Method for synchronizing visible light communication system frames based on OFDM

A technology for visible light communication and frame synchronization, which is applied in the field of optical communication and can solve problems such as misjudgment and affecting algorithm estimation accuracy.

Inactive Publication Date: 2013-12-25
FUDAN UNIV
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  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0015] Applying Park to an OFDM-based visible light communication system, the calculated value of the detection function will be around the correct peak N There are two high side peaks at / 4 samples, which will lead to misjudgment and affect the estimation accuracy of the algorithm

Method used

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  • Method for synchronizing visible light communication system frames based on OFDM
  • Method for synchronizing visible light communication system frames based on OFDM
  • Method for synchronizing visible light communication system frames based on OFDM

Examples

Experimental program
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Embodiment

[0039] Set the parameters of the example

[0040] Simulation environment: MATLAB

[0041] Channel Model: 10dB AWGN Channel

[0042] Number of OFDM subcarriers N : 128

[0043] cyclic prefix length : 16

[0044] threshold the th : 0.5

[0045] At the sending end, a training sequence is generated, and its specific implementation steps are:

[0046] The selected training sequence in the frequency domain is:

[0047] F={0 1 1 1 1 -1 1 -1 -1 -1 -1 1 -1 1 -1 1 -1 -1 -1 -1 -1 1 -1 -1 -1 1 -1 1 1 1 1 -1 1 -1 -1 1 1 -1 1 -1 -1 -1 1 -1 1 -1 -1 1 -1 -1 1 -1 -1 -1 -1 1 1 -1 -1 -1 -1 1 -1 1 0 1 -1 1 -1 -1 -1 -1 1 1 1 -1 -1 -1 -1 1 -1 -1 1 -1 -1 1 -1 1 -1 -1 -1 1 -1 1 1 -1 -1 1 -1 1 1 1 1 -1 1 -1 -1 -1 1 -1 -1 -1 -1 -1 1 -1 1 -1 1 -1 -1 -1 -1 1 - 1 1 1 1 1}.

[0048] The time-domain samples of the training sequence are obtained after inverse fast Fourier transform (IFFT) on the sequence F.

[0049] At the receiving end, frame synchronization detection is performed, and the sp...

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Abstract

The invention belongs to the technical field of an optical communication technology, and particularly relates to a method for synchronizing visible light communication system frames based on an OFDM. According to the method, a training sequence structure is constructed first, and then the training sequence structure is used for detecting a frame starting position. The method comprises the steps that a training sequence is used for designing a frame synchronizing detecting function, and the frame synchronizing detecting function is made to generate a peak like an impulse function at a specified position of the training sequence; a reasonable threshold value is set to find the peak of the curve of the frame synchronizing detecting function, and therefore the frame starting position is determined. The method for synchronizing the visible light communication system frames based on the OFDM can well overcome the defects of an SC algorithm and a Park algorithm, and has high estimation accuracy.

Description

technical field [0001] The invention belongs to the technical field of optical communication, in particular to an OFDM-based visible light communication system frame synchronization method. Background technique [0002] Visible light communication (VLC) is a new type of indoor short-distance wireless communication technology developed on the basis of white light LED technology. VLC technology uses the good modulation characteristics of LED to modulate information to the light intensity of LED, which has dual functions of communication and lighting, and has the advantages of good confidentiality and no electromagnetic interference. [0003] Orthogonal Frequency Division Multiplexing (OFDM) is a high-speed data transmission technology. It is widely used in various communication technologies because of its high spectrum utilization, ability to resist frequency selective fading, and simple channel equalization. Applying OFDM modulation technology to the visible light communicat...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): H04L27/26H04B10/116
Inventor 袁一凌徐峰冯辉杨涛胡波
Owner FUDAN UNIV
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