Transmission Apparatus Preamble Insertion for Channel Capacity
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Solution Overview
Problem
Existing non-legacy A-PPDU transmission methods face challenges in maximizing channel capacity and maintaining transmission efficiency due to differences in precoding matrices between PPDUs and difficulties in backward compatibility with legacy systems.
Innovation Solution
A transmission apparatus that inserts non-legacy STF and CEF into PPDUs other than the first PPDU, with an MCS change detection unit to adjust preambles and precoding matrices accordingly, ensuring compatibility and efficient channel utilization.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If preambles are inserted into every PPDU to maintain reception characteristics, then reception reliability is improved, but transmission overhead increases and transmission efficiency deteriorates
Solution Approach 1:
The patent applies local quality by selectively inserting preambles only in specific PPDUs (first PPDU and last PPDU) rather than uniformly in all PPDUs. This localized approach maintains necessary reception characteristics at critical points while avoiding redundant preamble overhead in intermediate PPDUs, thus resolving the contradiction between reliability and transmission efficiency.
Solution Approach 2:
The patent extracts the preamble function from every PPDU and concentrates it only where necessary (first and last PPDUs). By removing unnecessary preambles from intermediate PPDUs, the solution maintains essential reception capabilities while reducing overall overhead and improving transmission efficiency.
2Productivity
If precoding matrices are changed to match each PPDU's MCS, then channel capacity is maximized, but system complexity increases due to matrix management
Solution Approach 1:
The patent implements dynamic precoding matrix selection that adapts to each PPDU's MCS. The precoding matrix is changed according to the MCS of each PPDU, allowing the system to maximize channel capacity dynamically while maintaining manageable complexity through systematic matrix selection based on MCS values.
Solution Approach 2:
The patent changes the precoding matrix parameter according to MCS variations across different PPDUs. By linking precoding matrix selection to MCS parameters, the system achieves adaptive channel capacity optimization without requiring independent complex matrix management for each PPDU.
3Productivity
If preambles are reduced to improve transmission efficiency, then overhead is minimized, but reception characteristics may be degraded
Solution Approach 1:
The patent applies local quality by strategically placing preambles only at critical positions (first and last PPDUs) rather than uniformly distributing them. This localized preamble insertion maintains reception characteristics where most needed while minimizing overall overhead, thus resolving the contradiction between transmission efficiency and reception reliability.
4Adaptability or versatility
If legacy compatibility is maintained for all apparatuses, then system interoperability is ensured, but new features cannot be fully utilized by legacy devices
Solution Approach 1:
The patent achieves universality by designing a dual-mode system where the same transmission framework supports both legacy devices (using first MCS scheme) and non-legacy devices (using second MCS scheme with enhanced features). The base station can adaptively select which MCS scheme to use, ensuring broad compatibility while enabling advanced features for capable devices.
Data Source
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AI summary
A transmission apparatus (500) includes a generation circuit (501, 202, 203a, 203b, 204a, 204b, 205a, 205b) that generates a transmission signal in which a plurality of protocol data units in a physical layer are aggregated, an insertion circuit (506a, 506b) that inserts a preamble into each of a first protocol data unit and a second protocol data unit, where the preamble is used for at least one of synchronization of a transmission channel and estimation of the transmission channel, and a transmission circuit (507, 208a, 208b, 209a, 209b) that performs spatial processing on the transmission signal with the preamble inserted and transmits the transmission signal.