OFDMA Uplink Resource Allocation via Cyclic Shift Diversity
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Solution Overview
Problem
In dense Wi-Fi deployments, uplink bandwidth requests from multiple devices often collide, making it difficult for access points to distinguish between them, leading to unsuccessful transmissions and inefficient resource allocation.
Innovation Solution
The implementation of a two-phase OFDMA uplink resource allocation framework that uses cyclic shift diversity values to enable devices to transmit unique signals, allowing access points to identify and differentiate between devices, thereby preventing collisions and improving resource allocation efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If multiple devices transmit uplink bandwidth requests simultaneously on a shared resource unit, then resource allocation can be achieved, but signal collisions occur making it difficult for access points to distinguish between devices
Solution Approach 1:
The patent segments the uplink transmission by dividing the shared resource unit into multiple orthogonal frequency division multiplexing (OFDM) subcarriers. Each device is assigned specific subcarriers, allowing simultaneous transmissions to be separated in the frequency domain. This segmentation enables the access point to distinguish between devices while maintaining high resource allocation efficiency.
Solution Approach 2:
The patent introduces frequency domain dimensioning by allocating different subsets of OFDM subcarriers to different devices within the same resource unit. This dimensional separation transforms the collision problem from a time-domain issue into a frequency-domain resource allocation problem, allowing simultaneous transmissions to coexist without interference.
2Reliability
If cyclic shift diversity values are used to differentiate devices, then signal collision is prevented, but system complexity increases
Solution Approach 1:
The patent changes the cyclic shift parameter of the cyclic prefix for different devices. By applying different cyclic shift values to the training sequences or data symbols, each device's signal becomes distinguishable through correlation processing at the access point. This parameter-based differentiation provides a simple yet effective method for device identification without requiring complex signaling overhead.
Data Source
AI summary
This disclosure describes systems, methods, and devices related to a flexible connectivity framework. A first device may send a trigger frame to a second device. The first device may then receive an uplink bandwidth resource request from the second device. The first device may detect a high efficiency-long training field (HE-LTF) in the uplink bandwidth resource request. The first device may send an uplink multiuser trigger frame, and the first device may receive an uplink frame from the second device.