CAZAC-Based OOK Signal Generation Without DFT Hardware
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Solution Overview
Problem
Existing signal generation methods for on-off keying (OOK) signals, particularly OOK4, require discrete Fourier transform (DFT) hardware and complex waveform design, leading to bifurcation in specification and increased complexity, making it difficult to unify OOK1 and OOK4 waveforms.
Innovation Solution
Generate OOK signals using frequency domain representation with constant amplitude zero autocorrelation (CAZAC) sequences, phase ramping each waveform to align with bit positions, eliminating the need for DFT operations and enabling unified design for both OOK1 and OOK4 signals.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If DFT-based waveform generation is used for OOK4 signals, then signal generation capability is improved, but device complexity increases
Solution Approach 1:
The patent replaces the mechanical/DFT-based signal generation system with a direct frequency domain synthesis approach using CAZAC sequences. Instead of using DFT hardware to generate OOK waveforms, the invention directly constructs the frequency domain representation by modulating CAZAC sequences with phase ramps, thereby eliminating the need for complex DFT-based waveform generation hardware while maintaining signal generation capability
Solution Approach 2:
The invention changes the fundamental parameters of signal generation by switching from time-domain DFT-based methods to frequency-domain direct synthesis using CAZAC sequences with phase ramping. This parameter change allows OOK1 and OOK4 signals to be generated using the same unified frequency domain approach, reducing device complexity while preserving adaptability across different OOK modes
2Adaptability or versatility
If separate waveform designs are used for OOK1 and OOK4, then signal generation capability is improved, but device complexity increases
Solution Approach 1:
The patent implements a universal frequency domain generation method using CAZAC sequences that can generate both OOK1 and OOK4 signals through the same apparatus. By using phase ramping of CAZAC sequences in the frequency domain, the system achieves multi-functionality where a single unified design handles multiple OOK signal types, eliminating the need for separate waveform designs and reducing device complexity
3Adaptability or versatility
If DFT-based hardware is used, then signal generation capability is improved, but manufacturing complexity increases
Solution Approach 1:
The invention substitutes complex DFT-based hardware with a simpler frequency domain synthesis approach using pre-defined CAZAC sequences and phase ramping operations. This replacement significantly reduces manufacturing complexity as it eliminates the need for sophisticated DFT hardware while maintaining the capability to generate various OOK signal types through software-controlled frequency domain processing
Data Source
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AI summary
Embodiments relate to apparatuses and methods for generating an on-off keyed (OOK) signal. The apparatuses may comprise at least one processor and at least one memory storing instructions that when executed by the at least one processor cause the apparatus at least to perform: generating an on-off keyed signal for transmission over a set of symbols, at least one bit being conveyed within each symbol of the set of symbols and a payload of the on-off keyed signal being encoded using the at least one bit within each symbol of the set of symbols. An on and an off state for each bit is formed by at least one of the following: not generating a signal and generating a modulated waveform using frequency resources assigned for the on-off keyed signal. Generating the modulated waveform comprises modulating a waveform with a constant amplitude zero autocorrelation, CAZAC, sequence, wherein each generated modulated waveform within a single symbol of the set of symbols is modulated such that each generated modulated waveform is phase shifted with respect to each other. The apparatus is further caused to perform transmitting the on-off keyed signal to at least one user equipment.