Beam Grouping for Random Access Signaling Overhead Reduction

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Solution Overview

Problem

In future radio communication systems, such as 5G, the challenge is to efficiently perform random access procedures using beamforming while managing the increased complexity and overhead associated with high carrier wave frequencies, which can lead to significant radio wave propagation loss and latency issues.

Innovation Solution

The solution involves controlling the transmission and reception of signals by setting resources corresponding to respective beam patterns in the random access procedure, allowing for the grouping of multiple beam patterns into fewer resource groups, thereby reducing signaling overhead and latency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If beamforming is used in random access procedure, then communication efficiency is improved, but signaling overhead and latency increase

Engineering Contradiction:
Improvecommunication efficiencyVSAvoidlatency
Core Design Contradiction:
ProductivityVSLoss of time

Solution Approach 1:

Multiple beam patterns are merged into beam groups, where each beam group shares common random access resources. This consolidation reduces the total number of resources needed while maintaining the ability to support multiple beams, thereby reducing signaling overhead and latency without sacrificing communication efficiency.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

Random access resources are designed to serve multiple beam patterns within a beam group universally. A single random access resource can be used by multiple beams, eliminating the need for dedicated resources for each beam pattern, thus reducing overall signaling overhead and latency.

Inventive Principle:
Principle #6Universality (Multi-functionality)

2Reliability

If multiple beam patterns are used, then coverage and reliability are improved, but device complexity increases

Engineering Contradiction:
Improvecoverage reliabilityVSAvoidbeam management complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The set of beam patterns is segmented into beam groups, where each group is managed as a single entity with shared resources. This segmentation reduces the complexity of managing individual beam patterns while maintaining coverage reliability through the use of multiple beams within each group.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Multiple beam patterns are combined into beam groups that share common random access resources. This merging reduces the complexity of beam management by reducing the number of independent resources that need to be tracked and managed, while still providing reliable coverage through multiple beam options.

Inventive Principle:
Principle #5Merging (Combining)

3Measurement precision

If individual beam patterns are configured with dedicated resources, then beam selection precision is improved, but signaling overhead increases

Engineering Contradiction:
Improvebeam selection precisionVSAvoidsignaling overhead
Core Design Contradiction:
Measurement precisionVSLoss of information

Solution Approach 1:

Multiple beam patterns are merged into beam groups that share common random access resources. This merging reduces signaling overhead by eliminating redundant resource allocations while maintaining beam selection precision through the use of beam group indicators and reference signals that allow precise beam identification within each group.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The resource allocation moves from a one-to-one mapping (individual beam to individual resource) to a many-to-one mapping (multiple beams to shared resource). This dimensional change in resource organization reduces signaling overhead while beam selection precision is maintained through additional signaling dimensions such as beam group indicators and reference signal measurements.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

Data Source

PatentEP3487255B1Terminal, radio communication method, base station and system
Publication Date: 2021.12.22 NTT DOCOMO INC
  • EP3487255B1 patent drawingFigure 1
  • EP3487255B1 patent drawingFigure 2A~2B
  • EP3487255B1 patent drawingFigure 3A~3C

AI summary

To perform a random access procedure appropriately in communication using beamforming. A user terminal for communicating with a radio base station using a plurality of beams includes: a transmission section that transmits a random access preamble; a reception section that receives a random access response corresponding to the random access preamble; and a control section that controls transmission of the random access preamble and/or reception of the random access response using given resources associated with a plurality of beam patterns.