Dynamic SSB to RACH Resource Mapping in 5G NR

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Solution Overview

Problem

Current random access solutions in new radio (NR) communications technology do not provide the desired level of speed or customization for efficient wireless communication operations, particularly in mapping synchronization signal blocks to random access channel (RACH) resources, leading to inefficiencies and increased latency.

Innovation Solution

The method involves dynamically mapping synchronization signal blocks to RACH resources based on the number of actually transmitted blocks, allowing for efficient utilization of RACH resources and repurposing idle resources for additional transmissions, thereby reducing latency and improving communication efficiency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If current random access solutions are used in NR communications, then the system maintains simplicity in resource mapping, but the speed and customization level for efficient operation are insufficient

Engineering Contradiction:
ImproveRACH procedure speedVSAvoidresource mapping complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The patent implements dynamic mapping between synchronization signal blocks and RACH resources, where the mapping relationship is not fixed but can be adjusted based on actual transmission conditions. The base station dynamically determines which RACH resources correspond to which synchronization signal blocks, allowing the system to adapt to varying traffic conditions and improve access speed without requiring complex predefined mapping tables.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent changes the parameter of resource mapping from static to dynamic by introducing flexibility in associating RACH resources with synchronization signal blocks. The mapping parameters can be modified based on the number of actually transmitted blocks and system conditions, enabling faster random access procedures while maintaining manageable complexity through standardized dynamic adjustment rules.

Inventive Principle:
Principle #35Parameter changes

2Loss of time

If synchronization signal blocks are mapped to RACH resources without considering the number of actually transmitted blocks, then the mapping process is simple, but RACH resources are not efficiently utilized and latency increases

Engineering Contradiction:
ImproveRACH access latencyVSAvoidRACH resource utilization efficiency
Core Design Contradiction:
Loss of timeVSProductivity

Solution Approach 1:

The patent incorporates feedback mechanisms where the base station monitors the actual number of transmitted synchronization signal blocks and uses this information to adjust the RACH resource mapping accordingly. This feedback loop ensures that RACH resources are efficiently allocated based on real transmission conditions, reducing access latency while maximizing resource utilization efficiency through adaptive resource management.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The patent performs preliminary mapping configuration where the base station pre-determines the mapping between synchronization signal blocks and RACH resources based on the actual number of transmitted blocks before the random access procedure begins. This preliminary action allows UEs to quickly determine their access resources without additional signaling delays, thereby reducing latency while ensuring efficient resource utilization through advance planning.

Inventive Principle:
Principle #10Preliminary action

3Adaptability or versatility

If RACH resources are not repurposed for additional transmissions, then the resource allocation is straightforward, but additional uplink transmission opportunities are lost

Engineering Contradiction:
Improveuplink transmission flexibilityVSAvoidresource allocation complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent enables RACH resources to serve multiple functions: their primary function for random access and an additional function for other uplink transmissions when not fully utilized. This multi-functionality allows the system to increase uplink transmission flexibility by repurposing idle RACH resources for additional transmissions, thereby improving adaptability without significantly increasing allocation complexity through standardized repurposing rules.

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

Data Source

PatentEP3711415B1Mapping rules between synchronization signal blocks and random access channel resources
Publication Date: 2023.05.03 QUALCOMM INC
  • EP3711415B1 patent drawingFigure 1
  • EP3711415B1 patent drawingFigure 2
  • EP3711415B1 patent drawingFigure 3

AI summary

A node for wireless communication identifies a number of actually transmitted reference signals. The node identifies a number of available PRACH time-frequency resources and preamble indices in a time period. The node identifies a number of configured PRACH time-frequency resources or PRACH preamble indices per reference signal. The node determines that the available number of PRACH time-frequency resources or PRACH preamble indices within the time period is not an integer multiple of the product of the number of actually transmitted reference signals and the number of configured PRACH time-frequency resources or PRACH preamble indices per reference signal. The node maps the actually transmitted reference signals to the available PRACH time-frequency resources and preamble indices based on the identified information and determination.