Selective Linearization of Multi-Carrier RF Transmitters for LMR

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Solution Overview

Problem

Existing multi-carrier systems used in cellular technologies are not suitable for Land Mobile Radio (LMR) systems due to non-compliance with emission requirements, lack of optimization for dynamic carrier conditions, non-scalability, and non-fault tolerance.

Innovation Solution

A frequency agile multi-carrier system with a radio frequency (RF) transmitter that includes banks of multi-carrier power amplifiers with linearizers, an electronic processor to manage timestamped carrier configurations, and a method for selective linearization to ensure timely adaptation to dynamic carrier conditions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If cellular multi-carrier systems are used for LMR transmissions, then carrier signals can be transmitted over multiple channels, but the system does not comply with LMR emission requirements and is not optimized for dynamic carrier conditions

Engineering Contradiction:
Improveadaptability to dynamic carrier conditionsVSAvoidcompliance with emission requirements
Core Design Contradiction:
Adaptability or versatilityVSReliability

Solution Approach 1:

The patent implements dynamic carrier configuration where carrier attributes (frequency, bandwidth, power) are no longer static but can be adjusted in real-time based on LMR transmission requirements. The system dynamically reconfigures carrier parameters to comply with emission standards while maintaining adaptability to changing communication conditions, directly resolving the contradiction between adaptability and compliance.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system changes key parameters of carrier signals including frequency, bandwidth, and power levels dynamically. By implementing parameter changes rather than fixed attributes, the system can adapt to dynamic LMR conditions while ensuring emission compliance through controlled parameter adjustments, addressing both adaptability and reliability requirements.

Inventive Principle:
Principle #35Parameter changes

2Reliability

If traditional multi-carrier systems are used, then signal transmission over multiple carriers is achieved, but the systems lack scalability and fault tolerance

Engineering Contradiction:
Improvefault toleranceVSAvoidsystem scalability
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent segments the multi-carrier system into independent, modular carrier units that can be individually configured, activated, or deactivated. This segmentation enables fault tolerance by isolating failures to specific carriers while maintaining others, and provides scalability by allowing incremental addition or removal of carrier modules without redesigning the entire system.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The system implements universal carrier modules that can serve multiple functions and be configured for different purposes. These multi-functional carriers provide fault tolerance through redundancy and scalability by allowing the same modular units to be deployed in varying quantities and configurations based on system requirements.

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

3Adaptability or versatility

If carrier attributes are kept static as in cellular systems, then system simplicity is maintained, but the system cannot adapt to dynamic LMR carrier conditions

Engineering Contradiction:
Improvefrequency agilityVSAvoidcarrier configuration management
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The system performs preliminary configuration of carrier attributes based on anticipated LMR transmission requirements. By pre-configuring frequency, bandwidth, and power parameters according to expected dynamic conditions, the system achieves frequency agility without requiring complex real-time adjustments, reducing operational complexity while maintaining adaptability.

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentEP3884583B1Selective linearization of scalable fault tolerant frequency agile transmitters
Publication Date: 2025.04.23 MOTOROLA SOLUTIONS INC
  • EP3884583B1 patent drawingFigure 1
  • EP3884583B1 patent drawingFigure 2
  • EP3884583B1 patent drawingFigure 3

AI summary

Apparatus and method (400) for selective linearization of scalable fault tolerant frequency agile transmitters. In one embodiment, the method (400) includes receiving timestamped carrier configurations and segmenting the timestamped carrier configurations into time segments (520) having a pre-determined time length. The method (400) also includes determining composite carrier configuration in a present time segment (520) for a predetermined number of future time segments (520) and determining a correction solution of a plurality of correction solutions associated with the composite carrier configuration in a mapping of a plurality of carrier configurations and the plurality of correction solutions. The method (400) includes providing the correction solution to a linearizer of at least one of a plurality of multi-carrier power amplifiers (150). The plurality of power amplifiers are provided in one or more banks of multi-carrier power amplifiers (150).