Adaptive Baseband Predistortion Circuit for Lower 5G Transmitter Power

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Conventional predistortion circuits in wireless transmitters consume excessive power due to being designed to support the worst-case or most complex waveforms, leading to unnecessary energy waste and increased current consumption for less complex waveforms, particularly with the introduction of 5G NR and future communication standards.

Innovation Solution

A predistortion circuit that dynamically switches between simpler and more complex configurations based on operating characteristics, such as modulation schemes and power modes, reducing computation nodes and current consumption while maintaining signal quality.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If predistortion circuits are designed to support the worst-case or most complex waveforms, then signal quality requirements are met across all waveforms, but power consumption and current consumption increase excessively

Engineering Contradiction:
Improvesignal qualityVSAvoidpower consumption
Core Design Contradiction:
ReliabilityVSUse of energy by moving object

Solution Approach 1:

The predistortion circuit dynamically switches between different configurations (first and second configurations) based on the detected waveform complexity. The control circuit identifies whether the input waveform is complex or simple and activates the appropriate predistorter configuration, making the system adaptive rather than static. This resolves the contradiction by ensuring full predistortion capability is only activated when needed for complex waveforms, while simpler waveforms use a reduced configuration that consumes less power.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system changes operational parameters (predistorter configuration) based on the input waveform characteristics. When a complex waveform is detected, the system switches to the first configuration with full predistortion parameters; when a simple waveform is detected, it switches to the second configuration with reduced parameters. This parameter adaptation allows the circuit to maintain signal quality for complex waveforms while reducing power consumption for simpler waveforms.

Inventive Principle:
Principle #35Parameter changes

2Reliability

If predistortion circuits use more computation nodes to handle complex waveforms, then signal quality is maintained, but current consumption increases

Engineering Contradiction:
Improvesignal qualityVSAvoidcurrent consumption
Core Design Contradiction:
ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The predistortion circuit dynamically adjusts the number of active computation nodes based on waveform complexity. For complex waveforms, all computation nodes are activated to maintain signal quality. For simple waveforms, fewer computation nodes are activated, reducing current consumption. The control circuit manages this dynamic adjustment by switching between configurations that have different numbers of active computation nodes.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system extracts and removes unnecessary computation nodes from the active predistorter configuration when processing simple waveforms. Instead of always using the full complement of computation nodes, the control circuit selectively deactivates redundant nodes based on waveform analysis, thereby reducing current consumption without affecting signal quality for the given waveform complexity.

Inventive Principle:
Principle #2Taking out (Extraction)

3Adaptability or versatility

If predistortion circuits are designed for maximum complexity support, then all waveform types can be processed, but device complexity increases

Engineering Contradiction:
Improvewaveform supportVSAvoidcircuit complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The predistortion circuit is designed with multi-functionality, capable of operating in at least two different configurations to handle different waveform types. The first configuration supports complex waveforms with full predistortion processing, while the second configuration handles simpler waveforms with reduced processing. This universal design allows a single circuit to adapt to multiple waveform requirements without needing separate dedicated circuits for each waveform type.

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

Solution Approach 2:

The predistortion circuit is segmented into multiple configurations or modes that can be selectively activated. The control circuit divides the overall predistortion functionality into at least two distinct operational segments (first and second configurations), each optimized for different waveform complexities. This segmentation allows the system to provide comprehensive waveform support while managing device complexity by only activating the necessary segment for each given waveform.

Inventive Principle:
Principle #1Segmentation

Data Source

PatentEP3701691B1Predistortion circuit, method for generating a predistorted baseband signal, control circuit for a predistortion circuit, method to determine parameters for a predistortion circuit, and apparatus and method for predistorting a baseband signal
Publication Date: 2025.10.15 APPLE INC
  • EP3701691B1 patent drawingFigure 1~2
  • EP3701691B1 patent drawingFigure 3~4
  • EP3701691B1 patent drawingFigure 5~7

AI summary

A predistortion circuit for a wireless transmitter includes a signal input configured to receive a baseband signal. Further, the predistortion circuit includes a predistorter configured to generate a predistorted baseband signal using the baseband signal and a select of one of a first predistorter configuration and a second predistorter configuration.