KR100943531B1 - Method and Apparatus for Wireless Optical Communication - Google Patents

Abstract

A wireless optical communication apparatus and method are disclosed. A method of performing wireless optical communication with n user terminals in a wireless optical communication device including a plurality of semiconductor light sources, the method comprising: extracting data from optical signals received from the n user terminals and analyzing the data by trigonometric methods to obtain the n Generating location information for each of the user terminals; Selecting m semiconductor light sources corresponding to the position information among the plurality of semiconductor light sources; Allocating transmission data corresponding to each of the m semiconductor light sources selected; And transmitting the allocated transmission data to the user terminal through the selected m semiconductor light sources. The present invention has the effect of providing a wireless optical communication apparatus and method for improving the signal-to-noise ratio.

Optical communication, wireless, semiconductor light source

Description

Wireless optical communication device and method {Method and Apparatus for Wireless Optical Communication}

The present invention relates to wireless optical communications, and more particularly, to a wireless optical communications apparatus and method for improving signal to noise ratio.

 In general, wireless communication methods include microwave communication using microwave radio waves such as RF (Radio Frequency) and wireless optical communication using semiconductor laser light. Since wireless optical communication uses microwave semiconductor laser light of several hundred tera hertz band, there is no radio interference phenomenon and there is no administrative regulation on frequency band. In addition, wireless optical communication has the advantages of excellent call quality, data transfer through space, and significantly reduced cost and installation time required for fiber optic construction compared to wired optical communication.

In general, a wireless optical communication method uses a method in which a plurality of channels are generated by dividing a wavelength region in one laser light source, and data is transmitted through each generated channel. And, the transmission device is configured such that a plurality of laser light sources transmit the same data stream in order to transmit data over a large area. In this case, the wireless optical communication method may generate a plurality of channels for each wavelength of the laser to transmit data to the plurality of portable terminals.

However, when data is transmitted using a plurality of channels, a data transmission method using a laser light source may cause interference due to overlapping of lasers between adjacent channels, and a signal-to-noise ratio may be lowered due to multipath dispersion. . In this case, there is also a problem that the reliability of the transmitted data is deteriorated due to the lower signal-to-noise ratio.

In order to solve the above problem, the present invention is to provide a wireless optical communication apparatus and method for reducing the laser overlap between adjacent channels.

The present invention also provides a wireless optical communication apparatus and method for improving the signal-to-noise ratio.

The present invention also provides a wireless optical communication apparatus and method in which a plurality of semiconductor light sources independently transmit a signal.

According to an aspect of the present invention, in a method of performing wireless optical communication with n user terminals in a wireless optical communication device including a plurality of semiconductor light sources, extracting data from optical signals received from the n user terminals, Analyzing the data by triangulation to generate location information for each of the n user terminals; Selecting m semiconductor light sources corresponding to the position information among the plurality of semiconductor light sources; Allocating transmission data corresponding to each of the m semiconductor light sources selected; And transmitting the transmission data allocated through the selected m semiconductor light sources to the user terminal, wherein n is a natural number and m is a natural number less than or equal to n. do.

The transmission data may be data to be transmitted to the user terminal located in a transmission area corresponding to each of the m light sources, and the transmission area may be an area in which the user terminal may receive data by the same semiconductor light source.

According to another aspect of the present invention, a wireless optical communication device including a plurality of semiconductor light sources, comprising: an optical detector for extracting received data from optical signals received from a plurality of user terminal devices; A control unit which generates location information of the user terminal from the received data and allocates transmission data to the semiconductor light source corresponding to the location information; There is provided a wireless optical communication device including a transmission unit for transmitting the allocated transmission data to the user terminal through the semiconductor light source.

The control unit may include a position estimating unit configured to generate the position information of the user terminal by analyzing the received data by triangulation; An instruction unit for selecting m semiconductor light sources corresponding to the position information among the plurality of semiconductor light sources; And converting original data into transmission data corresponding to each of the selected m semiconductor light sources and allocating the converted data to the m semiconductor light sources.

The converted data may be data to be transmitted to the user terminal located in a transmission area corresponding to each of the m light sources, and the transmission area may be an area in which the user terminal may receive data by the same semiconductor light source. .

According to another aspect of the present invention, there is tangibly embodied a program of instructions that can be executed by a wireless optical communication device to perform a wireless optical communication method, and on a recording medium recording a program that can be read by the wireless optical communication device. The method of claim 1, further comprising: extracting data from optical signals received from the n user terminals, and analyzing the data by triangulation to generate location information for each of the n user terminals; Selecting m semiconductor light sources corresponding to the position information among the plurality of semiconductor light sources; Allocating transmission data corresponding to each of the m semiconductor light sources selected; And transmitting the allocated transmission data to the user terminal through the selected m semiconductor light sources, wherein n is a natural number and m is a natural number less than or equal to n. A medium is provided.

The present invention has the effect of providing a wireless optical communication device and method for reducing laser overlap between adjacent channels.

In addition, the present invention has the effect of providing a wireless optical communication device and method for improving the signal-to-noise ratio.

In addition, the present invention has the effect of providing a wireless optical communication device and method in which a plurality of semiconductor light sources independently transmit a signal.

As the invention allows for various changes and numerous embodiments, particular embodiments will be illustrated in the drawings and described in detail in the written description. However, this is not intended to limit the present invention to specific embodiments, it should be understood to include all transformations, equivalents, and substitutes included in the spirit and scope of the present invention. In the following description of the present invention, if it is determined that the detailed description of the related known technology may obscure the gist of the present invention, the detailed description thereof will be omitted.

Terms such as first and second may be used to describe various components, but the components should not be limited by the terms. The terms are used only for the purpose of distinguishing one component from another.

The terminology used herein is for the purpose of describing particular example embodiments only and is not intended to be limiting of the present invention. Singular expressions include plural expressions unless the context clearly indicates otherwise. In this application, the terms "comprise" or "have" are intended to indicate that there is a feature, number, step, operation, component, part, or combination thereof described in the specification, and one or more other features. It is to be understood that the present invention does not exclude the possibility of the presence or the addition of numbers, steps, operations, components, components, or a combination thereof. Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

Hereinafter, a functional unit of the wireless optical communication apparatus 100 according to an embodiment of the present invention will be described with reference to FIGS. 1 to 5.

1 is a diagram illustrating a functional unit of a wireless optical communication device according to an embodiment of the present invention, FIG. 2 is a diagram illustrating a control unit according to an embodiment of the present invention, and FIG. 3 is an embodiment of the present invention. FIG. 4 is a diagram illustrating a data transmission unit according to another embodiment of the present invention, and FIG. 5 is a diagram illustrating a sector according to an embodiment of the present invention.

Referring to FIG. 1, the wireless optical communication device 100 includes a light detector 110, a controller 120, and a transmitter 130.

The photo detector 110 includes a photo detector (PD). The light detector receives a light signal from the user terminal, and the light signal may include any data (hereinafter, referred to as 'receive data') that the user wants to transmit. The light detector 110 extracts data included in the received light signal. Here, the method of extracting data included in the received optical signal by the optical detector 110 is obvious to those skilled in the art, and a detailed description thereof will be omitted herein.

In addition, the light detector 110 transmits the extracted data to the controller 120 through the light detector. In this case, the photodetector may be either a photoconductor photodetector or a semiconductor photodetector.

The control unit 120 determines the location of the user terminal that has transmitted the received data from the light detector 110 using optical triangulation, and transmits the data to the user terminal (that is, data received from a device other than the user terminal). The data to be transmitted to the user terminal, hereinafter referred to as "transmission data" is transmitted to the transmitter 130. Hereinafter, the controller 120 will be described in detail with reference to FIG. 2.

2, the controller 120 includes a position estimator 210, an indicator 220, a converter 230, and a port allocator 240.

The position estimator 210 receives data from the light detector 110 and estimates the position of the user terminal using the optical triangulation method. Optical triangulation is a method of estimating the shape, size, position, etc. of a subject by using a laser or the like reflected on the subject. Subsequently, the position estimator 210 transmits the position information and the received data of the user terminal to the indicator 220. In addition, the location estimator 210 transmits the number of regions (hereinafter, referred to as “transmission region numbers”) to which the transmission data are to be transmitted to the indicator 220. For example, the indicator 220 calculates the number of transmission areas where the user terminal is located and transmits the number to the indicator 220 using the location information of the user terminal.

In this case, the transmission area refers to a service area allocated to transmit data per semiconductor light source included in the transmitter 130. Therefore, there may be a plurality of transmission areas in the whole area where wireless optical communication is serviced. Also, if there are multiple user terminals in the same transmission area, the number of transmission areas is calculated as one.

Subsequently, the indication unit 220 transmits the transmission unit 230 to transmit the original data (that is, data collected for transmission to all user terminals located in the entire optical communication service area) to the user terminals located in the corresponding transmission area for each transmission area. Control to convert to data. In particular, when the number of transmission zones is 2 or more, the indicator 220 transmits the original data and the number of transmission zones to the converter 230. The conversion unit 230 converts the original data into transmission data corresponding to the number of transmission areas and transmits the data to the port assignment unit 240. (Of course, the transmission data is transmitted from the original data to a user terminal located outside the area to be transmitted. For example, the conversion unit 230 receives the transmission area number K = 2 from the indicating unit 220, converts the original data into the transmission data S1 and S2, and then assigns the port allocation unit 240. To send). That is, the present invention transmits only data to be received by the user terminal located in the corresponding transmission area, compared to the conventional method of transmitting data to be received by the user terminal located outside the corresponding transmission area. As a result, the semiconductor light source transmitting data to the corresponding transmission area can reduce the number of data to be transmitted, thereby transmitting data using fewer channels, and prevent the signal-to-noise ratio from being lowered due to signal overlap. Subsequently, if the number of transmission areas is 1, the indicating unit 220 transmits the transmission data to the port assignment unit 240. At this time, the original data is generated by the external device and transmitted to the indicating unit 220. In order to clarify the gist of the invention, a description of a process of generating original data from an external device and transmitting the original data to the indicator 220 will be omitted. In addition, the indication unit 220 transmits the transmission area information to transmit the data to the port assignment unit 240. However, depending on the implementation, the indicator 220 may select a semiconductor light source to which data is to be allocated and transmit the information (referred to as 'semiconductor light source allocation information') to the port allocator 240.

The port allocating unit 240 allocates the transmission data received from the indicating unit 220 or the converting unit 230 to a corresponding port and transmits the transmitted data to the transmitting unit 130. For example, the port allocator 240 receives two transmission data S1 and S2 from the converter 230, and transmits transmission area information (or semiconductor light source allocation information) to transmit data from the indicator 220. The port allocator 240 then ports P3 and P5 to transmit the data S1 and S2 to the transmission region where the user terminal is located (assuming that the data streams S1 and S2 are transmitted to the transmission region through the ports P3 and P5). To allocate the data. The port allocator 240 then transmits the data streams S1 and S2 to the transmitter 130 through ports P3 and P5.

Referring back to FIG. 1, the transmitter 130 receives data from one or more ports from the port allocator 240. The transmitter 130 transmits data to the user terminal through a semiconductor light source corresponding to each port through which data is transmitted. For example, when the transmitter 130 receives data through the ports P3 and P5, the transmitter 130 transmits the data to the user terminal through the semiconductor light sources L3 and L5 corresponding to the respective ports. In addition, the transmitter 130 includes n (natural numbers) semiconductor light sources as shown in FIG. 3. At this time, each semiconductor light source is preset to transmit data only to a specific region.

In addition, as illustrated in FIG. 4, the transmitting unit 130 may have a semiconductor light source distributed therein. As illustrated in FIG. 5, a transmission region may be set in the transmitter 130 in which nine semiconductor light sources are distributed. 5 illustrates a case in which transmission areas corresponding to nine semiconductor light sources are set to one sector. At this time, it is apparent that the number of semiconductor light sources per sector may be changed in some cases. Since the transmitter 130 projects the laser circularly from the semiconductor light source, in order to transmit data to all regions, transmission regions corresponding to each semiconductor are set to overlap each other, such as 501 to 509. If the user terminal is located in an overlapping area, the port allocator 240 may be configured to transmit data as the predetermined number among the semiconductor light sources is the smallest. For example, assuming that the user terminal is located at 510 in FIG. 5, and the semiconductor light sources L1 to L9 are set to transmit data to the transmission areas 501 to 509, the port allocator 240 transmits data to the user terminal. Either L4 or L5 can be used for this purpose. In this case, the port allocator 240 allocates the data stream to a specific port so that L4 having a smaller assigned number transmits the data stream.

Although the above-described embodiment of the transmission area setting of the semiconductor light source has been described so that all the semiconductor light sources are set to transmit data to the area of the same width and shape, it may be set to a transmission area of different width and shape according to the environment in actual application. It can be obvious. In addition, the above-described transmitter 130 has been described as receiving data through one or more of the plurality of ports from the port allocator 240, but in some cases without the port allocator 240, the transmitter 130 is the indicator ( 220 or the data received from the converter 230 may be directly assigned to the corresponding semiconductor light source.

Hereinafter, a wireless optical communication method according to an exemplary embodiment of the present invention will be described with reference to FIG. 6. Each step described below may be performed by each internal component of the wireless optical communication device 100, but will be collectively described as a wireless optical communication device 100 for the convenience of understanding and explanation.

6 is a flowchart illustrating a wireless optical communication process according to an embodiment of the present invention.

Referring to FIG. 6, in step 610, the wireless optical communication apparatus 100 receives an optical signal from a user terminal and converts the optical signal into an electrical signal.

In operation 620, the wireless optical communication apparatus 100 extracts data from the received signal.

In operation 630, the wireless optical communication apparatus 100 estimates the location of the user terminal from the extracted data. In this case, the wireless optical communication device 100 may generate location information of the user terminal using a trigonometric method.

In operation 640, the wireless optical communication apparatus 100 determines whether the number of regions for transmitting data is one. For example, if the wireless optical communication apparatus 100 determines that there are two user terminals in the transmission area R1 and one user terminal in the transmission area R2 based on the location information, the wireless optical communication device 100 may determine the location of the transmission area. The number is judged to be two.

If the number of regions to transmit data is two or more, the wireless optical communication apparatus 100 divides the data stream according to the number of transmission regions in step 650.

In operation 660, the wireless optical communication apparatus 100 allocates a data stream to a port. The wireless optical communication device 100 includes as many ports as semiconductor light sources, and each semiconductor light source is set to transmit data only to a corresponding transmission area.

In operation 670, the wireless optical communication device 100 transmits a data stream to the user terminal.

At this time, it is apparent that the wireless optical communication apparatus 100 described above with reference to FIG. 6 may allocate and transmit data to be transmitted to each user terminal for each channel if there are two or more user terminals in the region to be transmitted.

Although the above has been described with reference to a preferred embodiment of the present invention, those skilled in the art to which the present invention pertains without departing from the spirit and scope of the present invention as set forth in the claims below It will be appreciated that modifications and variations can be made.

1 illustrates a functional unit of a wireless optical communication device according to an embodiment of the present invention.

2 is a diagram illustrating a control unit according to an embodiment of the present invention.

3 is a diagram illustrating a transmitting unit according to an embodiment of the present invention.

4 is a diagram illustrating data transmission of a transmission unit according to another embodiment of the present invention.

5 illustrates a sector according to an embodiment of the present invention.

6 is a flow chart illustrating a wireless optical communication process according to an embodiment of the present invention.

Claims (6)

A method of performing wireless optical communication with a user terminal in a wireless optical communication device including a plurality of semiconductor light sources, Generating location information on the user terminal according to the intensity of the optical signal received from the user terminal using optical triangulation; Selecting m semiconductor light sources corresponding to the position information among the plurality of semiconductor light sources; Allocating transmission data corresponding to each of the m semiconductor light sources selected; And Transmitting the transmission data allocated through the selected m semiconductor light sources to the user terminal, M is a natural number. The method of claim 1, The transmission data is data to be transmitted to the user terminal located in a transmission area corresponding to each of the m light sources, And the transmission area is an area in which the user terminal can receive data by the same semiconductor light source. In a wireless optical communication device including a plurality of semiconductor light source An optical detector including an optical detector for receiving an optical signal from a user terminal; A controller configured to generate position information of the user terminal according to the intensity of the optical signal using an optical triangulation method, and allocate transmission data to the semiconductor light source corresponding to the position information; And a transmitter for transmitting the allocated transmission data to the user terminal through the semiconductor light source. The method of claim 3, wherein The control unit A position estimator configured to generate position information of the user terminal using the intensity of the optical signal; An instruction unit for selecting m semiconductor light sources corresponding to the position information among the plurality of semiconductor light sources; A conversion unit for converting original data into transmission data corresponding to each of the selected m semiconductor light sources, and allocating the converted data to the m semiconductor light sources, M is a natural number. The method of claim 4, wherein The converted data is data to be transmitted to the user terminal located in a transmission area corresponding to each of the m light sources, And the transmission area is an area in which the user terminal can receive data by the same semiconductor light source. delete

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