Transmitting device applied to optical communication and optical communication test method and equipment

Abstract

The invention discloses a transmitting device applied to optical communication and an optical communication test method and equipment, and the transmitting device comprises at least two light-emitting devices which are used for emitting light; the light uniformizing part is arranged on the light emitting sides of the at least two light emitting devices and used for enabling emergent light of the at least two light emitting devices to enter the light uniformizing part and to be scattered in the light uniformizing part, so that the emergent light of the at least two light emitting devices is mixed and emitted from the light uniformizing part; and the light transmitting part is arranged on the light emitting side of the light uniformizing part and used for enabling emergent light of the light uniformizing part to be emitted after the angle is increased after the emergent light penetrates through the light transmitting part. According to the emitting device applied to the optical communication, the emergent light of the plurality of light emitting devices is mixed through the light uniformizing part, and the angle is increased after the emergent light of the plurality of light emitting devices further penetrates through the light transmitting part, so that the emitting angle of the emitting device applied to the optical communication is relatively large, the coverage range of the emergent light of the emitting device is increased, and feasibility is provided for wide-coverage visible light communication.

Description

Technical Field

[0001] The present invention relates to the field of optical communication, and in particular to a transmitting device applied to optical communication and an optical communication test method and equipment. Background Art

[0002] At present, traditional wireless communication technology has been widely used in daily life, and the demand for wireless communication technology has also grown exponentially. However, with the growing demand for higher data rates, lower latency, increased capacity and multiple connections, wireless communication technology faces major bottlenecks and challenges. Visible light communication (VLC) is expected to solve these problems. Unlike radio frequency communication, VLC has abundant spectrum resources, more stable anti-interference ability and stronger security. Most importantly, VLC can provide the dual functions of lighting and communication with the help of existing lighting infrastructure, which is an effective supplement to existing wireless networks, called "light fidelity technology" (LiFi). In the past few decades, research on VLC has made significant progress, achieving a breakthrough in communication rate through the optimization of transmitter and receiver equipment, the advancement of modulation and equalization algorithms, and the application of multi-input-multioutput (MIMO) technology.

[0003] In the prior art, visible light communication is mainly used in point-to-point communication systems, using lasers, such as laser diodes in transmitters, which have the advantages of high speed, long distance, and high power, so that visible light communication systems can achieve robust wireless optical connections between transmitters and mobile receivers. However, the narrow beam and concentrated spot of the laser require precise alignment to achieve high-capacity transmission, which severely limits the mobility of the communication system. However, from the perspective of daily life scenarios, a wide-coverage communication system is crucial for practical applications. Mobility is the basic advantage of wireless services, which provides users with flexibility and convenience and makes connections on the move possible. In the era of mobile Internet, people generally expect ubiquitous communication capabilities and need communication systems that adapt to mobility. Summary of the invention

[0004] The purpose of the present invention is to provide a transmitting device for optical communication, wherein the emitted light of the transmitting device increases the coverage range and provides feasibility for wide coverage visible light communication. The present invention also provides an optical communication test method and device.

[0005] To achieve the above object, the present invention provides the following technical solutions:

[0006] A transmitting device for optical communication, comprising:

[0007] at least two light emitting devices, the light emitting devices being used to emit light;

[0008] A light homogenizing portion, arranged on the light emitting side of the at least two light emitting devices, for making the emitted light of the at least two light emitting devices incident on the light homogenizing portion and scattered in the light homogenizing portion, so that the emitted light of the at least two light emitting devices is mixed and emitted from the light homogenizing portion;

[0009] The light-transmitting portion is arranged on the light-emitting side of the light-evening portion, and is used to increase the angle of the light emitted from the light-evening portion and emit it after passing through the light-transmitting portion.

[0010] Optionally, the at least two light-emitting devices are used to emit at least one monochromatic light, or the at least two light-emitting devices are used to emit at least two monochromatic lights and the at least two monochromatic lights are mixed to form white light.

[0011] Optionally, the light emitting device is used to emit light in a first wavelength band;

[0012] It also includes: a wavelength conversion layer, which is arranged on the light-emitting side of the light homogenizing part, and is used to make the first-wavelength-band light passing through the light homogenizing part incident on the wavelength conversion layer, and the wavelength conversion layer is excited to generate the second-wavelength-band light;

[0013] The light-transmitting portion is disposed on the light-emitting side of the wavelength conversion layer, and is used to increase the angle of the first-wavelength-band light passing through the wavelength conversion layer and the second-wavelength-band light generated by the wavelength conversion layer after passing through the light-transmitting portion and emitting.

[0014] Optionally, the wavelength conversion layer is arranged obliquely relative to the light homogenizing portion, and the light-transmitting portion is arranged on the first side, the second side or the third side of the wavelength conversion layer, the first side is on the side of the wavelength conversion layer opposite to the light homogenizing portion, the second side and the third side are opposite sides of the wavelength conversion layer, and the first wavelength band light reflected by the wavelength conversion layer is incident on the second side / the third side.

[0015] Optionally, the light-transmitting portion is disposed on the first side of the wavelength conversion layer, and a reflecting portion is disposed on the second side or / and the third side of the wavelength conversion layer, and the reflecting portion is used to reflect the first wavelength band light and the second wavelength band light from the wavelength conversion layer back to the wavelength conversion layer, and further propagate to the light-transmitting portion;

[0016] Alternatively, the light-transmitting portion is disposed on the second side of the wavelength conversion layer, and a reflecting portion is disposed on the first side or / and the third side of the wavelength conversion layer, and the reflecting portion is used to reflect the first wavelength band light and the second wavelength band light from the wavelength conversion layer back to the wavelength conversion layer, and further propagate to the light-transmitting portion;

[0017] Alternatively, the light-transmitting portion is arranged on the third side of the wavelength conversion layer, and a reflective portion is arranged on the first side and / or the second side of the wavelength conversion layer, and the reflective portion is used to reflect the first-band light and the second-band light from the wavelength conversion layer back to the wavelength conversion layer, and further propagate to the light-transmitting portion.

[0018] Optionally, the reflecting portion includes a focusing element and a reflecting layer, wherein the reflecting layer is arranged on a side of the focusing element away from the wavelength conversion layer, and the focusing element is used to allow the first-band light and the second-band light from the wavelength conversion layer to pass through and enter the reflecting layer, and to allow the first-band light and the second-band light reflected by the reflecting layer to converge and return to the wavelength conversion layer.

[0019] An optical communication test method, applied to any of the above transmitting devices for optical communication, comprising:

[0020] When the transmitting device sends out the light signal, the receiving device is moved to change the distance and / or orientation of the receiving device relative to the transmitting device, and the receiving device receives the light signal;

[0021] Communication performance data is obtained based on the electrical signal generated after the receiving device receives the optical signal, and the communication performance data reflects the communication performance between the transmitting device and the receiving device.

[0022] Optionally, in the process of the transmitting device sending the light signal, moving the receiving device so as to change the distance and / or orientation of the receiving device relative to the transmitting device comprises:

[0023] In the process of the transmitting device emitting a light signal, the receiving device is moved at a constant speed along the straight track, and the transmitting device is located on the central axis of the straight track;

[0024] Alternatively, the transmitting device is located on the central axis of the straight track, and the distance from the transmitting device to the straight track is different. At any distance, when the transmitting device sends a light signal, the receiving device moves at a constant speed along the straight track.

[0025] Optionally, obtaining the communication performance data according to the electrical signal generated after the receiving device receives the optical signal includes: demodulating the electrical signal and / or calculating a bit error rate according to the electrical signal;

[0026] Demodulating the electrical signal comprises: processing and modulating the electrical signal to generate a constellation diagram, wherein the constellation diagram comprises a plurality of constellation points, and for each element of the data to be restored of the electrical signal, calculating an absolute distance between the element of the data to be restored and each constellation point, and selecting a constellation point with a minimum absolute distance as a demodulated symbol;

[0027] Calculating the bit error rate according to the electrical signal includes: processing the electrical signal to obtain an input binary stream, comparing it with the demodulated output binary stream, finding the index of bit mismatch, and calculating the bit error rate.

[0028] An optical communication test device, comprising:

[0029] A track, used for installing a receiving device and capable of driving the receiving device to move along the track, wherein the receiving device is used for receiving the optical signal emitted by the transmitting device and generating an electrical signal;

[0030] A mobile station, used for installing the transmitting device and driving the transmitting device to move, wherein the transmitting device is any of the transmitting devices described above for optical communication;

[0031] The control device is used to obtain communication performance data based on the electrical signal generated after the receiving device receives the optical signal.

[0032] It can be known from the above technical scheme that the transmitting device applied to optical communication provided by the present invention comprises: at least two light-emitting devices, the light-emitting devices are used to emit light; a light-homogenizing portion, arranged on the light-emitting side of the at least two light-emitting devices, used to make the emitted light of the at least two light-emitting devices incident on the light-homogenizing portion and scattered in the light-homogenizing portion, so that the emitted light of the at least two light-emitting devices is mixed and emitted from the light-homogenizing portion; a light-transmitting portion, arranged on the light-emitting side of the light-homogenizing portion, used to make the emitted light of the light-homogenizing portion increase in angle after passing through the light-transmitting portion and then emit. The transmitting device applied to optical communication of the present invention emits light through multiple light-emitting devices, and the emitted light of multiple light-emitting devices is mixed through the light-homogenizing portion, and the angle is increased after further passing through the light-transmitting portion, so that the emission angle of the transmitting device applied to optical communication is larger, so that the emitted light of the transmitting device increases the coverage range, and provides feasibility for wide-coverage visible light communication.

[0033] The optical communication test method and device provided by the present invention realize optical communication test on a transmitting device used for optical communication. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0035] Figure 1 A schematic diagram of the structure of a transmitting device applied to optical communication provided by one embodiment of the present invention;

[0036] Figure 2 A flow chart of an optical communication test method provided by one embodiment of the present invention;

[0037] Figure 3 A schematic diagram of a track and a control device of an optical communication test device provided by an embodiment of the present invention;

[0038] Figure 4 A schematic diagram of an optical communication test device for performing an optical communication test provided by an embodiment of the present invention.

[0039] The reference numerals in the drawings of the specification include:

[0040] 100-transmitting device, 101-light emitting device, 102-light homogenizing unit, 103-wavelength conversion layer, 104-first lens, 105-second lens, 106-light transmitting unit, 107-heat sink, 108-receiving device, 109-mounting platform, 110-track, 111-control device, 112-cooling fan. DETAILED DESCRIPTION

[0041] In order to enable those skilled in the art to better understand the technical solutions in the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0042] This embodiment provides a transmitting device applied to optical communication, including:

[0043] at least two light emitting devices, the light emitting devices being used to emit light;

[0044] A light homogenizing portion, arranged on the light emitting side of the at least two light emitting devices, for making the emitted light of the at least two light emitting devices incident on the light homogenizing portion and scattered in the light homogenizing portion, so that the emitted light of the at least two light emitting devices is mixed and emitted from the light homogenizing portion;

[0045] The light-transmitting portion is arranged on the light-emitting side of the light-evening portion, and is used to increase the angle of the light emitted from the light-evening portion and emit it after passing through the light-transmitting portion.

[0046] The emitted light of the at least two light emitting devices is incident on the light homogenizing portion, and is scattered in the light homogenizing portion when entering the light homogenizing portion, so that the emitted light of the at least two light emitting devices is mixed and further emitted from the light homogenizing portion.

[0047] The light emitted from the light-homogenizing portion is incident on the light-transmitting portion, and then emitted after passing through the light-transmitting portion. The angle of the light refers to the angle of the light relative to the optical axis, that is, the angle between the light and the optical axis. The angle increase of the light emitted from the light-homogenizing portion after passing through the light-transmitting portion means that the angle of the light emitted from the light-homogenizing portion relative to the optical axis after passing through the light-transmitting portion is greater than the angle of the light emitted from the light-homogenizing portion relative to the optical axis before passing through the light-transmitting portion.

[0048] The transmitting device used for optical communication in the present embodiment emits light through a plurality of light-emitting devices. The emitted light of the plurality of light-emitting devices is mixed by a light-uniforming portion, and the angle is increased after further passing through a light-transmitting portion, thereby making the emission angle of the transmitting device used for optical communication larger, and increasing the coverage range of the emitted light of the transmitting device, thereby providing feasibility for wide-coverage visible light communication.

[0049] In some embodiments, the at least two light emitting devices are used to emit at least one monochromatic light, the at least two light emitting devices can emit one monochromatic light, or the at least two light emitting devices emit two or more monochromatic lights. In practical applications, it can be set according to the optical communication scenario and requirements.

[0050] In some embodiments, the at least two light emitting devices are used to emit at least two monochromatic lights and the at least two monochromatic lights are mixed to form white light, and the transmitting device used for optical communication emits white light. Exemplarily, the at least two light emitting devices may include a red light emitting device, a green light emitting device, and a blue light emitting device, and the three light emitting devices are arranged in a set quantity ratio to mix into white light.

[0051] In some embodiments, the at least two light emitting devices are arranged in an array, and the emitted light of the at least two light emitting devices is incident on the light homogenizing portion. In this embodiment, the arrangement of the at least two light emitting devices is not limited, and the at least two light emitting devices can be but are not limited to being arranged in a square array or in a circular array.

[0052] In some embodiments, a heat sink is provided on the non-light emitting side of the at least two light emitting devices, and the heat sink is used to transfer the heat generated by the light emitting devices to the heat sink and dissipate it. The non-light emitting end of the light emitting device may be in contact with the heat sink. The heat sink may be, but is not limited to, a heat sink.

[0053] In some embodiments, the light emitting device may be a light emitting device that emits laser, which has the performance of high power and high brightness. The light emitting device may be, but is not limited to, a laser diode.

[0054] The output light of the at least two light-emitting devices is incident on the light-homogenizing part and scattered in the light-homogenizing part, so that the output light of the at least two light-emitting devices is mixed, and the output light of the at least two light-emitting devices is converted into a non-directional point light source, and is formed into a uniform wide-angle light source through scattering, thereby expanding the emission angle. If the light-homogenizing part is not provided, the output light of each light-emitting device will produce strong spot noise, and the spot noise will make the optical signal received by the receiving device unstable; the light may encounter different substances (such as particles and water droplets in the air) in the propagation path, resulting in the scattering of light, and these scattered lights interfere with the unscattered light, resulting in uneven intensity of the received optical signal; the optical signal may also reach the receiving device through different paths (multipath propagation) during the transmission process, and the optical signal propagates along different paths to reach the receiving device. When the light waves of these different paths meet, interference may occur, resulting in fluctuations in the intensity of the optical signal; the provision of a light-homogenizing part can alleviate these effects.

[0055] In some embodiments, the light homogenizing portion is also used to make the output light of the at least two light-emitting devices incident on the light homogenizing portion and scattered in the light homogenizing portion, so that the output light intensity of the light homogenizing portion is uniform. The output light of the at least two light-emitting devices is homogenized by the light homogenizing portion to reduce the speckle noise, so that not only the output light of each light-emitting device is mixed evenly, but also the output light intensity after passing through the light homogenizing portion is uniform. In some embodiments, the light homogenizing portion can be a light homogenizing layer, and the layered structure shortens the light mixing distance, which helps to reduce the volume of the emitting device. The light homogenizing portion can adopt, but is not limited to, a scattering sheet.

[0056] In some embodiments, the light emitting device is used to emit light of the first wavelength band; the transmitting device applied to optical communication further includes: a wavelength conversion layer, which is arranged on the light-emitting side of the light-homogenizing part, and is used to make the light of the first wavelength band passing through the light-homogenizing part incident on the wavelength conversion layer, and the wavelength conversion layer is excited to generate light of the second wavelength band; the light-transmitting part is arranged on the light-emitting side of the wavelength conversion layer, and is used to make the light of the first wavelength band passing through the wavelength conversion layer and the light of the second wavelength band generated by the wavelength conversion layer increase the angle and emit after passing through the light-transmitting part. The emitted light of the transmitting device applied to optical communication is a mixed light of the first wavelength band light and the second wavelength band light. In this embodiment, the wavelength range of the first wavelength band light and the wavelength range of the second wavelength band light are not limited respectively, and can be set according to application requirements in practical applications. The wavelength conversion layer will produce a wider luminous spectrum and can generate a smoother color transition. Compared with emitting a mixed light of multiple monochromatic lights through at least two light-emitting devices, relying solely on the mixing of the light emitted by the light-emitting device may cause the color contour of the mixed light to be sharp and unnatural. In terms of structural design, the circuit using multiple light-emitting devices that emit multiple monochromatic lights is more complicated, while the circuit using a single light-emitting device that emits light in the first band is relatively simple. At the same time, by reducing the dependence on multiple light-emitting devices, the loss of the overall system can be reduced and the lifespan can be improved.

[0057] In some embodiments, the wavelength conversion layer is tilted relative to the light homogenizing portion, and the light-transmitting portion is disposed on the first side, the second side, or the third side of the wavelength conversion layer, the first side is on the side of the wavelength conversion layer opposite to the light homogenizing portion, the second side and the third side are opposite sides of the wavelength conversion layer, and the first wavelength band light reflected by the wavelength conversion layer is incident on the second side / the third side. The wavelength conversion layer is tilted relative to the light homogenizing portion means that the optical axis of the wavelength conversion layer is not parallel to the optical axis of the light homogenizing portion.

[0058] The light-transmitting portion can be arranged on the first side of the wavelength conversion layer, that is, it can be arranged on the side of the wavelength conversion layer opposite to the light-homogenizing portion. The first-band light through the light-homogenizing portion is incident on the wavelength conversion layer, irradiating the wavelength conversion layer to generate the second-band light, and the second-band light generated by the wavelength conversion layer and the first-band light passing through the wavelength conversion layer are both emitted from the light-transmitting portion. The light-transmitting portion can also be arranged on the second side / third side of the wavelength conversion layer, the first-band light through the light-homogenizing portion is incident on the wavelength conversion layer, irradiating the wavelength conversion layer to generate the second-band light, and the second-band light generated by the wavelength conversion layer can be emitted from the light-transmitting portion arranged on the second side / third side of the wavelength conversion layer. If the first-band light reflected from the wavelength conversion layer is incident on the second side / third side of the wavelength conversion layer, and the light-transmitting portion is arranged on the second side / third side of the wavelength conversion layer, the first-band light reflected from the wavelength conversion layer can be emitted from the light-transmitting portion.

[0059] In some embodiments, the light-transmitting portion is disposed on the first side of the wavelength conversion layer, and a reflecting portion is disposed on the second side or / and the third side of the wavelength conversion layer, and the reflecting portion is used to reflect the first wavelength band light and the second wavelength band light from the wavelength conversion layer back to the wavelength conversion layer, and further propagate to the light-transmitting portion. In this way, the light energy utilization rate can be improved, which helps to improve the brightness of the output light of the emitting device.

[0060] In some embodiments, a light-transmitting portion is disposed on the second side of the wavelength conversion layer, and a reflective portion is disposed on the first side or / and the third side of the wavelength conversion layer, and the reflective portion is used to reflect the first wavelength band light and the second wavelength band light from the wavelength conversion layer back to the wavelength conversion layer, and further propagate to the light-transmitting portion. In this way, the light energy utilization rate can be improved, which helps to improve the brightness of the output light of the emitting device.

[0061] In some embodiments, a light-transmitting portion is disposed on the third side of the wavelength conversion layer, and a reflective portion is disposed on the first side or / and the second side of the wavelength conversion layer, and the reflective portion is used to reflect the first wavelength band light and the second wavelength band light from the wavelength conversion layer back to the wavelength conversion layer, and further propagate to the light-transmitting portion. In this way, the light energy utilization rate can be improved, which helps to increase the output light power of the emitting device.

[0062] In some embodiments, the reflective portion includes a light-collecting element and a reflective layer, wherein the reflective layer is disposed on the side of the light-collecting element away from the wavelength conversion layer, and the light-collecting element is used to allow the first wavelength band light and the second wavelength band light from the wavelength conversion layer to pass through and enter the reflective layer, and to converge the first wavelength band light and the second wavelength band light reflected by the reflective layer and return to the wavelength conversion layer. The reflective portion is provided with a light-collecting element to converge the reflected light, thereby preventing the light from being directly reflected by the reflective layer and scattered without output, thereby improving the output light power of the emitting device. The light-collecting element may be, but is not limited to, a lens.

[0063] For example, reference may be made to Figure 1 , Figure 1 A schematic diagram of the structure of a transmitting device for optical communication provided in one embodiment, as shown in the figure, the transmitting device includes a plurality of light-emitting devices 101, a light homogenizing portion 102, and a wavelength conversion layer 103. The plurality of light-emitting devices 101 are arranged in an array, and the light homogenizing portion 102 is disposed on the light-emitting side of the plurality of light-emitting devices 101. The wavelength conversion layer 103 is disposed on the light-emitting side of the light homogenizing portion 102 and is disposed obliquely, and the light-transmitting portion 106 is disposed on the third side of the wavelength conversion layer 103.

[0064] A first lens 104 is disposed on a first side of the wavelength conversion layer 103, and a reflective layer is disposed on a side of the first lens 104 away from the wavelength conversion layer 103. The second-band light generated by the wavelength conversion layer 103 and the first-band light passing through the wavelength conversion layer 103 are incident on the first lens 104 and are reflected back to the wavelength conversion layer 103. A second lens 105 is disposed on a second side of the wavelength conversion layer 103, and a reflective layer is disposed on a side of the second lens 105 away from the wavelength conversion layer 103. The second-band light generated by the wavelength conversion layer 103 and the first-band light reflected by the wavelength conversion layer 103 are incident on the second lens 105 and are reflected back to the wavelength conversion layer 103. The angle between the optical axis of the wavelength conversion layer 103 and the optical axis of the light homogenizing portion 102 may be 45°. Figure 1 As shown, the non-light emitting ends of the plurality of light emitting devices 101 are in contact with the heat sink 107 .

[0065] In some embodiments, the wavelength conversion layer 103 may include a base layer and a wavelength conversion material disposed on the base layer. The wavelength conversion material includes but is not limited to phosphor. The base layer may be but is not limited to a glass base. Exemplarily, the light emitting device 101 emits blue light, that is, the first wavelength band light is blue light, and the wavelength conversion layer 103 uses yellow fluorescent glass, and the blue light emitted by the light emitting device 101 and the light generated by the yellow fluorescent glass being irradiated by the blue light are mixed into white light.

[0066] In this embodiment, the structure of the light-transmitting portion 106 is not limited, as long as the angle of the emitted light can be increased after passing through the light-transmitting portion 106. The light from the light-homogenizing portion 102 or the light from the wavelength conversion layer 103 is refracted and passes through the light-transmitting portion 106, and the light-transmitting portion 106 can further homogenize the light and expand the emission angle. The light-transmitting portion 106 can be a lens.

[0067] In some embodiments, the transmitting device used for optical communication also includes a shell, the shell is provided with a light outlet, the light-emitting device 101 and the light-homogenizing portion 102 are arranged in the shell, or the light-emitting device 101, the light-homogenizing portion 102, the wavelength conversion layer 103 and the reflecting portion are arranged in the shell, and the light-transmitting portion 106 is arranged at the light outlet.

[0068] In a specific example, the emitting device is provided with 14 InGaN / GaN quantum well laser diodes forming a high-power blue laser array as a light source, emitting 452nm blue light, and the wavelength conversion layer 103 uses yellow fluorescent glass. The first lens, the second lens and the third lens are sequentially arranged on the first side, the second side and the third side of the wavelength conversion layer 103, each with a diameter of 25 mm, and all of them are plano-convex lenses. An emitting device emitting white light is formed, with a wide field of view and an emission angle of 40°.

[0069] This embodiment also provides an optical communication test method, which is applied to the transmitting device for optical communication described in any of the above embodiments, and can be referred to Figure 2 , Figure 2 A flowchart of an optical communication test method provided by an embodiment is shown in the figure. The optical communication test method includes the following steps:

[0070] S11: When the transmitting device sends out the optical signal, the receiving device is moved to change the distance and / or orientation of the receiving device relative to the transmitting device, and the receiving device receives the optical signal;

[0071] S12: Obtain communication performance data based on the electrical signal generated after the receiving device receives the optical signal, wherein the communication performance data reflects the communication performance between the transmitting device and the receiving device.

[0072] In the optical communication test method of this embodiment, the transmitting device used for optical communication emits light through multiple light-emitting devices, and the emitted light of the multiple light-emitting devices is mixed by the light-homogenizing part, and further increases the angle of the emitted light after passing through the light-transmitting part, so that the emission angle of the transmitting device is larger, and the emitted light of the transmitting device increases the coverage range, which provides feasibility for wide-coverage visible light communication. The optical communication test method of this embodiment realizes the optical communication test of the transmitting device used for optical communication.

[0073] In some embodiments, during the process of the transmitting device emitting a light signal, the receiving device is moved so that the distance or / and orientation of the receiving device relative to the transmitting device changes, including: during the process of the transmitting device emitting a light signal, the receiving device is moved at a constant speed along a straight track, and the transmitting device is on the central axis of the straight track. The transmitting device is on the central axis of the straight track, and the transmitting device emits a light signal. During this process, the receiving device moves at a constant speed along the straight track, and the receiving device receives the light signal. Furthermore, communication performance data is obtained based on the electrical signal generated by the receiving device after receiving the light signal, so that a communication test is performed on the transmitting device.

[0074] In some embodiments, during the process of the transmitting device emitting a light signal, the receiving device is moved, and the distance or / and orientation of the receiving device relative to the transmitting device is changed, including: the transmitting device is on the central axis of the straight track, and the distance from the transmitting device to the straight track is different, and at any distance, during the process of the transmitting device emitting a light signal, the receiving device is moved at a constant speed along the straight track. The distance from the transmitting device to the straight track is different, and at any distance, the transmitting device emits a light signal, during which the receiving device moves at a constant speed along the straight track, and the receiving device receives the light signal, and then obtains communication performance data based on the electrical signal generated after the receiving device receives the light signal. For different distances from the transmitting device to the straight track, the communication performance data corresponding to each distance can be obtained. In this way, a communication test is performed on the transmitting device.

[0075] In some embodiments, obtaining communication performance data according to the electrical signal generated after the receiving device receives the optical signal includes: demodulating the electrical signal. Demodulating the electrical signal includes: processing and modulating the electrical signal to generate a constellation diagram, the constellation diagram includes multiple constellation points, for each element of the data to be recovered in the electrical signal, calculating the absolute distance between the element of the data to be recovered and each constellation point, and selecting the constellation point with the smallest absolute distance as the demodulated symbol. The demodulation process mainly finds the minimum distance between the received signal and the complex number mapping to recover the signal. In this way, the continuous signal can be converted back to the form of discrete symbols, that is, the analog signal is demodulated into a digital signal. In some embodiments, the received data can be obtained by processing the LMS algorithm (least mean squares algorithm), which is an adaptive filtering algorithm. The constellation diagram can be generated by pulse amplitude modulation, and the constellation diagram represents the symbol sent by the transmitting device.

[0076] In some embodiments, obtaining communication performance data according to the electrical signal generated after the receiving device receives the optical signal includes: calculating the bit error rate according to the electrical signal. Calculating the bit error rate according to the electrical signal includes: processing the electrical signal to obtain an input binary stream, comparing it with the demodulated output binary stream, finding the index of bit mismatch, and calculating the bit error rate. The original data is preprocessed to obtain an input binary stream, which is compared with the demodulated output binary stream. Find the index of all bit mismatches, that is, find the location of all error bits and store them. The bit error rate (BER) is the ratio of the number of error bits to the total number of bits, which can be expressed as: BER=number of error bits / total number of bits.

[0077] In some embodiments, obtaining communication performance data according to the electrical signal generated after the receiving device receives the optical signal includes: sampling the electrical signal. Sampling the electrical signal includes: sampling the electrical signal once every preset number of samples, that is, downsampling, which can reduce the computational burden. Exemplarily, one sample out of every two samples can be selected from the received data after retiming, so as to perform sampling. In practical applications, the electrical signal generated by the receiving device can be forwarded to an oscilloscope for sampling, and then demodulated and the bit error rate BER can be calculated.

[0078] This embodiment also provides an optical communication test device, including:

[0079] A track 110, for installing a receiving device 108 and driving the receiving device 108 to move along the track 110, wherein the receiving device 108 is used to receive the optical signal emitted by the transmitting device 100 and generate an electrical signal;

[0080] A mobile platform, used for installing the transmitting device 100 and driving the transmitting device 100 to move, wherein the transmitting device 100 is a transmitting device applied to optical communication as described in any one of the above embodiments;

[0081] The control device 111 is used to obtain communication performance data according to the electrical signal generated by the receiving device 108 after receiving the optical signal.

[0082] In the optical communication test equipment of this embodiment, the transmitting device used for optical communication emits light through multiple light-emitting devices, and the emitted light of the multiple light-emitting devices is mixed by the light-homogenizing part, and further passes through the light-transmitting part to increase the angle of the emitted light, so that the emission angle of the transmitting device is larger, and the emitted light of the transmitting device increases the coverage range, providing feasibility for wide-coverage visible light communication. The optical communication test equipment of this embodiment realizes the optical communication test of the transmitting device used for optical communication.

[0083] In some embodiments, a mounting platform 109 is provided on the track 110, and the receiving device 108 is mounted on the mounting platform 109. The mounting platform 109 moves along the track 110, thereby driving the receiving device 108 to move along the track 110. The track 110 may be a straight track. In some embodiments, the mounting platform 109 is connected to a motor, and the motor rotates to drive the mounting platform 109 to slide on the track 110. The receiving device 108 may use, but is not limited to, a silicon photodiode (SiPM).

[0084] The mobile station may be a movable cart. In some embodiments, a cooling fan 112 is provided on one side of the launch device 100 for dissipating heat from the launch device 100. The cooling fan 112 may be connected to the heat sink 107 of the launch device 100, and the heat generated by the launch device 100 is transferred to the heat sink 107. The heat conducted by the heat sink 107 is further efficiently dissipated to the external environment through the cooling fan 112.

[0085] For example, reference may be made to Figure 3 and Figure 4 , Figure 3 A schematic diagram of a track and a control device of an optical communication test device provided by an embodiment, Figure 4 A schematic diagram of an optical communication test device for performing an optical communication test is provided in an embodiment. In a specific example, the track 110 is 1.2 m long, the safety margin at both ends is 0.2 m, the overall moving range along the track 110 is 0.8 m, and the corresponding coordinate is 0-0.8 m. The motor rotates to drive the mounting platform 109 to slide on the track 110, and the pitch of the synchronous belt is 162 mm per revolution, which means that when the speed is set to 1S / r, the mounting platform 109 moves forward 162 mm in one second. The control device 111 is located on one side of the track 110, so that the mounting platform 109 can move at different predetermined speeds.

[0086] The transmitting device 100 is mounted on a movable mobile platform to change the distance between the transmitting device 100 and the receiving device 108, so that the mobile communication performance at different distances can be studied. Since the emitted light of the transmitting device 100 covers a wide range, the entire track can be within the coverage of the light spot, so that theoretically, the receiving device 108 can communicate through a visible light link when moving along the track 110. The control device 111 adjusts the speed of the receiving device 108 moving along the track 110 through the motor to explore the impact of different speed conditions on the received signal.

[0087] Through experiments, when the emission angle of the transmitting device 100 is about 40°, the maximum communication rate can exceed 2.5 Gbps at a distance of 5m. This research not only demonstrates the feasibility of using laser-based white light emitting devices for visible light communication applications and solid-state lighting, but also highlights the potential for advancing the development of next-generation optical wireless communication technology.

[0088] In these experiments, On-Off Keying (OOK) signals were transmitted at a rate of 500Mbps. The system exhibited stable communication performance at distances of 1 and 2 meters, showing adaptability to disturbances caused by movement. However, starting from 3 meters, the increase in distance and speed resulted in a wider fluctuation range of the bit error rate (BER). At a distance of 4 meters, the system was still able to support a transmission rate of 500Mbps at a speed of 0.48 m / s. The choice of this speed takes into account the mobile communication needs of indoor environments such as offices and classrooms. Although distance and mobility affect the performance of the system, it maintains a certain degree of reliability. The transmission rate at 1 meter is 3.24Gbps, and at a distance of 5 meters, the maximum communication rate can exceed 2.5Gbps, which can cover more than 10m 2 The area of ​​the optical fiber is small, the communication rate is maintained above 1.5 Gbps, and it has strong robustness, which is of great significance in practical optical wireless communication systems. On-Off Keying (OOK) is a switching modulation method that is simple and easy to use and is suitable for low-rate and short-distance transmission scenarios.

[0089] The above is a detailed introduction to the transmitting device and optical communication test method and equipment provided by the present invention for optical communication. Specific examples are used in this article to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only used to help understand the method and core idea of ​​the present invention. It should be pointed out that for ordinary technicians in this technical field, without departing from the principle of the present invention, several improvements and modifications can be made to the present invention, and these improvements and modifications also fall within the scope of protection of the claims of the present invention.

Claims

1. A transmitting device for optical communication, characterized in that: include: at least two light emitting devices, the light emitting devices being used to emit light; A light homogenizing portion, arranged on the light emitting side of the at least two light emitting devices, for making the emitted light of the at least two light emitting devices incident on the light homogenizing portion and scattered in the light homogenizing portion, so that the emitted light of the at least two light emitting devices is mixed and emitted from the light homogenizing portion; The light-transmitting portion is arranged on the light-emitting side of the light-evening portion, and is used to increase the angle of the light emitted from the light-evening portion and emit it after passing through the light-transmitting portion.

2. The transmitting device for optical communication according to claim 1, characterized in that: The at least two light emitting devices are used to emit at least one monochromatic light, or the at least two light emitting devices are used to emit at least two monochromatic lights and the at least two monochromatic lights are mixed to form white light.

3. The transmitting device for optical communication according to claim 1, characterized in that: The light emitting device is used to emit light in a first wavelength band; It also includes: a wavelength conversion layer, which is arranged on the light-emitting side of the light homogenizing part, and is used to make the first-wavelength-band light passing through the light homogenizing part incident on the wavelength conversion layer, and the wavelength conversion layer is excited to generate the second-wavelength-band light; The light-transmitting portion is disposed on the light-emitting side of the wavelength conversion layer, and is used to increase the angle of the first-wavelength-band light passing through the wavelength conversion layer and the second-wavelength-band light generated by the wavelength conversion layer after passing through the light-transmitting portion and emitting.

4. The transmitting device for optical communication according to claim 3, characterized in that: The wavelength conversion layer is arranged obliquely relative to the light homogenizing portion, and the light-transmitting portion is arranged on the first side, the second side or the third side of the wavelength conversion layer, the first side is on the side of the wavelength conversion layer opposite to the light homogenizing portion, the second side and the third side are opposite sides of the wavelength conversion layer, and the first wavelength band light reflected by the wavelength conversion layer is incident on the second side / the third side.

5. The transmitting device for optical communication according to claim 4, characterized in that: The light-transmitting portion is disposed on the first side of the wavelength conversion layer, and a reflecting portion is disposed on the second side or / and the third side of the wavelength conversion layer, and the reflecting portion is used to reflect the first wavelength band light and the second wavelength band light from the wavelength conversion layer back to the wavelength conversion layer, and further propagate to the light-transmitting portion; Alternatively, the light-transmitting portion is disposed on the second side of the wavelength conversion layer, and a reflecting portion is disposed on the first side or / and the third side of the wavelength conversion layer, and the reflecting portion is used to reflect the first wavelength band light and the second wavelength band light from the wavelength conversion layer back to the wavelength conversion layer, and further propagate to the light-transmitting portion; Alternatively, the light-transmitting portion is arranged on the third side of the wavelength conversion layer, and a reflective portion is arranged on the first side and / or the second side of the wavelength conversion layer, and the reflective portion is used to reflect the first-band light and the second-band light from the wavelength conversion layer back to the wavelength conversion layer, and further propagate to the light-transmitting portion.

6. The transmitting device for optical communication according to claim 5, characterized in that: The reflecting portion includes a focusing element and a reflecting layer, wherein the reflecting layer is arranged on a side of the focusing element away from the wavelength conversion layer, and the focusing element is used to allow the first-band light and the second-band light from the wavelength conversion layer to pass through and be incident on the reflecting layer, and to allow the first-band light and the second-band light reflected by the reflecting layer to converge and return to the wavelength conversion layer.

7. An optical communication test method, applied to the transmitting device for optical communication according to any one of claims 1 to 6, characterized in that: include: When the transmitting device sends out the light signal, the receiving device is moved to change the distance and / or orientation of the receiving device relative to the transmitting device, and the receiving device receives the light signal; Communication performance data is obtained based on the electrical signal generated after the receiving device receives the optical signal, and the communication performance data reflects the communication performance between the transmitting device and the receiving device.

8. The optical communication test method according to claim 7, characterized in that: In the process of the transmitting device sending the light signal, moving the receiving device so that the distance and / or the orientation of the receiving device relative to the transmitting device changes includes: In the process of the transmitting device emitting a light signal, the receiving device is moved at a constant speed along the straight track, and the transmitting device is located on the central axis of the straight track; Alternatively, the transmitting device is located on the central axis of the straight track, and the distance from the transmitting device to the straight track is different. At any distance, when the transmitting device sends a light signal, the receiving device moves at a constant speed along the straight track.

9. The optical communication test method according to claim 7, characterized in that: Obtaining the communication performance data according to the electrical signal generated after the receiving device receives the optical signal includes: demodulating the electrical signal and / or calculating a bit error rate according to the electrical signal; Demodulating the electrical signal comprises: processing and modulating the electrical signal to generate a constellation diagram, wherein the constellation diagram comprises a plurality of constellation points, and for each element of the data to be restored of the electrical signal, calculating an absolute distance between the element of the data to be restored and each constellation point, and selecting a constellation point with a minimum absolute distance as a demodulated symbol; Calculating the bit error rate according to the electrical signal includes: processing the electrical signal to obtain an input binary stream, comparing it with the demodulated output binary stream, finding the index of bit mismatch, and calculating the bit error rate.

10. An optical communication test device, characterized in that: include: A track, used for installing a receiving device and capable of driving the receiving device to move along the track, wherein the receiving device is used for receiving the optical signal emitted by the transmitting device and generating an electrical signal; A mobile station, used for installing the transmitting device and driving the transmitting device to move, wherein the transmitting device is the transmitting device applied to optical communication according to any one of claims 1 to 6; The control device is used to obtain communication performance data based on the electrical signal generated after the receiving device receives the optical signal.

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