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Pulse and OFDMD double-data modulation method

A dual modulation, pulse modulation technology, applied in the field of communication, can solve the problem of inability to use independently

Inactive Publication Date: 2010-05-19
EAST CHINA UNIV OF SCI & TECH
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  • Summary
  • Abstract
  • Description
  • Claims
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Problems solved by technology

But for the usual single-chip white light LED, only the excitation light (usually blue light) can be controlled, and the corresponding warm color light intensity can be obtained through the intensity of the excitation light (this ratio is determined by the internal specific color composition of the LED), two are actually closely related and cannot be used independently

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  • Pulse and OFDMD double-data modulation method
  • Pulse and OFDMD double-data modulation method
  • Pulse and OFDMD double-data modulation method

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Embodiment Construction

[0035] The scenario of using lighting LED to realize communication is generally as follows: figure 2 As shown, LEDs (2-1) individually or in arrays and clusters can realize desired illumination in various forms and simultaneously become light transmitters. The most common is to be installed on the roof of the room, made into a desk lamp and placed on the table, or installed above the seats of cars and airplanes. And the light receiver (2-2) is usually located below the lighting LED. Different from RF wireless transmission, illumination light generally has a certain directionality (2-3), especially when LED is used, the range of illumination is relatively easy to control. This directionality is beneficial to achieve multiple access / multiple communication to a certain extent.

[0036] The transceiver of the visible light communication system generally consists of image 3 shown. The transmitter consists of a controller (3-1), a modulator (3-2), a driver (3-3) and a light-em...

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Abstract

The invention discloses a double-data modulation method of pulse and OFDM. An optical spectrum of a single chip white light LED is formed by exciting fluorescent powder of yellow color or red-green color and the like by a blue light, and the shape of the whole optical spectrum has two relative independent peak values, wherein the responding speed of the blue light is higher than that of a warm color light. The invention can be used for transmitting data by pulse modulation of the blue light and can be used as a carrier wave for the warm color light OFDM modulation, thus a double channel high-speed data transmission is realized. In addition, the blue light can be used as a reference simultaneously for OFDM symbol synchronization, direct current offset estimation and channel estimation.

Description

technical field [0001] The invention belongs to the technical field of communication, and specifically relates to a device and method for dual data modulation and demodulation of pulse and OFDM when using lighting LEDs to realize short-distance communication. Background technique [0002] Visible light communication based on lighting LED is an emerging short-range wireless communication method, which is expected to replace or supplement the current short-range RF wireless communication technology to improve communication speed, reduce cost and environmental electromagnetic radiation. At present, the feasibility of using LED communication for lighting in different environments has been initially confirmed, including applications in indoor and intelligent transportation. [0003] One of the important technical aspects of communication is the modulation of the communication data signal. According to different communication systems and application requirements, broadly speaking...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): H04L27/26
Inventor 樊凌涛
Owner EAST CHINA UNIV OF SCI & TECH
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