to different operational scenarios.

Inventive Principle:
Principle #15Dynamics

3Reliability

If aggregation level is increased to improve coverage, then more REs are allocated to PDCCH, but the code rate increases and scheduling efficiency decreases

Engineering Contradiction:
ImprovePDCCH coverageVSAvoidscheduling efficiency
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The patent changes multiple parameters simultaneously: it optimizes the aggregation level configuration, adjusts the number of OFDM symbols for PDCCH transmission, and modifies the initial BWP bandwidth. This multi-parameter optimization achieves a code rate of 0.065 that provides both sufficient coverage and efficient scheduling, avoiding the inefficiency of higher code rates associated with increased aggregation levels.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP3755089B1Downlink control information (DCI) transmission method and device
Publication Date: 2022.10.26 VIVO MOBILE COMM CO LTD
  • EP3755089B1 patent drawingFigure 1~2
  • EP3755089B1 patent drawingFigure 3~4
  • EP3755089B1 patent drawingFigure 5

AI summary

The present disclosure discloses a downlink control information (DCI) transmission method, a device and a network equipment, wherein the method includes: determining a DCI format for transmitting the downlink control information (DCI), the DCI format comprising: a time domain resource allocation field, an aggregation transmission indication field, a first indication field or a second indication field, the first indication field indicating a configuration value of a time domain resource and a configuration value of a modulation order, the second indication field indicating a configuration value of a time domain resource and a configuration value of an aggregate transmission indication; and transmitting the DCI according to the DCI format.