Wireless Communication Device OFDMA Frame Bit Complementation

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Wireless LAN systems using CSMA/CA access procedures face inefficiencies in dynamic bandwidth variations, requiring effective data frame configuration for OFDMA multiplexing, especially when transmitting to multiple wireless terminals with varying data sizes and modulation rates.

Innovation Solution

A wireless communication device and method that uses bit complementation to adjust OFDMA frames by calculating and adding padding bits to ensure efficient data transmission across multiple subcarriers, optimizing frame lengths and modulation rates for concurrent data transmission to multiple wireless terminals.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If data complementation is performed in both MAC layer and PHY layer, then frame length alignment is achieved, but communication efficiency deteriorates due to redundant padding

Engineering Contradiction:
Improveframe length alignmentVSAvoidcommunication efficiency
Core Design Contradiction:
Manufacturing precisionVSProductivity

Solution Approach 1:

The invention extracts the data complementation function from the MAC layer and relocates it to the PHY layer alone. The MAC layer padding is removed entirely, while the PHY layer performs all necessary data complementation based on the determined frame length, thereby eliminating redundant padding operations and improving communication efficiency while maintaining frame length alignment.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The invention changes the operational dimension of data complementation from a two-layer approach (MAC and PHY) to a single-layer approach (PHY only). By shifting the complementation responsibility entirely to the PHY layer and using PHY-layer parameters (subcarrier count, modulation rate, coding rate) to determine frame length, the system achieves the same alignment goal with reduced overhead.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Productivity

If OFDMA frames are configured for multiple wireless terminals with varying data sizes, then concurrent transmission capability is improved, but frame configuration complexity increases

Engineering Contradiction:
Improveconcurrent transmission capabilityVSAvoidframe configuration complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The invention changes the frame configuration approach by determining frame length dynamically based on PHY layer parameters (number of subcarriers, modulation rate, coding rate) rather than using fixed MAC layer parameters. This allows flexible adaptation to different data sizes and transmission conditions for multiple terminals while simplifying the configuration process through standardized PHY layer calculations.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The invention performs preliminary determination of the frame length at the PHY layer before data transmission, using the known parameters of subcarrier count, modulation rate, and coding rate. This preliminary action enables all multiple terminals to be configured with appropriately sized frames in advance, facilitating efficient concurrent transmission without complex real-time adjustments.

Inventive Principle:
Principle #10Preliminary action

3Manufacturing precision

If frame length is determined by MAC layer padding, then data alignment is achieved, but bandwidth utilization deteriorates due to excessive padding

Engineering Contradiction:
Improvedata alignmentVSAvoidbandwidth utilization
Core Design Contradiction:
Manufacturing precisionVSLoss of energy

Solution Approach 1:

The invention inverts the traditional approach by determining frame length at the PHY layer based on physical transmission parameters rather than adjusting data to fit MAC layer frame structures. This inversion allows the frame length to be optimized for actual transmission requirements, minimizing unnecessary padding and improving bandwidth utilization while maintaining proper data alignment through PHY layer processing.

Inventive Principle:
Principle #13The other way round (Inversion)

Data Source

PatentEP3244558B1Wireless communication device and wireless communication method
Publication Date: 2021.09.15 KDDI CORP
  • EP3244558B1 patent drawingFigure 1
  • EP3244558B1 patent drawingFigure 2
  • EP3244558B1 patent drawingFigure 3

AI summary

A wireless communication device transmits data to multiple wireless terminals at the same timing. The wireless communication device includes a complement calculation part configured to calculate the amount of complement for transmission data for each wireless terminal among multiple wireless terminals on multiple subcarriers distributed and assigned thereto, a complementation part configured to complement transmission data using the amount of complement calculated for each wireless terminal, and a transmitter configured to transmit the complemented transmission data to multiple wireless terminals via multiple subcarriers. The wireless communication device further includes a frame generator configured to generate frames (e.g. OFDMA frames) used to multiplex and transmit the complemented transmission data to multiple wireless terminals. The complement calculation part calculates the amount of complement based on the number of available subcarriers, which is determined via carrier sensing.