Preamble Sequence Generation for WLAN PAPR Optimization
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Solution Overview
Problem
Current wireless communication systems, particularly in WLANs, face challenges in maximizing communication performance, minimizing Peak to Average Power Ratio (PAPR) degradation, and efficiently managing channel access as the number of apparatuses increases, especially in machine-to-machine (M2M) communication scenarios.
Innovation Solution
A sequence generation method that includes designing a basic sequence structure composed of C52s and D12s, with phase rotation factors applied to secure consistent PAPR across varying communication bandwidths, allowing for efficient transmission in IEEE 802.11 systems by generating sequences for preambles in user equipment, optimizing AGC performance and minimizing PAPR.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If the number of apparatuses in WLAN system is increased, then M2M communication capability is improved, but channel access efficiency deteriorates and interference increases
Solution Approach 1:
The patent introduces a new sequence structure with phase rotation factors that changes the mathematical parameters of the preamble sequence. By applying phase rotation factors (e.g., e^(-jπ/4), e^(-jπ/2), e^(-j3π/4)) to the basic sequence, the patent optimizes the sequence properties for M2M communication scenarios with many apparatuses, improving channel access efficiency and reducing interference in dense network environments.
2Measurement precision
If AGC gain is maximized, then signal reception performance is improved, but PAPR degradation increases
Solution Approach 1:
The patent carefully adjusts the phase rotation factors applied to the preamble sequence to optimize the balance between AGC gain and PAPR. By selecting specific phase rotation values and applying them to specific portions of the sequence (e.g., applying phase rotation to C52 portions but not D12 portions), the patent achieves maximum AGC gain while controlling PAPR degradation within acceptable limits.
Solution Approach 2:
The patent applies phase rotation factors selectively to different portions of the preamble sequence rather than uniformly across the entire sequence. Specifically, phase rotation is applied to C52 portions while D12 portions remain unrotated, creating local variations in sequence properties that optimize both AGC performance and PAPR characteristics in different regions of the transmission.
3Device complexity
If sequence structure is simplified, then generation complexity is reduced, but adaptability to different bandwidths deteriorates
Solution Approach 1:
The patent designs a universal basic sequence structure comprising C52 and D12 portions that can function across multiple bandwidth configurations (20 MHz, 40 MHz, 80 MHz). By defining a core sequence template that can be replicated and phase-rotated, the patent achieves bandwidth adaptability without requiring completely different sequence designs for each bandwidth, thus maintaining low generation complexity while supporting multiple bandwidths.
Data Source
AI summary
Disclosed is a sequence generation method for: generating a basic sequence structure comprising C52, which is composed of 52 tones, and D12, which is composed of 12 tones; selecting any one among a plurality of phase rotation factors, which are determined in advance for a bandwidth and applied to the basic sequence structure by unit of C52 or C52D12; and generating a sequence inserted into a preamble to be transmitted to a terminal.