Puncturing Pattern Control for OFDM Interference Mitigation
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Solution Overview
Problem
Wireless communication systems face challenges in efficiently managing OFDM-based wireless transmissions due to intermittent interference, which existing technologies like IEEE 802.11ax are not designed to handle effectively, especially when using multi-RU transmissions and DCM, leading to potential data loss and increased code rates.
Innovation Solution
The method involves redundantly modulating user data onto multiple subcarriers across different RUs based on preconfigured puncturing patterns to mitigate intermittent interference, ensuring that at least one copy of the data remains unaltered, thereby supporting DCM and preamble puncturing without requiring new code rates.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If preamble puncturing is applied to mute RUs with intermittent interference, then data loss is prevented, but code rate increases and transmission efficiency decreases
Solution Approach 1:
The patent applies preliminary action by pre-configuring puncturing patterns before transmission. The transmitter determines which RUs may be punctured in advance and maps DCM pairs accordingly, so that when intermittent interference occurs, the correct RUs are already identified for puncturing without requiring real-time reformatting or new code rates.
Solution Approach 2:
The patent changes the parameter of code rate management by reusing existing channel codes instead of requiring new code rates. By combining DCM redundancy with selective RU puncturing based on pre-configured patterns, the system maintains reliable transmission without increasing code rate, thus preserving transmission efficiency.
2Reliability
If DCM is used to enhance robustness against interference, then transmission reliability improves, but system complexity increases
Solution Approach 1:
The patent applies segmentation by dividing the bandwidth into multiple RUs and further dividing user data into DCM pairs, where each pair consists of two subcarriers. This segmentation allows selective puncturing of individual RUs while maintaining DCM protection at the pair level, reducing system complexity by enabling granular control without requiring complete reformatting of the transmission structure.
Solution Approach 2:
The patent uses preliminary action by pre-configuring puncturing patterns that identify which RUs can be safely punctured. This allows the system to combine DCM robustness with selective puncturing without requiring complex real-time decisions about which RUs to mute, thereby reducing system complexity while maintaining transmission reliability.
3Productivity
If multiple RUs are allocated to a single user to increase bandwidth, then data rate increases, but vulnerability to intermittent interference increases
Solution Approach 1:
The patent applies local quality by treating each RU differently based on its interference characteristics. Instead of uniformly protecting all RUs allocated to a user, the system identifies specific RUs that are vulnerable to intermittent interference and applies puncturing only to those local regions, while leaving other RUs intact for high-rate transmission.
Solution Approach 2:
The patent uses preliminary action by pre-configuring puncturing patterns that identify which RUs should be protected from intermittent interference. This allows the system to allocate multiple RUs to increase data rate while having predetermined strategies in place for protecting specific vulnerable RUs, thereby maintaining reliability without sacrificing overall productivity.
Data Source
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AI summary
A wireless transmitter (10, 11) transmits user data using Orthogonal Frequency Division Multiplexing modulation on a shared wireless medium having a bandwidth organized in multiple resource units. Based on a mapping of the user data to the resource units, the wireless transmitter (10, 11) modulates a symbol of the user data onto a first set of subcarriers of a first resource unit of the resource units and redundantly modulates the symbol onto a second set of subcarriers of a second resource unit of the resource units. The mapping of the user data to the resource units is based on possible puncturing patterns applied to the resource units.