DCM Modulation Phase Rotation for Wireless LAN Signal Integrity
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Solution Overview
Problem
In wireless LAN systems, the mixing of information from multiple stations in the signaling field (SIG B) leads to performance deterioration, particularly in IEEE 802.11ax standardization, where individual control information and data fields are combined, affecting transmission efficiency.
Innovation Solution
The implementation of Dual Carrier Modulation (DCM) for the HE-SIG B and data fields, using BPSK or QPSK schemes, where symbols are mapped to subcarriers and phase-shifted to prevent information mixing, with an indicator in the HE-SIG A field determining the modulation scheme, ensuring efficient transmission.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If information from multiple stations is mixed in the signaling field (SIG B), then the data transmission capacity is increased, but the transmission performance deteriorates
Solution Approach 1:
The patent divides the signaling field into separate sections for different stations (STA1, STA2, etc.) using station-specific indicators and resource unit allocations. Each station's control information is segmented into dedicated resource units rather than being mixed together, allowing individual processing and maintaining transmission performance while supporting multiple stations.
Solution Approach 2:
The patent applies different modulation schemes (BPSK, QPSK, QAM) to different parts of the signaling field based on the specific requirements of each station's information. By tailoring the modulation quality locally to each station's data characteristics and channel conditions, the system optimizes transmission performance for each segment while maintaining overall high capacity.
2Productivity
If DCM modulation is applied to HE-SIG B and data fields, then transmission efficiency is improved, but the system complexity increases
Solution Approach 1:
The patent implements dynamic modulation where the modulation scheme (BPSK, QPSK, or QAM) is selected based on channel conditions and data requirements. The system dynamically adjusts the modulation order and resource unit allocation for each station, allowing high transmission efficiency when conditions permit while reducing complexity when channel conditions are poor or for simpler data types.
Solution Approach 2:
The patent changes key transmission parameters including modulation order, resource unit size, and subcarrier allocation based on station-specific requirements and channel conditions. By adaptively adjusting these parameters, the system achieves high transmission efficiency for complex data while using simpler configurations for basic transmissions, effectively managing the complexity-efficiency tradeoff.
Data Source
AI summary
Disclosed according to one embodiment of the present invention is a method whereby a first station (STA) transmits signals using dual carrier modulation (DCM) in a wireless LAN system, comprising: modulating HE-SIG B field information and/or data field information on a wireless frame transmitted by the first STA and transmitting same to a second STA, wherein in the case of modulating the HE-SIG B field information and/or the data field information in a BPSK mode, if a random symbol C1 among symbols modulated in the BPSK mode is mapped to a subcarrier K, a symbol formed by rotating the phase of the symbol C1 is mapped to a subcarrier K+N/2 in a repeating manner, wherein N corresponds to the number of subcarriers of a resource unit for transmitting the HE-SIG B field information and the data field information and K is a random integer equal to or less than N/2.