PRACH Preamble Sequence Detection Using Timing Correlation

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Solution Overview

Problem

In the context of 5G NR PRACH, existing M-stage preamble sequences may not be detected accurately when multiple UEs transmit over the same time-frequency resource, leading to collisions and detection failures.

Innovation Solution

A method and device are introduced to determine preamble sequences by analyzing the relative timing positions of preamble sub-sequences received from UEs, where if the difference in detection instances between sub-sequences is below a threshold, they are determined to belong to the same preamble sequence, ensuring accurate detection.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If M-stage preamble sequences are used to support dynamic TDD and self-contained structure, then adaptability is improved, but detection accuracy deteriorates when multiple UEs transmit over the same time-frequency resource

Engineering Contradiction:
Improveadaptability to dynamic TDDVSAvoiddetection accuracy
Core Design Contradiction:
Adaptability or versatilityVSMeasurement precision

Solution Approach 1:

The preamble sequence is divided into multiple stages (first stage and second stage), where each stage contains multiple preamble sub-sequences. This segmentation allows the system to maintain adaptability for dynamic TDD while improving detection accuracy by analyzing timing relationships across stages to resolve collisions when multiple UEs transmit over the same resource.

Inventive Principle:
Principle #1Segmentation

2Productivity

If multiple UEs transmit preamble sequences over the same time-frequency resource, then resource utilization is improved, but collision probability increases leading to detection failures

Engineering Contradiction:
Improveresource utilizationVSAvoiddetection reliability
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The system uses timing feedback from detecting preamble sub-sequences in the first stage to guide the detection and association of preamble sub-sequences in the second stage. By comparing timing relationships between stages, the network can reliably identify which sub-sequences belong to the same UE, thereby maintaining high detection reliability even when multiple UEs share the same time-frequency resource.

Inventive Principle:
Principle #23Feedback

Data Source

PatentEP3606268B1Method and device for determining preamble sequence of physical random access channel
Publication Date: 2021.03.31 CHINA ACAD OF TELECOMM TECH
  • EP3606268B1 patent drawingFigure 1~2
  • EP3606268B1 patent drawingFigure 3A~3B
  • EP3606268B1 patent drawingFigure 4~5

AI summary

Disclosed are a method and device for determining a preamble sequence of a physical random access channel. The method comprises: receiving each preamble subsequence in previous stage, and determining the time each preamble subsequence is detected at a detection window; receiving each preamble subsequence in this stage, and determining the time each preamble subsequence is detected at the detection window; and determining preamble subsequences belonging to the same preamble sequence according to the time of each preamble subsequence detected in this stage and the time of each preamble subsequence detected in the previous stage. By means of the present application, whether preamble subsequences belong to the same preamble sequence can be determined, and thus the fuzzy problem of the M-order preamble sequence solution of the next-generation wireless communication physical random access channel that multiple users select the same time-frequency resource sending condition can be avoided, so as to effectively guarantee the reliability of the preamble sequence solution.