CAZAC Subcarrier Mapping for OOK Modulation Flatness
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current methods for generating OOK modulation signals using Manchester code for OFDM base in Wake-up Radio (WUR) systems do not adequately maintain flat frequency characteristics and low Cubic Metric/Peak to Average Power Ratio (CM/PAPR), leading to interference and inefficient power consumption.
Innovation Solution
A radio transmission device and method that maps a CAZAC sequence to subcarriers at determined intervals, performs inverse Fast Fourier Transform (IFFT) processing, and applies Manchester coding to generate an OOK modulation signal, ensuring flat frequency characteristics and low CM/PAPR.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional methods are used to generate OOK modulation signals for WUR, then the transmission can be implemented, but the frequency characteristics become non-flat and CM/PAPR increases
Solution Approach 1:
The patent applies parameter changes by mapping CAZAC sequences to subcarriers at specific intervals (e.g., every other subcarrier) rather than continuously, and by applying Manchester coding to the time-domain signal. These parameter modifications to the signal generation process ensure flat frequency characteristics and low CM/PAPR while maintaining reliable WUR reception.
2Reliability
If transmission power is increased to improve reception performance, then reception performance improves, but power consumption increases
Solution Approach 1:
The patent changes the signal parameters by using CAZAC sequences with specific properties and applying Manchester coding, which results in low CM/PAPR. This allows the system to maintain good reception performance without needing to increase transmission power, thereby reducing power consumption in the WUR system.
3Ease of manufacture
If conventional OOK modulation is used without CAZAC sequence mapping, then the modulation can be generated, but frequency characteristics are not flat
Solution Approach 1:
The patent modifies the modulation generation process by introducing CAZAC sequence mapping to subcarriers at determined intervals and applying Manchester coding to the time-domain signal. These parameter changes ensure that the frequency characteristics remain flat while still allowing for practical modulation generation.
4Measurement precision
If subcarriers are used at dense intervals, then frequency resolution improves, but CM/PAPR increases
Solution Approach 1:
The patent optimizes the subcarrier interval parameter by mapping CAZAC sequences to subcarriers at determined intervals (e.g., every other subcarrier) rather than using dense intervals. This parameter setting achieves an optimal balance, providing sufficient frequency resolution while maintaining low CM/PAPR for efficient power amplification.
Data Source
AI summary
A signal generator 10 generates an OOK (on-off keying) modulation signal by mapping a CAZAC (constant amplitude zero auto-correlation) sequence to N subcarriers (N being an integer that is greater than or equal to 2) arranged at a determined interval among M subcarriers (M being an integer that is greater than or equal to 3) that are adjacent in the frequency domain, carrying out inverse fast Fourier transform (IFFT) processing on the mapped CAZAC sequence, and carrying out Manchester coding on a time domain signal generated by the IFFT processing. A radio transmitter 107 transmits the OOK modulation signal.