Visible light communication apparatus and method thereof, electronic device

Abstract

The application discloses a visible light communication device and method thereof and an electronic device, and belongs to the electronic technical field.The visible light communication system comprises a signal generating device, a light emitting driving circuit, a light emitting element, a photoelectric sensing device, a sensing driving circuit and a signal receiving device; the light emitting driving circuit comprises a digital-to-analog converter and a first operational amplifier; the signal generating device, the digital-to-analog converter, the first operational amplifier and the light emitting element are sequentially electrically connected; the sensing driving circuit comprises a transimpedance amplifier, a high-pass filter, a second operational amplifier and an analog-to-digital converter; the signal receiving device comprises a sampling decision module and a signal processing module; the photoelectric sensing device, the transimpedance amplifier, the high-pass filter, the second operational amplifier, the analog-to-digital converter, the sampling decision module and the signal processing module are sequentially electrically connected. By adopting the application, the influence of optical noise can be reduced, and the signal-to-noise ratio of a signal is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of electronics, in particular to a visible light communication device and method thereof, and an electronic device. BACKGROUND

[0002] Visible light communication technology can be a communication mode that directly transmits optical signals in air by using visible light as an information carrier.

[0003] Generally, a visible light communication device includes a light transmitting device and a light receiving device, the light transmitting device includes a signal generating device and a light emitting element, the light receiving device includes a photoelectric sensing device, a sensing driving circuit and a signal receiving device, the signal generating device is used to generate a signal with certain content, the light emitting element is used to transmit the signal through light, the photoelectric sensing device is used to receive the optical signal and convert it into an electrical signal, the sensing driving circuit is used to amplify and convert the electrical signal, and the signal receiving device is only used to receive the signal and perform quality detection and other processing on the received signal.

[0004] In the above light communication process, the signal is affected by light noise generated by sunlight, artificial light sources and the like, and these noises cause the signal-to-noise ratio of the signal to decrease. SUMMARY

[0005] The present application provides a visible light communication device and method thereof, and an electronic device, which can solve the technical problems existing in the related art. The technical solutions of the visible light communication device and method thereof, and the electronic device are as follows:

[0006] In a first aspect, the present application provides a visible light communication device, which includes a signal generating device, a light emitting driving circuit, a light emitting element, a photoelectric sensing device, a sensing driving circuit and a signal receiving device.

[0007] The light emitting driving circuit includes a digital-to-analog converter and a first operational amplifier, and the signal generating device, the digital-to-analog converter, the first operational amplifier and the light emitting element are electrically connected in sequence.

[0008] The sensing driving circuit includes a transimpedance amplifier, a high-pass filter, a second operational amplifier and an analog-to-digital converter, the signal receiving device includes a sampling judgment module and a signal processing module, and the photoelectric sensing device, the transimpedance amplifier, the high-pass filter, the second operational amplifier, the analog-to-digital converter, the sampling judgment module and the signal processing module are electrically connected in sequence.

[0009] In a possible implementation, the signal generating device includes a signal generating module and an equalizer, and the equalizer is electrically connected with the signal generating module and the digital-to-analog converter respectively.

[0010] the signal generation module is configured to generate a signal;

[0011] the equalizer is configured to perform frequency adjustment on the signal generated by the signal generation module based on a bandwidth of the light-emitting element;

[0012] the sampling decision module is configured to perform sampling decision on the received signal with a sampling interval of 2kπ / ω to recover the signal, where k is a positive integer, ω is a frequency angle of the signal after frequency adjustment, and ω is an inverse of the bandwidth of the light-emitting element.

[0013] In a possible implementation, the high-pass filter is an RC (Resistance-Capacitance Circuits) high-pass filter.

[0014] In a possible implementation, the inductive driving circuit further includes a low-pass filter, and the low-pass filter is electrically connected to the second operational amplifier and the analog-to-digital converter, respectively.

[0015] In a possible implementation, the low-pass filter is a Butterworth low-pass filter, and an order of the Butterworth low-pass filter is greater than a first preset order value.

[0016] In a possible implementation, the first preset order value is 5.

[0017] In a possible implementation, the signal receiving device further includes a band-pass filter, and the band-pass filter is electrically connected to the analog-to-digital converter and the sampling decision module, respectively, and the band-pass filter is configured to perform band-pass filtering on the digital signal sent by the analog-to-digital converter and send the band-pass filtered signal to the sampling decision module.

[0018] In a possible implementation, the band-pass filter is a FIR (Finite Impulse Response) band-pass filter, and an order of the FIR band-pass filter is greater than a second preset order value.

[0019] In a possible implementation, the second preset order value is 10.

[0020] In a possible implementation, the FIR band-pass filter is a parallel FIR band-pass filter.

[0021] In a possible implementation, a low-frequency stop band of the band-pass filter is 100 kHz-200 kHz, and a high-frequency stop band of the band-pass filter is 50 MHz-70 MHz.

[0022] In a possible implementation, the signal generating device comprises a signal generating module and a Manchester encoding module, and the Manchester encoding module is electrically connected with the signal generating module and the digital-to-analog converter respectively.

[0023] The signal receiving device further comprises a Manchester decoding module, and the Manchester decoding module is electrically connected with the sampling decision module.

[0024] In a second aspect, the embodiments of the present application provide a visible light communication method, which is applied to the visible light communication device as described above, and the visible light communication method comprises:

[0025] The signal generating device generates a first electrical signal, and sends the digital signal to the digital-to-analog converter, wherein the first electrical signal is a digital signal, the digital-to-analog converter converts the first electrical signal into an analog signal corresponding to the first electrical signal, and sends the analog signal corresponding to the first electrical signal to the first operational amplifier, the first operational amplifier amplifies the analog signal corresponding to the first electrical signal to obtain a first amplified signal, and sends the first amplified signal to the light emitting element, and the light emitting element converts the first amplified signal into a light output signal and sends the light output signal outward.

[0026] The photoelectric sensing device receives a light receiving signal, converts the light receiving signal into a current signal corresponding to the light receiving signal, and sends the current signal corresponding to the light receiving signal to the transimpedance amplifier, the transimpedance amplifier converts the current signal corresponding to the light receiving signal into a voltage signal, and sends the voltage signal to the high-pass filter, the high-pass filter performs high-pass filtering on the voltage signal to obtain a high-pass filtered signal, and sends the high-pass filtered signal to the second operational amplifier, the second operational amplifier amplifies the high-pass filtered signal to obtain a second amplified signal, and sends the second amplified signal to the analog-to-digital converter, the analog-to-digital converter converts the second amplified signal into a digital signal corresponding to the second amplified signal, and sends the digital signal corresponding to the second amplified signal to the sampling decision module, the sampling decision module performs sampling decision on the digital signal corresponding to the second amplified signal to obtain a second electrical signal, and sends the second electrical signal to the signal processing module.

[0027] In a possible implementation, when the signal generating device comprises a signal generating module and an equalizer, the signal generating device generates a first electrical signal, comprising:

[0028] The signal generation module generates a to-be-sent signal and sends the to-be-sent signal to the equalizer, and the equalizer performs frequency adjustment on the to-be-sent signal to obtain the first electric signal, wherein a frequency angle ω of the first electric signal is an inverse of a bandwidth of the light-emitting element;

[0029] The sampling decision module performs sampling decision on the digital signal corresponding to the second amplified signal to obtain a second electric signal, including:

[0030] The sampling decision module samples the digital signal corresponding to the second amplified signal at a sampling interval of 2kπ / ω to obtain a plurality of sampling values, performs decision processing on the plurality of sampling values to obtain a second electric signal corresponding to the plurality of sampling values, wherein k is a positive integer.

[0031] In a possible implementation, when the inductive driving circuit further includes a low-pass filter, the second operational amplifier performs amplification processing on the high-pass filtered signal to obtain a second amplified signal, and sends the second amplified signal to the analog-to-digital converter, and the analog-to-digital converter converts the second amplified signal into a digital signal corresponding to the second amplified signal, including:

[0032] The second operational amplifier performs amplification processing on the high-pass filtered signal to obtain a second amplified signal, and sends the second amplified signal to the low-pass filter, the low-pass filter performs low-pass filtering processing on the second amplified signal to obtain a low-pass filtered signal, and sends the low-pass filtered second amplified signal to the analog-to-digital converter, and the analog-to-digital converter converts the low-pass filtered second amplified signal into a digital signal corresponding to the second amplified signal.

[0033] In a possible implementation, when the signal receiving device further includes a band-pass filter, the analog-to-digital converter converts the second amplified signal into a digital signal corresponding to the second amplified signal, and sends the digital signal corresponding to the second amplified signal to the sampling decision module, and the sampling decision module performs sampling decision on the digital signal corresponding to the second amplified signal to obtain a second electric signal, including:

[0034] The analog-to-digital converter converts the second amplified signal into a digital signal corresponding to the second amplified signal, and sends the digital signal corresponding to the second amplified signal to the band-pass filter, the band-pass filter performs band-pass filtering processing on the digital signal corresponding to the second amplified signal to obtain a band-pass filtered signal, and sends the band-pass filtered signal to the sampling decision module, and the sampling decision module performs sampling decision on the band-pass filtered signal to obtain the second electric signal.

[0035] In a possible implementation, when the signal generating device comprises a signal generating module and a Manchester encoding module, and the signal receiving device further comprises a Manchester decoding module, the signal generating device generates a first electrical signal, comprising:

[0036] The signal generating module generates a to-be-sent signal, and sends the to-be-sent signal to the Manchester encoding module, the Manchester encoding module performs Manchester encoding processing on the to-be-sent signal to obtain the first electrical signal.

[0037] The analog-to-digital converter converts the second amplified signal into a digital signal corresponding to the second amplified signal, and sends the digital signal corresponding to the second amplified signal to the sample decision module, the sample decision module performs sample decision on the digital signal corresponding to the second amplified signal to obtain a second electrical signal, comprising:

[0038] The analog-to-digital converter converts the second amplified signal into a digital signal corresponding to the second amplified signal, and sends the digital signal corresponding to the second amplified signal to the Manchester decoding module, the Manchester decoding module performs Manchester decoding processing on the digital signal corresponding to the second amplified signal to obtain a third electrical signal, and sends the third electrical signal to the sample decision module, the sample decision module performs sample decision on the third electrical signal to obtain the second electrical signal.

[0039] In a third aspect, an electronic device is provided, and the electronic device comprises the visible light communication device according to any one of the preceding aspects.

[0040] The technical solutions provided in the embodiments of the present application have at least the following beneficial effects:

[0041] The visible light communication device provided in the embodiments of the present application comprises a signal generator, a light-emitting driving circuit, a light-emitting element, a photoelectric sensing device, a sensing driving circuit and a signal receiver, wherein the sensing driving circuit comprises a high-pass filter, and can filter direct current components and low-frequency alternating current components generated by light noises such as sunlight and artificial light sources, thereby reducing the influence of the light noises and improving the signal-to-noise ratio of the signal.

[0042] It should be understood that the foregoing general description and the following detailed description are only exemplary and explanatory, and cannot limit the present application. BRIEF DESCRIPTION OF DRAWINGS

[0043] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed to be used in the embodiments will be briefly introduced. Obviously, the drawings in the following description only constitute some embodiments of the present application, and other drawings can be obtained by those skilled in the art without any creative effort.

[0044] Figure 1 is a structural schematic diagram of a visible light communication device according to an embodiment of the present application;

[0045] Figure 2 is a circuit topology schematic diagram of a trans-impedance amplifier and an RC high-pass filter according to an embodiment of the present application;

[0046] Figure 3 is a schematic diagram of signal sampling according to an embodiment of the present application;

[0047] Figure 4 is a structural schematic diagram of a visible light communication device according to an embodiment of the present application;

[0048] Figure 5 is a schematic diagram of signal sampling according to an embodiment of the present application;

[0049] Figure 6 is a structural schematic diagram of an equalizer according to an embodiment of the present application;

[0050] Figure 7 is a structural schematic diagram of a visible light communication device according to an embodiment of the present application;

[0051] Figure 8 is a filter characteristic curve schematic diagram of a 7th order Butterworth low-pass filter according to an embodiment of the present application;

[0052] Figure 9 is a structural schematic diagram of a visible light communication device according to an embodiment of the present application;

[0053] Figure 10 is a structural schematic diagram of a visible light communication device according to an embodiment of the present application;

[0054] Figure 11 is a Manchester coding schematic diagram according to an embodiment of the present application;

[0055] Figure 12 is an architecture schematic diagram of a Manchester coding module and a Manchester decoding module according to an embodiment of the present application;

[0056] Figure 13 is an execution flow schematic diagram of a Manchester coding module according to an embodiment of the present application;

[0057] Figure 14 This is a schematic diagram illustrating the execution flow of a Manchester decoding module according to an embodiment of this application;

[0058] Figure 15 This is a schematic flowchart illustrating a visible light communication method according to an embodiment of this application;

[0059] Figure 16 This is a schematic flowchart illustrating a visible light communication method according to an embodiment of this application;

[0060] Figure 17 This is a schematic flowchart illustrating a visible light communication method according to an embodiment of this application;

[0061] Figure 18 This is a schematic flowchart illustrating a visible light communication method according to an embodiment of this application;

[0062] Figure 19 This is a flowchart illustrating a visible light communication method according to an embodiment of this application.

[0063] Legend

[0064] 1. Signal generating device; 2. Light-emitting driving circuit; 3. Light-emitting element; 4. Photoelectric sensing device; 5. Sensing driving circuit; 6. Signal receiving device;

[0065] 11. Signal generation module; 12. Equalizer; 13. Manchester encoding module;

[0066] 21. Digital-to-analog converter; 22. First operational amplifier;

[0067] 51. Transimpedance amplifier; 52. High-pass filter; 53. Second operational amplifier; 54. Analog-to-digital converter; 55. Low-pass filter;

[0068] 61. Sampling and Decision Module; 62. Signal Processing Module; 63. Bandpass Filter; 64. Manchester Decoding Module. Detailed Implementation

[0069] To make the objectives, technical solutions, and advantages of this application clearer, the embodiments of this application will be described in further detail below with reference to the accompanying drawings.

[0070] This application provides a visible light communication device, such as... Figure 1 As shown, the visible light communication device includes a signal transmitting end and a signal receiving end. The signal transmitting end includes a signal generating device 1, a light-emitting driving circuit 2, and a light-emitting element 3. The signal receiving end includes a photoelectric sensing device 4, a sensing driving circuit 5, and a signal receiving device 6.

[0071] As the device of the signal sending end, the signal generating device 1, the light emitting driving circuit 2 and the light emitting element 3 are electrically connected in sequence, wherein the signal generating device 1 is used to generate an electric signal with a certain meaning based on user demand, and then send the generated electric signal to the light emitting driving circuit 2 for amplification processing, so that the signal can drive the light emitting element 3 to emit light. After receiving the electric signal sent by the light emitting driving circuit 2, the light emitting element 3 converts the electric signal into a light output signal and transmits the light output signal through the air.

[0072] As the device of the signal receiving end, the photoelectric sensing device 4, the sensing driving circuit 5 and the signal receiving device 6 are electrically connected in sequence, wherein the photoelectric sensing device 4 is used to accept the light receiving signal transmitted through the air, and convert the light receiving signal into an electric signal and send it to the sensing driving circuit 5. The sensing driving circuit 5 is used to provide a high level for the photoelectric sensing device 4 to make the photoelectric sensing device 4 work. The signal receiving device 6 is used to sample and judge the electric signal sent by the sensing driving circuit 5, etc. to recover the electric signal generated by the signal generating device 1, so as to obtain the meaning of the electric signal.

[0073] In a possible implementation, the signal generating device 1 and the signal receiving device 6 can be realized by an FPGA (Field Programmable Gate Array, Field Programmable Gate Array) development board.

[0074] In the embodiment of the application, the light emitting driving circuit 2 includes a digital-to-analog converter 21 and a first operational amplifier 22, and the signal generating device 1, the digital-to-analog converter 21, the first operational amplifier 22 and the light emitting element 3 are electrically connected in sequence. The digital-to-analog converter 21 is used to convert the received digital signal into an analog signal, and the first operational amplifier 22 is used to amplify the analog signal to a certain extent, so that it can drive the light emitting element 3 to emit light.

[0075] The sensing driving circuit 5 includes a transimpedance amplifier 51, a high-pass filter 52, a second operational amplifier 53 and an analog-to-digital converter 54. The transimpedance amplifier 51 is used to convert a current signal into a voltage signal. The high-pass filter 52 can filter the light noise. The second operational amplifier 53 is used to amplify the filtered signal, and then send the amplified signal to the analog-to-digital converter 54. The analog-to-digital converter 54 is used to convert the analog signal into a digital signal.

[0076] The high-pass filter 52 is used to filter the light noise. The light noise is usually a direct current component or a low-frequency alternating current component. For example, the sunlight is a direct current component, and the artificial light source is usually a low-frequency alternating current component. The high-pass filter 52 provided in the inductive driving circuit 5 can attenuate the direct current component and the low-frequency alternating current component generated by the light noise, thereby improving the signal-to-noise ratio of the signal, and providing the communication performance and reliability of the visible light communication device.

[0077] The signal receiving device 6 includes a sampling decision module 61 and a signal processing module 62. The sampling decision module 61 is used to sample the received signal, thereby recovering the signal to obtain the electrical signal generated by the signal generating device 1. The signal processing module 62 is used to perform signal detection and the like.

[0078] In a possible implementation, the high-pass filter 52 provided in the inductive driving circuit 5 can be an RC high-pass filter. Since the frequency of the light noise is relatively fixed, the RC high-pass filter is sufficient to filter the light noise. In addition, the RC high-pass filter has a relatively simple structure, and thus the filtering efficiency is relatively fast.

[0079] For example, as shown in FIG. 5, Figure 2 Figure 2 a circuit topology of the transimpedance amplifier 51 and the RC high-pass filter 52 is shown. Of course, the circuit can also be in other forms, and the embodiments of the present application do not make a specific limitation on this.

[0080] In a possible implementation, the high-pass filter 52 can be provided between the transimpedance amplifier 51 and the second operational amplifier 53, or can be provided between the second operational amplifier and the analog-to-digital converter 54, and can also filter the light noise. The embodiments of the present application do not make a specific limitation on the position of the high-pass filter 52.

[0081] In a possible implementation, since the visible light communication device is used to realize signal transmission through baseband transmission, the transmission characteristics of the baseband transmission system are not ideal, the frequency band is limited, the signal has a long tail in the time domain, and interference is caused between adjacent symbols. For example, as shown in FIG. 6, Figure 3 three symbols are shown. Since the frequency of the signal generated by the signal generating device 1 is not a fixed value when the signal with different meanings is generated, when sampling is performed based on a certain sampling interval in the sampling decision module 61, the collected signal can be as shown in FIG. 7. Figure 3 As can be seen, t3, t4, t5, and t6 are obviously interfered by the adjacent symbols. In the embodiments of the present application, in order to reduce the influence of the above-mentioned inter-symbol interference, the following settings can be made.

[0082] For example, as shown in FIG. 8, Figure 4 ​As shown, the signal generating device 1 can include a signal generating module 11 and an equalizer 12, and the equalizer 12 is electrically connected with the signal generating module 11 and the digital-to-analog converter 21 respectively. The signal generating module 11 is configured to generate a signal with a certain meaning, and send the generated signal to the equalizer 12. The equalizer 12 is configured to adjust the frequency of the signal, so that the frequency of the signal is adjusted to a preset value. When sampling in the sampling decision module 61, the sampling interval can be set to collect the signal at the maximum amplitude, so as to reduce the interference between code elements as much as possible and improve the signal-to-noise ratio of the signal. Figure 5 As shown, the collected signal can be as shown in Figure 5 The t7, t8 and t9 are all at the maximum amplitude of the signal, and the adjacent code elements have less influence on the signal at the maximum amplitude.

[0083] For the frequency adjustment function of the equalizer 12, the frequency of the signal generated by the signal generating module 11 can be adjusted based on the bandwidth of the light emitting element 3, so as not to affect the light emitting performance of the light emitting element 3.

[0084] For the sampling decision module 61, it can be used to sample and judge the received signal with a sampling interval of 2kπ / ω to recover the signal, where k is a positive integer, ω is the frequency angle of the signal after frequency adjustment, and ω is the inverse of the bandwidth of the light emitting element 3.

[0085] That is, first, the inverse of the bandwidth of the light emitting element 3 is determined as the frequency angle of the signal after frequency adjustment of the equalizer, and the frequency of the adjusted signal is ω / 2π. The sampling interval can be set to 2kπ / ω, so that the maximum amplitude of the signal can be collected, and the influence of the code interference can be avoided as much as possible, thereby improving the signal-to-noise ratio.

[0086] In one possible implementation, as shown in Figure 6 The structure of the equalizer 12 can be that the equalizer 12 includes a filtering module, an error calculation module and an updating module. Before the equalizer 12 is put into use, a plurality of training samples can be used to update the filtering coefficients in the filtering module, that is, the training samples include an input signal and an expected signal, and the expected signal is a signal after frequency adjustment of the input signal.

[0087] The input signal is input into the filtering system for filtering, and then the filtered signal and the expected signal are input into the error calculation module for calculation. The calculated error value is input into the updating module, and the updating module updates the filtering coefficients in the filtering module based on the error value. In this way, the filtering coefficients in the filtering module are updated through a plurality of training samples, so as to obtain a usable equalizer.

[0088] In a possible implementation, the electrical noise is inevitably generated in the process of the electrical signal transmission, which reduces the signal-to-noise ratio of the signal, especially when the first operational amplifier 22 and the second operational amplifier 53 amplify the signal, the generated electrical noise is particularly serious, and the electrical noise is usually high-frequency electrical noise. In the embodiment of the present application, in order to reduce the influence of the high-frequency electrical noise on the signal, the following setting can be made:

[0089] As shown in Figure 7 , the induction driving circuit 5 can further include a low-pass filter 55, and the low-pass filter 55 is electrically connected with the second operational amplifier 53 and the analog-to-digital converter 54 respectively. In this way, the low-pass filter 55 is connected after the second operational amplifier 53, and the high-frequency electrical noise generated in the circuit can be filtered, so as to improve the signal-to-noise ratio of the signal.

[0090] In a possible implementation, because there are many types of chips used in the circuit, the frequency range of the electrical noise cannot be calculated definitely, and therefore, in the embodiment of the present application, the low-pass filter 55 can be a Butterworth low-pass filter. The slope between the passband and the stopband of the Butterworth low-pass filter can be adjusted, and therefore, the slope of the Butterworth low-pass filter can be adjusted to make the stopband frequency as close to the passband frequency as possible. In this way, the high-frequency electrical noise can be filtered in a larger range as far as possible under the condition that the signal can pass, so as to improve the filtering performance and the signal-to-noise ratio of the signal.

[0091] The adjustment method of the slope of the Butterworth low-pass filter is to increase the order of the Butterworth low-pass filter to increase the slope between the passband and the stopband. Therefore, in the embodiment of the present application, the order of the Butterworth low-pass filter can be greater than a first preset order value. When the order of the Butterworth low-pass filter is greater than the first preset order value, the slope is also greater, and the stopband frequency is closer to the passband frequency.

[0092] In a possible implementation, the first preset order value can be 5, and of course, it can also be other values, which can be set according to the demand. The order of the Butterworth low-pass filter can also be any reasonable value. For example, the Butterworth low-pass filter can be a 7-order Butterworth low-pass filter with a 50MHz passband and a 100MHz stopband. The selected operational amplifier chip can be AD8056, which has a gain bandwidth product of 300MHz, two channels, a small overall structure size, a gain error of 0.01% and a phase error of 0.02% when the load is 150Ω, and high filtering performance. The filtering characteristic curve is as shown in Figure 8As shown, it can be seen that the gain of the signal is-3db when the frequency is 50MHz, and the gain of the signal is-40db when the frequency is 100MHz, so that the signal with the frequency below 50MHz can pass almost without loss, but the signal with the frequency higher than 100MHz is attenuated seriously and almost all filtered out by the 7th order Butterworth low-pass filter, and the filtering performance is better, which is beneficial to improve the signal-to-noise ratio of the signal.

[0093] In a possible implementation, a band-pass filter can be further added to the visible light communication device in any of the foregoing embodiments of the present application, and the optical noise and the electrical noise in the signal are filtered out by the band-pass filter to improve the signal-to-noise ratio of the signal, for example, as shown in FIG. 6. Figure 9 As shown, the band-pass filter 63 can be set as follows:

[0094] The signal receiving device 6 can further include a band-pass filter 63 electrically connected to the analog-to-digital converter 54 and the sample decision module 61, wherein the band-pass filter 63 is configured to perform band-pass filtering on the digital signal sent by the analog-to-digital converter 54 and send the band-pass filtered signal to the sample decision module 61 for signal recovery.

[0095] The band-pass filter 63 is arranged at the front end of the signal receiving device 6, and the signal can be band-pass filtered before being processed, and the band-pass filter 63 can be a series combination of a low-pass filter and a high-pass filter, so that the direct current component and the low-frequency alternating current component in the optical noise and the high-frequency electrical noise are filtered out, and the signal-to-noise ratio of the signal is further improved.

[0096] It can be understood that the band-pass filter 63 is a digital filter configured to filter the digital signal. Generally, the filtering performance of the digital filter is much higher than that of the analog filter, and therefore, the band-pass filter 63 can be used as the last filter before the signal is processed, so that the noise interference caused by the optical noise and the electrical noise in the signal can be reduced to the minimum, and the signal-to-noise ratio of the signal can be maximally improved.

[0097] In a possible implementation, the band-pass filter 63 can be a FIR band-pass filter, and the slope between the passband and the stopband of the FIR band-pass filter can be adjusted by adjusting the order of the FIR band-pass filter, so as to improve the filtering performance of the FIR band-pass filter.

[0098] The adjustment method of the slope of the FIR band-pass filter is to increase the order of the FIR band-pass filter to increase the slope between the passband and the stopband. Therefore, in the present embodiment, the order of the FIR band-pass filter can be greater than the second preset order value, that is, when the order of the FIR band-pass filter is greater than the second preset order value, the slope is also greater, the stopband frequency is closer to the passband frequency, and the filtering performance is better.

[0099] In a possible implementation, the second preset order value can be 10, and of course, can also be other values, which can be set according to requirements. The order of the FIR band-pass filter can also be any reasonable value. For example, the FIR band-pass filter can be a 15-order FIR band-pass filter. When the order is 15, the implementation of the FIR band-pass filter needs 16 multipliers, 15 adders, and 15 sets of delay registers. In order to stabilize the data in the first row of the signal, a set of delay registers can be added at the front end of the FIR band-pass filter, that is, a total of 16 sets of delay registers.

[0100] In a possible implementation, the FIR band-pass filter can be a parallel FIR band-pass filter, and parallel processing can improve the filtering efficiency of the FIR band-pass filter. For example, for a 15-order FIR band-pass filter, parallel design is adopted, and in one clock cycle, the multiplication and addition operations of 16 delay registers are performed at the same time, and then the ripple value is output under the driving of the clock. Then, 16 filter coefficients of the high-pass part in the FIR band-pass filter are calculated according to the least square method. After amplification processing of the 16 filter coefficients, the filter coefficients are stored in the delay registers. For example, if the bit width of the delay register is 12 bits, the amplification multiple of the filter coefficient can be 2 11 After amplification processing of the filter coefficients, the filter coefficients can also be subjected to approximation processing (that is, the decimal point is eliminated), and then the processed filter coefficients are stored in the delay registers. The filter coefficients of the low-pass part are the same as those of the high-pass part, which will not be described herein.

[0101] In a possible implementation, the low-frequency stop band of the band-pass filter 63 can be 100 kHz-200 kHz, and the high-frequency stop band can be 50 MHz-70 MHz. Of course, it can also be other stop band frequencies, which can be set according to the frequency range of the optical noise and the electrical noise in the actual situation, and the embodiments of the present application do not limit this.

[0102] In a possible implementation, the influence of the optical noise can also be reduced by encoding in the signal generation device 1 on the basis of any one of the above visible light communication devices, as shown in the following table. Figure 10 The corresponding settings can be as follows:

[0103] The signal generation device 1 can include a signal generation module 11 and a Manchester encoding module 13. The Manchester encoding module 13 is electrically connected to the signal generation module 11 and the digital-to-analog converter 21. The signal receiving device 6 can also include a Manchester decoding module 64, which is electrically connected to the sampling decision module 61.

[0104] As shown in the following table, the Manchester encoding module 13 can be configured to perform Manchester encoding on the signal generated by the signal generation module 11, and the Manchester decoding module 64 can be configured to perform Manchester decoding on the signal received by the signal receiving device 6. Figure 11As shown, the Manchester encoding module 13 is configured to perform an exclusive-OR operation on the signal generated by the signal generation module 11 and the clock signal, so as to obtain a Manchester encoded signal. Since the Manchester encoded signal is not sensitive to artificial light noise, the artificial light noise can be effectively reduced, thereby improving the signal-to-noise ratio of the signal.

[0105] The Manchester decoding module 64 provided in the signal receiving device 6 can be configured to perform off-line digital signal decoding on the received signal or use an operational amplifier to decode the signal, and the embodiments of the present application do not limit the Manchester decoding module 64.

[0106] In a possible implementation manner, as shown in Figure 12 The Manchester encoding module 13 and the Manchester decoding module 64 can be implemented by using an FPGA development board, and both of the modules are implemented in the structure of a state machine, and the execution flowchart of the state machine is as shown in Figure 13 and Figure 14 As shown in Figure 13 is an execution flowchart of the Manchester encoding module 13, Figure 14 is an execution flowchart of the Manchester decoding module 64.

[0107] Manchester encoding module 13: When it is detected that the encoding enable is high, the state machine starts to execute, and when the value of clk_b is 1, it waits in S1 state. When the value of clk_b is 0, it is determined whether the input value is 1 or 0. If it is 1, it jumps to S2 state and assigns enc_out as 1. After reaching S2 state, it jumps back to S1 state unconditionally and assigns enc_out as 0. If it is 0, it jumps to S3 state and assigns enc_out as 0. After reaching S3 state, it jumps back to S1 state unconditionally and assigns enc_out as 1.

[0108] Manchester decoding module 64: When it is detected that dec_en is high, the state machine executes, and when the value of clk_b is 0, it waits in S1. When the value of clk_b is 1, it is determined whether the value of enc_out is 1 or 0. If it is 1, it jumps to S2 state and assigns dec_out. S2 state unconditionally jumps to S1 state. If it is 0, it jumps to S3 state and assigns dec_out as 0. S3 state unconditionally jumps to S1 state.

[0109] Wherein, clk_b is a baseband clock, used as a synchronization signal, clk_f is a frequency band clock, which is a working clock of the system, rst_n is a system reset signal, enc_in is a signal generated by the signal generation module 11, enc_en is an encoding enable, enc_out is a signal after Manchester encoding, dec_en is a decoding enable, and dec_out is a signal output after decoding.

[0110] If the Manchester encoding module 13 is arranged in the signal generation device 1 with the equalizer 12, the Manchester encoding module 13 can be located between the signal generation module 11 and the equalizer 12, or between the equalizer 12 and the digital-to-analog converter 21, and the embodiment of the present application does not limit this.

[0111] If the Manchester decoding module 64 is arranged in the signal receiving device 6 with the band-pass filter 63, the Manchester decoding module 64 can be located between any two adjacent devices of the analog-to-digital converter 54, the sampling decision module 61 and the band-pass filter 63, and the embodiment of the present application does not limit this.

[0112] The technical scheme provided by the embodiment of the present application at least has the following beneficial effects:

[0113] The embodiment of the present application provides a visible light communication device, which comprises a signal generation device 1, a light-emitting driving circuit 2, a light-emitting element 3, a photo-sensing device 4, a sensing driving circuit 5 and a signal receiving device 6, wherein the sensing driving circuit 5 comprises a high-pass filter 52, which can filter the direct current component and low-frequency alternating current component generated by light noise such as sunlight and artificial light source, thereby reducing the influence of the light noise and improving the signal-to-noise ratio of the signal.

[0114] The embodiment of the present application further provides a visible light communication method, which is applied to any one of the above visible light communication devices, as shown in the figure, the method comprises the following steps. Figure 15

[0115] For the signal sending end: the signal generation device 1 generates a first electric signal, and sends a digital signal to the digital-to-analog converter 21, wherein the first electric signal is a digital signal. The digital-to-analog converter 21 converts the first electric signal into an analog signal corresponding to the first electric signal, and sends the analog signal corresponding to the first electric signal to the first operational amplifier 22. The first operational amplifier 22 amplifies the analog signal corresponding to the first electric signal to obtain a first amplified signal, and sends the first amplified signal to the light-emitting element 3. The light-emitting element 3 converts the first amplified signal into a light output signal, and sends the light output signal outward.

[0116] ​For the signal receiving end: the photoelectric sensing device 4 receives the light receiving signal, converts the light receiving signal into a current signal corresponding to the light receiving signal, and sends the current signal corresponding to the light receiving signal to the transimpedance amplifier 51; the transimpedance amplifier 51 converts the current signal corresponding to the light receiving signal into a voltage signal and sends the voltage signal to the high-pass filter 52; the high-pass filter 52 performs high-pass filtering on the voltage signal to obtain a high-pass filtered signal and sends the high-pass filtered signal to the second operational amplifier 53; the second operational amplifier 53 amplifies the high-pass filtered signal to obtain a second amplified signal and sends the second amplified signal to the analog-to-digital converter 54; the analog-to-digital converter 54 converts the second amplified signal into a digital signal corresponding to the second amplified signal and sends the digital signal corresponding to the second amplified signal to the sample decision module 61; and the sample decision module 61 performs sample decision on the digital signal corresponding to the second amplified signal to obtain a second electrical signal and sends the second electrical signal to the signal processing module 62.

[0117] The light receiving signal received by the photoelectric sensing device 4 is extremely susceptible to light noise of ambient light during transmission. In the embodiment of the present application, the high-pass filter 52 provided in the sensing driving circuit 5 can attenuate the direct current component and low-frequency alternating current component generated by the light noise, thereby improving the signal-to-noise ratio of the signal.

[0118] In a possible implementation, in a visible light communication device, the signal generating device 1 can include a signal generating module 11 and an equalizer 12, as shown in Figure 16 Under the structure of such a visible light communication device, the processing flow in the signal generating device 1 and the sample decision device 61 can include:

[0119] The signal generating module 11 generates a to-be-sent signal and sends the to-be-sent signal to the equalizer 12; the equalizer 12 performs frequency adjustment on the to-be-sent signal to obtain a first electrical signal, wherein the frequency angle ω of the first electrical signal is the inverse of the bandwidth of the light emitting element 3.

[0120] The sample decision module 61 samples the digital signal corresponding to the second amplified signal at a sampling interval of 2kπ / ω to obtain a plurality of sample values, and performs decision processing on the plurality of sample values to obtain a second electrical signal corresponding to the plurality of sample values.

[0121] The equalizer 12 can perform frequency adjustment on signals of different frequencies so that the frequency of the signal is adjusted to a preset value. In this way, when sampling in the sample decision module 61, the sampling interval can be set to capture the maximum amplitude of the signal, thereby minimizing the interference between code elements and improving the signal-to-noise ratio of the signal.

[0122] In a possible implementation, in the visible light communication device, the inductive driving circuit 5 can further include a low-pass filter 55, as shown in the following figure. Figure 17 Under the structure of the visible light communication device, the processing flow in the inductive driving circuit 5 can include the following steps:

[0123] The second operational amplifier 53 amplifies the signal processed by the high-pass filter to obtain a second amplified signal, and sends the second amplified signal to the low-pass filter 55. The low-pass filter 55 performs low-pass filtering on the second amplified signal to obtain a low-pass filtered signal, and sends the low-pass filtered second amplified signal to the analog-to-digital converter 54. The analog-to-digital converter 54 converts the low-pass filtered second amplified signal into a digital signal corresponding to the second amplified signal.

[0124] During the transmission of the electrical signal, electrical noise is generated, especially when the first operational amplifier 22 and the second operational amplifier 53 amplify the signal. Therefore, in the embodiment of the present application, the low-pass filter 55 is connected after the second operational amplifier 53 to filter the high-frequency electrical noise existing in the second amplified signal, thereby improving the signal-to-noise ratio of the signal.

[0125] In a possible implementation, in the visible light communication device, the signal receiving device 6 can further include a band-pass filter 63, as shown in the following figure. Figure 18 Under the structure of the visible light communication device, the processing flow in the inductive driving circuit 5 and the signal receiving device 6 can include the following steps:

[0126] The analog-to-digital converter 54 converts the second amplified signal into a digital signal corresponding to the second amplified signal, and sends the digital signal corresponding to the second amplified signal to the band-pass filter 63. The band-pass filter 63 performs band-pass filtering on the digital signal corresponding to the second amplified signal to obtain a band-pass filtered signal, and sends the band-pass filtered signal to the sample decision module 61. The sample decision module 61 performs sample decision on the band-pass filtered signal to obtain a second electrical signal.

[0127] Before the sample decision module 61 performs sample decision, the band-pass filtering on the digital signal corresponding to the second amplified signal can filter out the direct current component and low-frequency alternating current component in the optical noise, as well as the high-frequency electrical noise, thereby further improving the signal-to-noise ratio of the signal.

[0128] In a possible implementation, in the visible light communication device, the signal generating device 1 can include a signal generation module 11 and a Manchester encoding module 13, and the signal receiving device 6 can further include a Manchester decoding module 64, as shown in the following figure. Figure 19As shown, under the structure of the visible light communication device, the processing flow in the signal generating device 1, the induction driving circuit 5 and the signal receiving device 6 can include:

[0129] The signal generating module 11 generates a to-be-sent signal and sends the to-be-sent signal to the Manchester coding module 13, and the Manchester coding module 13 performs Manchester coding processing on the to-be-sent signal to obtain a first electrical signal.

[0130] The analog-to-digital converter 54 converts the second amplified signal into a digital signal corresponding to the second amplified signal, and sends the digital signal corresponding to the second amplified signal to the Manchester decoding module 64, and the Manchester decoding module 64 performs Manchester decoding processing on the digital signal corresponding to the second amplified signal to obtain a third electrical signal, and sends the third electrical signal to the sampling decision module 61, and the sampling decision module 61 performs sampling decision on the third electrical signal to obtain a second electrical signal.

[0131] The Manchester coded signal (i.e. the first electrical signal described above) is not sensitive to artificial light source noise, so it can effectively reduce the artificial light source noise, thereby improving the signal-to-noise ratio of the signal.

[0132] The embodiments of the present application also provide an electronic device, which comprises any one of the visible light communication devices described above, for example, the electronic device can be a terminal or a computer or the like, and is used for sending information and receiving information, thereby realizing processing or control of the electronic device.

[0133] The above description is only optional embodiments of the present application, and is not used to limit the present application, and any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A visible light communication device, characterized in that, The visible light communication device includes a signal generating device (1), a light-emitting driving circuit (2), a light-emitting element (3), a photoelectric sensing device (4), a sensing driving circuit (5), and a signal receiving device (6); The signal generating device (1) includes a signal generating module (11) and an equalizer (12). The light-emitting driving circuit (2) includes a digital-to-analog converter (21) and a first operational amplifier (22). The signal generating module (11), the equalizer (12), the digital-to-analog converter (21), the first operational amplifier (22), and the light-emitting element (3) are electrically connected in sequence. The signal generating module (11) is used to generate a signal, and the equalizer (12) is used to adjust the frequency of the signal generated by the signal generating module (11) based on the bandwidth of the light-emitting element (3). The sensing drive circuit (5) includes a transimpedance amplifier (51), a high-pass filter (52), a second operational amplifier (53), and an analog-to-digital converter (54). The signal receiving device (6) includes a sampling decision module (61) and a signal processing module (62). The photoelectric sensing device (4), the transimpedance amplifier (51), the high-pass filter (52), the second operational amplifier (53), the analog-to-digital converter (54), the sampling decision module (61), and the signal processing module (62) are electrically connected in sequence. The high-pass filter (52) is used to attenuate the DC component and low-frequency AC component generated by optical noise. The sampling decision module (61) is used to sample and decide the received signal with a sampling interval of 2kπ / ω to recover the signal. k is a positive integer, ω is the frequency angle of the signal after frequency adjustment, and ω is the reciprocal of the bandwidth of the light-emitting element (3).

2. The visible light communication device according to claim 1, characterized in that, The high-pass filter (52) is an RC high-pass filter.

3. The visible light communication device according to claim 1, characterized in that, The induction drive circuit (5) further includes a low-pass filter (55), which is electrically connected to the second operational amplifier (53) and the analog-to-digital converter (54).

4. The visible light communication device according to claim 3, characterized in that, The low-pass filter (55) is a Butterworth low-pass filter, and the order of the Butterworth low-pass filter is greater than the first preset order value.

5. The visible light communication device according to claim 1, characterized in that, The signal receiving device (6) further includes a bandpass filter (63), which is electrically connected to the analog-to-digital converter (54) and the sampling decision module (61). The bandpass filter (63) is used to perform bandpass filtering on the digital signal sent by the analog-to-digital converter (54) and send the bandpass-filtered signal to the sampling decision module (61).

6. The visible light communication device according to claim 5, characterized in that, The bandpass filter (63) is an FIR bandpass filter, and the order of the FIR bandpass filter is greater than the second preset order value.

7. The visible light communication device according to claim 6, characterized in that, The FIR bandpass filter is a parallel FIR bandpass filter.

8. The visible light communication device according to claim 5, characterized in that, The bandpass filter (63) has a low-frequency stopband of 100kHz-200kHz and a high-frequency stopband of 50MHz-70MHz.

9. The visible light communication device according to claim 1, characterized in that, The signal generating device (1) further includes a Manchester encoding module (13), which is electrically connected to the equalizer (12) and the digital-to-analog converter (21). The signal receiving device (6) further includes a Manchester decoding module (64), which is electrically connected to the sampling decision module (61).

10. A visible light communication method, characterized in that, The visible light communication method is applied to the visible light communication device as described in any one of claims 1-9, wherein the visible light communication method comprises: The signal generation module (11) generates a signal to be sent and sends the signal to be sent to the equalizer (12). The equalizer (12) adjusts the frequency of the signal to be sent based on the bandwidth of the light-emitting element (3) to obtain a first electrical signal and sends the first electrical signal to the digital-to-analog converter (21). The first electrical signal is a digital signal and the frequency angle of the first electrical signal is the reciprocal of the bandwidth of the light-emitting element (3). The digital-to-analog converter (21) converts the first electrical signal into an analog signal corresponding to the first electrical signal and sends the analog signal corresponding to the first electrical signal to the first operational amplifier (22). The first operational amplifier (22) amplifies the analog signal corresponding to the first electrical signal to obtain a first amplified signal and sends the first amplified signal to the light-emitting element (3). The light-emitting element (3) converts the first amplified signal into a light output signal and sends the light output signal outward. The photoelectric sensor (4) receives a light receiving signal, converts the light receiving signal into a current signal corresponding to the light receiving signal, and sends the current signal corresponding to the light receiving signal to the transimpedance amplifier (51). The transimpedance amplifier (51) converts the current signal corresponding to the light receiving signal into a voltage signal and sends the voltage signal to the high-pass filter (52). The high-pass filter (52) performs high-pass filtering on the voltage signal, attenuating the DC component and low-frequency AC component generated by optical noise, to obtain a high-pass filtered signal. The high-pass filtered signal is then sent to the second operational amplifier (53), which amplifies the high-pass filtered signal. The second amplified signal is obtained and sent to the analog-to-digital converter (54). The analog-to-digital converter (54) converts the second amplified signal into a digital signal corresponding to the second amplified signal and sends the digital signal corresponding to the second amplified signal to the sampling decision module (61). The sampling decision module (61) samples the digital signal corresponding to the second amplified signal at a sampling interval of 2kπ / ω to obtain multiple sample values. The multiple sample values ​​are processed to obtain the second electrical signal corresponding to the multiple sample values ​​and the second electrical signal is sent to the signal processing module (62). Here, k is a positive integer, ω is the frequency angle of the first electrical signal, and ω is the reciprocal of the bandwidth of the light-emitting element (3).

11. The visible light communication method according to claim 10, characterized in that, When the sensing drive circuit (5) further includes a low-pass filter (55), the second operational amplifier (53) amplifies the signal after the high-pass filtering to obtain a second amplified signal, and sends the second amplified signal to the analog-to-digital converter (54). The analog-to-digital converter (54) converts the second amplified signal into a digital signal corresponding to the second amplified signal, including: The second operational amplifier (53) amplifies the high-pass filtered signal to obtain a second amplified signal, and sends the second amplified signal to the low-pass filter (55). The low-pass filter (55) performs low-pass filtering on the second amplified signal to obtain a low-pass filtered signal, and sends the low-pass filtered second amplified signal to the analog-to-digital converter (54). The analog-to-digital converter (54) converts the low-pass filtered second amplified signal into a digital signal corresponding to the second amplified signal.

12. The visible light communication method according to claim 10, characterized in that, When the signal receiving device (6) further includes a bandpass filter (63), the analog-to-digital converter (54) converts the second amplified signal into a digital signal corresponding to the second amplified signal, and sends the digital signal corresponding to the second amplified signal to the sampling decision module (61). The sampling decision module (61) samples and decides on the digital signal corresponding to the second amplified signal to obtain a second electrical signal, including: The analog-to-digital converter (54) converts the second amplified signal into a digital signal corresponding to the second amplified signal, and sends the digital signal corresponding to the second amplified signal to the bandpass filter (63). The bandpass filter (63) performs bandpass filtering on the digital signal corresponding to the second amplified signal to obtain a bandpass filtered signal, and sends the bandpass filtered signal to the sampling decision module (61). The sampling decision module (61) performs sampling decision on the bandpass filtered signal to obtain the second electrical signal.

13. The visible light communication method according to claim 10, characterized in that, When the signal generating device (1) further includes a Manchester encoding module (13) and the signal receiving device (6) further includes a Manchester decoding module (64), the equalizer (12) adjusts the frequency of the signal to be transmitted based on the bandwidth of the light-emitting element (3) to obtain the first electrical signal, including: The equalizer (12) adjusts the frequency of the signal to be transmitted based on the bandwidth of the light-emitting element (3), and sends the frequency-adjusted signal to the Manchester encoding module (13). The Manchester encoding module (13) performs Manchester encoding processing on the frequency-adjusted signal to obtain the first electrical signal. The analog-to-digital converter (54) converts the second amplified signal into a digital signal corresponding to the second amplified signal, and sends the digital signal corresponding to the second amplified signal to the sampling decision module (61). The sampling decision module (61) samples and decides on the digital signal corresponding to the second amplified signal to obtain a second electrical signal, including: The analog-to-digital converter (54) converts the second amplified signal into a digital signal corresponding to the second amplified signal, and sends the digital signal corresponding to the second amplified signal to the Manchester decoding module (64). The Manchester decoding module (64) performs Manchester decoding processing on the digital signal corresponding to the second amplified signal to obtain a third electrical signal, and sends the third electrical signal to the sampling decision module (61). The sampling decision module (61) performs sampling decision on the third electrical signal to obtain the second electrical signal.

14. An electronic device, characterized in that, The electronic device includes a visible light communication device as described in any one of claims 1-9.

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