UL MU-MIMO Frame Synchronization via Poll and ACK
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Solution Overview
Problem
Current uplink multi-user multiple-input and multiple-output (MU-MIMO) technologies face challenges in synchronizing data frame reception between multiple stations (STAs) and an access point (AP), leading to abnormal data reception due to timing errors exceeding 100 nanoseconds.
Innovation Solution
A method for transmitting and receiving frames in MU-MIMO communication involves sending an uplink multi-user poll (UL MU poll) frame with identification information to determine transmission STAs, followed by simultaneous data frame transmission and acknowledgement (ACK) frames, using MU-MIMO technology or in an unbeamformed state, to ensure synchronized data reception.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If simultaneous data frame transmission from multiple STAs to AP is implemented using UL MU-MIMO technology, then productivity is improved, but timing synchronization accuracy deteriorates leading to abnormal data reception
Solution Approach 1:
The AP sends a UL MU poll frame before the STAs transmit data frames, preliminarily establishing the transmission timing and synchronization requirements. This preliminary action allows STAs to align their transmission schedules before actual data transmission begins, ensuring timing accuracy while maintaining simultaneous transmission capability
Solution Approach 2:
The AP sends an ACK frame after receiving data frames from multiple STAs, providing feedback on successful reception. This feedback mechanism allows the system to verify timing synchronization accuracy and adjust future transmissions accordingly, maintaining both productivity and timing precision
2Reliability
If beamforming is applied to data frame transmission, then signal reception performance is improved, but timing synchronization between multiple STAs becomes more difficult to maintain
Solution Approach 1:
The transmission process is segmented into distinct phases: poll frame transmission, data frame transmission with beamforming, and ACK frame transmission. Each phase has specific timing requirements that can be independently controlled, allowing beamforming to be applied to data frames while maintaining overall timing synchronization through the structured segmentation of the communication protocol
3Loss of time
If multiple STAs transmit data frames simultaneously to AP, then loss of time is reduced, but device complexity increases due to synchronization requirements
Solution Approach 1:
Multiple STAs are merged into a coordinated transmission group managed by the AP. The AP consolidates timing control and sends a single UL MU poll frame that coordinates all STAs in the group, reducing individual STA complexity while enabling simultaneous transmission that minimizes time loss
Data Source
AI summary
Provided is a method of transmitting and receiving a frame for a multi-user multiple-input and multiple-output (MU-MIMO) communication in an access point (AP), the method including determining at least one transmission station (STA), transmitting, to the transmission STA, an uplink multi-user poll (UL MU poll) frame requesting a data frame, receiving the data frame from the at least one transmission STA simultaneously, and transmitting an acknowledgement (ACK) frame to the at least one transmission STA in response to the receiving.