Cross-AP Channel Sounding for Concurrent Wi‑Fi Transmission
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Solution Overview
Problem
The challenge of performing channel sounding across multiple access points (APs) to enable concurrent data transmission without interference, particularly in scenarios where insufficient frequency resources require intra-frequency deployment, is unresolved in existing wireless fidelity technologies.
Innovation Solution
A method and apparatus for channel sounding across APs, utilizing user association frames to determine channel sounding results based on identification information and synchronization, reducing unnecessary sounding and improving data transmission rates by ensuring synchronized and accurate channel state assessment.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If multiple APs are deployed on the same frequency to improve network coverage and capacity, then the number of available frequency resources is increased, but interference between APs increases
Solution Approach 1:
The patent performs channel sounding before actual data transmission to obtain channel state information (CSI) of neighboring APs. This preliminary measurement enables the AP to calculate interference nulling weights in advance, allowing concurrent transmission without interference while maintaining multiple AP deployments on the same frequency
2Productivity
If interference nulling mode is used to allow concurrent data transmission, then the network transmission rate is improved, but channel sounding complexity increases
Solution Approach 1:
The patent enables each AP to autonomously perform channel sounding on its own and request/obtain channel state information from neighboring APs. The AP independently calculates interference nulling weights using received CSI and transmits data without requiring centralized coordination, thereby reducing overall system complexity while maintaining high transmission rates
Solution Approach 2:
The patent implements a feedback mechanism where APs exchange channel state information through association response frames. Each AP uses the feedback CSI from neighboring APs to adjust its transmission parameters and calculate interference nulling weights, enabling adaptive concurrent transmission that maintains high productivity
3Productivity
If channel sounding is performed across all APs to enable interference nulling, then concurrent data transmission is achieved, but the amount of information exchange increases
Solution Approach 1:
The patent extracts only the necessary channel state information (CSI) from the complete signal data. Instead of exchanging all raw signal data between APs, the system extracts and transmits only the essential CSI parameters needed for interference nulling, significantly reducing information exchange overhead while maintaining concurrent transmission capability
Solution Approach 2:
The patent applies channel sounding and CSI acquisition locally at each AP for its own transmission. Each AP performs channel sounding on its dedicated channel and requests only the CSI from neighboring APs that are actually causing interference, rather than exchanging information with all APs in the network, thereby reducing overall information exchange requirements
Data Source
AI summary
This application discloses a channel sounding method and a communication apparatus. The method includes: A first access point performs channel sounding on a channel sounding frame sent by a first station, and sends a user association frame to a second access point. The second access point determines, based on identification information of the first station in the user association frame, a first channel sounding result that matches the first station from a plurality of second channel sounding results. The first station is associated with the first access point, and is not associated with the second access point. The plurality of second channel sounding results are obtained by the second access point by performing sounding on a plurality of channel sounding frames from a plurality of stations.