CN105187111B - Signal acquiring method, device based on visible light communication and visible light communication system - Google Patents

Abstract

Embodiments of the present invention provide a signal acquisition method and device based on visible light communication, and a visible light communication system. The specific implementation steps of the method include: receiving multiple initial signals, wherein the multiple initial signals are generated by the sending end After the source visible light signal is transmitted through the channel and received by different branches, the source visible light signal at least includes: a source preset sequence and a source pseudo-random sequence carrying data, and each initial signal includes at least: a target preset sequence and the target pseudo-random sequence carrying data; according to the target preset sequence in each initial signal, calculate the signal-to-noise ratio of each branch; according to the calculated signal-to-noise ratio of each branch, the multiple The target pseudo-random sequence in the initial signal is combined to obtain the signal to be used at the receiving end corresponding to the source pseudo-random sequence. In this embodiment, the transmission performance of the visible light communication system is further improved by conveniently and accurately calculating the signal-to-noise ratio of multiple branches.

Description

Signal acquisition method, device and visible light communication system based on visible light communication

technical field

The present invention relates to the technical field of visible light communication, in particular to a signal acquisition method and device based on visible light communication, and a visible light communication system.

Background technique

Visible light communication technology refers to a communication method that uses light in the visible light band as an information carrier, does not use optical fiber and other wired channel transmission media, and uses air as a medium to transmit optical signals. As indoor lighting equipment, LED lights have the advantages of long service life, good modulation performance, high corresponding sensitivity, and high transmission power. As the light source of visible light communication system, the rapid popularization of LED lights has greatly promoted the development of visible light communication technology.

Due to the increasing use of mobile digital terminals, especially the increasing user demand for video services, wireless spectrum resources are becoming increasingly scarce, and the introduction of visible light communication is a huge expansion of the communication spectrum. Among them, visible light has a huge bandwidth of 380-780nm (equivalent to 405THz), which can alleviate the imminent depletion of wireless spectrum resources. At the same time, visible light communication technology utilizes the characteristics of high-speed modulation of LED lights to realize lighting and Internet communication, as well as intelligent control of terminals such as household appliances and security equipment. In addition, since visible light communication has no electromagnetic pollution, it can be used as an effective supplement to existing wireless communication and has broad application scenarios. transportation and other fields.

The fading effect is one of the main factors affecting the quality of visible light communication. Among them, the fast fading caused by multipath interference can reach a depth of 30-40dB. In the prior art, the space diversity reception combining technology is a commonly used technology in short-wave communication, and is used to reduce the influence of fast fading in short-wave communication. Among them, the so-called space diversity reception combining technology is a commonly used technology for reducing the impact of fast fading in short-wave communication, that is, receiving signals carrying the same message with little correlation with each other on several branches, and through combining technology Then, the signals of each branch are combined and output, thereby greatly reducing the influence of fast fading at the receiving end and improving the reliability of transmission. Specifically, common space diversity reception combining methods include: maximum ratio combining, equal gain combining, selective combining, and the like.

In the space diversity reception combining method, the signal-to-noise ratio of each branch needs to be calculated when obtaining the combined signal. At present, in wireless communication, commonly used SNR calculation methods include: based on maximum likelihood estimation, using training sequences or decision feedback sequences to construct likelihood functions; or matrix-based methods, using newly created and noisy 2 , the relationship between order 4 matrices to estimate the signal-to-noise ratio. However, these methods all require the system to have achieved clock synchronization and carrier synchronization, but these conditions are difficult to realize for visible light communication systems.

Contents of the invention

The purpose of the embodiments of the present invention is to provide a signal acquisition method and device based on visible light communication, and a visible light communication system, so as to realize convenient and accurate calculation of the signal-to-noise ratio in the visible light communication system and improve the transmission performance of the visible light communication system. The specific technical scheme is as follows:

In the first aspect, the present invention provides a signal acquisition method based on visible light communication, which is applied to the receiving end, and the method includes:

Receive multiple initial signals, wherein the multiple initial signals are formed by receiving source visible light signals generated by the sending end through channels and received by different branches, and the source visible light signals at least include: source preset sequence and bearer The source pseudo-random sequence of the data, each initial signal at least includes: a target preset sequence and a target pseudo-random sequence carrying data, the target preset sequence corresponds to the source preset sequence, and the target pseudo-random sequence corresponds to The source pseudo-random sequence corresponds to;

Calculate the corresponding signal-to-noise ratio of each branch according to the target preset sequence in each initial signal;

According to the calculated signal-to-noise ratio of each branch, the target pseudo-random sequences in the plurality of initial signals are combined to obtain the signal to be used at the receiving end corresponding to the source pseudo-random sequence.

Further, the target preset sequence includes: a first sequence and a second sequence, the first sequence corresponds to the digital signal 1 part of the source preset sequence, and the second sequence corresponds to the source preset sequence digital signal 0 part;

According to the target preset sequence in each initial signal, calculating the corresponding signal-to-noise ratio of each branch includes:

According to the first sequence in the initial signal received by each branch, calculate the average value of the power sum of the signal and noise of each corresponding branch;

According to the second sequence in the initial signal received by each branch, calculate the noise power of each corresponding branch;

The signal-to-noise ratio of each branch is calculated according to the average value of the sum of signal and noise power of each branch and the corresponding noise power of each branch.

Further, according to the first sequence in the initial signal received by each branch, calculating the average value of the sum of the signal and noise power of each corresponding branch includes:

Each bit signal of the first sequence in the initial signal received by each branch is the sum of the signal and noise amplitudes of the corresponding branch, according to the length of the first sequence in each initial signal and the corresponding signal and noise of each branch The sum of the amplitudes of each branch is calculated as the average value of the sum of the amplitudes of the signal and noise of each branch;

According to the average value of the sum of the signal and noise amplitudes of each branch, the average value of the power sum of the signal and noise of each branch is calculated using the following formula:

Wherein, the S _r is the average value of the sum of the signal and noise power of any branch r, the M _r is the average value of the sum of the signal and noise amplitude of the branch r, and the R _v (λ) is a voltage spectral responsivity, and for a certain wavelength λ, the R _v (λ) is a constant.

Further, the calculating the noise power of each branch according to the second sequence in the initial signal received by each branch includes:

Each bit signal of the second sequence in the initial signal received by each branch is the amplitude of the noise of the corresponding branch, and the noise power of each branch is calculated using the following formula:

Wherein, the D _r is the noise power of any branch r, the n is the length of the second sequence in the signal transmitted by the branch r, and the x _r1 , x _r2 , x _r3 ..., x _rn is the signal amplitude of each bit of the second sequence in the signal transmitted by the branch r; the T _r is the average value of the signal amplitude of each bit of the second sequence of the branch r;

Use the following formula to calculate the signal-to-noise ratio of each branch:

Wherein, the SNR _r is the signal-to-noise ratio of any branch r, the S _r is the average value of the power sum of the signal and the noise of the branch r, and the D _r is the power of the branch r The noise power of r.

Further, according to the calculated signal-to-noise ratio of each branch, the target pseudo-random sequences in the plurality of initial signals are combined to obtain the receiving terminal corresponding to the source pseudo-random sequence to be used Signals include:

Calculate the signal-to-noise ratio of each branch according to the calculated signal-to-noise ratio of each branch;

Determining the signal-to-noise ratio of each branch as the weight of each branch;

According to the weight value of each branch, the target pseudo-random sequence in the initial signal received from each branch is combined by using a preset combination method to obtain the signal to be used at the receiving end corresponding to the source pseudo-random sequence, and the preset The combination mode is set to be one of the following: equal gain combination, maximum ratio combination and selective combination.

Further, before calculating the signal-to-noise ratios of corresponding branches according to the target preset sequence in each initial signal, it also includes:

Each of the initial signals is subjected to a sliding mean filtering process to filter out high-frequency noise in each of the initial signals.

In the second aspect, the present invention provides a signal acquisition device based on visible light communication, which is applied to the receiving end, and the device includes:

The receiving module is configured to receive multiple initial signals, wherein the multiple initial signals are formed by receiving source visible light signals generated by the sending end through channels and received by different branches, and the source visible light signals at least include: A preset sequence and a source pseudo-random sequence carrying data, each initial signal at least includes: a target preset sequence and a target pseudo-random sequence carrying data, the target preset sequence corresponds to the source preset sequence, the The target pseudo-random sequence corresponds to the source pseudo-random sequence;

A calculation module, configured to calculate the corresponding signal-to-noise ratio of each branch according to the target preset sequence in each initial signal;

An execution module, configured to combine the target pseudo-random sequences in the plurality of initial signals according to the calculated signal-to-noise ratio of each branch, and obtain the receiving terminal corresponding to the source pseudo-random sequence to be used Signal.

Further, the target preset sequence includes: a first sequence and a second sequence, the first sequence corresponds to the digital signal 1 part of the source preset sequence, and the second sequence corresponds to the source preset sequence digital signal 0 part;

The calculation module is specifically used for:

According to the first sequence in the initial signal received by each branch, calculate the average value of the power sum of the signal and noise of each corresponding branch;

According to the second sequence in the initial signal received by each branch, calculate the noise power of each corresponding branch;

The signal-to-noise ratio of each branch is calculated according to the average value of the sum of signal and noise power of each branch and the corresponding noise power of each branch.

Further, the device also includes:

The mean filtering processing module is configured to perform a moving mean filtering process on each of the initial signals, so as to filter out high-frequency noise in each of the initial signals.

In a third aspect, the present invention provides a visible light communication system, the system comprising: a sending end and a receiving end;

The sending end is used to generate a source pseudo-random sequence, and combine the generated source pseudo-random sequence with a source preset sequence to generate a source visible light signal; send the source visible light signal;

The receiving end is used to receive multiple initial signals, wherein the multiple initial signals are formed by receiving source visible light signals generated by the transmitting end through channels and received by different branches, and the source visible light signals at least include: A source preset sequence and a source pseudo-random sequence carrying data, each initial signal at least includes: a target preset sequence and a target pseudo-random sequence carrying data, the target preset sequence corresponds to the source preset sequence, and the The target pseudo-random sequence corresponds to the source pseudo-random sequence; according to the target preset sequence in each initial signal, calculate the corresponding signal-to-noise ratio of each branch; according to the calculated signal-to-noise ratio of each branch and combining the target pseudo-random sequences in the plurality of initial signals to obtain the signal to be used at the receiving end corresponding to the source pseudo-random sequence.

In the visible light communication-based signal acquisition method and device and visible light communication system provided by the embodiments of the present invention, a preset sequence can be added to each frame of data sent by the sending end, and the receiving end can After receiving the signal, the real-time signal-to-noise ratio of each branch can be calculated according to the preset sequence in the signal, and the received signals of each branch can be combined and processed according to the real-time signal-to-noise ratio of each branch, which is convenient and accurate The final received signal can be obtained accurately, which can improve the transmission performance of the visible light communication system.

Description of drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings that need to be used in the description of the embodiments or the prior art. Obviously, the accompanying drawings in the following description are only These are some embodiments of the present invention. Those skilled in the art can also obtain other drawings based on these drawings without creative work.

Fig. 1 shows a flowchart of an embodiment of a signal acquisition method based on visible light communication provided by the present invention;

Fig. 2 shows a flow chart of another embodiment of a signal acquisition method based on visible light communication provided by the present invention;

Fig. 3 shows a schematic structural diagram of an embodiment of a signal acquisition device based on visible light communication provided according to the present invention;

Fig. 4 shows a schematic structural diagram of an embodiment of a visible light communication system provided according to the present invention.

Detailed ways

The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only some, not all, embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without making creative efforts belong to the protection scope of the present invention.

It should be noted that, in the case of no conflict, the embodiments of the present invention and the features in the embodiments can be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and examples.

In the visible light communication system, the optical signal sent by the sending end can be transmitted through the air, and the receiving end receives the optical signal to realize the signal transmission. Fading effect is one of the main factors affecting the quality of visible light communication, especially the fast fading caused by multipath interference. In order to reduce the impact of fast fading on the quality of visible light communication, the same signal can be transmitted through multiple branches. After receiving the signals transmitted by multiple branches, the receiving end will combine and output the multiple signals, thereby reducing the fast fading. influences.

When the receiving end obtains the combined signal, it needs to calculate the signal-to-noise ratio of each branch. However, the existing methods for calculating the signal-to-noise ratio cannot conveniently and accurately calculate the signal-to-noise ratio of each branch, thus affecting the transmission performance of the visible light communication system.

The signal acquisition method provided by the embodiment of the present invention can be applied to a visible light communication system. When the sending end sends a signal, a preset sequence can be added to each frame of data, and then the signal can be transmitted through multiple branches. After receiving the signal received by each branch, the receiving end can use the A preset sequence is used to calculate the signal-to-noise ratio of each branch. Specifically, the sending end may use an LED light emitting device to send out an optical signal, and the optical signal may include a preset sequence and a pseudo-random sequence carrying data.

In order to accurately calculate the signal-to-noise ratio of each branch, the receiving end needs to obtain information including only noise and comprehensive information of signal and noise. Therefore, the preset sequence can be set to include two parts, one part is a digital signal 1, and the other part is a digital signal 0. When the transmitting end sends a digital signal 1, the light-emitting device sends out an optical signal, and the optical signal is superimposed with the noise in the channel during the propagation process, so the optical receiving device at the receiving end obtains the sum of the amplitude of the signal and noise; while sending a digital signal 0 When , the light-emitting device does not send an optical signal, so the light-receiving device at the receiving end gets the magnitude of the noise.

It can be understood that since the preset sequence is used to calculate the signal-to-noise ratio of each channel transmission signal, it is a statistical result. Therefore, the larger the length of the preset sequence, the more accurate the calculated signal-to-noise ratio of each channel transmission signal. However, if the length of the preset sequence is too large, the transmission efficiency of the visible light communication system will be affected. Therefore, generally, the length of the preset sequence can be set to be smaller than the length of the pseudo-random sequence. Specifically, the length of the preset sequence can be set to be related to the length of the pseudo-random sequence. For example, the ratio of the length of the preset sequence to the length of the pseudo-random sequence can be set within a certain range (such as 0.01-0.1).

Alternatively or additionally, the lengths of the two parts respectively corresponding to the digital signals 1 and 0 in the preset sequence may be the same or different. Generally, the two parts in the preset sequence corresponding to the digital signals 1 and 0 can be set to have the same length.

By adding a preset sequence to the signal sent by the sending end, the signal acquisition method provided by the embodiment of the present invention can accurately calculate the real-time signal-to-noise ratio of each branch, thereby improving the accuracy of the received signal and improving the visible light communication system transmission performance.

Please refer to FIG. 1 , which shows a flowchart of an embodiment of a signal acquisition method based on visible light communication according to the present invention.

As shown in Figure 1, the signal acquisition method based on visible light communication provided by this embodiment is applied to the receiving end and may include the following steps:

Step 101, receiving multiple initial signals.

In this embodiment, the receiving end may receive multiple initial signals. The above-mentioned multiple initial signals are formed by the source visible light signal generated by the sending end through channel transmission and received by different branches. The source visible light signal at least includes: a source preset sequence and a source pseudo-random sequence carrying data; each initial signal is at least Including: the target preset sequence and the target pseudo-random sequence carrying data. The target preset sequence is formed after the source preset sequence is transmitted through the channel and received by different branches. The target pseudo-random sequence is the source pseudo-random sequence transmitted through the channel. And it is formed after being received by different branches.

In a visible light communication system, in order to reduce the impact of fast fading on the quality of visible light communication, multiple branches can be used to receive visible light signals from the same source. The above multiple branches may be mutually independent branches. When multiple independent branches are used to receive the same source visible light signal, the multiple initial signals received by the receiving end will also have a small correlation, so that the receiving end can recover the source visible light signal relatively correctly.

In this embodiment, the sending end can send out the source visible light signal through the LED light emitting device. The above-mentioned source visible light signal may include: a frame header, a source preset sequence, and a source pseudo-random sequence carrying data. When the receiving end receives the initial signal, it can use the frame header to judge whether the initial signal should be received or discarded.

It can be understood that after receiving each initial signal, the receiving end may first filter each initial signal to filter out other light components except blue in each received initial signal, thereby increasing the 3dB bandwidth of the visible light communication system. It is also possible to further convert the original signal into a digital signal through photoelectric conversion and analog signal/digital signal conversion, so as to perform processing such as frame header detection and signal merging on the original signal.

Step 102, according to the target preset sequence in each initial signal, calculate the corresponding signal-to-noise ratio of each branch.

In this embodiment, the corresponding signal-to-noise ratio of each branch may be calculated according to the target preset sequence in each initial signal. The above-mentioned target preset sequence includes: a first sequence and a second sequence, the first sequence corresponds to the digital signal 1 part of the source preset sequence, and the second sequence corresponds to the digital signal 0 part of the source preset sequence.

In an optional implementation of this embodiment, the corresponding signal-to-noise ratio of each branch can be calculated according to the target preset sequence in each initial signal according to the following steps: According to the initial signal received by each branch According to the first sequence of the corresponding branches, the average value of the sum of the signal and noise power of each branch is calculated; according to the second sequence of the initial signal received by each branch, the noise power of each branch is calculated; according to each branch Calculate the signal-to-noise ratio of each branch by taking the average value of the sum of the power of the signal and noise, and the corresponding noise power of each branch.

Specifically, each bit signal of the first sequence in the initial signal received by each branch is the sum of the signal and noise amplitude of the corresponding branch, according to the length of the first sequence in each initial signal and the corresponding The sum of signal and noise amplitudes, calculate the average value of the sum of signal and noise amplitudes of each branch; calculate the signal and noise of each branch according to the average value of the sum of signal and noise amplitudes of each branch The average value of the power sum; each bit signal of the second sequence in the initial signal received by each branch is the amplitude of the noise of the corresponding branch, and the noise power of each corresponding branch is calculated according to the second sequence in each initial signal ; Calculate the signal-to-noise ratio of each branch according to the average value of the sum of signal and noise power of each branch and the corresponding noise power of each branch.

For example, the source preset sequence sent by the sending end may be 1000 bits (bits), the first 500 bits are digital signal 1, and the last 500 bits are digital signal 0. The first 500 bits of any target preset sequence received by the receiving end is the sum of signal and noise amplitudes, and the last 500 bits are the noise amplitude of the branch. The first 500 bits of data in the target preset sequence are averaged to obtain the average value of the sum of the signal and noise amplitudes of the branch.

The photoelectric conversion devices commonly used at the receiving end include photodiodes (PIN) and photomultiplier tubes (PMT). Within a certain range of light intensity, the amplitude of the optical signal received by these devices is proportional to the optical power, namely:

Among them, R _v (λ) is the voltage spectral responsivity, for a specific wavelength, the voltage spectral responsivity of the light-emitting device is a constant value, V(λ) is the voltage of the received optical signal, P(λ) is the voltage of the received optical signal Optical power, so within a certain light intensity unit, the amplitude of the optical signal received by the photoelectric conversion device is proportional to the optical power, and normal lighting and experiments are within this light intensity range.

Therefore, after obtaining the average value of the sum of signal and noise amplitudes of each branch, the following formula can be used to calculate the average value of the sum of signal and noise power of any branch r:

Among them, S _r is the average value of the sum of the signal and noise power of any branch r, M _r is the average value of the sum of the signal and noise amplitude of the branch r, and R _v (λ) is the voltage spectral response rate, for a certain wavelength λ, R _v (λ) is a constant.

For the noise amplitude of the branch r in the last 500 bits, since the optical communication is used for indoor communication, the indoor optical noise amplitude follows a normal distribution, so the variance of the noise amplitude is the noise power. Therefore, the last 500 bits of the received target preset sequence can be calculated to obtain the amplitude variance D _r , that is, the noise power.

First, the average value T _r of the last 500 bits can be calculated:

Then calculate the noise power of the branch r according to the average value T _r of the noise amplitude:

After obtaining the average value S _r of the sum of signal and noise power of branch r and the noise power D _r of this branch r, the SNR of this branch r can be calculated by the following formula:

Using the same method for other branches, the signal-to-noise ratios of all branches are sequentially obtained as SNR ₁ , SNR ₂ , SNR ₃ . . . SNR _n . Furthermore, various diversity reception combining methods can be realized according to the ratio.

Step 103, according to the calculated signal-to-noise ratio of each branch, combine the target pseudo-random sequences in the multiple initial signals to obtain the signal to be used at the receiving end corresponding to the source pseudo-random sequences.

After obtaining the signal-to-noise ratio of each branch, the receiving end can combine the target pseudo-random sequences in multiple initial signals to obtain the signal to be used at the receiving end corresponding to the source pseudo-random sequence.

Specifically, the signal-to-noise ratio of each branch can be calculated according to the calculated signal-to-noise ratio of each branch, and then the signal-to-noise ratio of each branch is determined as the weight of each branch, Then, according to the weights of each branch, the target pseudo-random sequence in the initial signal received from each branch is combined using a preset combination method to obtain the signal to be used at the receiving end corresponding to the source pseudo-random sequence. For example, the target pseudo-random sequences in each initial signal can be combined by using any existing combination method, such as equal gain combination, maximum ratio combination, and selective combination.

The signal acquisition method based on visible light communication provided in this embodiment can add a preset sequence to each frame of data sent by the sending end. After receiving the signal transmitted by each branch, the receiving end can The real-time signal-to-noise ratio of each branch is obtained by calculating the preset sequence of each branch, and the received signals of each branch are further combined and processed according to the real-time signal-to-noise ratio of each branch, and the final received signal is obtained conveniently and accurately. The signal can improve the transmission performance of the visible light communication system.

Please refer to FIG. 2 , which shows a flow chart of another embodiment of a signal acquisition method based on visible light communication according to the present invention.

As shown in Figure 2, the signal acquisition method based on visible light communication provided by this embodiment is applied to the receiving end and may include the following steps:

Step 201, receiving multiple initial signals.

Step 201 in this embodiment is basically the same as step 101 in the foregoing embodiment corresponding to FIG. 1 , and will not be repeated here.

Step 202, performing a sliding mean filtering process on each initial signal, so as to filter out high-frequency noise in each initial signal.

In this embodiment, after receiving multiple initial signals, the receiving end may firstly perform a sliding mean filtering process on each initial signal. Specifically, it is possible to store the collected results of each initial signal, calculate the average value of each sampling point, and then process each initial signal by means of digital signal processing, so as to filter out high-frequency noise in each initial signal.

Step 203, according to the target preset sequence in each initial signal, calculate the corresponding signal-to-noise ratio of each branch.

Step 204, according to the calculated signal-to-noise ratio of each branch, combine the target pseudo-random sequences in the multiple initial signals to obtain the signal to be used at the receiving end corresponding to the source pseudo-random sequences.

Steps 203-204 in this embodiment are basically the same as steps 102-103 in the above-mentioned embodiment corresponding to FIG. 1 , and will not be repeated here.

In the signal acquisition method based on visible light communication provided in this embodiment, after receiving multiple initial signals, the receiving end may first perform a sliding mean filtering process on each initial signal, thereby filtering out high-frequency noise in each initial signal, which can Improve the accuracy of the received signal and improve the transmission performance of the visible light communication system.

Please refer to FIG. 3 , which shows a schematic structural diagram of an embodiment of a signal acquisition device based on visible light communication according to the present application.

As shown in FIG. 3 , the signal acquisition device based on visible light communication provided in this embodiment may include: a receiving module 310 , a computing module 320 and an executing module 330 .

The receiving module 310 is configured to receive multiple initial signals, wherein the multiple initial signals are formed by receiving source visible light signals generated by the sending end through channels and received by different branches. The source visible light signals at least include: source preset sequence and The source pseudo-random sequence carrying data, each initial signal at least includes: a target preset sequence and a target pseudo-random sequence carrying data, the target preset sequence corresponds to the source preset sequence, and the target pseudo-random sequence corresponds to the source pseudo-random sequence ;

The calculation module 320 is used to calculate the corresponding signal-to-noise ratio of each branch according to the target preset sequence in each initial signal;

The execution module 330 is used for combining the target pseudo-random sequences in multiple initial signals according to the calculated signal-to-noise ratio of each branch to obtain the signal to be used at the receiving end corresponding to the source pseudo-random sequences.

In an optional implementation of this embodiment, the target preset sequence includes: a first sequence and a second sequence, the first sequence corresponds to the digital signal 1 part of the source preset sequence, and the second sequence corresponds to the digital signal of the source preset sequence signal 0 part;

The calculation module 320 is specifically used for:

According to the first sequence in the initial signal received by each branch, calculate the average value of the power sum of the signal and noise of each corresponding branch;

According to the second sequence in the initial signal received by each branch, calculate the noise power of each corresponding branch;

The signal-to-noise ratio of each branch is calculated according to the average value of the sum of signal and noise power of each branch and the corresponding noise power of each branch.

In another optional implementation manner of this embodiment, the signal acquisition device based on visible light communication provided by this embodiment further includes:

The mean value filter processing module is used for performing sliding mean value filter processing on each initial signal, so as to filter out high-frequency noise in each initial signal.

The signal acquisition device based on visible light communication provided in this embodiment can add a preset sequence to each frame of data sent by the sending end. After receiving the signals transmitted by each branch, the receiving end can first The initial signal is processed by sliding mean filtering to filter out the high-frequency noise in each initial signal, and then the real-time signal-to-noise ratio of each branch is calculated according to the preset sequence in the signal, and further according to the real-time signal of each branch The noise ratio combines the received signals of each branch to obtain the final received signal conveniently and accurately, which can improve the transmission performance of the visible light communication system.

Please refer to FIG. 4 , which shows a schematic structural diagram of an embodiment of a visible light communication system according to the present application.

As shown in FIG. 4 , the visible light communication system provided in this embodiment may include: a sending end 410 and a receiving end 420 .

The sending end 410 is used to generate the source pseudo-random sequence, and combine the generated source pseudo-random sequence with the source preset sequence to generate the source visible light signal; transmit the source visible light signal;

The receiving end 420 is used to receive multiple initial signals, wherein the multiple initial signals are formed by receiving source visible light signals generated by the transmitting end through channels and received by different branches. The source visible light signals at least include: source preset sequence and The source pseudo-random sequence carrying data, each initial signal at least includes: a target preset sequence and a target pseudo-random sequence carrying data, the target preset sequence corresponds to the source preset sequence, and the target pseudo-random sequence corresponds to the source pseudo-random sequence ; According to the target preset sequence in each initial signal, calculate the corresponding signal-to-noise ratio of each branch; according to the calculated signal-to-noise ratio of each branch, the target pseudo-random sequence in multiple initial signals Combining processing is performed to obtain the signal to be used at the receiving end corresponding to the source pseudo-random sequence.

In the visible light communication system provided in this embodiment, a preset sequence can be added to each frame of data sent by the sending end. After receiving the signal transmitted by each branch, the receiving end can Calculate the real-time signal-to-noise ratio of each branch, and further combine and process the received signals of each branch according to the real-time signal-to-noise ratio of each branch, so as to obtain the final received signal conveniently and accurately, which can improve the visibility of visible light. Transmission performance of communication systems.

It should be noted that in this article, relational terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply that there is a relationship between these entities or operations. There is no such actual relationship or order between them. Furthermore, the term "comprises", "comprises" or any other variation thereof is intended to cover a non-exclusive inclusion such that a process, method, article, or apparatus comprising a set of elements includes not only those elements, but also includes elements not expressly listed. other elements of or also include elements inherent in such a process, method, article, or device. Without further limitations, an element defined by the phrase "comprising a ..." does not preclude the presence of additional identical elements in the process, method, article, or apparatus that includes the element.

Each embodiment in this specification is described in a related manner, the same and similar parts of each embodiment can be referred to each other, and each embodiment focuses on the differences from other embodiments. In particular, for the system embodiment, since it is basically similar to the method embodiment, the description is relatively simple, and for relevant parts, refer to part of the description of the method embodiment.

The above are only preferred embodiments of the present invention, and are not intended to limit the protection scope of the present invention. Any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the present invention are included in the protection scope of the present invention.

Claims (8)

1. a kind of signal acquiring method based on visible light communication, which is characterized in that it is applied to receiving terminal, the method includes：

Receive multiple initial signals, wherein the multiple initial signal is that the source visible light signal that transmitting terminal generates passes through channel After transmission, it is formed by by different branch reception, the source visible light signal includes at least：Source predetermined sequence and carrying data Source pseudo-random sequence, each initial signal include at least：The target pseudo-random sequence of target predetermined sequence and carrying data, institute It is corresponding with the source predetermined sequence to state target predetermined sequence, the target pseudo-random sequence is corresponding with the source pseudo-random sequence；

According to the target predetermined sequence in each initial signal, the signal-to-noise ratio of corresponding every branch is calculated；

According to the signal-to-noise ratio for each branch being calculated, the target pseudo-random sequence in the multiple initial signal is carried out Merging treatment obtains the receiving terminal signal to be utilized corresponding to the source pseudo-random sequence；

Wherein, the target predetermined sequence includes：First ray and the second sequence, the First ray correspond to the source and preset sequence 1 part of digital signal of row, second sequence pair answer the digital signaling zero part of the source predetermined sequence；

Target predetermined sequence in each initial signal of basis, the signal-to-noise ratio for calculating corresponding every branch include：

First ray in the initial signal received according to each branch, calculate corresponding each branch signal and noise power it The average value of sum；

The second sequence in the initial signal received according to each branch calculates the noise power of corresponding each branch；

According to the average value of the sum of the power of the signal of each branch and noise, and the accordingly noise power of each branch, meter Calculate the signal-to-noise ratio of each branch.

2. according to the method described in claim 1, it is characterized in that, in the initial signal received according to each branch One sequence, the average value for calculating the sum of the signal of corresponding each branch and the power of noise include：

Each bit signal of First ray is the signal and noise of respective branch in the initial signal that each branch receives The sum of amplitude, according to the length of First ray in each initial signal and the corresponding signal of each branch and the sum of the amplitude of noise, meter Calculate the average value of the sum of the signal of each branch and the amplitude of noise；

The average value of the sum of amplitude according to the signal of each branch and noise, the letter of every branch is calculated using following formula Average value number with the sum of the power of noise：

Wherein, the S_rFor the average value of the sum of the power of the signal and noise of any branch r, the M_rFor branch r described in this The average value of the sum of the amplitude of signal and noise, the R_v(λ) is Voltage Spectroscopy responsiveness, for determining wavelength X, the R_v (λ) is constant.

3. according to the method described in claim 2, it is characterized in that, in the initial signal received according to each branch Two sequences, the noise power for calculating corresponding each branch include：

Each bit signal of the second sequence is the amplitude of the noise of respective branch in the initial signal that each branch receives, profit The noise power of every branch is calculated with following formula：

Wherein, the D_rFor the noise power of any branch r, the n is the second sequence in the signal that the branch r is transmitted Length, the x_r1,x_r2,x_r3...,x_rnEach bit signal amplitude of second sequence in the signal transmitted for branch r described in this； The T_rFor the average value of each bit signal amplitude of the second sequence of branch r described in this；

The signal-to-noise ratio of each branch is calculated using following formula：

Wherein, the SNR_rFor the signal-to-noise ratio of any branch r, the S_rFor the sum of the power of the signal of branch r described in this and noise Average value, the D_rFor the noise power of branch r described in this.

4. according to any methods of claim 1-3, which is characterized in that described according to each branch being calculated Signal-to-noise ratio merges processing to the target pseudo-random sequence in the multiple initial signal, obtains the source pseudo-random sequence Corresponding receiving terminal signal to be utilized includes：

According to the signal-to-noise ratio for each branch being calculated, the signal-to-noise ratio ratio of each branch is calculated；

The signal-to-noise ratio ratio of each branch is determined as to the weights of corresponding each branch；

According to the weights of each branch, merged in the way of default merging pseudo- from the target in the initial signal that every branch receives Random sequence, obtains the receiving terminal signal to be utilized corresponding to the source pseudo-random sequence, and the default merging mode is following One：Equal gain combining, maximum-ratio combing and selection combination.

5. according to any methods of claim 1-3, which is characterized in that the target in each initial signal of the basis Predetermined sequence, calculating before the signal-to-noise ratio of each branch, further include accordingly：

Sliding mean filter processing is carried out to each initial signal, is made an uproar with filtering out the high frequency in each initial signal Sound.

6. a kind of signal acquisition device based on visible light communication, which is characterized in that be applied to receiving terminal, described device includes：

Receiving module, for receiving multiple initial signals, wherein the multiple initial signal is the source visible light that transmitting terminal generates Signal is formed by, the source visible light signal is included at least after transmission by different branch reception：Source predetermined sequence With the source pseudo-random sequence of carrying data, each initial signal includes at least：The target of target predetermined sequence and carrying data Pseudo-random sequence, the target predetermined sequence is corresponding with the source predetermined sequence, and the target pseudo-random sequence is pseudo- with the source Random sequence corresponds to；

Computing module, for according to the target predetermined sequence in each initial signal, calculating the signal-to-noise ratio of corresponding every branch；

Execution module, for the signal-to-noise ratio according to each branch being calculated, to the target in the multiple initial signal Pseudo-random sequence merges processing, obtains the receiving terminal signal to be utilized corresponding to the source pseudo-random sequence；

Wherein, the target predetermined sequence includes：First ray and the second sequence, the First ray correspond to the source and preset sequence 1 part of digital signal of row, second sequence pair answer the digital signaling zero part of the source predetermined sequence；

The computing module is specifically used for：

First ray in the initial signal received according to each branch, calculate corresponding each branch signal and noise power it The average value of sum；

The second sequence in the initial signal received according to each branch calculates the noise power of corresponding each branch；

According to the average value of the sum of the power of the signal of each branch and noise, and the accordingly noise power of each branch, meter Calculate the signal-to-noise ratio of each branch.

7. device according to claim 6, which is characterized in that further include：

Mean filter processing module, it is described to filter out for carrying out sliding mean filter processing to each initial signal High-frequency noise in each initial signal.

8. a kind of visible light communication system, which is characterized in that the system comprises：Transmitting terminal and receiving terminal；

The transmitting terminal is used for generating source pseudo-random sequence, and the source pseudo-random sequence of generation is merged generation source with source predetermined sequence Visible light signal；Send the source visible light signal；

The receiving terminal is for receiving multiple initial signals, wherein the multiple initial signal is that the source that transmitting terminal generates is visible Optical signal is formed by, the source visible light signal is included at least after transmission by different branch reception：Preset sequence in source The source pseudo-random sequence of row and carrying data, each initial signal include at least：The mesh of target predetermined sequence and carrying data Pseudo-random sequence is marked, the target predetermined sequence is corresponding with the source predetermined sequence, the target pseudo-random sequence and the source Pseudo-random sequence corresponds to；According to the target predetermined sequence in each initial signal, the signal-to-noise ratio of corresponding every branch is calculated；Root According to the signal-to-noise ratio for each branch being calculated, place is merged to the target pseudo-random sequence in the multiple initial signal Reason, obtains the receiving terminal signal to be utilized corresponding to the source pseudo-random sequence；

Wherein, the target predetermined sequence includes：First ray and the second sequence, the First ray correspond to the source and preset sequence 1 part of digital signal of row, second sequence pair answer the digital signaling zero part of the source predetermined sequence；

The receiving terminal, is specifically used for：

First ray in the initial signal received according to each branch, calculate corresponding each branch signal and noise power it The average value of sum；The second sequence in the initial signal received according to each branch calculates the noise power of corresponding each branch；Root According to the average value of the sum of the power of the signal and noise of each branch, and the noise power of corresponding each branch, each is calculated The signal-to-noise ratio on road.