LiFi optical communication test evaluation method

Abstract

The invention discloses a LiFi (Light Fidelity) optical communication test evaluation method, which relates to an optical communication technology, and is characterized by comprising the following steps of: evaluating a vertical distance signal, and measuring and calculating to obtain a data rate Vbps under a plurality of vertical distance independent variables; the irradiation angle signals are evaluated, and the data rate Abps of each irradiation angle under the fixed vertical distance is measured and calculated; evaluating an anti-interference signal, and measuring and calculating to obtain a data rate Lbps under environmental interference; and performing comprehensive evaluation to obtain a data rate Vbps, a data rate Abps and a data rate Lbps so as to output an evaluation coefficient Xlight, and the formula of the evaluation coefficient Xlight is as follows: Xlight = (Vbps + Abps + Lbps) / 3. According to the invention, systematic evaluation detection is carried out through the vertical distance signal, the irradiation angle signal and the anti-interference signal, the stability and the transmission condition of the optical communication technology can be objectively analyzed, the data rate condition is converted into the weight along with the adjustment of a single variable, and the coefficient is evaluated by combining vertical transmission, irradiation angle transmission and the interference condition. Therefore, the transmission stability and the transmission efficiency of optical communication can be objectively fed back.

Description

Technical Field

[0001] The present invention relates to optical communication technology, and more specifically, to a LiFi optical communication test and evaluation method. Background Art

[0002] Visible light wireless communication, also known as "light fidelity technology", is a new wireless transmission technology that uses the visible light spectrum (such as the light emitted by a light bulb) for data transmission. LIFI implants a tiny chip in the LED and uses fast light pulses to wirelessly transmit information. It encodes information in light at different rates and uses electrical signals to control the light-emitting diode (LED) to emit high-speed flashing signals that are invisible to the naked eye to transmit information. For example, LED on represents 1, and off represents 0. Information can be transmitted by quickly switching on and off. The system made with this technology can cover the range of indoor lighting. Computers do not need to be connected by wires as long as the lights are turned on indoors. They can access the Internet without WIFI.

[0003] The Chinese patent with publication number CN112152709B discloses an optical fidelity LiFi control method, device, mobile terminal and medium for a mobile terminal. The technical key points are: the mobile terminal includes multiple LiFi receivers with different directions, and the method includes: detecting the signal strength of the currently working LiFi receiver; judging whether switching is required according to the signal strength of the currently working LiFi receiver; if so, sending a polling request to multiple non-working LiFi receivers to obtain the signal strength of multiple non-working LiFi receivers; and selecting a switching target for switching according to the signal strength of multiple non-working LiFi receivers.

[0004] As a communication application of LiFi optical fidelity communication technology, the above scheme detects the signal strength through multiple LiFi receivers facing different directions in the mobile terminal. When the LiFi signal strength is weak, it sends a polling request to multiple LiFi receivers in non-working state to obtain the corresponding signal strength and then switch. However, although the polling control method can ensure the normal and good information transmission of optical communication, it is also easy to cause delays in accessing resources during the polling process, affecting the transmission efficiency.

[0005] It is found in a large number of applications that there is currently a lack of technology on the market for objective and systematic evaluation of optical communications. Summary of the invention

[0006] In view of the deficiencies in the prior art, the object of the present invention is to provide a LiFi optical communication test and evaluation method.

[0007] The above technical objectives of the present invention are achieved through the following technical solutions: A LiFi optical communication test and evaluation method, characterized in that it includes:

[0008] Vertical distance signal evaluation: the vertical distance between the transceiver module and the light source element is continuously and linearly adjusted through the vertical adjustment rod as the independent variable, and the data rate V at several vertical distances is measured. bps ;

[0009] Irradiation angle signal evaluation: fix the light source element at a specified position in a dark environment, and set the specified position as the origin of the spatial quadrant. Keep the vertical coordinate Z unchanged, and move the transceiver in a straight radial direction or an equal pitch spiral direction to measure the data rate A of each irradiation angle under a fixed vertical distance. bps ;

[0010] Anti-interference signal evaluation: fix the light source element at a specified position in a dark environment, determine that the transceiver is located at a fixed spatial coordinate position, move the light interference source in a straight radial direction or an equal pitch spiral direction, and calculate the data rate L under environmental interference. bps ;

[0011] Comprehensive evaluation to obtain data rate V bps , Data rate A bps and data rate L bps To output the evaluation coefficient X weight , the formula is: X weight =(V bps +A bps +L bps ) / 3.

[0012] The present invention is further configured as follows: the step of anti-interference signal evaluation also includes: fixing the light source element at a designated position in a dark environment as the center origin, and establishing a spatial coordinate position, and then placing the light interference source in sequence at points equidistant from the light source element, and adjusting the lighting brightness of the light interference source at each equidistant point, including but not limited to 25%, 50%, 75% and 100% of the maximum illumination of the transceiver.

[0013] The present invention is further configured that the steps of vertical distance signal evaluation, irradiation angle signal evaluation and anti-interference signal evaluation further include:

[0014] Build a line light source point illumination model, use the line light source equal illumination curve method, and calculate the distribution curve formula of the lateral light intensity of the line light source according to the line light source light intensity distribution curve: θ =I0f(θ);

[0015] The distribution curve formula of longitudinal light intensity is: θ·α =Iθ·0 f(α), where I θ is the light intensity in the θ direction; I0 is the light intensity in the normal direction of the light emitting surface of the linear light source, I θ·α is the light intensity in the direction that makes an angle θ with the symmetry plane passing through the longitudinal axis and an angle α with the symmetry plane perpendicular to the longitudinal axis;

[0016] I θ·0 It is the light intensity perpendicular to the axis of the light source on the θ plane. The θ plane is a plane passing through the longitudinal axis of the light source and forming an angle θ with the vertical plane passing through the longitudinal axis.

[0017] The present invention is further configured as follows: the line light source used for the vertical distance signal evaluation includes standard light source A, standard light source B, standard light source C, standard light source D, and standard light source E according to color temperature, and the color temperatures of the standard light source A, standard light source B, standard light source C, standard light source D, and standard light source E are divided into 256K, 4874K, 6774K, 5403K, and 6504K.

[0018] The present invention is further configured as follows: the standard light source A, the standard light source B, the standard light source C, the standard light source D and the standard light source E are distributed according to their longitudinal axial light intensity, and their light intensity distribution formula is:

[0019] Standard light source AI θ·α =I θ·0 cosα;

[0020] Standard light source B Standard light source CI θ·α =I θ·0 cos 2 α;

[0021] Standard light source DI θ·α =I θ·0 cos 3 α;

[0022] Standard light source EI θ·α =I θ·0 cos 4 α.

[0023] The present invention is further configured as follows: constructing a line light source point illumination model, or using the azimuth coefficient method, the calculation point measurement point P is aligned with one end A of the line light source AB, the normal of the horizontal plane forms an angle β with the incident light plane APB (θ plane), and the distribution curve formula of the longitudinal light intensity of the line light source AB is: I θ·α =I θ·0 cos n α, where n = 1, 2, 3, 4; or

[0024] The present invention is further configured as follows: the light intensity per unit length of the line light source AB in the θ plane perpendicular to the light source axis AB is: The normal illumination of the line light source AB at the measurement point P is: or Where l is the unit length of the line light source in the AB direction, and R is the irradiation radius from the measuring point P to the A end;

[0025] Where h is the vertical height of end A from point P, and D is the horizontal distance of measuring point P from end A.

[0026] The present invention is further configured to: calculate the horizontal illumination E of point P h It can be calculated based on the illumination loss: Where AF is the horizontal azimuth factor, or

[0027] The present invention is further configured as follows: when evaluating the vertical range signal, the irradiation angle is set to 0, and a speed test is performed at (0°, 1 / 2MER), and the data rate V is recorded respectively. bps , to obtain the average data rate V average , and record it as DR1, we get

[0028] When evaluating the irradiance angle signal, perform a beam angle θ test, and perform a speed test at θ / 2 and a vertical distance of 1 / 2MER, and record the data rate A respectively. bps , to obtain the average data rate A average , and record it as DR2, we get

[0029] When evaluating the anti-interference signal, set the irradiation angle to 0, perform the speed test at (0°, 1 / 2MER), adjust the illumination brightness of the light interference source, set the total interference to 25% MLI, 50% MLI, 75% MLI and 100% MLI, and record the data rate L respectively. bps1 , L bps2 , L bps3 and L bps4 , record them as DR3, DR4, DR5 and DR6, and get

[0030] In summary, the present invention has the following beneficial effects:

[0031] Through systematic evaluation and detection of vertical distance signals, irradiation angle signals and anti-interference signals, the stability and transmission conditions of optical communication technology can be objectively analyzed, and the data rate conditions can be converted into weights as a single variable is adjusted. Combined with vertical transmission, irradiation angle transmission and evaluation coefficients under interference conditions, objective feedback on the transmission stability and transmission efficiency of optical communication can be obtained. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 is a schematic diagram of the longitudinal and transverse light intensity distribution curves of the line light source;

[0033] Figure 2 It is the relative light intensity distribution curve of five types of line light sources in the longitudinal plane;

[0034] Figure 3 is the normal illumination generated by the line light source at point P;

[0035] Figure 4 It is the linear attenuation curve of illumination value and effective illumination distance. DETAILED DESCRIPTION

[0036] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0037] like Figure 1-Figure 4 As shown, a LiFi optical communication test and evaluation method includes:

[0038] Vertical distance signal evaluation: the vertical distance between the transceiver module and the light source element is continuously and linearly adjusted through the vertical adjustment rod as the independent variable, and the data rate V at several vertical distances is measured. bps The specific steps include: when evaluating the vertical distance signal, setting the irradiation angle to 0, that is, fixing the light source element at a specified position in a dark environment, and taking the fixed position as the origin, performing a speed test at (0°, 1 / 2MER), and then continuously linearly adjusting the spatial position of the transceiver module along the vertical direction through the vertical adjustment rod, only changing the vertical coordinate Z to make a linear change, and at the same time equipping the vertical adjustment rod with an ultrasonic ranging module or a Hall ranging sensor, and realizing that when the vertical height of the transceiver module is linearly adjusted, the vertical height change can be synchronously recorded through the ultrasonic ranging module or the Hall ranging sensor, so that when the vertical distance is adjusted, the transceiver module receives the optical signal emitted by the light source element based on the LiFi optical communication technology, and measures the data rate V at different vertical distances. bps1 、Vbps2 、V bps3 、V bps4 ,......V bpsn , where the corresponding vertical distances are equally spaced. In this embodiment, the equally spaced intervals are 0.5 m, and the data rate is selected from the data collected 5 minutes after the displacement adjustment, and the data rate V is recorded respectively. bps , to obtain the average data rate V average , and record it as DR1, we get

[0039] Irradiation angle signal evaluation: fix the light source element at a specified position in a dark environment, and set the specified position as the origin of the spatial quadrant. Keep the vertical coordinate Z unchanged, and move the transceiver in a straight radial direction or an equal pitch spiral direction to measure the data rate A of each irradiation angle under a fixed vertical distance. bps Specifically, when evaluating the irradiation angle signal, a beam angle θ test is performed, and a speed test is performed at θ / 2 and a vertical distance 1 / 2MER, and the data rate A is recorded respectively. bps , to obtain the average data rate A average , and record it as DR2, we get

[0040] Anti-interference signal evaluation: fix the light source element at a specified position in a dark environment, determine that the transceiver is located at a fixed spatial coordinate position, move the light interference source in a straight radial direction or an equal pitch spiral direction, and calculate the data rate L under environmental interference. bps ;

[0041] Comprehensive evaluation to obtain data rate V bps , Data rate A bps and data rate L bps To output the evaluation coefficient X weight , the formula is: X weight =(V bps +A bps +L bps ) / 3, through comprehensive evaluation, the vertical distance signal evaluation, irradiation angle signal evaluation and anti-interference signal evaluation are converted into the data rate of the standard evaluation coefficient X weight , thus being able to objectively provide feedback on the transmission stability and efficiency of optical communications.

[0042] Among them, the step of anti-interference signal evaluation also includes: fixing the light source element at a designated position in a dark environment as the center origin, and establishing a spatial coordinate position, and then placing the light interference source at points equidistant from the light source element in sequence, and adjusting the lighting brightness of the light interference source at each equidistant point, including but not limited to 25%, 50%, 75% and 100% of the maximum illumination of the transceiver. Specifically, in this embodiment, when performing anti-interference signal evaluation, the irradiation angle is set to 0, and a speed test is performed at (0°, 1 / 2MER). The lighting brightness of the light interference source is adjusted, and the total interference is set to 25% MLI, 50% MLI, 75% MLI and 100% MLI respectively, and the data rate L is recorded respectively. bps1 , L bps2 , L bps3 and L bps4 , record them as DR3, DR4, DR5 and DR6, and get

[0043] like Figure 1 As shown, the steps of vertical distance signal evaluation, irradiance angle signal evaluation and anti-interference signal evaluation also include:

[0044] Use the line light source equal illumination curve method or the azimuth coefficient method to build a line light source point illumination model;

[0045] According to the linear light source equal illumination curve method, the distribution curve formula of the lateral light intensity of the linear light source is calculated based on the linear light source light intensity distribution curve: θ =I0f(θ); the distribution curve formula of longitudinal light intensity is: I θ·α =I θ·0 f(α), where I θ is the light intensity in the θ direction, I0 is the light intensity in the normal direction of the light emitting surface of the linear light source, I θ·α is the light intensity in the direction that makes an angle θ with the symmetry plane passing through the longitudinal axis and an angle α with the symmetry plane perpendicular to the longitudinal axis; I θ·0 It is the light intensity perpendicular to the axis of the light source on the θ plane. The θ plane is a plane passing through the longitudinal axis of the light source and forming an angle θ with the vertical plane passing through the longitudinal axis.

[0046] The line light sources used for vertical distance signal evaluation include standard light source A, standard light source B, standard light source C, standard light source D, and standard light source E according to color temperature. The color temperatures of standard light source A, standard light source B, standard light source C, standard light source D, and standard light source E are 256K, 4874K, 6774K, 5403K, and 6504K, and the light intensity distribution formula of standard light source A, standard light source B, standard light source C, standard light source D, and standard light source E is as follows:

[0047] Standard light source AI θ·α =Iθ·0 cosα;

[0048] Standard light source B Standard light source CI θ·α =I θ·0 cos 2 α;

[0049] Standard light source DI θ·α =I θ·0 cos 3 α;

[0050] Standard light source EI θ·α =I θ·0 cos 4 α.

[0051] When the azimuth coefficient method is used to build the line light source point illumination model, the calculation point P is aligned with one end A of the line light source AB, and the normal of the horizontal plane forms an angle β with the incident light plane APB (θ plane). The distribution curve formula of the longitudinal light intensity of the line light source AB is: I θ·α =I θ·0 cos n α, where n = 1, 2, 3, 4; or The light intensity per unit length of the line light source AB in the θ plane perpendicular to the light source axis AB is: The normal illumination of the line light source AB at the measurement point P is: or Where l is the unit length of the line light source in the AB direction, and R is the irradiation radius from the measuring point P to the A end;

[0052] Among them according to Figure 3 It can be seen from the normal illumination generated by the line light source AB at point P that: Where h is the vertical distance between end A and point P, recorded as d, in meters (m), D is the horizontal distance between the measured point P and end A, and the horizontal illumination E of the measured point P is h It can be calculated based on the illumination loss: Where AF is the horizontal azimuth factor, or

[0053] In this embodiment, a strip lamp with a width not exceeding 1 / 4 of the length is used as a linear lamp as a test object, and the light sensing module of the receiver is placed horizontally upward, and the length and width are both less than 1 / 10 of the linear lamp. A point illumination calculation model of the linear lamp in space is established, and the horizontal illumination E of the measured point P is calculated. h It can be calculated based on the illumination loss: Get the normal illumination of any point on the horizontal plane. In the test, we only consider C90-C270 (i.e. Figure 1 The longitudinal plane in the figure), so here θ is 0°, then the above equation becomes: In the test, we ignored the slight change of AF on the central axis of the lamp. Considering that the illumination change in actual application has an upper and lower limit, we took the maximum illumination value as i max , the maximum effective vertical illumination distance d of the transceiver module lamp max , and i max -d max The curve should follow the characteristics of an inverse function, and the following theoretical mathematical relationship (inverse attenuation curve) is established: where i max , d max All are positive values, reference Figure 4 For comparison.

[0054] After testing, for distance test: if Well, the optical communication system performed well in the distance test;

[0055] For irradiance angle test: Then the optical communication system performs well in the irradiance angle test;

[0056] For anti-interference ability test: Then the optical communication system performs well in the anti-interference ability test. (Note: BW is the theoretical bandwidth of the optical communication system)

[0057] The above is only a preferred embodiment of the present invention, and the protection scope of the present invention is not limited to the above embodiments. All technical solutions under the concept of the present invention belong to the protection scope of the present invention. It should be pointed out that for ordinary technicians in this technical field, some improvements and modifications without departing from the principle of the present invention should also be regarded as the protection scope of the present invention.

Claims

1. A LiFi optical communication test and evaluation method, characterized in that: include: Vertical distance signal evaluation: the vertical distance between the transceiver module and the light source element is continuously and linearly adjusted through the vertical adjustment rod as the independent variable, and the data rate V at several vertical distances is measured. bps ; Irradiation angle signal evaluation: fix the light source element at a specified position in a dark environment, and set the specified position as the origin of the spatial quadrant. Keep the vertical coordinate Z unchanged, and move the transceiver in a straight radial direction or an equal pitch spiral direction to measure the data rate A of each irradiation angle under a fixed vertical distance. bps ; Anti-interference signal evaluation: fix the light source element at a specified position in a dark environment, determine that the transceiver is located at a fixed spatial coordinate position, move the light interference source in a straight radial direction or an equal pitch spiral direction, and calculate the data rate L under environmental interference. bps ; Comprehensive evaluation to obtain data rate V bps , Data rate A bps and data rate L bps To output the evaluation coefficient X weight , the formula is: X weight =(V bps +A bps +L bps ) / 3.

2. The LiFi optical communication test and evaluation method according to claim 1, characterized in that: The step of anti-interference signal evaluation also includes: fixing the light source element at a designated position in a dark environment as the center origin, and establishing a spatial coordinate position, and then placing the light interference source in sequence at points equidistant from the light source element, and adjusting the lighting brightness of the light interference source at each equidistant point, including but not limited to 25%, 50%, 75% and 100% of the maximum illumination of the transceiver.

3. The LiFi optical communication test and evaluation method according to claim 1, characterized in that: The steps of vertical distance signal evaluation, irradiation angle signal evaluation and anti-interference signal evaluation also include: Build a line light source point illumination model, use the line light source equal illumination curve method, and calculate the distribution curve formula of the lateral light intensity of the line light source based on the line light source light intensity distribution curve: θ =I0f(θ); The distribution curve formula of longitudinal light intensity is: I θ·α =I θ·0 f(α), where I θ is the light intensity in the θ direction; I0 is the light intensity in the normal direction of the light emitting surface of the linear light source, I θ·α is the light intensity in the direction that makes an angle θ with the symmetry plane passing through the longitudinal axis and an angle α with the symmetry plane perpendicular to the longitudinal axis; It is the light intensity perpendicular to the axis of the light source on the θ plane. The θ plane is a plane passing through the longitudinal axis of the light source and forming an angle θ with the vertical plane passing through the longitudinal axis.

4. The LiFi optical communication test and evaluation method according to claim 3, characterized in that: The line light sources used for the vertical distance signal evaluation include standard light source A, standard light source B, standard light source C, standard light source D, and standard light source E according to color temperature. The color temperatures of the standard light source A, standard light source B, standard light source C, standard light source D, and standard light source E are 256K, 4874K, 6774K, 5403K, and 6504K.

5. The LiFi optical communication test and evaluation method according to claim 4, characterized in that: The standard light source A, standard light source B, standard light source C, standard light source D and standard light source E are distributed according to their longitudinal axial light intensity, and their light intensity distribution formula is: Standard light source AI θ·α =I θ·0 cosα; Standard light source B Standard light source CI θ·α =I θ·0 cos 2 α; Standard light source DI θ·α =I θ·0 cos 3 α; Standard light source EI θ·α =I θ·0 cos 4 α.

6. The LiFi optical communication test and evaluation method according to claim 3, characterized in that: Build a line light source point illumination model, or use the azimuth coefficient method, and align the calculation point P with one end A of the line light source AB. The normal of the horizontal plane forms an angle β with the incident light plane APB (θ plane). The distribution curve formula of the longitudinal light intensity of the line light source AB is: I θ·α =I θ·0 cos n α, where n = 1, 2, 3, 4; or 7. The LiFi optical communication test and evaluation method according to claim 6, characterized in that: The light intensity per unit length of the line light source AB in the θ plane perpendicular to the light source axis AB is: The normal illumination of the line light source AB at the measurement point P is: or Where l is the unit length of the line light source in the AB direction, and R is the irradiation radius from the measuring point P to the A end; Where h is the vertical height of end A from point P, and D is the horizontal distance of measuring point P from end A.

8. The LiFi optical communication test and evaluation method according to claim 7, characterized in that: Measure the horizontal illumination E at point P h It can be calculated based on the illumination loss: Where AF is the horizontal azimuth factor, or 9. The LiFi optical communication test and evaluation method according to claim 1, characterized in that: When evaluating vertical range signals, set the irradiation angle to 0, perform a speed test at (0°, 1 / 2MER), and record the data rate V bps , to obtain the average data rate V average , and record it as DR1, we get When evaluating the irradiance angle signal, perform a beam angle θ test, and perform a speed test at θ / 2 and a vertical distance of 1 / 2MER, and record the data rate A respectively. bps , to obtain the average data rate A average , and record it as DR2, we get When evaluating the anti-interference signal, set the irradiation angle to 0, perform the speed test at (0°, 1 / 2MER), adjust the illumination brightness of the light interference source, set the total interference to 25% MLI, 50% MLI, 75% MLI and 100% MLI, and record the data rate L respectively. bps1 , L bps2 , L bps3 and L bps4 , record them as DR3, DR4, DR5 and DR6, and get

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