Narrow-Bandwidth RU Mapping to Avoid DC Tone Overlap
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Solution Overview
Problem
Narrow bandwidth operating devices face challenges in efficiently transmitting within wide bandwidth spectrum due to overlapping data tones with direct current (DC) tones, leading to reduced transmission quality and lack of defined procedures for operation within wider PPDU bandwidths.
Innovation Solution
The solution involves shifting and mapping non-contiguous subcarrier indices of narrow bandwidth devices to align with wide bandwidth channels, using tone plans that split the PPDU bandwidth into segments, and implementing specific field training protocols to maintain transmission quality.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If narrow bandwidth devices transmit within wide bandwidth spectrum, then spectrum utilization is improved, but data tones overlap with DC tones causing reduced transmission quality
Solution Approach 1:
The patent divides the wide bandwidth spectrum into multiple segments or subchannels, allowing narrow bandwidth devices to be allocated specific segments that do not overlap with DC tones. This segmentation enables spectrum utilization improvement while avoiding the harmful overlap between data tones and DC tones.
Solution Approach 2:
The patent introduces an intermediary mechanism (resource unit allocation system with shifting values) that mediates between the wide bandwidth spectrum and narrow bandwidth devices. The system calculates shifting values based on resource unit indices to properly position data tones away from DC tones, enabling compatible operation without direct tone overlap.
2Adaptability or versatility
If narrow bandwidth devices operate in wide bandwidth channels, then device compatibility is improved, but lack of defined procedures reduces operational reliability
Solution Approach 1:
The patent changes operational parameters by defining specific shifting values and resource unit allocation procedures tailored for narrow bandwidth devices operating in wide bandwidth channels. These parameter changes include modifying tone mapping procedures and defining specific field training protocols, which provide clear operational guidance and improve reliability.
Solution Approach 2:
The patent performs preliminary actions by pre-defining the shifting values and resource unit allocation procedures before actual transmission occurs. The system pre-calculates the appropriate shifting based on resource unit indices and prepares the tone mapping in advance, ensuring reliable operation when narrow bandwidth devices transmit in wide bandwidth channels.
3Ease of manufacture
If tone plans are used to map tones for PPDU transmission, then transmission structure is improved, but overlapping tones with DC tones reduces transmission quality
Solution Approach 1:
The patent applies local quality by creating tone plans with different mapping characteristics for different regions of the spectrum. Specifically, the tone mapping is locally adjusted around DC tone regions to avoid overlap, while maintaining the overall structured approach of tone plans for PPDU transmission. This allows structured transmission without harmful tone overlaps.
Data Source
AI summary
This disclosure provides methods, components, devices and systems for transmission of resource units by narrow bandwidth operating devices in wide bandwidth spectrum. A station (STA) may identify or receive a resource unit (RU) allocation including a global RU index for a wide bandwidth. The STA may translate the global RU index into a local RU index for a local tone plan, may map the assigned RU to distributed RU (dRU) tones over a corresponding distribution bandwidth, and may shift the mapped dRU tones to align with the wide bandwidth. The STA also may support transmission of short training fields (STFs) and long training fields (LTFs) using a similar mapping and shifting, or using tones of the wide bandwidth that fall within the distribution bandwidth region. A STA also may support a tone plan splitting a wide bandwidth into segments of the distribution bandwidth to allow direct mapping.