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Visible light communication and positioning integration method and system based on OFDM (Orthogonal Frequency Division Multiplexing)

A technology of visible light communication and optical signal, applied in the field of wireless optical communication, can solve the problems that the research can only realize communication or single positioning, cannot apply to a single LED array, split the two functions of communication and positioning, achieve precise positioning, and improve the application sexual effect

Pending Publication Date: 2022-04-19
NANJING UNIV OF INFORMATION SCI & TECH +1
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0003] At present, certain research results have been accumulated in visible light communication and positioning; in visible light communication, in order to achieve high-speed data communication, Orthogonal Frequency Division Multiplexing (OFDM) is widely used. OFDM is a multi-carrier modulation The method has many advantages such as high spectral efficiency and effective resistance to intersymbol interference, so it is favored; for the IM / DD method in the field of visible light communication, a variety of special OFDM modulation systems have been formed. The commonly used OFDM schemes include DC bias Optical OFDM (DCO-OFDM), asymmetrically limited OFDM (ACO-OFDM), etc.; In the aspect of indoor positioning based on visible light communication, some research progress has also been made. Currently, commonly used visible light positioning methods include Received Signal Strength (RSS ) algorithm, time-of-arrival (TOA) algorithm, time-difference-of-arrival (TDOA) algorithm, angle-of-arrival (AOA) algorithm, etc.; although some achievements have been made in two aspects of visible light communication and positioning, most of the research can only realize communication or The single function of positioning separates the two functions of communication and positioning; in existing smart terminals, communication and positioning are two important functions that are indispensable. Therefore, it is necessary to organically integrate visible light communication and positioning into one system ; In addition, in the existing indoor positioning algorithm, it usually needs to rely on multiple LED arrays to achieve positioning, which cannot be applied to the situation of a single LED array, and ideally regards the light-emitting diode (LED) array as a point for positioning. In the environment, the distance between the receiver and the LED is usually small, so treating the LED array as a point will reduce the positioning accuracy

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  • Visible light communication and positioning integration method and system based on OFDM (Orthogonal Frequency Division Multiplexing)
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  • Visible light communication and positioning integration method and system based on OFDM (Orthogonal Frequency Division Multiplexing)

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Embodiment 1

[0050] Such as figure 1 As shown, the embodiment of the present invention provides an OFDM-based method for integrating visible light communication and positioning, including the following steps:

[0051] S1. Obtain a received signal converted from the optical signal sent by the LED array.

[0052] The light signal sent by the LED array is obtained by the following method:

[0053] Such as image 3 As shown in the process of the sending end in the figure, the number of subcarriers of the OFDM system is expressed as N, and the sending end uses a single LED array to transmit signals, and the LED array consists of N T composed of LEDs, the frequency domain signal on the ith subcarrier of OFDM is expressed as Q i , where i=0, 1, ..., N-1, and the frequency domain signal Q on the first subcarrier 1 It is set to 1+j, where j is an imaginary unit, and the frequency domain signal of the i (i≠1) subcarrier is the transmitted modulation symbol.

[0054] For the frequency domain sig...

Embodiment 2

[0093] An embodiment of the present invention provides an OFDM-based visible light communication and positioning integrated system, including:

[0094] Received signal acquisition module: used to acquire the received signal converted from the light signal sent by the LED array;

[0095] Visible light communication module: used to perform fast Fourier transform and frequency domain equalization on the received signal to obtain an equalized signal, calculate the estimated value of the scale factor according to the equalized signal, and calculate the judgment amount of the subcarrier in OFDM according to the estimated value of the scale factor to determine the transmission signal to complete visible light communication;

[0096] Positioning module: used to calculate the received signal to obtain the average received light intensity, input the average received light intensity into the preset positioning model to obtain the coordinates of the center position of the receiver, and co...

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Abstract

The invention discloses a visible light communication and positioning integration method and system based on OFDM, and belongs to the technical field of wireless optical communication, and the method comprises the steps: obtaining a receiving signal converted from an optical signal emitted by an LED array; performing fast Fourier transform and frequency domain equalization on the received signal to obtain an equalized signal, calculating a scaling factor estimated value according to the equalized signal, and calculating a decision amount of sub-carriers in OFDM according to the scaling factor estimated value so as to decide a sent signal and complete visible light communication; calculating the received signals to obtain average receiving light intensity, inputting the average receiving light intensity into a preset positioning model to obtain coordinates of the center position of the receiver, and completing positioning; visible light communication and positioning functions are organically integrated, visible light communication and indoor accurate positioning can be realized at the same time, the visible light communication and the indoor accurate positioning do not influence each other, and the applicability is effectively improved.

Description

technical field [0001] The invention relates to an OFDM-based visible light communication and positioning integration method and system, belonging to the technical field of wireless optical communication. Background technique [0002] Visible light communication uses the illumination light emitted by light-emitting diodes (LEDs) to communicate. It has many advantages such as high communication rate and no electromagnetic interference. Compared with the traditional satellite positioning, this positioning method has higher accuracy indoors, and does not need to invest in a large amount of positioning infrastructure, which saves the cost of the positioning system and presents a broad application prospect. [0003] At present, certain research results have been accumulated in visible light communication and positioning; in visible light communication, in order to achieve high-speed data communication, Orthogonal Frequency Division Multiplexing (OFDM) is widely used. OFDM is a mu...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): H04B10/116H04L27/26H04W4/33H04W4/80
CPCH04B10/116H04W4/80H04W4/33H04L27/2601
Inventor 李宝龙陆波丁文杰陈佳伟
Owner NANJING UNIV OF INFORMATION SCI & TECH