RF Transmission Format Adaptation via Noise Interference Feedback

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Solution Overview

Problem

Radio frequency communication systems face inefficiencies due to reliance on estimation-based methods for determining suitable coding and modulation schemes, leading to resource wastage and performance degradation, especially in interference-limited environments where FEC can worsen interference and ARQ is wasteful.

Innovation Solution

Implementing a system where radio frequency communication devices can adapt transmission formats based on real-time channel condition feedback, using ACK/NACK messages to determine if reception is noise or interference limited, allowing for precise adaptation of coding, modulation, and packet length without trial-and-error methods.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If FEC is applied to counteract noise, then error correction capability is improved, but packet length increases and interference probability increases

Engineering Contradiction:
Improveerror correction capabilityVSAvoidinterference probability
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent implements dynamic adaptation of transmission format by the receiving device based on real-time channel conditions. The receiver determines whether noise or interference is the primary error cause and signals this back to the transmitter, which then dynamically adjusts the transmission format (FEC strength, packet length, modulation scheme) to match current channel characteristics, resolving the contradiction between error correction and interference susceptibility

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent changes transmission parameters (coding scheme, packet length, modulation) based on channel condition feedback. The receiver measures channel conditions, determines the primary error cause, and the transmitter adjusts parameters accordingly - using stronger FEC when noise-limited and weaker FEC/shorter packets when interference-limited, thus optimizing the balance between error correction and interference probability

Inventive Principle:
Principle #35Parameter changes

2Reliability

If ARQ is used to handle interference, then decoding reliability is improved, but resource wastage increases due to retransmissions

Engineering Contradiction:
Improvedecoding reliabilityVSAvoidresource wastage
Core Design Contradiction:
ReliabilityVSLoss of energy

Solution Approach 1:

Instead of always performing full retransmissions as in traditional ARQ, the patent applies partial action by transmitting only the necessary additional information or adjusted packets based on the specific channel condition. When interference is detected, the receiver signals this and the transmitter sends targeted corrections or retransmits only affected portions, reducing resource wastage while maintaining decoding reliability

Inventive Principle:
Principle #16Partial or excessive action

Solution Approach 2:

The patent implements feedback mechanisms where the receiving device signals back to the transmitter whether noise or interference is the primary error cause. This feedback enables the transmitter to adapt the transmission format before retransmission, choosing the most efficient approach (FEC adjustment, packet length modification, or targeted retransmission) rather than blind full retransmission, thus reducing resource wastage while maintaining reliability

Inventive Principle:
Principle #23Feedback

3Adaptability or versatility

If estimation-based methods are used to select coding and modulation schemes, then adaptability is improved, but convergence time increases

Engineering Contradiction:
Improvescheme selection adaptabilityVSAvoidconvergence time
Core Design Contradiction:
Adaptability or versatilityVSLoss of time

Solution Approach 1:

The patent applies preliminary action by having the receiving device determine the primary error cause (noise or interference) immediately upon receiving the transmission format and before attempting decoding. This preliminary determination is signaled back to the transmitter, which can then pre-adjust subsequent transmission formats based on this advance knowledge, avoiding time-consuming trial-and-error estimation and achieving faster convergence

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent uses feedback to transmit the determined primary error cause from receiver to transmitter, enabling the transmitter to adapt transmission formats based on actual channel conditions rather than estimation. This feedback loop dramatically reduces convergence time by eliminating trial-and-error approaches while maintaining high adaptability to changing channel conditions

Inventive Principle:
Principle #23Feedback

4Reliability

If retransmission packets are sent at full length and power, then decoding reliability is improved, but interference to other users increases

Engineering Contradiction:
Improveretransmission reliabilityVSAvoidinterference to other users
Core Design Contradiction:
ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The patent implements dynamic adjustment of retransmission parameters based on channel condition feedback. When interference is detected, the receiver signals this and the transmitter adapts the retransmission format - potentially using shorter packets, adjusted power levels, or different coding schemes - to maintain decoding reliability while minimizing interference to other users sharing the unlicensed spectrum

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent changes retransmission parameters (packet length, transmission power, coding scheme) based on the determined primary error cause. When interference is the dominant factor, the transmitter reduces packet length and/or power for retransmissions while maintaining sufficient reliability through adaptive formatting, thus reducing harmful interference to other users while preserving decoding success

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP3042464B1Improved adaptation of transmission format
Publication Date: 2020.04.29 TELEFONAKTIEBOLAGET LM ERICSSON (PUBL)
  • EP3042464B1 patent drawingFigure 1~2
  • EP3042464B1 patent drawingFigure 3~7
  • EP3042464B1 patent drawingFigure 8

AI summary

A radio frequency communication device(100A) comprising ar adio frequency communication interface (130) and a controller (110), wherein said controller (110) is configured to: transmit a message through said radio frequency communication interface (130)to a receiving radio frequency communication device(100B) using a transmission format; receive an indication on whether the reception of the message is primarily limited by noise (N) or interference (I); adapt said transmission format; and retransmit said message using said adapted transmission format.