STF Sequence Phase Rotation for PAPR Optimization in 320 MHz WLAN
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Solution Overview
Problem
Current WLAN systems face challenges in efficiently transmitting Physical Protocol Data Units (PPDUs) over broadbands, particularly in achieving optimized Peak to Average Power Ratio (PAPR) and subcarrier efficiency, especially with the increased bandwidth requirements of next-generation standards like IEEE 802.11be/EHT.
Innovation Solution
A method and apparatus are proposed to configure a Short Training Field (STF) sequence for the 80 MHz band, considering 20 MHz-based preamble puncturing patterns, which involves applying phase rotation to a repeated sequence and using a predefined M sequence to optimize PAPR during PPDU transmission.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a conventional STF sequence is used for broadband transmission, then the system maintains compatibility with existing standards, but the PAPR is not optimized and subcarrier efficiency is reduced
Solution Approach 1:
The patent applies parameter changes by modifying the STF sequence through phase rotation operations. Specifically, the sequence is rotated by angles of π/4, 3π/4, 5π/4, or 7π/4 to optimize the peak-to-average power ratio while maintaining sequence validity. This transformation changes the signal parameters to achieve better PAPR characteristics without compromising the sequence's functional properties.
Solution Approach 2:
The patent introduces dynamic adaptability by selecting different phase rotation angles based on the specific transmission conditions and bandwidth configuration. The system dynamically adjusts the STF sequence through phase rotation operations adapted to the broadband environment, allowing optimization of PAPR for different transmission scenarios rather than using a fixed sequence.
2Productivity
If the bandwidth is increased to meet next-generation standard requirements, then throughput is improved, but the complexity of signal configuration increases
Solution Approach 1:
The patent applies segmentation by dividing the broadband into multiple 20 MHz sub-bands and applying preamble puncturing patterns that selectively activate specific segments. The STF sequence is configured based on these segmented bandwidth allocations, allowing the system to handle broadband transmissions by combining multiple standardized 20 MHz units with controlled puncturing patterns.
Solution Approach 2:
The patent achieves universality by creating a STF sequence configuration that works across multiple bandwidth types (80 MHz, 160 MHz, 320 MHz) through a unified approach. The same phase rotation methodology and sequence construction principles apply regardless of the specific bandwidth, allowing a single solution to serve multiple bandwidth requirements and reducing configuration complexity.
3Productivity
If preamble puncturing is applied to optimize spectral efficiency, then subcarrier utilization is improved, but the sequence generation becomes more complex
Solution Approach 1:
The patent applies preliminary action by pre-defining the M sequence and establishing the phase rotation rules before the actual transmission occurs. The sequence generation process uses these pre-established patterns and operations, which simplifies the real-time sequence generation complexity while maintaining optimized spectral efficiency through the puncturing pattern.
Data Source
AI summary
Proposed are a method and a device for receiving a PPDU in a wireless LAN system. Specifically, a reception STA receives a PPDU through a broadband from a transmission STA, and decodes the PPDU. The broadband is a 320 MHz band or a (160+160) MHz band. The PPDU includes an STF signal. The STF signal is generated on the basis of a first STF sequence for the broadband. The first STF sequence is obtained by applying a phase rotation to a sequence in which a second STF sequence for a 80 MHz band is repeated. The first STF sequence is a sequence in which a preconfigured M sequence is repeated, and is defined by a formula {M−1 −M 0 −M −1 M 0 M −1 −M 0 −M −1 M 0 −M 1 M 0 M 1 −M 0 −M 1 M 0 M 1 −M}*(1+j)/sqrt(2). A first preamble puncturing pattern includes all patterns of a band obtained by puncturing a 20 MHz band in the 320 MHz band or the (160+160) MHz band.