Distributive Resource Units for OFDMA Power Spectral Density Compliance
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Solution Overview
Problem
Wireless communication systems, such as IEEE 802.11ax (WI-FI® 6) systems, face limitations in transmitter (TX) power due to government-regulated power spectral density (PSD) requirements, which restricts the efficient use of resource units (RUs) in orthogonal frequency division multiple access (OFDMA) systems.
Innovation Solution
The implementation of distributive resource units (dRUs) that allocate subcarriers across the entire OFDMA bandwidth, allowing for non-consecutive subcarrier allocation and improved frequency diversity, while maintaining compliance with PSD regulations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional resource units (RUs) are used with consecutive subcarriers, then the structure is simple and easy to implement, but the frequency diversity is limited and TX power efficiency is reduced due to PSD constraints
Solution Approach 1:
The patent segments the RU structure by separating neighboring subcarriers with guard subcarriers, transforming the conventional consecutive subcarrier allocation into a distributed pattern. This segmentation increases frequency diversity by spreading subcarriers across different frequency regions, while the systematic structure of the segmentation maintains implementation simplicity.
Solution Approach 2:
The patent introduces a new dimension to RU structure by adding guard subcarriers between neighboring subcarriers. This dimensional change in the frequency domain creates a distributed subcarrier pattern that enhances frequency diversity without requiring complex modulation or coding schemes, thus improving reliability while maintaining structural simplicity.
2Productivity
If TX power is increased to improve communication performance, then spectral efficiency improves, but PSD requirements are violated
Solution Approach 1:
The patent segments the frequency spectrum by inserting guard subcarriers between data-carrying subcarriers. This segmentation distributes the TX power across a wider frequency range, reducing the power spectral density at any single frequency point while maintaining the total power needed for high spectral efficiency, thus satisfying PSD constraints without sacrificing productivity.
Solution Approach 2:
The patent transitions from a concentrated power spectrum approach to a distributed power spectrum approach by spacing subcarriers apart with guard subcarriers. This dimensional redistribution in the frequency domain allows the system to achieve high spectral efficiency through better frequency diversity while keeping the power spectral density within regulated limits.
3Reliability
If subcarriers are separated by guard subcarriers to improve frequency diversity, then communication reliability improves, but the number of usable subcarriers decreases
Solution Approach 1:
The patent applies segmentation by dividing the frequency spectrum into separated subcarrier groups with guard subcarriers in between. This segmentation improves communication reliability through enhanced frequency diversity, while the systematic and efficient use of guard subcarriers minimizes the impact on the total number of usable subcarriers.
Solution Approach 2:
The patent changes the parameter of subcarrier spacing by introducing guard subcarriers between neighboring subcarriers. This parameter change improves frequency diversity and communication reliability, while the optimized guard subcarrier placement ensures that the reduction in usable subcarriers is minimized, maintaining an acceptable quantity for data transmission.
Data Source
AI summary
A communication method has the step of: transmitting or receiving first data using a first resource unit (RU) of a plurality of first RUs in a first frequency band having a first bandwidth (BW) for orthogonal frequency division multiple access (OFDMA); wherein each of the plurality of first RUs has a plurality of subcarriers; and wherein, in the first RU, at least two neighboring subcarriers thereof are separated by one or more subcarriers belonging to one or more other first RUs of the plurality of first RUs.