Distributed Resource Unit Tone Mapping for Low-Latency WLAN
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Solution Overview
Problem
Existing WLAN systems face challenges in providing advanced wireless communication environments with improved transmission rates, reliability, and reduced latency, particularly in supporting low latency and ultra-high reliability for real-time traffic.
Innovation Solution
A method and device utilizing a distributed resource unit tone plan in a WLAN system, where physical layer protocol data units (PPDUs) are mapped onto distributed resource units (DRUs) across multiple 20 MHz channels, defining subcarriers for efficient bandwidth utilization.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If distributed resource units (DRUs) are used to map PPDUs across multiple 20 MHz channels, then bandwidth utilization and transmission rate are improved, but system complexity and resource allocation overhead increase
Solution Approach 1:
The 40 MHz channel is segmented into multiple 20 MHz sub-channels, with each sub-channel containing specific DRUs. For example, the first 20 MHz channel includes DRU 1-1 and DRU 1-2, while the second 20 MHz channel includes DRU 2-1 and DRU 2-2. This segmentation allows parallel transmission across multiple channels, improving overall transmission rate while maintaining manageable complexity through structured resource organization.
Solution Approach 2:
The patent introduces a frequency-domain dimension by distributing resource units across multiple 20 MHz channels instead of using a single contiguous channel. PPDUs are mapped to different DRUs in the frequency domain, enabling simultaneous transmissions on multiple channels. This dimensional expansion increases bandwidth utilization without proportionally increasing processing complexity.
2Quantity of substance
If 26-tone DRUs are distributed across 40 MHz bandwidth, then spectral efficiency and bandwidth utilization are improved, but the number of subcarrier definitions and configuration parameters increase
Solution Approach 1:
Each 20 MHz channel has its own local DRU configuration with specific subcarrier definitions. For instance, DRU 1-1 in the first 20 MHz channel uses subcarriers {0, 3, 6, 9, 12, 15, 18, 21, 24, 27, 30, 33, 36, 39, 42, 45}, while DRU 2-1 in the second 20 MHz channel uses subcarriers {512, 515, 518, 521, 524, 527, 530, 533, 536, 539, 542, 545, 548, 551, 554, 557}. This local quality approach allows independent optimization of each DRU while maintaining overall system coherence.
Solution Approach 2:
The patent pre-defines the subcarrier allocations for all DRUs before transmission. The subcarrier sets for each DRU are determined in advance based on the channel bandwidth and DRU configuration, eliminating the need for dynamic subcarrier calculation during transmission. This preliminary action reduces real-time processing complexity while maximizing bandwidth utilization.
3Productivity
If multiple PPDUs are transmitted simultaneously on different DRUs, then throughput and spectral efficiency are improved, but interference management and signal detection complexity increase
Solution Approach 1:
The system segments the frequency spectrum into orthogonal DRUs with non-overlapping subcarrier sets. Each DRU operates independently with its own subcarrier allocation, ensuring orthogonality between simultaneous transmissions. This segmentation prevents inter-channel interference while enabling parallel transmissions, improving throughput without proportionally increasing detection complexity.
Solution Approach 2:
The patent uses a structured DRU mapping scheme as an intermediary between the physical layer and the application layer. This intermediate structure organizes subcarriers into predefined DRUs with clear boundaries and orthogonality relationships, simplifying the detection process by providing a systematic framework for signal separation and interference management.
Data Source
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AI summary
Disclosed are a distributed resource unit tone plan-based transmission or reception method and device in a wireless LAN system. A method carried out by a first station (STA) in a wireless local area network (WLAN) system, according to one embodiment of the present disclosure, may comprise the steps of: generating a PPDU including one or more fields, the one or more fields being mapped onto one or more DRUs; and transmitting the PPDU to one or more second STAs over a bandwidth including a first 20 MHz channel and a second 20 MHz channel. An available subcarrier in the first 20 MHz channel and the second 20 MHz channel may be a subcarrier among 512 subcarriers in a 40 MHz channel including the first 20 MHz channel and the second 20 MHz channel, excluding five DC subcarriers, 16 null subcarriers, 23 guard subcarriers, and 36 pilot subcarriers.