CN216774778U

CN216774778U - Li-Fi transceiver

Info

Publication number: CN216774778U
Application number: CN202220329032.6U
Authority: CN
Inventors: 崔洪玮
Original assignee: Shimin Technology Co ltd
Current assignee: Shimin Technology Co ltd
Priority date: 2022-02-17
Filing date: 2022-02-17
Publication date: 2022-06-17
Anticipated expiration: 2032-02-17

Abstract

The present invention provides a Li-Fi transceiver, comprising: the Wi-Fi signal transmission device comprises a shell and a receiving and transmitting circuit board, wherein the receiving and transmitting circuit board is arranged in the shell, a transmitting assembly for converting Wi-Fi signals into optical signals to be transmitted and a receiving assembly for recovering the received optical signals into the Wi-Fi signals are arranged on the receiving and transmitting circuit board, and SMA interfaces connected with Wi-Fi equipment are arranged in the transmitting assembly and the receiving assembly. Therefore, the wireless sensor network can be directly connected with Wi-Fi equipment, and the transceiver can convert Wi-Fi electric signals and visible light signals into each other to perform high-speed and reliable bidirectional communication.

Description

Li-Fi transceiver

Technical Field

The utility model relates to the technical field of optical communication, in particular to a Li-Fi transceiver.

Background

Wi-Fi is a wireless communication technology widely used at present, but with the popularization of wireless communication equipment, Wi-Fi is limited by limited spectrum resources and faces the problem of interference caused by serious channel congestion. Li-Fi is a wireless communication technology capable of transmitting data by using visible light, infrared light and the like, and the used visible spectrum has abundant spectrum resources, so that the problem of channel congestion can be fundamentally solved; but the development is slow as a new communication technology.

The current Li-Fi transceiver device can not be directly and effectively connected with the existing Wi-Fi device.

SUMMERY OF THE UTILITY MODEL

The utility model solves the problem that the existing Li-Fi receiving and transmitting equipment cannot be effectively connected with Wi-Fi equipment.

To solve the above problems, the present invention provides a Li-Fi transceiver comprising:

the Wi-Fi signal transmission device comprises a shell and a receiving and transmitting circuit board, wherein the receiving and transmitting circuit board is arranged in the shell, a transmitting assembly for converting Wi-Fi signals into optical signals to be transmitted and a receiving assembly for recovering the received optical signals into the Wi-Fi signals are arranged on the receiving and transmitting circuit board, and SMA interfaces connected with Wi-Fi equipment are arranged in the transmitting assembly and the receiving assembly.

Therefore, the wireless communication device can be directly connected with Wi-Fi equipment, and the transceiver can convert Wi-Fi electric signals and visible light signals into each other to perform high-speed and reliable bidirectional communication.

Preferably, the sending component comprises:

the SMA interface, the down-conversion circuit, the emission end post-stage amplification circuit, the LED drive circuit and the LED lamp panel are connected in sequence.

Preferably, the receiving assembly comprises:

the system comprises a silicon PIN photodiode, a trans-impedance amplifier circuit, a band-pass filter, a receiving end post-stage amplification circuit, an up-conversion circuit and the SMA interface which are connected in sequence.

Preferably, a circulator is further disposed on the transceiver circuit board, and a port of the circulator is sequentially communicated with the up-conversion circuit, one SMA interface, and the down-conversion circuit.

Preferably, the output port of the up-conversion circuit and the input port of the down-conversion circuit are connected with the port of the circulator through a T-shaped attenuator.

Preferably, a down-conversion mixer circuit is arranged on the down-conversion circuit, and the down-conversion mixer circuit is communicated with the phase-locked loop circuit and the SMA interface of the sending component.

Preferably, an up-conversion mixer circuit is arranged on the up-conversion circuit, and the up-conversion mixer circuit is communicated with the phase-locked loop circuit and the SMA interface of the receiving assembly.

Preferably, on the transceiving circuit board, two output ports of the phase-locked loop are respectively connected with the up-conversion mixer circuit and the down-conversion mixer circuit.

Preferably, the transceiver circuit board is further provided with a radio frequency single-pole double-throw switch, an input end of the radio frequency single-pole double-throw switch is connected with the down-conversion mixer circuit, and two output ends of the radio frequency single-pole double-throw switch are respectively connected with the transmitting end post-stage amplifying circuit and the high-order low-pass filter. And the output end of the high-order low-pass filter is connected with a microcontroller. The radio frequency single-pole double-throw switch can switch the output end connection of the down-conversion circuit under the control of the microcontroller.

Preferably, the shell back plate is provided with an opening and a condensing lens fixed through a threaded sleeve at a position corresponding to the silicon PIN photodiode/the LED lamp panel.

Preferably, the receiving and dispatching circuit board is further provided with an OLED screen, and the OLED screen is fixed on the receiving and dispatching circuit board through a copper column and a screw, and an accommodating space is formed between the receiving and dispatching circuit board and the OLED screen.

Preferably, the LED lamp panel comprises a plurality of 0603 packaged LED lamp beads to form a light-emitting surface.

Drawings

FIG. 1 is a schematic diagram of a front side structure of a Li-Fi transceiver according to an embodiment of the utility model;

fig. 2 is a schematic diagram of a backside structure of a Li-Fi transceiver according to an embodiment of the present invention.

In the figure: 1. a housing; 2. a down-conversion circuit; 3, an LED driving circuit; 4. a circulator; an OLED screen; 6. a phase-locked loop circuit; 7. a microcontroller; 8. debugging and downloading interfaces of the microcontroller program; 9. temperature compensation crystal oscillator; 10. an up-conversion circuit; 11. the small plate module is inserted on the bottom plate; 12. a receiver front-end circuit; 13. a power interface; 14-1/2/3.SMA interface; 15-1/2. T-shaped attenuator; 16. a down-conversion mixer circuit; 17. a radio frequency single pole double throw switch; 18. a transmitting end post-stage amplifying circuit; 19. a high order low pass filter; 20. a microcontroller serial interface; 21-1, a system reset key; 21-2/3 function selection and control keys; 22. a microcontroller USB interface; 23. a system status indicator light; 24. a dial switch; 25. an upconversion mixer circuit; 26. a board-to-board connector; 27. a receiving end post-stage amplifying circuit; 28. a band-pass filter; 29. a transimpedance amplifier circuit; 30. a silicon PIN photodiode; 31. a heat radiation fan; 32, an LED lamp panel; 33. a single 0603 encapsulates the LED lamp bead.

Detailed Description

In order to make the aforementioned objects, features and advantages of the present invention comprehensible, embodiments accompanied with figures are described in detail below.

The embodiment of the application provides a Li-Fi transceiver which is used for being effectively connected with existing Wi-Fi equipment. As shown in fig. 1 and fig. 2, which are a front-side structural schematic diagram and a back-side structural schematic diagram of a Li-Fi transceiver according to an embodiment of the present invention; wherein the Li-Fi transceiver comprises:

the Wi-Fi signal transmission device comprises a shell 1 and a receiving and transmitting circuit board, wherein the receiving and transmitting circuit board is arranged in the shell, a transmitting assembly for converting Wi-Fi signals into optical signals to be transmitted and a receiving assembly for recovering the received optical signals into the Wi-Fi signals are arranged on the receiving circuit board, and SMA interfaces connected with Wi-Fi equipment are arranged in the transmitting assembly and the receiving assembly.

Among them, the SMA (subminiatureversion a) interface is a connection method, also called SMA connector. The antenna is suitable for the application in the microwave field with the frequency range up to 26.5GHz, is used for connecting radio frequency signals, and has the characteristics of wide frequency band, excellent performance, high reliability and long service life. The standard SMA has two forms, namely an external thread and a hole at one end and an internal thread and a needle at the other end; the reversed polarity RP-SMA is an external thread and a needle at one end, and an internal thread and a hole at the other end.

Therefore, the sending component is connected with the Wi-Fi equipment through the SMA interface, and converts Wi-Fi signals into optical signals to be sent out; the receiving assembly is connected with the Wi-Fi device through the SMA interface, and the received optical signals are restored to Wi-Fi signals and transmitted to the Wi-Fi device.

Therefore, the wireless communication device can be directly connected with Wi-Fi equipment, and the transceiver can convert Wi-Fi electric signals and visible light signals into each other to perform high-speed and reliable bidirectional communication. As such, the Li-Fi transceiver may be compatible with the 802.11Wi-Fi protocol.

Wherein, the circuit board is fixed on the shell through the copper column and the screw.

Preferably, the shell design that frame and ya keli panel are pegged graft is printed in the adoption 3D, and is succinct pleasing to the eye, plays fine guard action to internal circuit.

Preferably, the sending component comprises:

the SMA interface (14-1), the down-conversion circuit 2, the emission end post-stage amplification circuit 18, the LED drive circuit 3 and the LED lamp panel 32 are connected in sequence.

The LED driving circuit 3 can provide a static bias voltage to maintain the LED in a normally on state. The voltage change of the previous stage signal is converted into the current change through the LED by using a radio frequency MOS as a Voltage Control Current Source (VCCS). The DC-DC voltage conversion chip is used for supplying power for the LED instead of a common LDO chip, so that the heat productivity is reduced, and the safety and the stability of the system are improved.

Preferably, the receiving assembly comprises:

the system comprises a silicon PIN photodiode 30, a trans-impedance amplifier circuit 29, a band-pass filter 28, a receiving end post-stage amplification circuit 27, an up-conversion circuit 10 and the SMA interface (14-3) which are connected in sequence.

Preferably, a circulator 4 is further disposed on the transceiver circuit board, and a port of the circulator is sequentially communicated with the up-conversion circuit 10, one SMA interface (14-2), and the down-conversion circuit 2.

Therefore, the circulator can send the Wi-Fi signals received by the up-conversion circuit and converted by the up-conversion circuit to the Wi-Fi equipment through the SMA interface (14-2), and send the Wi-Fi signals of the Wi-Fi equipment to the down-conversion circuit 2 through the SMA interface (14-2), so that the Wi-Fi signals are converted into optical signals to be transmitted out, and a circulator scheme is formed. The circulator is used for collecting signals in two different directions of transmitting and receiving of the Wi-Fi to the same SMA interface without mutual interference.

The circulator 4 can be soldered on the reserved PCB pad by tools such as a reflow oven and a hot air gun.

Thus, by changing the welding direction of the uppermost resistor of the T-shaped attenuator (15-1/2), the compatibility of two communication schemes of a single interface of the circulator and a double interface of the transmitting and receiving separation can be realized. When the resistance of the T-shaped attenuator (15-1/2) is welded at the end of the circulator 4, the connection between the SMA interface (14-1) and the down-conversion circuit 2 and the connection between the SMA interface (14-3) and the up-conversion circuit 10 are cut off, and the scheme of the circulator is adopted at this time; when the T-shaped attenuator (15-1/2) is resistance-welded at the corresponding SMA interface (14-1/3), the connection between the circulator 4 and the down-conversion circuit 2 and the up-conversion circuit 10 is cut off, which is the transmit-receive separation scheme.

Preferably, be provided with down-conversion mixer circuit 16 on the down-conversion circuit 2, still be provided with the intercommunication in proper order on the receiving and dispatching circuit board down-conversion mixer circuit 16, high order low pass filter 19, microcontroller 7, phase-locked loop circuit 6, down-conversion mixer circuit with phase-locked loop circuit, send the SMA (14-1) interface intercommunication of subassembly.

The phase-locked loop circuit 6 outputs at least one local oscillator signal with a set frequency in a time-sharing manner under the control of the microcontroller 7; the down-conversion frequency mixer circuit 16 mixes the local oscillator signal and the input Wi-Fi signal to obtain an intermediate frequency signal; a high-order low-pass filter 19 filters the intermediate frequency signal; the microcontroller 7 is provided with an A/D converter which samples the filtered intermediate frequency signal; and the microcontroller 7 determines the Wi-Fi channel occupied by the Wi-Fi signal according to the sampling results corresponding to different set frequencies.

It should be noted here that, during the channel detection process, the phase-locked loop circuit 6 outputs the local oscillator signals of the center frequencies of the respective channels in a traversing manner under the control of the microcontroller 7. When the system works normally, the phase-locked loop circuit 6 outputs a local oscillator signal with fixed working frequency under the control of the microcontroller 7.

The output signal frequency of the phase-locked loop circuit 6 is controlled by the microcontroller 7 through a three-wire serial interface, and the phase-locked loop reference signal is provided by a temperature compensation crystal oscillator 9.

Preferably, the transceiver circuit board is further provided with a radio frequency single-pole double-throw switch 17, an input end of the radio frequency single-pole double-throw switch is connected with the down-conversion mixer circuit 16, and two output ends of the radio frequency single-pole double-throw switch are respectively connected with the transmitting end post-stage amplifying circuit 18 and the high-order low-pass filter 19.

Thus, the radio frequency single-pole double-throw switch 17 is controlled by the microcontroller 7, and when the equipment is in a normal working state, the radio frequency single-pole double-throw switch 7 is connected with the down-conversion mixer circuit 16 and the transmitting end post-stage amplifying circuit 18; when the device is in the channel auto-detect state, the rf single-pole double-throw switch 17 will connect the down-conversion mixer circuit 16, and the high order low pass filter 19.

Therefore, when a Wi-Fi channel occupied by an input Wi-Fi signal needs to be detected, the intermediate frequency signal is input into a high-order low-pass filter for filtering and subsequent processing, so that the occupied Wi-Fi channel is accurately detected; and after the Wi-Fi channel is detected, outputting the intermediate frequency signal. Thus, through the switching of the single-pole double-throw switch, the down-conversion mixer circuit 16 can assist in realizing two mutually independent functions of Wi-Fi channel detection and intermediate-frequency signal output, and the use flexibility of the Li-Fi transceiver is greatly improved.

Wherein, OLED screen 5, it is fixed in on the circuit board through copper post and screw, and the screen winding displacement is pegged graft through arranging the needle with row mother of reserving on the circuit board, and the design that the screen is higher than the circuit board can reserve the space for microcontroller 7 and phase-locked loop circuit 6 and temperature compensation crystal oscillator 9, makes the device overall arrangement compacter reasonable, practices thrift PCB material, reduce cost.

The microcontroller 7 can control the on-off direction of the radio frequency single-pole double-throw switch 17; AD sampling is carried out on the signal from the high-order low-pass filter 19, and the current Wi-Fi channel is judged through code logic; controlling the refreshing display of the OLED screen 5; controlling the frequency of the output signal of the phase-locked loop circuit 6; detecting a lock state of the phase-locked loop circuit 6; controlling the on and off of the system status indicator lamp 23; detecting the on-off state of the dial switch 24; detecting whether the function keys (21-2) and (21-3) are pressed and responding; the small board module 11 plugged on the bottom board is controlled through a three-wire serial interface.

Wherein the passband bandwidth of the bandpass filter 28 is consistent with the Wi-Fi channel bandwidth.

The small board modules 11 inserted in the bottom board are inserted in the bottom board through the board-to-board connectors 26, and different small board modules 11 are designed with different functions, so that a user can conveniently change the small board modules according to different application scenes.

Wherein, install radiator fan additional at the region that generates heat, guarantee user safety in utilization, extension equipment life.

Wherein, install lens additional in transceiver LED and photodiode trompil department, improve effective communication distance.

Wherein, lens use the screw sleeve to be fixed in the casing bottom plate, convenience of customers changes to adjust effective communication distance and signal coverage.

The Wi-Fi channel adjustment is supported through keys, and the power-on default Wi-Fi channel is changed through the dial switch.

The Wi-Fi channel automatic detection is supported, the transceiver can measure the signal intensity of each Wi-Fi channel, the working channel of the current Wi-Fi equipment is judged according to the measurement result, the phase-locked loop signal frequency is adjusted in a self-adaptive mode, and the equipment usability is improved.

The OLED screen is adopted, so that information such as the running time of equipment, the current output frequency of a phase-locked loop, the locking state of the phase-locked loop, the current Wi-Fi channel, the state of a dial switch and the like is displayed clearly and visually.

The design of pluggable platelets is adopted, a user can select different modules such as AGC (automatic gain control) and short-circuit lines according to application scenes or experimental requirements to realize the function expansion of the transceiver, the operation parameters of the platelets can be adjusted through a three-wire serial interface connected with a microcontroller, and the adaptability and the flexibility of the equipment in the face of different application scenes are improved.

The method and the device support automatic storage of user parameter settings, and facilitate quick recovery of the running state of a user before power failure.

The two communication schemes of using a circulator or transmitting and receiving separation are supported, and a user can select the welding direction of the jumper resistor according to a use scene, so that the communication scheme is changed, and the compatibility of the equipment to different signal sources is improved.

Thus, the shell is composed of a 3D printing outer frame, an acrylic panel and the like and is used for protecting the internal circuit board. The shell is provided with a heat radiation fan in a circuit board heating area so as to improve the reliability of the system and prolong the service life of equipment. Lens are installed to the casing in LED lamp plate and silicon PIN photodiode trompil department, and on lens used the screw sleeve to be fixed in the casing backplate, convenience of customers changed. The effective communication distance and signal coverage can be changed by replacing the lens.

The circuit board integrated phase-locked loop is used as a local oscillator, so that the portability, the usability and the reliability of the system are improved. The circuit board integrated microcontroller supports two modes of key and dial switch to switch channels and supports automatic detection of the channels so as to improve the usability of the system. The circuit board has independent LED lamp plate design, and convenience of customers changes, can prolong the whole life of system. The small expansion plate module is connected with the bottom plate in a plug-in mode through a plate-to-plate connector, and a user can select a proper module to perform an experiment according to a specific application scene. The circuit board is compatible to be connected to a signal source by using a circulator single interface or by using a separate interface for transceiving, and a user can switch between the two communication schemes by changing the welding direction of the jumper resistor. The signal source may be a commercial Wi-Fi network card or a Software Defined Radio (SDR) platform.

The OLED screen is fixed on the front face of the circuit board through screws and copper columns, and the screen connecting line is connected to the circuit board through the row pins and the row nuts in an inserting mode. The OLED screen is used for displaying information such as current phase-locked loop frequency, Wi-Fi channels, running time, phase-locked loop locking states and dial switch states, and is clear and visual.

When the equipment is powered on, the on-off state of the dial switch can be detected, a default working channel is determined, the corresponding working frequency of the phase-locked loop is set, the on-off state of the dial switch is detected in a polling mode when the equipment runs normally, and if the on-off state of the dial switch is changed by a user at the moment, the equipment sets the working frequency according to a specific coding rule and takes effect immediately. When a user presses the key 21-2 for a short time, the device enters a parameter setting interface of a small plate module, taking an AGC module as an example, the microcontroller controls the output level of a DAC on a control plate through a three-wire serial interface so as to control the upper limit gain of the AGC, and if the key operation of the user is not detected within 5 seconds, the device automatically stores the module parameters configured by the user, exits the parameter setting interface and returns to a main interface. When a user presses a key 21-3 for a short time, the device enters a channel automatic detection mode, the microcontroller 7 controls the radio frequency single-pole double-throw switch 17 to cut off the connection between the down-conversion mixer circuit 16 and the transmitting end post-stage amplifying circuit 18 and switch on the down-conversion mixer circuit 16 and the high-order low-pass filter 19, then the microcontroller performs AD sampling on the low-pass filtered signal to acquire the signal intensity under the current working frequency, and under the mode, the microcontroller changes the output signal frequency of the phase-locked loop, sequentially evaluates all channels and judges the current Wi-Fi working channel according to code logic. After the channel detection is completed, the device will report the judgment result to the user, if the judgment is successful, the device will automatically jump to the Wi-Fi channel working frequency indicated by the judgment result, and reconnect the down-conversion mixer circuit 16 and the transmitting end post-stage amplifying circuit 18. When a user presses any one key 21-2 or 21-3 for three seconds, the equipment ignores the channel value preset by the dial switch, enters a manual configuration state, the user can perform rolling selection on all channels through the keys 21-2 and 21-3, and if the key operation of the user is not detected within 5 seconds, the equipment automatically exits the manual configuration state.

Before communication begins, the working channel of the Li-Fi transceiver needs to be adjusted to be consistent with the signal source. When a Li-Fi transceiver is used for communication, taking a circulator communication scheme as an example, an antenna interface of Wi-Fi equipment needs to be connected to a circulator SMA interface (14-2) of the Li-Fi transceiver through a coaxial line, and the Li-Fi transceivers of both communication parties are placed in opposite directions, so that the respective silicon PIN photodiodes 30 of both parties can receive irradiation from the LED lamp panel 32 of the opposite party.

It is noted that, herein, relational terms such as first and second, and the like may be used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Also, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising an … …" does not exclude the presence of other identical elements in a process, method, article, or apparatus that comprises the element.

All the embodiments in the application are described in a relevant manner, and the same and similar parts among the embodiments can be referred to each other, and each embodiment focuses on the differences from the other embodiments. Reference is made to the preceding description of the embodiments.

Although the present invention is disclosed above, the present invention is not limited thereto. Various changes and modifications may be effected therein by one skilled in the art without departing from the spirit and scope of the utility model as defined in the appended claims.

Claims

1. A Li-Fi transceiver, comprising:

2. The Li-Fi transceiver of claim 1, wherein the transmit component comprises:

3. The Li-Fi transceiver of claim 2, wherein the receive component comprises:

4. The Li-Fi transceiver of claim 3, wherein the transceiver circuit board is further provided with a circulator, and a port of the circulator is sequentially communicated with the up-conversion circuit, one of the SMA interfaces, and the down-conversion circuit.

5. The Li-Fi transceiver of claim 4, wherein an output port of the up-conversion circuit, an input port of the down-conversion circuit, and a port of the circulator are connected by a T-shaped attenuator.

6. The Li-Fi transceiver of any one of claims 2-5, wherein a down-conversion mixer circuit is disposed on the down-conversion circuit, and the transceiving circuit board further comprises the down-conversion mixer circuit, the high-order low-pass filter, the microcontroller, and the phase-locked loop circuit, which are sequentially connected to each other, and the down-conversion mixer circuit is connected to the phase-locked loop circuit and the SMA interface of the transmitting assembly.

7. The Li-Fi transceiver of claim 6, wherein the transceiver circuit board is further provided with a radio frequency single-pole double-throw switch, an input end of the radio frequency single-pole double-throw switch is connected to the down-conversion mixer circuit, and two output ends of the radio frequency single-pole double-throw switch are respectively connected to the transmitting end post-stage amplifying circuit and the high-order low-pass filter.

8. The Li-Fi transceiver of any one of claims 3 to 5, wherein the housing back plate is provided with an opening and a condenser lens fixed by a threaded sleeve at a position corresponding to the silicon PIN photodiode/the LED lamp panel.

9. The Li-Fi transceiver of any one of claims 1 to 5, wherein the transceiver circuit board is further provided with an OLED screen, the OLED screen being fixed to the transceiver circuit board by copper posts and screws with an accommodation space therebetween.

10. The Li-Fi transceiver of any one of claims 2-5, wherein the LED lamp panel comprises a light emitting surface formed by a plurality 0603 of encapsulated LED lamp beads.