Wireless Preamble Structure for Low-PAPR Synchronization
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Solution Overview
Problem
Existing wireless communication preambles face challenges in enhancing automatic gain control, signal detection, and time and frequency synchronization performances, leading to increased complexity and peak-to-average-power ratio (PAPR), which hinder further improvements in synchronization estimation.
Innovation Solution
A method and apparatus for generating a preamble by assigning a first base sequence and a modified sequence, such as a complex conjugate or sign-different sequence, to the frequency domain of a time interval, along with a TD sequence for automatic gain control and signal detection, and NRP/RP sequences for robust synchronization, reducing complexity and improving synchronization performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional preamble structures with multiple OFDM symbols and RP sequences are used, then time and frequency synchronization can be achieved, but the complexity and PAPR increase, hindering further synchronization estimation improvements
Solution Approach 1:
The patent segments the base sequence into multiple segments and applies different phase rotations to each segment within the same time interval. This segmentation allows the preamble to maintain good autocorrelation properties for synchronization while reducing the PAPR compared to conventional multi-symbol structures. The phase-rotated segments can be independently optimized to balance synchronization performance and complexity.
Solution Approach 2:
The patent transitions from the conventional time-domain segmentation (multiple OFDM symbols) to frequency-domain segmentation with phase rotation. By applying phase rotations in the frequency domain within a single time interval, the patent achieves synchronization functionality without increasing time-domain complexity, effectively moving the design dimension from temporal to spectral domain.
2Measurement precision
If conventional preamble structures are used, then signal detection can be performed, but automatic gain control and signal detection performances cannot be further enhanced
Solution Approach 1:
The patent applies different phase rotation parameters to different segments of the base sequence, creating local variations in the frequency domain. This local quality differentiation allows the preamble to provide robust signal detection across different frequency regions while maintaining overall structure simplicity. Each segment can be optimized for specific detection requirements without complicating the entire preamble structure.
3Measurement precision
If preambles are designed to improve synchronization performance, then time and frequency synchronization can be enhanced, but the peak-to-average-power ratio increases
Solution Approach 1:
The patent changes the phase rotation parameters applied to different base sequence segments to optimize the power distribution. By carefully selecting phase rotation values, the patent can shape the time-domain signal to reduce peak power while maintaining frequency-domain properties necessary for synchronization. This parameter optimization directly addresses the PAPR issue while preserving synchronization performance.
Data Source
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AI summary
Disclosed is a technique related to a method and apparatus for generating a preamble and a data frame for wireless communication, and to a synchronization estimation method using the preamble. According to the technique, a method for generating a frame for wireless communication is disclosed, wherein the method comprises: a step of generating a modified sequence using a first base sequence for synchronization estimation; and a step of allocating the first base sequence and the modified sequence to the frequency domain of a first timeslot to generate a preamble. The modified sequence includes a complex conjugated sequence of the first base sequence or a sequence having a code different from that of the first base sequence.