Broadband PPDU Reception Using Phase-Rotated STF Sequences
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The existing wireless LAN systems face challenges in efficiently utilizing increased bandwidth and spatial streams due to the need for improved signaling techniques, particularly in the context of the next-generation EHT standard (IEEE 802.11be) which requires optimized PAPR and compatibility with previous standards like 802.11ax.
Innovation Solution
A method and apparatus for configuring an STF sequence for broadband transmission in the 802.11be system, using a modified STF sequence for 80/160 MHz bands that considers 20 MHz-based preamble puncturing and RF capabilities, enabling efficient decoding of PPDU signals.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the existing STF sequence for 80/160 MHz band is used for broadband transmission, then compatibility with previous standards is maintained, but optimized PAPR for broadband cannot be achieved
Solution Approach 1:
The broadband STF sequence is constructed by repeating the 160 MHz STF sequence multiple times (specifically, the sequence defined in clause 27.2.103 is repeated to form the broadband sequence). This segmentation approach allows the broadband sequence to be built from the existing 160 MHz sequence structure, maintaining compatibility while enabling broadband operation.
Solution Approach 2:
The patent applies phase rotation to the repeated STF sequence to optimize PAPR for broadband transmission. Specifically, a phase rotation of π/4 is applied to certain elements of the repeated sequence, transforming the sequence from a simple repetition into an optimized broadband sequence that achieves better peak-to-average power ratio characteristics while maintaining compatibility with the 802.11ax standard.
2Productivity
If increased bandwidth is used for higher throughput, then subcarrier efficiency improves, but signal decoding becomes more difficult
Solution Approach 1:
The STF sequence is designed with preliminary phase rotation applied to the repeated 160 MHz sequence before transmission. This preliminary action optimizes the signal characteristics for broadband transmission, making the signal more suitable for detection and decoding while maintaining the higher throughput enabled by increased bandwidth.
3Adaptability or versatility
If preamble puncturing is applied for 20 MHz-based transmission, then flexibility is improved, but sequence configuration becomes more complex
Solution Approach 1:
The patent defines a universal STF sequence configuration for broadband that works with various preamble puncturing patterns. The sequence structure defined in clause 27.2.103 can be applied across different bandwidth configurations (80 MHz, 160 MHz, 240 MHz, 320 MHz) and puncturing patterns, providing multi-functionality that reduces the need for separate sequence configurations for each scenario.
Data Source
AI summary
A method and a device for receiving a PPDU in a wireless LAN system are presented. Particularly, a reception STA receives a PPDU from a transmission STA through a broadband and decodes the PPDU. The broadband is the 320 MHz band or 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 the sequence in which phase rotation is applied to the sequence in which a second STF sequence is repeated. The second STF sequence is the STF sequence for the 160 MHz band defined in the 802.11ax wireless LAN system. The first sequence is the sequence in which a preset M sequence is repeated, and is defined as {M1−M0−M1−M0−M−1M0−M1−M0−M−1M0M−1M0M1−M0M−1M}*(1+j)/sqrt(2).