A-PPDU Bandwidth Signaling for Legacy-Compatible 60 GHz Transmission
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Solution Overview
Problem
Next Generation 60 GHz (NG60) WiGig devices need to maintain compatibility with legacy devices while supporting higher data transmission speeds by using variable channel bandwidths, requiring an efficient method for configuring and transmitting Aggregate Physical Layer Convergence Protocol Data Units (A-PPDUs) to maximize transmission efficiency.
Innovation Solution
The configuration and transmission of A-PPDUs involve using non-legacy headers and headers with duplicated fields, allowing for transmission over both standard and variable channel bandwidths, with specific formatting and processing techniques to ensure compatibility and efficiency, including the use of SC and OFDM modulation, and GI management to maintain interference avoidance and power efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If NG60 WiGig devices use variable channel bandwidths to achieve higher data transmission speeds, then transmission speed is improved, but compatibility with legacy WiGig devices deteriorates
Solution Approach 1:
The A-PPDU is segmented into multiple PPDUs that can be transmitted in sequence. Each PPDU contains a header field with bandwidth indication information that specifies the channel bandwidth used for that particular PPDU or subsequent PPDUs. This segmentation allows the transmission to adapt to different bandwidth requirements while maintaining a structured format that legacy devices can partially process.
Solution Approach 2:
Different portions of the A-PPDU transmission use different channel bandwidths according to local requirements. The header field of each PPDU locally indicates the bandwidth to be used, allowing specific segments of the transmission to operate at higher speeds while other segments maintain compatibility with legacy devices. This local adaptation resolves the contradiction between speed improvement and legacy compatibility.
2Productivity
If A-PPDU transmission uses multiple PPDUs with different channel bandwidths, then transmission efficiency is improved, but format complexity increases
Solution Approach 1:
The header field of each PPDU preliminarily indicates the channel bandwidth to be used for that PPDU or subsequent PPDUs in the A-PPDU sequence. This preliminary indication allows receiving devices to pre-configure their processing parameters before actually receiving the data portions, simplifying the handling of variable bandwidth transmissions and reducing format complexity despite the efficiency gains from multiple bandwidth configurations.
3Adaptability or versatility
If NG60 devices support both LF PPDUs and MF PPDUs for legacy compatibility, then adaptability is improved, but device complexity increases
Solution Approach 1:
The A-PPDU transmission mechanism is designed with universal functionality to handle both Legacy Format (LF) PPDUs and Mixed Format (MF) PPDUs. The header field structure and bandwidth indication mechanism work uniformly regardless of whether the transmission uses standard or variable channel bandwidths. This multi-functionality allows a single device implementation to support both legacy and next-generation formats, improving adaptability while minimizing the need for separate processing paths and reducing overall device complexity.
Data Source
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AI summary
In a transmission device a duplicating unit duplicates, out of first physical layer convergence protocol data units (PPDUs) an (N - 1) count (where in N is an integer of 2 or greater) of a first PPDU transmitted at a standard channel bandwidth, in a frequency axis direction. A GI insertion unit adds a guard interval to each of the first PPDU transmitted at the standard channel bandwidth, the duplicated first PPDU transmitted at the standard channel bandwidth, a first PPDU, out of the first PPDUs, transmitted at a variable channel bandwidth that is N times the standard channel bandwidth, and a second PPDU transmitted at the variable channel bandwidth, and outputs as an aggregate physical layer convergence protocol data unit (A-PPDU). An RF frontend transmits the A-PPDU.