JP2018133689A5

JP2018133689A5 -

Info

Publication number: JP2018133689A5
Application number: JP2017025917A
Authority: JP
Filing date: 2017-02-15
Publication date: 2018-12-06
Anticipated expiration: 2037-02-15

Description

この発明に係る可視光通信システムにおいては、可視光を発光して情報を送信する送信装置と、前記送信装置からの前記可視光を受光して前記情報を受信する受信装置とを備える可視光通信システムであって、前記送信装置は、第１の情報を第１の中心周波数で平均振幅レベルが一定となる第１の変調方式を用いて第１の変調信号を生成する第１の変調部と、第２の情報を前記第１の中心周波数よりも低い第２の中心周波数で一次変調を行ない、第２の変調方式を用いた二次変調を行ない第２の変調信号を生成する第２の変調部と、前記第１の変調信号及び前記第２の変調信号を加算して重畳信号を生成する加算部と、前記重畳信号に基づいて前記可視光の強さを制御して発光する発光部とを備え、前記受信装置は、前記送信装置から発光された光を受光する受光部と、前記受光部が受光して得られた信号から一定期間ごとの平均を算出する平均算出部と、前記平均算出部の算出結果について、前記二次変調に対応した二次復調を行ない前記一次変調に対応した一次復調を行なって前記第２の情報を取得する第１の復調部とを備えることを特徴とするものである。
In the visible light communication system according to the present invention, a visible light communication comprising: a transmitting device that emits visible light to transmit information; and a receiving device that receives the visible light from the transmitting device and receives the information. In the system, the transmission device includes: a first modulation unit that generates a first modulation signal by using a first modulation method in which the average amplitude level of the first information is constant at a first center frequency; The second information is subjected to primary modulation at a second center frequency lower than the first center frequency, and second modulation using the second modulation method is performed to generate a second modulated signal. a modulation unit, wherein the first modulation signal and the second modulated signal and adder for generating a sum to superimposed signals, the light emitting unit that emits light by controlling the intensity of the visible light based on the superimposition signal And the receiving device emits light from the transmitting device. A light receiving unit that receives the received light, an average calculating unit that calculates an average for each predetermined period from a signal obtained by receiving the light, and a calculation result of the average calculating unit corresponding to the secondary modulation And a first demodulator that performs secondary demodulation and performs primary demodulation corresponding to the primary modulation to acquire the second information.

Claims

A visible light communication system comprising: a transmission device that emits visible light to transmit information; and a reception device that receives the visible light from the transmission device and receives the information,
The transmitter is
A first modulation unit that generates a first modulation signal by using a first modulation method in which the average amplitude level of the first information is constant at the first center frequency;
Performing second order modulation of the second information at a second center frequency lower than the first center frequency;
A second modulation unit that performs secondary modulation using the second modulation method and generates a second modulation signal;
An adder for adding the first modulated signal and the second modulated signal to generate a superimposed signal;
And a light emitting portion that emits light by controlling the intensity of the visible light based on the superimposition signal,
The receiving device is:
A light receiving unit for receiving light emitted from the transmission device;
An average calculating unit that calculates an average for each predetermined period from the signal obtained by receiving the light;
A first demodulator that performs secondary demodulation corresponding to the secondary modulation and obtains the second information by performing primary demodulation corresponding to the primary modulation with respect to a calculation result of the average calculator. A visible light communication system.

The receiving device is:
An offset removing unit for removing a DC component from the calculation result of the average calculating unit;
A subtracting unit for subtracting the result of the offset removing unit from the signal obtained by receiving the light;
2. The apparatus according to claim 1, further comprising: a second demodulator that acquires the first information using a first demodulation method corresponding to the first modulation method for the result of the subtraction unit. Visible light communication system.

The second modulation scheme is spread spectrum using a unique code,
The first demodulator includes:
2. The visible signal according to claim 1, wherein at least the eigencode used by the transmission apparatus is held, spectrum despreading is performed using the eigencode based on a calculation result of the average calculation unit, and the primary demodulation is performed. Optical communication system.

The unique code is provided with a plurality different the transmitting device respectively,
In the receiving device,
The first demodulating unit holds the inherent code used in the provided transmission device, and is obtained by performing spectrum despreading using the inherent code from the calculation result of the average calculating unit. The visible light communication system according to claim 3, wherein the primary demodulation is performed on a spectrum despreading result.

5. The visible light communication system according to claim 3, wherein a chip length of the unique code is longer than a period of the first center frequency and not more than a period of the second center frequency. .

The transmitter further inputs luminous intensity information,
The second modulation unit includes:
A primary modulation section for performing primary modulation of the second information at the second center frequency;
A first spread spectrum section that performs spread spectrum using the unique code for the output of the primary modulation section;
A light intensity adjustment signal generator that generates a light intensity adjustment signal based on the light intensity information;
A second spread spectrum unit for performing spread spectrum using a second unique code having a direct relationship with the unique code for the light intensity adjustment signal;
6. The second modulation signal is obtained by alternately selecting the result of the first spread spectrum unit and the result of the second spread spectrum unit in terms of time. The visible light communication system according to any one of the above.

The receiving device is:
An offset removing unit for removing a DC component from the calculation result of the average calculating unit;
A subtracting unit for subtracting the result of the offset removing unit from the signal obtained by receiving the light;
A second demodulator that obtains the first information using a first demodulation method corresponding to the first modulation method for the result of the subtraction unit;
The visible light communication system according to any one of claims 3 to 6, wherein the visible light communication system is characterized.

The second demodulator is
It further includes an SN ratio calculation unit that calculates an SN ratio based on each spectrum despread result obtained by performing spectrum despreading using each of the unique codes from the calculation result of the average calculation unit. The visible light communication system according to claim 7 .

The second demodulator is
The visible light communication system according to claim 8 , wherein execution of the first demodulator is controlled when the SN ratio is higher than a predetermined threshold.

A visible light communication system comprising: a transmission device that emits visible light to transmit information; and a reception device that receives the visible light from the transmission device and receives the information,
The transmitter is
A first modulation unit that generates a first modulation signal by using a first modulation method in which the average amplitude level of the first information is constant at the first center frequency;
A second modulation unit that performs second-order modulation of second information at a second center frequency lower than the first center frequency to generate a second modulation signal;
An adder for adding the first modulated signal and the second modulated signal to generate a superimposed signal;
And a light emitting portion that emits light by controlling the intensity of the visible light based on the superimposition signal,
The receiving device is:
A light receiving unit for receiving light emitted from the transmission device;
An average calculation unit for calculating an average for each predetermined period from the signal obtained by receiving the light;
A visible light communication system, comprising: a first demodulation unit that obtains the second information by performing primary demodulation corresponding to the primary modulation from a calculation result of the average calculation unit.

  A first modulation unit that generates a first modulation signal by using a first modulation method in which the average amplitude level of the first information is constant at the first center frequency;
  Performing second order modulation of the second information at a second center frequency lower than the first center frequency;
A second modulation unit that performs secondary modulation using the second modulation method and generates a second modulation signal;
  An adder for adding the first modulated signal and the second modulated signal to generate a superimposed signal;
  A light emitting unit that emits light by controlling the intensity of visible light based on the superimposed signal;
With
A transmission apparatus characterized by the above.

  A first modulation signal is generated by using the first modulation method in which the average amplitude level of the first information is constant at the first center frequency, and the second information is lower than the first center frequency. The first modulation is performed at the center frequency of 2, the second modulation is performed using the second modulation method, and the second modulation signal is generated, and the first modulation signal and the second modulation signal are added and superimposed. A light-receiving unit that generates a signal and receives light emitted by controlling the intensity of visible light based on the superimposed signal;
  An average calculating unit that calculates an average for each predetermined period from the signal obtained by receiving the light;
  A first demodulating unit that obtains the second information by performing secondary demodulation corresponding to the secondary modulation and performing primary demodulation corresponding to the primary modulation with respect to a calculation result of the average calculating unit;
With
A receiving apparatus.

A visible light communication method of a visible light communication system comprising: a transmission device that emits visible light to transmit information; and a reception device that receives the visible light from the transmission device and receives the information,
The transmitter is
A first modulation step of generating a first modulated signal by using a first modulation scheme in which the first information has a constant average amplitude level at a first center frequency;
Performing second order modulation of the second information at a second center frequency lower than the first center frequency;
A second modulation step of performing second order modulation using a second modulation scheme to generate a second modulated signal;
An adding step of adding the first modulated signal and the second modulated signal to generate a superimposed signal;
And a light emitting step of emitting light by controlling the intensity of the visible light based on the superimposition signal,
The receiving device is:
A light receiving step for receiving light emitted from the transmitter ;
An average calculating step for calculating an average for each predetermined period from the signal obtained by receiving the light;
A first demodulation step of obtaining the second information by performing secondary demodulation corresponding to the secondary modulation and performing primary demodulation corresponding to the primary modulation with respect to a calculation result of the average calculation step. A visible light communication method.

A visible light communication method of a visible light communication system comprising: a transmission device that emits visible light to transmit information; and a reception device that receives the visible light from the transmission device and receives the information,
The transmitter is
A first modulation step of generating a first modulated signal by using a first modulation scheme in which the first information has a constant average amplitude level at a first center frequency;
A second modulation step of performing primary modulation of the second information at a second center frequency lower than the first center frequency to generate a second modulated signal;
An adding step of adding the first modulated signal and the second modulated signal to generate a superimposed signal;
A light emission step of emitting light by controlling the intensity of the visible light based on the superposition signal,
The receiving device is:
A light receiving step for receiving light emitted from the transmitter ;
An average calculating step for calculating an average for each predetermined period from the signal obtained by receiving the light;
A visible light communication method comprising: a first demodulation step of obtaining the second information by performing primary demodulation corresponding to the primary modulation with respect to a calculation result of the average calculation step.