HEW PPDU Format Phase Rotation OFDM Subcarriers
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Solution Overview
Problem
Current wireless local area network (WLAN) technologies face challenges in achieving high efficiency and compatibility across different frequency bands, particularly in congested environments, with existing standards like IEEE 802.11n and 802.11ac, which struggle to optimize data transmission rates and coexist with legacy systems.
Innovation Solution
The proposed High Efficiency WLAN (HEW) system uses a modified Physical Layer Protocol Data Unit (PPDU) format with increased OFDM subcarriers per unit frequency, achieved by larger FFT sizes, and phase rotation techniques to support multiple users and bands, ensuring backward compatibility and reduced Peak-to-Average Power Ratio (PAPR), allowing for efficient data transmission across 2.4 GHz, 5 GHz, and 60 GHz bands.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If larger FFT sizes and increased OFDM subcarriers are used to improve data transmission efficiency, then throughput and transmission rate are improved, but Peak-to-Average Power Ratio (PAPR) increases causing signal distortion and reduced system reliability
Solution Approach 1:
The patent applies phase rotation techniques that modify the phase parameters of OFDM subcarriers to reduce PAPR. By changing the phase distribution of subcarriers through rotation in the complex plane, the patent achieves lower peak power values while maintaining the same data transmission rate and efficiency, thus resolving the contradiction between productivity and reliability
2Productivity
If new WLAN standards and protocols are implemented to achieve higher throughput, then data transmission rate is improved, but compatibility with legacy systems deteriorates
Solution Approach 1:
The patent designs the HEW PPDU format with universal compatibility features that allow it to function across multiple WLAN standards. The frame structure incorporates elements that can be interpreted by both legacy systems and HEW systems, enabling the same transmission format to achieve high throughput while maintaining backward compatibility with different WLAN generations
3Productivity
If OFDMA and MU-MIMO techniques are deployed to support multiple users simultaneously, then system capacity and efficiency are improved, but device complexity and signal processing requirements increase
Solution Approach 1:
The patent segments the wireless medium into multiple orthogonal frequency subcarriers and spatial streams that can be independently allocated to different users. By dividing the resources into manageable subcarriers and applying user-specific phase rotations, the patent reduces the processing complexity at each user device while maintaining high system capacity through parallel transmissions
Data Source
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AI summary
A method for transmitting data in a wireless local area network and a device suing the same are provided. The device transmits a plurality of medium access control protocol data units (MPDUs) to at least one destination station. Duration fields in all of the plurality of MPDUs are set to a same value.