HE and EHT Traffic Alignment for Orthogonal WLAN Multiplexing
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Solution Overview
Problem
Existing wireless communication systems face challenges in simultaneously supporting high efficiency (HE) and extremely high throughput (EHT) wireless traffic due to incompatibilities in transmission durations and bandwidths, leading to misalignment and interference between HE and EHT devices.
Innovation Solution
The method involves aligning pre-modulated and modulated fields of HE and EHT preamble PPDU portions in time, ensuring orthogonality through techniques such as padding and maintaining consistent symbol durations and guard intervals, allowing simultaneous transmission over different portions of the bandwidth.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If HE and EHT transmissions are transmitted simultaneously without alignment, then transmission diversity is achieved, but time misalignment and interference occur between different traffic types
Solution Approach 1:
The patent applies preliminary action by aligning the preambles of HE and EHT transmissions before actual data transmission. The access point adjusts the timing of HE or EHT preambles in advance to ensure they start at the same time, preventing time misalignment and interference during the transmission process. This preliminary timing adjustment resolves the contradiction by establishing proper synchronization before productivity gains from simultaneous transmission are realized.
2Adaptability or versatility
If different bandwidths are used for HE and EHT traffic, then bandwidth flexibility is improved, but orthogonal multiplexing becomes difficult
Solution Approach 1:
The patent applies segmentation by dividing the total bandwidth into separate subbands for HE and EHT transmissions. Each traffic type is assigned to a specific frequency subband, allowing orthogonal multiplexing without requiring the transmissions to occupy the entire bandwidth. This resolves the contradiction by enabling bandwidth flexibility for different traffic types while simplifying multiplexing through clear frequency separation.
3Adaptability or versatility
If HE and EHT preambles have different durations, then protocol compatibility is maintained, but time synchronization is compromised
Solution Approach 1:
The patent applies parameter changes by dynamically adjusting the duration of HE or EHT preambles to match each other. The access point identifies which preamble type (HE or EHT) has the shorter duration and extends it through padding or additional symbols, ensuring both preambles have equal duration. This resolves the contradiction by maintaining protocol compatibility for both HE and EHT devices while achieving time synchronization for orthogonal multiplexing.
Data Source
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Figure 3A~3B
AI summary
This disclosure provides systems, methods, apparatus, including computer programs encoded on computer storage media for orthogonal multiplexing of high efficiency (HE) and extremely high throughput (EHT) wireless traffic. Devices in a wireless local area network (WLAN) may operate under HE or EHT conditions. An access point (AP) may support both HE and EHT communications with WLAN devices. To enable substantially simultaneous downlink HE and EHT transmissions and substantially simultaneous uplink HE and EHT transmissions, the AP may support orthogonal frequency-division multiple access (OFDMA) of HE and EHT transmissions. For example, pre-HE and pre-EHT modulated fields, HE and EHT modulated fields, and payloads may be aligned in time for the HE and EHT transmissions. The AP may ensure orthogonality for multiplexing the HE and EHT transmissions based on the alignment. In some implementations, a trigger frame may be utilized to indicate uplink transmission alignments.