5G PRACH Timing Estimation Under Large Frequency Offsets

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Solution Overview

Problem

The current M-stage preamble sequence scheme in 5G NR PRACH experiences reduced estimation accuracy of timing position due to larger frequency offsets, leading to imprecise PRACH timing position estimation.

Innovation Solution

A method and device that correct the timing position estimation by accumulating correlation value powers within detection windows for each preamble subsequence, determining peak and noise powers, and adjusting for frequency offset errors using normalized frequency offsets and root index values to derive accurate timing locations.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If the current M-stage preamble sequence scheme is used, then the PRACH preamble detection can be performed, but the estimation accuracy of timing position deteriorates under large frequency offsets

Engineering Contradiction:
Improvetiming position estimation accuracyVSAvoidfrequency offset impact
Core Design Contradiction:
Measurement precisionVSObject-affected harmful factors

Solution Approach 1:

The patent combines multiple preamble subsequences (first and second preamble subsequences) into a unified detection framework. By accumulating correlation values from both subsequences and jointly determining the timing position, the system merges the information from multiple sequences to overcome the timing estimation degradation caused by frequency offsets, thereby improving measurement precision under adverse frequency conditions

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The patent modifies the detection parameters by introducing a joint detection mechanism that accounts for frequency offset effects. Instead of independently detecting each preamble subsequence using traditional methods, the system changes the detection approach to accumulate correlation values and determine timing positions considering the frequency offset impact, thus adapting the detection parameters to maintain accuracy under frequency variations

Inventive Principle:
Principle #35Parameter changes

2Measurement precision

If traditional preamble detection algorithm is used, then detection process is simple, but timing position estimation becomes imprecise under large frequency offsets

Engineering Contradiction:
ImprovePRACH timing position estimation accuracyVSAvoiddetection algorithm complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent segments the preamble detection process into distinct stages: obtaining the first and second preamble subsequences, calculating correlation values for each subsequence separately, accumulating these correlation values, and finally determining the timing position. This segmentation allows the complex detection task to be broken down into manageable steps, improving timing estimation accuracy while maintaining a structured and implementable detection algorithm

Inventive Principle:
Principle #1Segmentation

Data Source

PatentEP3609110B1Method and device for estimating timing location
Publication Date: 2021.09.22 DATANG MOBILE COMM EQUIP CO LTD
  • EP3609110B1 patent drawingFigure 1~2
  • EP3609110B1 patent drawingFigure 3
  • EP3609110B1 patent drawingFigure 4

AI summary

Disclosed in the present application is a method and a device of estimating a timing location. The method comprised: for each preamble subsequence, acquiring a detection window in which a peak value of a correlation value power of each preamble subsequence is located; accumulating the correlation value powers of all corresponding locations in the acquired detection window of each preamble subsequence, to obtain a cumulative sum of the correlation value powers corresponding to each location, wherein, in the accumulation, the correlation value powers of the preamble subsequence are within detection window in which peak values of respective correlation value powers are located; accumulating and determining, according to the correlation value power, peak power and noise power; and estimating, according to the peak power and the noise power, a timing location. The present application can solver the problem of a current M-stage preamble sequence solution in which a larger large frequency offset greatly impacts timing location estimation precision.