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Visible light communication method and device fusing OOK modulation with OFDM modulation

A visible light communication and OOK technology, applied in the field of digital signal transmission, can solve the problems of entering the nonlinear area of ​​the system, not fully utilizing channel resources, and large signal amplitude, avoiding excessive signal amplitude, improving transmission rate and channel resource utilization. rate effect

Active Publication Date: 2015-11-04
TSINGHUA UNIV
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0005] However, on the one hand, since the OOK modulation depth is usually relatively large, loading a positive OFDM signal on the OOK modulated pulse "1" will easily cause the signal amplitude to be too large and enter the nonlinear region of the system, resulting in truncation and deteriorating system performance.
On the other hand, the existing method only transmits the OFDM signal when the OOK modulation sends a "1" signal, and does not send the OFDM signal when the OOK modulation sends a "0" signal. Therefore, the channel resources are not fully utilized.

Method used

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  • Visible light communication method and device fusing OOK modulation with OFDM modulation
  • Visible light communication method and device fusing OOK modulation with OFDM modulation
  • Visible light communication method and device fusing OOK modulation with OFDM modulation

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Embodiment 1

[0037] In this embodiment, the visible light communication method of the present invention that integrates OOK modulation and OFDM modulation includes the following steps, for example:

[0038] Step 1: Receive externally provided OOK signals to be fused and OFDM signals to be fused, specifically including:

[0039] The received OOK signal to be fused is a binary pulse sequence, in which pulse is "1", no pulse is "0", and the amplitude is 1, which can be expressed as In this formula, a k is a sequence of binary code elements, the value is 1 or 0; N 1 is the length of the logic state (for example, 0 or 1) of the OOK signal; g[n] is the rectangular window sequence; k represents the number of logic state.

[0040] The received OFDM signal to be fused, specifically includes: the constellation mapping symbol obtained after the data is mapped through the 16QAM constellation, and after forming a Hermitian symmetric structure, the data is only transmitted on the odd subcarrier, the ...

Embodiment 2

[0053] In this embodiment, the visible light communication method of the present invention that integrates OOK modulation and OFDM modulation includes the following steps, for example:

[0054] Step 1: Receive externally provided OOK signals to be fused and OFDM signals to be fused, specifically including:

[0055] The received OOK signal to be fused is a binary pulse sequence, in which pulse is "1", no pulse is "0", and the amplitude is 1, which can be expressed as In this formula, a k is a sequence of binary code elements, the value is 1 or 0; N 1 is the length of the logic state of the OOK signal; g[n] is the rectangular window sequence; k represents the number of logic state.

[0056] The received OFDM signal to be fused, specifically includes: the constellation mapping symbol obtained after the data is mapped by the 64QAM constellation, and after the Hermitian symmetric structure is formed, the data is only transmitted on the odd subcarrier, the even subcarrier is set ...

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Abstract

The invention provides a visible light communication method and device fusing OOK modulation with OFDM modulation. The method comprises the steps of: receiving an external OOK signal to be fused and an OFDM signal to be fused; carrying out time synchronization on the OOK signal and the OFDM signal; carrying out signal superposition on the OOK signal and the OFDM signal after the time synchronization so as to obtain a superposed signal, wherein the signal superposition modes includes: when the OOK signal is 1, a positive signal of the corresponding OFDM signal is set to zero, a negative signal is unchanged, an obtained nonpositive OFDM signal is loaded to the OOK signal which is 1, and when the OOK signal is 0, the negative signal of the corresponding OFDM signal is set to zero, the positive signal is unchanged, and an obtained nonnegative OFDM signal is loaded to the OOK signal which is 0; and modulating the superposed signal to a visible light driving current so as to obtain a visible light communication signal, and sending the visible light communication signal. According to the invention, the OOK modulation is fused with the OFDM modulation, demodulation of different types of receivers is supported, and the transmission rate and the channel resource utilization rate are simultaneously improved.

Description

technical field [0001] The present invention relates to the technical field of digital signal transmission, in particular to a visible light communication method and device combining OOK modulation and OFDM modulation. Background technique [0002] VLC (Visible Light Communication, Visible Light Communication) is a technical means to realize wireless communication on the basis of LED lighting, which uses a light source to send out high-frequency signals that cannot be detected by the naked eye to transmit information. With its wide spectrum, green energy saving, deep coverage, and the characteristics of organic combination with lighting, it has a good development prospect. [0003] In visible light communication, commonly used modulation methods include OOK (On-Off Keying, binary on-off keying) modulation, PPM (Pulse Position Modulation, pulse position modulation) modulation, DMT (Discrete Multi-Tone, discrete multi-tone) modulation and OFDM (Orthogonal Frequency Division M...

Claims

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Application Information

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IPC IPC(8): H04B10/116
CPCH04B10/116
Inventor 杨昉高俊男丁文伯宋健
Owner TSINGHUA UNIV
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