WLAN Spatial Reuse via STA Grouping and Power Control
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Solution Overview
Problem
In densely deployed WLAN environments, repeaters experience interference due to overlapping coverage regions, limiting their ability to use available bandwidth effectively and resulting in lower throughput compared to links between APs and repeaters.
Innovation Solution
Implementing a spatial reuse mechanism that groups non-AP STAs based on their location within repeaters' coverage regions, allowing for the allocation and reuse of resource units (RUs) without causing interference, using techniques like received power ratios and channel status information to differentiate between overlapping and non-overlapping groups, and adjusting transmit power to prevent interference.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If repeaters are allocated with completely different RUs to avoid transmission interference, then interference among repeaters is avoided, but the repeaters cannot use the full bandwidth and network throughput is limited
Solution Approach 1:
The bandwidth is segmented into multiple RUs (Resource Units), and different groups of non-AP STAs are assigned to different RUs. Non-overlapping groups use dedicated RUs while overlapping groups share RUs with power adjustment, enabling both interference avoidance and efficient bandwidth utilization
Solution Approach 2:
Different transmission strategies are applied to different spatial regions: non-overlapping groups receive dedicated RU allocation while overlapping groups use power-adjusted RU sharing. This localized quality differentiation allows simultaneous interference avoidance and bandwidth efficiency in different regions
2Productivity
If multiple repeaters transmit simultaneously to overlapping groups using the same RUs, then bandwidth utilization is improved, but transmission interference occurs among repeaters
Solution Approach 1:
Transmit power is adjusted as a controllable parameter for overlapping groups. The coordinating repeater transmits at normal power while non-coordinating repeaters reduce power when transmitting to overlapping groups on shared RUs, changing the power parameter to prevent interference while maintaining bandwidth utilization
Solution Approach 2:
The system uses feedback mechanisms where the coordinating repeater identifies overlapping groups based on received power ratios and channel status information, then coordinates with non-coordinating repeaters to adjust their transmit power accordingly, creating a closed-loop control system
3Measurement precision
If repeaters use received power ratios and channel status information to identify overlapping groups, then RU allocation accuracy is improved, but system complexity increases
Solution Approach 1:
Channel status information is obtained through preliminary sounding signals exchanged between repeaters and non-AP STAs before the actual data transmission. This preliminary measurement enables accurate identification of overlapping groups without adding complexity during the data transmission phase
Data Source
AI summary
Systems and methods of WLAN communication including efficient spatial reuse mechanisms for relay transmissions between a repeater network and non-AP STAs in OFDMA. The non-AP STAs are grouped based on their connectivity with the individual repeaters and the radio coverage regions of the repeaters. Each group is either a non-overlapping group with the constituent non-AP STAs located in a non-overlapping coverage region of a particular repeater, or an overlapping group with the constituent non-AP STAs located in an overlapping coverage region of two or more repeaters. Based on the grouping, certain RUs (or subchannels) are reused for multiple groups without causing inter-group interference, thereby expanding the bandwidths used in the relay operations. RU allocation based on grouping can be used in combination with transmit power adjustment to achieve efficient spatial reuse in OFDMA.