NDP Frame HE-Part Structure for Wireless LAN Sounding
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Solution Overview
Problem
The existing wireless LAN systems, particularly the 802.11ax standard, face challenges in efficiently performing NDP sounding operations due to inefficiencies in channel quality estimation methods, leading to increased signaling overhead.
Innovation Solution
A method is introduced that involves transmitting a null data packet announcement (NDP-A) frame and an NDP frame with specific fields such as HE-signaling A (HE-SIG A), HE-short training field (HE-STF), and HE-long training field (HE-LTF) to enable efficient channel quality estimation, optimized for High Efficiency (HE) systems by minimizing signaling overhead.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If traditional NDP sounding methods are used in 802.11ax systems, then channel quality estimation can be performed, but signaling overhead increases and efficiency decreases
Solution Approach 1:
The patent extracts and removes unnecessary fields from the NDP frame structure. Specifically, it eliminates the HE-SIG B field and data field from NDP frames, keeping only the essential HE-SIG A field, HE-STF, and HE-LTF. This extraction of non-essential elements reduces signaling overhead while preserving the core channel sounding functionality.
Solution Approach 2:
The patent changes the parameter configuration of the NDP frame by modifying the HE-SIG A field to contain only necessary sounding-related information rather than full data transmission control information. This parameter optimization reduces the frame size and signaling overhead while maintaining effective channel quality estimation.
2Ease of operation
If comprehensive control information is included in NDP frames, then data transmission control is improved, but channel quality estimation efficiency deteriorates due to increased overhead
Solution Approach 1:
The patent segments the control information into different parts: essential sounding control information is retained in the HE-SIG A field, while data transmission control information is removed or minimized. This segmentation allows the system to focus on channel sounding efficiency without the burden of comprehensive data transmission control in the NDP frame.
Solution Approach 2:
The patent applies partial action by including only the necessary portion of control information in the NDP frame's HE-SIG A field, rather than complete data transmission control information. This partial inclusion suffices for channel quality estimation purposes while reducing overhead and improving sounding efficiency.
Data Source
AI summary
An embodiment of the present invention suggests a method in which an access point (AP) obtains channel quality information in a wireless LAN system. The AP transmits, to at least one station (STA), a null data packet announcement (NDP-A) frame including information on transmission of a subsequent null data packet (NDP) frame, and transmits an NDP frame to the at least one station on the basis of information on the NDP-A frame. Further, the AP receives, from the at least one STA, a feedback frame including downlink channel quality information. At this time, the NDP frame includes an L-part for a legacy STA and a high efficiency (HE)-part for a HE STA, wherein the HE-part consists of a HE-signaling A (HE-SIG A) field, a HE-short training field (HE-STF), and a HE-long training field (HE-LTF).