1×EHT-STF Sequence Repetition for 320 MHz Preamble Puncturing
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Solution Overview
Problem
The increased number of spatial streams in the next-generation wireless LAN system (EHT/IEEE 802.11be) requires improved signaling techniques to efficiently transmit and receive Physical Protocol Data Units (PPDUs) over broader bandwidths, such as 240 MHz or 320 MHz, while maintaining compatibility with previous standards like 802.11ax.
Innovation Solution
A method is proposed to configure a 1×EHT-STF sequence by repeating an STF sequence for a 40 MHz band, considering a limited preamble puncturing pattern and RF capability, to optimize Peak to Average Power Ratio (PAPR) and facilitate subcarrier estimation and automatic gain control at the receiving end.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If an STF sequence is configured for broadband (240 MHz or 320 MHz) by repeating the 40 MHz STF sequence, then the PAPR is optimized and subcarrier estimation and AGC are facilitated, but the device complexity increases due to the need to handle multiple bandwidth configurations and puncturing patterns
Solution Approach 1:
The broadband STF sequence is segmented into multiple 40 MHz sub-sequences that are repeated and arranged in a specific pattern. This segmentation allows the receiver to process the broadband signal by combining results from multiple narrower bandwidth segments, improving reliability while managing complexity through modular processing
Solution Approach 2:
The patent changes the frequency domain parameters of the STF sequence by repeating the 40 MHz sequence across broader bandwidths (240 MHz, 320 MHz) and applying different puncturing patterns. This parameter transformation enables optimized PAPR characteristics and facilitates subcarrier estimation without requiring entirely new sequence designs for each bandwidth
2Reliability
If the STF sequence is repeated for broader bandwidths to optimize PAPR, then the signal quality improves, but the manufacturing precision requirements increase for maintaining sequence integrity across multiple repetitions
Solution Approach 1:
The 40 MHz STF sequence is copied and repeated multiple times across broader bandwidths (240 MHz, 320 MHz) according to defined patterns. This copying approach ensures sequence integrity is maintained through exact replication, with precision requirements managed by the deterministic nature of the repetition pattern rather than requiring complex generation algorithms
Solution Approach 2:
The STF sequence structure employs a nested pattern where 40 MHz sequences are embedded within 240 MHz and 320 MHz bandwidths in a hierarchical arrangement. This nesting provides a structured framework that simplifies sequence configuration and reduces precision requirements by establishing clear positional relationships between repeated elements
3Adaptability or versatility
If preamble puncturing is applied to the broadband signal, then the RF capability is improved and subcarrier estimation is facilitated, but the loss of information increases in the punctured regions
Solution Approach 1:
Different puncturing patterns are applied to different frequency sub-bands within the broadband signal. This local differentiation allows RF capabilities to be optimized for specific frequency regions while maintaining signal integrity in other regions, reducing overall information loss by adapting the puncturing strategy to local channel conditions and RF characteristics
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 from a transmission STA through a broadband and decodes the PPDU. 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 on the basis of a first preamble puncturing pattern of the broadband. When the broadband is a 320 MHz band, the first preamble puncturing pattern includes a pattern in which a 40 MHz or 80 MHz band is punctured in the broadband. The first STF sequence is a sequence including an M sequence and is defined as {M 0 −M 0 M 0 −M 0 M 0 −M 0 −M 0 M 0 M 0 −M 0 −M 0 M 0 −M 0 M 0 M 0 −M}*(1+j)/sqrt(2).