DCM Signal Duplication With Phase Rotation For PAPR Reduction
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Solution Overview
Problem
Current duplication schemes in wireless communications, such as those in IEEE 802.11be, result in increased peak-to-average power ratio (PAPR), leading to signal distortion and the need for reduced transmit power, which limits the range and efficiency of wireless local area networks (WLANs).
Innovation Solution
The proposed solution involves encoding data using dual carrier modulation (DCM) and duplicating it across a full signal bandwidth, followed by multiplication with a modulation vector to achieve reduced PAPR, specifically using techniques like 'no modulation', 'half -1/1', 'alternating +/-1', 'Cyclic Shift Diversity', and 'scrambled +/-1' to minimize PAPR in transmission.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If data is duplicated across full signal bandwidth using current duplication schemes, then bandwidth utilization and transmit power are improved, but PAPR increases causing signal distortion
Solution Approach 1:
The patent applies different modulation strategies to different portions of the duplicated signal. Specifically, it uses phase rotation on the second half of the duplicated subcarriers while keeping the first half unchanged, creating local variations in signal properties that reduce overall PAPR while maintaining bandwidth utilization benefits
2Object-generated harmful factors
If transmit power is reduced to lower peak power, then PAPR is effectively managed, but transmission range and efficiency decrease
Solution Approach 1:
The patent changes the phase parameter of the modulated signal by applying phase rotation (multiplication by e^(jθ)) to the duplicated subcarriers. This parameter change allows the signal to maintain its power level while reducing peak amplitude variations, thereby improving transmission efficiency without sacrificing peak power control
3Length of moving object
If duplication is applied over larger bandwidth, then WLAN range is extended, but signal distortion increases due to increased PAPR
Solution Approach 1:
The patent divides the duplicated bandwidth into two portions and applies different processing: the first half remains unchanged while the second half undergoes phase rotation. This local differentiation allows the system to extend WLAN range through bandwidth duplication while minimizing signal distortion through selective phase manipulation in specific bandwidth portions
Data Source
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AI summary
Dual carrier modulation, DCM, encoded data is generated in a first half of a full signal bandwidth (510). The DCM encoded data generated in the first half of the full signal bandwidth is duplicated in a second half of the full signal bandwidth (520). The duplicated DCM encoded data in the second half of the full signal bandwidth is multiplied by a modulation vector to result in a reduced peak-to-average power ratio, PAPR, in transmission (530).