Trigger Frame MCS Group Signaling for Multi-Stream Wi-Fi
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Solution Overview
Problem
Existing wireless communication standards face challenges in efficiently indicating modulation and coding schemes (MCS) for multiple spatial streams using a small number of bits, leading to increased signaling overheads as the number of spatial streams and MCS types increase.
Innovation Solution
A modulation and coding scheme indication method using a trigger frame with specific fields to indicate an MCS group and the number of spatial streams, allowing flexible indication of MCSs across multiple streams with reduced overheads.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If one index is used to indicate MCS for each spatial stream individually, then MCS indication precision is improved, but signaling overhead increases exponentially with the number of spatial streams
Solution Approach 1:
The patent segments the MCS indication into two parts: a first field indicating an MCS group (shared by multiple spatial streams) and a second field indicating which specific MCS within that group is used for each spatial stream. This segmentation allows the system to benefit from both coarse-grained grouping (reducing overhead) and fine-grained selection (maintaining precision).
Solution Approach 2:
The patent introduces a grouping dimension to the MCS indication scheme. Instead of directly indicating MCS for each spatial stream in a flat structure, it creates a hierarchical structure with MCS groups as the first dimension and spatial stream-specific MCS selection as the second dimension. This dimensional change enables more efficient encoding.
2Productivity
If the number of spatial streams increases to support more antennas, then communication capacity is improved, but the complexity of MCS indication increases
Solution Approach 1:
The patent merges the MCS indication for multiple spatial streams into a single MCS group indication when all streams use MCS from the same group. This merging reduces the complexity of MCS indication while still supporting a large number of spatial streams, as the group-level indication applies to all streams simultaneously.
Solution Approach 2:
The patent implements a dynamic MCS indication mechanism where the second field is only present and used when spatial streams require different MCS within the indicated group. When all streams use the same MCS, the indication is simplified to just the first field. This dynamic approach adapts the indication complexity to the actual communication needs.
Data Source
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AI summary
Embodiments of this application disclose a modulation and coding scheme indication method and a corresponding apparatus. This application is applied to a wireless local area network system that supports one or more of a next-generation Wi-Fi protocol of IEEE 802.11ax (for example, 802.11be, Wi-Fi 7, or EHT), a next-generation Wi-Fi protocol of IEEE 802.11be (for example, 802.11bn, Wi-Fi 8, or UHR), Wi-Fi AI, a millimeter wave (mmWave), an ultra wideband (UWB), and sensing (sensing). The method includes: generating a trigger frame, where the trigger frame includes a first field and a second field, the first field indicates a first MCS group used by a PPDU sent by a first device, and the second field indicates a number of spatial streams corresponding to one or more MCSs in the first MCS group; and sending the trigger frame. This can reduce bit overheads.