PPDU U-SIG Repetition for WLAN Range Extension
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Solution Overview
Problem
Current wireless local area network (WLAN) standards face limitations in extending the transmission range of wireless LAN signals, particularly in high-bandwidth environments, where existing technologies struggle to efficiently utilize bandwidth and maintain signal integrity across different frequency bands.
Innovation Solution
The proposed solution involves configuring a physical protocol data unit (PPDU) with an extended range (ER) preamble and duplicate transmission modes, incorporating a legacy signal (L-SIG) field, repeated L-SIG (RL-SIG) field, and a Universal Signal (U-SIG) field, where the receiving station determines the transmission mode based on constellation mapping patterns, allowing for enhanced signal reception and range extension.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If wide bandwidth (160/320 MHz) is used for high throughput, then data rate and throughput are improved, but transmission range and signal integrity deteriorate
Solution Approach 1:
The patent segments the transmission process into two distinct modes: extended range mode using 20 MHz bandwidth for reliable transmission, and high throughput mode using wide bandwidth (160/320 MHz) for high data rate. The PPDU structure is segmented into different fields (L-SIG, RL-SIG, U-SIG) that carry mode indication information, allowing the system to select the appropriate bandwidth segment based on transmission requirements.
Solution Approach 2:
The patent implements dynamic transmission mode selection where the system can switch between extended range mode and high throughput mode based on channel conditions and transmission requirements. The PPDU format dynamically adapts by including mode indication fields that tell the receiver how to interpret the subsequent data, enabling flexible bandwidth utilization.
2Productivity
If wide bandwidth is used for high throughput, then data rate is improved, but transmission range deteriorates
Solution Approach 1:
The patent divides the operational bandwidth into segments, allowing the system to use 20 MHz bandwidth for extended range transmissions and 160/320 MHz bandwidth for high throughput transmissions. The PPDU structure includes specific fields (L-SIG, RL-SIG, U-SIG) that segment the transmission parameters to indicate the intended bandwidth mode.
Solution Approach 2:
The patent changes the bandwidth parameter dynamically based on transmission requirements. By modifying the bandwidth parameter from 20 MHz to 160/320 MHz, the system can adapt between extended range and high throughput modes. The PPDU format includes parameter indication fields that specify the bandwidth configuration for the subsequent data transmission.
3Length of stationary object
If duplicate transmission mode is used for extended range, then transmission range is improved, but device complexity increases
Solution Approach 1:
The patent uses copying by repeating the L-SIG field (creating RL-SIG) to indicate extended range mode. This repetition provides a simple mechanism for mode indication without requiring complex encoding. The U-SIG field also contains repeated bit information from previous symbols, providing redundancy that simplifies receiver processing.
Solution Approach 2:
The patent implements periodic repetition of the L-SIG field across multiple symbols (first symbol, second symbol with repetition, third symbol, fourth symbol with repetition). This periodic structure creates a predictable pattern that simplifies receiver synchronization and mode detection while providing robustness against transmission errors.
4Productivity
If constellation mapping pattern is used for mode determination, then transmission efficiency is improved, but measurement precision requirements increase
Solution Approach 1:
The patent performs preliminary action by embedding mode indication information directly into the PPDU structure fields (L-SIG, RL-SIG, U-SIG) before the data transmission begins. The receiving station can determine the transmission mode from these preliminary fields without needing to analyze the entire data stream, reducing measurement precision requirements.
Solution Approach 2:
The patent incorporates feedback mechanisms where the U-SIG field contains bit information that is repeated from previous symbols. This feedback structure allows the receiver to verify mode indication information and correct potential errors, reducing the precision requirements for constellation mapping detection.
Data Source
AI summary
The present specification provides a technical feature for extended range transmission in a wireless LAN signal. A physical protocol data unit (PPDU) of the present specification may include a universal signal (U-SIG) field. The U-SIG field may be received through first to the fourth symbols, the second symbol may include information in which bit information of the first symbol is repeated, and the fourth symbol may include information in which bit information of the third symbol is repeated. The receiving STA of the present specification may determine the transmission mode of the PPDU based on constellation mapping pattern of the first and second symbols.