Frequency Hopping Sequence Spacing to Reduce Inter-Channel Interference

Solution Overview

Problem

Existing channel hopping schemes do not account for Inter Channel Interference (ICI), leading to increased error rates and performance degradation due to adjacent channel interference during retransmissions.

Innovation Solution

The proposed solution involves generating a frequency hopping sequence where adjacent transmission channel numbers are at least a predetermined distance apart, using a processing unit to rearrange the sequence and ensure that retransmissions occur on channels that are not affected by previous channel interference.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional frequency hopping sequences are used, then channel diversity is achieved, but inter-channel interference causes increased error rates during retransmissions

Engineering Contradiction:

Improveerror rateVSAvoidinter-channel interference

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent applies local quality by ensuring that specific local properties of the frequency hopping sequence (channel separation distance) are optimized to prevent inter-channel interference. By enforcing a minimum separation distance between consecutive channels in the hopping sequence, the patent locally addresses the interference problem at each hop point rather than treating all channels uniformly.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The patent changes the parameter of channel separation distance in the frequency hopping sequence from a conventional small or zero separation to a predetermined minimum distance. This parameter change ensures that retransmissions occur on channels sufficiently far from previous channels, thereby avoiding inter-channel interference while maintaining the benefits of frequency hopping.

Inventive Principle:

Principle #35Parameter changes

2Adaptability or versatility

If frequency hopping is used to avoid interference, then channel diversity is improved, but adjacent channels in the hopping sequence may still be close causing ICI

Engineering Contradiction:

Improvechannel diversityVSAvoidadjacent channel interference

Core Design Contradiction:

Adaptability or versatilityVSObject-affected harmful factors

Solution Approach 1:

The patent applies local quality by ensuring that specific local properties of the frequency hopping sequence (channel separation distance) are optimized to prevent inter-channel interference. By enforcing a minimum separation distance between consecutive channels in the hopping sequence, the patent locally addresses the interference problem at each hop point rather than treating all channels uniformly.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The patent changes the parameter of channel separation distance in the frequency hopping sequence from a conventional small or zero separation to a predetermined minimum distance. This parameter change ensures that retransmissions occur on channels sufficiently far from previous channels, thereby avoiding inter-channel interference while maintaining the benefits of frequency hopping.

Inventive Principle:

Principle #35Parameter changes

3Productivity

If retransmissions are performed on consecutive channels in the hopping sequence, then transmission efficiency is maintained, but inter-channel interference from previous transmissions affects retransmission success

Engineering Contradiction:

Improvetransmission efficiencyVSAvoidretransmission success rate

Core Design Contradiction:

ProductivityVSReliability

Solution Approach 1:

The patent applies preliminary action by pre-calculating and pre-determining the frequency hopping sequence with minimum channel separation before actual data transmission begins. This preliminary arrangement of the hopping sequence ensures that when retransmissions are needed, the channels are already known to be sufficiently separated from previous channels, preventing inter-channel interference without requiring complex real-time calculations.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent changes the parameter of channel separation distance in the frequency hopping sequence from a conventional small or zero separation to a predetermined minimum distance. This parameter change ensures that retransmissions occur on channels sufficiently far from previous channels, thereby avoiding inter-channel interference while maintaining the benefits of frequency hopping.

Inventive Principle:

Principle #35Parameter changes

Data Source

PatentUS12348263B2Enhanced channel hopping sequence

Publication Date: 2025.07.01 TEXAS INSTRUMENTS INC

AI summary

A system and method for enhanced channel hopping sequence is described. A pseudo random channel hopping sequence is redistributed using certain system specific parameters for separating adjacent transmission channels within a predetermined number of consecutive transmission channel numbers in the random channel hopping sequence to improve inter-channel interference between adjacent transmission channels.