Data Modulation Constellation Scaling for 5G Amplifier Linearity

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Solution Overview

Problem

In high-frequency wireless communication systems like 5G, terminals at different distances from the service node experience varying modulation manners, leading to high peak-to-average power ratios that strain power amplifiers, necessitating inefficient power back-off and affecting modulation efficiency.

Innovation Solution

A data modulation method that determines a modulation parameter A based on the modulation manner, using a target constellation point symbol to flexibly adjust power control, ensuring signals remain in the linear region of the power amplifier, thereby improving efficiency and reliability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If power back-off is applied to maintain power amplifier linearity, then the power amplifier works in linear region, but modulation efficiency decreases and power consumption increases

Engineering Contradiction:
Improvepower amplifier linearityVSAvoidmodulation efficiency
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The patent applies preliminary action by pre-calculating and storing optimal constellation point adjustments in a lookup table before transmission. The service node determines the modulation parameter based on the modulation manner and retrieves the pre-computed adjustment values, avoiding real-time complex calculations and enabling quick power back-off while maintaining efficiency

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent changes the modulation parameter (amplitude scaling factor) based on the modulation manner to adjust the constellation point density. By modifying the parameter A that scales the constellation points, the system adapts the signal characteristics to match power amplifier constraints while optimizing efficiency

Inventive Principle:
Principle #35Parameter changes

2Productivity

If high-order modulation is used to improve data rate, then transmission capacity increases, but peak-to-average power ratio increases causing power amplifier strain

Engineering Contradiction:
Improvedata transmission rateVSAvoidpower amplifier performance
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The patent applies local quality by adjusting constellation points differently based on their position and the specific modulation manner. Different modulation modes (QPSK, 16QAM, 64QAM, 256QAM) receive different scaling factors A, creating locally optimized signal characteristics for each modulation type while maintaining overall system performance

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The system dynamically adapts the modulation parameter A according to the modulation manner being used. The service node determines the appropriate scaling factor based on the current modulation mode, enabling flexible adjustment of constellation density to balance data rate and power amplifier stress

Inventive Principle:
Principle #15Dynamics

3Reliability

If power back-off is increased to reduce signal distortion, then linearity improves, but out-of-band leakage increases and spectrum efficiency decreases

Engineering Contradiction:
Improvesignal linearityVSAvoidout-of-band leakage
Core Design Contradiction:
ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The patent optimizes the modulation parameter A to achieve the right balance between linearity and spectral containment. By carefully selecting the scaling factor for each modulation manner, the system maintains sufficient power back-off to ensure linearity while avoiding excessive back-off that would cause significant out-of-band leakage

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP4152711B1Data modulation method and device, data demodulation method and device, service node, terminal, and medium
Publication Date: 2025.08.13 ZTE CORP
  • EP4152711B1 patent drawingFigure 1~3
  • EP4152711B1 patent drawingFigure 4~5
  • EP4152711B1 patent drawingFigure 6~7

AI summary

Provided are a data modulation method and device, a data demodulation method and device, a service node, a terminal, and a medium. The data modulation method is applied to the service node, and the data modulation method includes that: a modulation parameter A is determined according to a modulation manner of data; and the data is modulated according to a target constellation point symbol, where the target constellation point symbol is a product of A and X, and X is an initial constellation point symbol corresponding to the modulation manner.