EVM Measurement Apparatus for 5G Phase Noise Correction

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Solution Overview

Problem

Current measurement standards for 5G communication systems do not adequately account for Common Phase Error (CPE) and Inter-carrier Interference (ICI) corrections when determining Error Vector Magnitude (EVM) in high-frequency and high-modulation order scenarios, leading to inaccurate assessment of transmission apparatus performance.

Innovation Solution

A measurement apparatus and method that account for CPE/ICI corrections by using Phase Tracking Reference Signals (PT-RS) and adjusting EVM requirement values based on the necessity of these corrections, allowing for appropriate determination of EVM measurement values in both high-frequency and high-modulation order conditions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If CPE/ICI correction is applied in reception apparatus for high-frequency and high-modulation order signals, then error rate characteristics improve, but existing measurement standards cannot accurately evaluate transmission apparatus performance

Engineering Contradiction:
Improveerror rate characteristicsVSAvoidEVM measurement accuracy
Core Design Contradiction:
ReliabilityVSMeasurement precision

Solution Approach 1:

The patent changes the EVM requirement threshold parameter based on the modulation order. For high-modulation order schemes (64QAM, 256QAM) used in high-frequency bands where CPE/ICI correction is necessary, higher EVM thresholds are applied. This allows accurate performance evaluation that accounts for the improved error rate characteristics achieved through CPE/ICI correction while maintaining measurement precision.

Inventive Principle:
Principle #35Parameter changes

2Ease of operation

If standard test standards are used for EVM measurement, then measurement simplicity is maintained, but accurate assessment of transmission apparatus performance in high-frequency scenarios is compromised

Engineering Contradiction:
Improvemeasurement simplicityVSAvoidperformance assessment accuracy
Core Design Contradiction:
Ease of operationVSMeasurement precision

Solution Approach 1:

The patent introduces dynamic adjustment of EVM requirement thresholds based on operating conditions (frequency band and modulation order). The measurement system automatically selects appropriate thresholds: standard thresholds for low-frequency/low-modulation scenarios, and adjusted higher thresholds for high-frequency/high-modulation scenarios where CPE/ICI correction is applied. This maintains ease of operation through automated selection while improving measurement precision for different conditions.

Inventive Principle:
Principle #15Dynamics

Data Source

PatentUS11711178B2Measurement apparatus and measurement method
Publication Date: 2023.07.25 PANASONIC INTELLECTUAL PROPERTY CORP OF AMERICA
  • US11711178B2 patent drawing
  • US11711178B2 patent drawing
  • US11711178B2 patent drawing

AI summary

An EVM measurement value is appropriately determined while CPE/ICI correction is taken into account. In a measurement apparatus (300), an EVM measurer (305) measures a modulation quality of a signal transmitted from a transmission apparatus. An EVM determiner (306) determines whether or not the measurement value of the modulation quality is equal to or less than a first requirement value, in a case where correction relating to a phase noise of the transmission apparatus is necessary in a reception apparatus. The first requirement value herein is higher than a second requirement value used in the determination of the measurement value in a case where the correction relating to the phase noise of the transmission apparatus is unnecessary in the reception apparatus.