Hybrid M-FSK OFDM Waveform for Visible Light Communication
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Solution Overview
Problem
Existing visible light communication technologies face limitations in transmitting high-speed data and simultaneously handling different types of information, as they typically struggle with the general M-FSK scheme's difficulty in transmitting high-speed data and the limitation of FSK-modulating only the same information before multiplexing with OFDM.
Innovation Solution
A hybrid waveform technology that modulates two different types of information using M-FSK and OFDM, mixing the modulated signals into one waveform for transmission through an LED light source, allowing for simultaneous communication of high-speed and low-speed data by using a signal transmission device with a modulator and a receiver that demodulates the signals using a rolling-shutter camera.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If M-FSK scheme is used for visible light communication, then low-speed data transmission is achieved, but high-speed data transmission capability is limited
Solution Approach 1:
The patent combines M-FSK modulation and OFDM modulation into a hybrid waveform system. The M-FSK modulator handles low-speed data while the OFDM modulator handles high-speed data, and both modulated signals are merged into a single composite signal that is transmitted through the LED light source. This merging allows the system to simultaneously achieve both low-speed and high-speed data transmission capabilities.
Solution Approach 2:
The hybrid waveform system is designed to perform multiple functions: it can transmit both low-speed data (via M-FSK) and high-speed data (via OFDM) through the same communication channel and LED light source. The receiver can separately demodulate and extract both types of data from the composite signal, making the system universal in handling different data transmission requirements.
2Adaptability or versatility
If FSK modulation is applied to the same information before multiplexing with OFDM, then signal compatibility is maintained, but information diversity is limited
Solution Approach 1:
The patent segments the information stream into different channels: one channel is modulated using M-FSK for low-speed data, and another channel is modulated using OFDM for high-speed data. Each modulation type processes different portions of the information independently, allowing diverse information types to be transmitted simultaneously without requiring complex cross-modulation of the same information.
Solution Approach 2:
After separate modulation of different information types using M-FSK and OFDM, the patent merges the two modulated signals into a single hybrid waveform. This merging occurs in the time domain where the M-FSK modulated signal and OFDM modulated signal are combined and transmitted together through the LED light source, maintaining signal compatibility while preserving information diversity.
Data Source
AI summary
A device for transmitting a signal according to some embodiments of the present disclosure relates to a device for transmitting a signal using a hybrid waveform. The device may include a modulator configured to modulate an input signal and a signal transmitter configured to transmit the modulated final transmission signal through an LED light source, wherein the modulator is configured to modulate first information into a pulse signal based on frequency shift keying (FSK), and modulate second information into an orthogonal frequency division multiplexing (OFDM) signal, wherein the first information and the second information are different from each other and mix the pulse signal and the OFDM signal into one waveform to generate the final transmission signal.