Communication system and link optimization method thereof

Abstract

The present application provides a communication system and a link optimization method thereof, which relate to the field of communication. The system includes: an indoor communication subsystem, an outdoor communication subsystem, and a terahertz transmission channel connected between the indoor communication subsystem and the outdoor communication subsystem; the indoor communication subsystem is used to obtain an optical signal carrying transmission data, and restore the optical signal to an original transmission signal, and transmit it to the outdoor communication subsystem using the terahertz transmission channel; the outdoor communication subsystem is used to receive the original transmission signal output by the indoor communication subsystem, and allocate a first channel capacity and a second channel capacity to the original transmission signal, so that the original transmission signal is transmitted to a ground satellite receiving facility based on the first channel capacity and the second channel capacity. The present application solves the problems of low spectrum utilization and limited channel capacity in related technologies.

Description

Technical Field

[0001] The present application relates to the field of communications, and in particular, to a communication system and a link optimization method thereof. Background Art

[0002] With the development of mobile communication network technology, the number of mobile terminals and network traffic will increase dramatically in the future, and the beautiful vision of the interconnection of all things, such as the Internet of Things, the Internet of People, and the Internet of Vehicles, will be realized. Therefore, very high requirements are placed on the performance of future wireless mobile communication systems.

[0003] In recent years, the development of wireless communication has mainly focused on the use of spectrum in the UHF band (300MHz to 3000MHz), and the frequency band currently used for mobile communications only accounts for a small part of the electromagnetic wave band, such as 900MHz, 1800MHz, 2.6GHz and other bands below 6GHz. The spectrum of these bands is relatively crowded and relatively scarce, and the spectrum utilization rate is relatively low, making it difficult to meet the business growth demand for 1,000 times the capacity in the future.

[0004] From the above, we can see that how to meet the capacity requirements and spectrum utilization of communication systems still needs to be solved. Summary of the invention

[0005] The present application provides a communication system and a link optimization method thereof, which can solve the problem that the capacity requirements and spectrum utilization of the communication system cannot be met in the related technology. The technical solution is as follows:

[0006] According to one aspect of the present application, a communication system includes: an indoor communication subsystem, an outdoor communication subsystem, and a terahertz transmission channel connected between the indoor communication subsystem and the outdoor communication subsystem; wherein the indoor communication subsystem is used to obtain an optical signal carrying transmission data, and restore the optical signal to an original transmission signal, and transmit it to the outdoor communication subsystem using the terahertz transmission channel; the outdoor communication subsystem is used to receive the original transmission signal output by the indoor communication subsystem, and allocate a first channel capacity and a second channel capacity to the original transmission signal, so that the original transmission signal is transmitted to a ground satellite receiving facility based on the first channel capacity and the second channel capacity.

[0007] In an exemplary embodiment, the indoor communication subsystem includes: a transmitting end and a receiving end; wherein the transmitting end is used to receive the original transmission signal sent by the terminal and convert the original transmission optical signal into the optical signal carrying transmission data; the receiving end is used to convert the optical signal into the electrical signal and perform signal preprocessing on the electrical signal to obtain the original transmission signal.

[0008] In an exemplary embodiment, the receiving end includes: a concentrator, a photodetector, and a signal processor; wherein the concentrator is used to receive the optical signal emitted by the transmitting end and send the optical signal to the photodetector in a concentrated manner; the photodetector is used to collect the optical signal and perform photoelectric conversion on the optical signal to obtain the electrical signal; the signal processor is used to perform at least one signal preprocessing of equalization, demodulation, and decoding on the electrical signal to obtain the original transmission signal.

[0009] In an exemplary embodiment, the LED signal source includes one or more of an ultraviolet LED, a phosphor LED, and a tricolor LED.

[0010] In an exemplary embodiment, the outdoor communication subsystem includes a channel capacity calculation module and a channel capacity allocation module; wherein the channel capacity calculation module is used to calculate the total channel capacity required for the original sending signal; and the channel capacity allocation module is used to allocate and predict the total channel capacity according to the Markov algorithm to obtain the first channel capacity and the second channel capacity.

[0011] In an exemplary embodiment, the channel capacity calculation module includes at least one of the following calculation units: a channel gain calculation unit, a concentrator gain calculation unit, a spectrum efficiency calculation unit, and a signal-to-noise ratio calculation unit.

[0012] In an exemplary embodiment, the first channel is a terahertz transmission channel.

[0013] In an exemplary embodiment, the second channel is a visible light communication (VLC) channel.

[0014] According to one aspect of the present application, a communication system link optimization method is applied to the communication system as described above, wherein the communication system includes an indoor communication subsystem, an outdoor communication subsystem, and a terahertz transmission channel connected between the indoor communication subsystem and the outdoor communication subsystem; the method includes: the indoor communication subsystem acquires an optical signal carrying transmission data; the optical signal is restored to an original transmission signal, and is transmitted to the outdoor communication subsystem using the terahertz transmission channel; the outdoor communication subsystem receives the original transmission signal output by the indoor communication subsystem, and allocates a first channel capacity and a second channel capacity to the original transmission signal, so that the original transmission signal is transmitted to a ground satellite receiving facility based on the first channel capacity and the second channel capacity.

[0015] The beneficial effects of the technical solution provided by this application are:

[0016] In the above technical solution, an optical signal carrying transmission data is obtained through an indoor communication subsystem; the optical signal is restored to the original transmission signal, and transmitted to the outdoor communication subsystem using a terahertz transmission channel; the outdoor communication subsystem receives the original transmission signal output by the indoor communication subsystem, and allocates a first channel capacity and a second channel capacity to the original transmission signal, so that the original transmission signal is transmitted to the ground satellite receiving facility based on the first channel capacity and the second channel capacity. Different channels are allocated for communication according to the total channel capacity required for the original transmission signal, and a VLC visible light communication channel is used for indoor communication scenarios, and a terahertz transmission channel is used for outdoor communication scenarios, which greatly improves the transmission rate while providing a larger channel capacity for indoor communication, thereby solving the problem that the capacity requirements of the communication system cannot be met in the related technology. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in describing the embodiments of the present application are briefly introduced below.

[0018] Figure 1 A communication system according to an embodiment of the present application is shown;

[0019] Figure 2 A communication system link optimization method is shown according to an embodiment of the present application. DETAILED DESCRIPTION

[0020] The embodiments of the present application are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present application, and cannot be interpreted as limiting the present application.

[0021] It will be understood by those skilled in the art that, unless expressly stated, the singular forms "one", "said", and "the" used herein may also include plural forms. It should be further understood that the term "comprising" used in the specification of the present application refers to the presence of the features, certificates, steps, operations, elements and / or components, but does not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components and / or groups thereof. It should be understood that when we refer to an element as being "connected" or "coupled" to another element, it may be directly connected or coupled to the other element, or there may be intermediate elements. In addition, the "connection" or "coupling" used herein may include wireless connection or wireless coupling. The term "and / or" used herein includes all or any unit and all combinations of one or more associated listed items.

[0022] As mentioned above, the spectrum of the existing frequency band is relatively crowded and scarce, and the utilization rate is relatively low, which makes it difficult to meet the business growth demand of 1000 times the capacity in the future. A complementary technology to the existing wireless RF communication technology is OWC (Optical Wireless Communication), which includes infrared, visible and ultraviolet light, and can effectively improve the spectrum utilization rate and alleviate the current problem of tight RF communication bands. However, the improvement of spectrum utilization rate has a certain limit and cannot be increased wirelessly, and this improvement is far from enough to meet the capacity requirements of future wireless communication systems.

[0023] It can be seen from the above that the related technologies still have the problems of lack of spectrum and insufficient communication capacity.

[0024] To this end, the communication system provided by the present application can solve the problems of lack of spectrum and insufficient communication capacity in related technologies. Accordingly, the present application also provides a communication system link optimization method.

[0025] In order to make the objectives, technical solutions and advantages of the present application clearer, the implementation methods of the present application will be further described in detail below with reference to the accompanying drawings.

[0026] In an exemplary embodiment, if Figure 1 As shown, a communication system 10 is shown, including an indoor communication subsystem 110 , an outdoor communication subsystem 120 , and a terahertz transmission channel 130 connected between the indoor communication subsystem 110 and the outdoor communication subsystem 120 .

[0027] The indoor communication subsystem 110 is used to obtain the optical signal carrying the transmission data, restore the optical signal to the original transmission signal, and transmit it to the outdoor communication subsystem 120 via the terahertz transmission channel 130 .

[0028] The outdoor communication subsystem 120 is used to receive the original transmission signal output by the indoor communication subsystem 110, and allocate a first channel capacity and a second channel capacity to the original transmission signal, so that the original transmission signal is transmitted to the ground satellite receiving facility based on the first channel capacity and the second channel capacity. Specifically, the first channel refers to a terahertz channel; the second channel refers to a visible light communication (VLC) channel.

[0029] Based on the above system, different channel capacities are allocated to the original transmitted signals to adapt to the communication methods in different scenarios. For example, in indoor scenarios, such as subways, tunnels, navigation, cabins and mines, where wireless communication is not smooth, visible light communication channels are used for communication to fill the blind spots of wireless communication coverage; in outdoor scenarios, such as ground-to-ground satellite base stations, communication is carried out through terahertz channels, which greatly improves the transmission rate while providing greater capacity for wireless channels.

[0030] In an exemplary embodiment, the indoor communication subsystem 110 includes a transmitting end 1110 and a receiving end 1120 .

[0031] The transmitting end 1110 is used to receive the original transmission signal sent by the terminal and convert the original transmission optical signal into an optical signal carrying transmission data.

[0032] In a possible implementation, the transmitting end 1110 includes an LED signal source for converting an original transmission optical signal into an optical signal carrying transmission data, and transmitting the optical signal to the receiving end 1120 .

[0033] Optionally, the LED light source includes one or more of ultraviolet LED, phosphor LED, and tricolor LED. Among them, ultraviolet LED (UV-LED) has large energy loss and low light efficiency; phosphor LED (PC-LED) has simple structure and low cost; tricolor LED (RGB-LED) has fast response speed and high bandwidth, and is suitable for high-speed communication.

[0034] The receiving end 1120 is used to convert the optical signal into an electrical signal and perform signal preprocessing on the electrical signal to obtain an original transmission signal.

[0035] In a possible implementation, the receiving end 1120 includes a concentrator 1121 , a photodetector 1122 , and a signal processor 1123 .

[0036] The concentrator 1121 is used to receive the optical signal transmitted by the transmitting end, and send the optical signal to the photodetector 1122 in a concentrated manner.

[0037] The photoelectric detector 1122 is used to collect light signals and perform photoelectric conversion on the light signals to obtain electrical signals.

[0038] The signal processor is used to perform at least one signal preprocessing of equalization, demodulation and decoding on the electrical signal to obtain the original transmission signal.

[0039] Based on the above subsystems, communication based on visible light communication technology is realized, so that there are signals wherever light can cover, which is conducive to filling the blind spots of wireless communication coverage, such as subways, tunnels, navigation, cabins and mines and other areas with poor wireless communication.

[0040] In an exemplary embodiment, the outdoor communication subsystem 120 includes: a channel capacity calculation module 1210 and a channel capacity allocation module 1220 .

[0041] The channel capacity calculation module 1210 is used to calculate the total channel capacity required for the original transmission signal.

[0042] The channel capacity allocation module 1220 is used to allocate and predict the total channel capacity according to the Markov algorithm to obtain the first channel capacity and the second channel capacity.

[0043] In a possible implementation, the channel capacity calculation module includes: at least one of a channel gain calculation unit, a concentrator gain calculation unit, a spectrum efficiency calculation unit, and a signal-to-noise ratio calculation unit.

[0044] Specifically, the channel gain that can be obtained by the i-th receiving end is calculated according to the following calculation formula:

[0045]

[0046] Where m is the Lambert coefficient, ψ i is the light incident angle, Φ i is the light emission angle, A pd is the light receiver area, d i is the distance between the LED signal source and the i-th receiver, T(ψ i ) is the gain of the optical filter, G(ψ i ) is the gain of the condenser, FOV represents the field of view, and n represents the refractive index of the condenser.

[0047] Optionally, G(ψ i ) is calculated according to the following formula:

[0048]

[0049] Specifically, the spectrum efficiency is calculated according to the following formula:

[0050]

[0051] Among them, γ i is the signal to interference plus noise ratio, γ i The expression is as follows:

[0052]

[0053] Among them, P ele,i is the received power of the ith terminal, P t,i is the optical transmission power, S is the responsivity, g i is the channel gain, Pt,i represents the power received from the tth LED signal source, g t,i represents the channel gain of the tth LED signal source, N0 is the noise power, B is the channel bandwidth, and I is the interference.

[0054] Visible light communication is greatly affected by the environment and is affected by factors such as the angle between the receiving end and the LED signal source, the transmission power, and the responsiveness. Therefore, in order to achieve higher-speed communication, the receiving end and the transmitting end need to be aligned in angle and must not be blocked by the external environment.

[0055] In a possible implementation, after the total channel capacity is calculated, the total channel capacity is allocated and predicted according to a Markov algorithm to obtain a first channel capacity and a second channel capacity.

[0056] Specifically, a prediction model is constructed based on the Markov algorithm, and the terahertz signal and VLC signal at the current moment are substituted respectively to predict the strong and weak transition probability of the terahertz signal and VLC signal in the next time period. The Markov transition probability matrix model formula is:

[0057] X(k+1)=X(k)×P.

[0058] Among them, X(k) represents the state vector of the trend analysis and prediction object at time t=k, P represents the one-step transition probability matrix, and X(k+1) represents the state vector of the trend analysis and prediction object at time t=k+1.

[0059] For example, the probability of wireless signal gain increase (db / km) in the previous period is [0.3, 0.7], the probability of gain transfer (db / km) when the wireless signal becomes stronger in the current period is [0.6, 0.4], and the probability of gain transfer (db / km) when the wireless signal becomes weaker in the current period is [0.3, 0.7].

[0060] The Markov model is used to calculate the gain transfer probability when the wireless signal becomes stronger in the next period: 0.3x0.6+0.3x0.7=0.39; the gain transfer probability when the wireless signal becomes weak in the next period: 0.3x0.4+0.7x0.7=0.61.

[0061] Obtain three sets of terahertz and VLC real-time wireless values ​​and model prediction results in the historical logs, extract 100 prediction samples respectively, and calculate the difference between the predicted value and the actual value. If the difference is negative, it is the error value; if the difference is positive, it is the accuracy rate. The difference is scored 1 point for every 10%, and the channel capacity is allocated to the total channel capacity according to the score.

[0062] As shown in Table 1, if the error rate between the terahertz signal and the actual value is -30%, -3 points are recorded; if the error rate between the VLC signal and the actual value is 30%, +3 points are recorded. The 100 prediction results are counted. If the terahertz signal score is greater than the VLC signal, terahertz is used as the main signal wireless technology of the ground satellite receiving facility to provide more channel capacity for signal transmission; if the terahertz signal score is less than the VLC signal, VLC is used as the main signal wireless technology of the ground satellite receiving facility to provide more channel capacity for signal transmission.

[0063] Table 1 Prediction sample analysis results

[0064]

[0065] Based on the above subsystems, the terahertz transmission channel is used to realize the communication of the indoor and outdoor communication subsystems, which not only provides multiple transmission channels with larger capacity for indoor wireless channels, effectively improving the transmission rate within the limited transmission distance outdoors, but also quickly transmits indoor wireless signals to nearby ground satellite receiving facilities, thereby providing more efficient radio waves for the integrated ground-to-earth link backhaul.

[0066] In an exemplary embodiment, Figure 2 As shown, the present application provides a communication system link optimization method, which is applied to the communication system as described above, and the method may include the following steps:

[0067] Step 210: The indoor communication subsystem acquires an optical signal carrying transmission data.

[0068] Step 230: restore the optical signal to the original transmission signal and transmit it to the outdoor communication subsystem using the terahertz transmission channel.

[0069] Step 250, the outdoor communication subsystem receives the original transmission signal output by the indoor communication subsystem, and allocates a first channel capacity and a second channel capacity to the original transmission signal, so that the original transmission signal is transmitted to the ground satellite receiving facility based on the first channel capacity and the second channel capacity.

[0070] Compared with related technologies, the channel capacity of the original transmitted signal is calculated, so that different channel capacities are allocated to the original transmitted signal to adapt to the communication methods in different scenarios. For example, in indoor scenarios, such as subways, tunnels, navigation, cabins and mines, where wireless communication is poor, visible light communication channels are used for communication to fill the blind spots of wireless communication coverage; in outdoor scenarios, such as ground-to-ground satellite base stations, communication is carried out through terahertz channels, which provides greater capacity for wireless channels while greatly improving the transmission rate.

[0071] In addition, the communication system realized by combining visible light communication and terahertz also has the following beneficial effects:

[0072] (1) The advantages of using terahertz technology are greater bandwidth and faster transmission rates. At the same time, the size of the antenna will be reduced, which is not only beneficial to micro-satellite systems, but also indoor wireless communications using terahertz can provide multiple data channels per terahertz or greater capacity.

[0073] (2) The advantages of terahertz waves are wide available bandwidth, concentrated beams, improved energy efficiency, good directionality, and less impact from interference. The attenuation rates of radio waves in different frequency bands vary in different environments and weather conditions.

[0074] (3) High rate: Visible light communication technology can provide high-speed data communication services and can provide a solution for future high-speed wireless communication systems, for example, realizing the 6G system's Internet of Vehicles and indoor coverage of smart homes.

[0075] (4) Abundant spectrum resources: Since the electromagnetic waves used in current wireless communications only account for a small part of the electromagnetic wave spectrum, most of the spectrum resources have not been developed and utilized. Visible light communication technology can provide a large amount of potential available spectrum (terahertz-level bandwidth), and the spectrum use is not restricted.

[0076] (5) No electromagnetic radiation problem: As we all know, Wi-Fi technology uses radio frequency signals, which are radio electromagnetic waves. The greater the power of the device, the higher the radiation, and there will also be problems such as electromagnetic interference. Visible light uses light wave signals, which will not cause electromagnetic interference and electromagnetic radiation problems. Since visible light communication does not generate electromagnetic radiation and is not easily affected by external electromagnetic interference, it can be widely used in special occasions that are sensitive to electromagnetic interference or even must eliminate electromagnetic interference, such as hospitals, aircraft, gas stations, chemical plants, etc.

[0077] (6) High density and low cost: At present, LED lights have been widely used due to their advantages such as safety, energy saving and long life. When using visible light communication, there is no need to deploy lights, which saves costs. At the same time, indoor visible light communication technology can use its indoor lighting source as a base station, combined with other wireless and wired communication technologies, to provide users with convenient indoor wireless communication services.

[0078] (7) High confidentiality: Since the frequency of visible light communication is higher than that of terahertz, it is easily interfered with and absorbed by the external environment. It is more suitable for indoor and close-range communication. As long as the light is blocked, there will be no information leakage, so it has high confidentiality. The network built by visible light communication technology is more secure. The transmission medium used by this technology is visible light, which cannot penetrate obstructions such as walls. The transmission is limited to the user's line of sight, which means that the transmission of network information is limited to a building, effectively preventing the transmission information from being intercepted by external malicious parties, and ensuring the security of the information.

[0079] It should be understood that, although the steps in the flowchart of the accompanying drawings are displayed in sequence as indicated by the arrows, these steps are not necessarily executed in sequence in the order indicated by the arrows. Unless otherwise specified herein, there is no strict order restriction on the execution of these steps, and they can be executed in other orders. Moreover, at least a part of the steps in the flowchart of the accompanying drawings may include multiple sub-steps or multiple stages, and these sub-steps or stages are not necessarily executed at the same time, but can be executed at different times, and their execution order is not necessarily sequential, but can be executed in turn or alternately with other steps or at least a part of the sub-steps or stages of other steps.

[0080] The above descriptions are only some embodiments of the present invention. It should be pointed out that, for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A communication system, characterized in that: The communication system includes an indoor communication subsystem, an outdoor communication subsystem, and a terahertz transmission channel connected between the indoor communication subsystem and the outdoor communication subsystem; wherein, The indoor communication subsystem is used to obtain an optical signal carrying transmission data, and restore the optical signal to an original transmission signal, and transmit it to the outdoor communication subsystem using the terahertz transmission channel; The outdoor communication subsystem is used to receive the original transmission signal output by the indoor communication subsystem, and allocate a first channel capacity and a second channel capacity to the original transmission signal, so that the original transmission signal is transmitted to a ground satellite receiving facility based on the first channel capacity and the second channel capacity, wherein the first channel refers to a terahertz channel; the second channel refers to a visible light communication channel.

2. The system according to claim 1, characterized in that The indoor communication subsystem includes: a transmitting end and a receiving end; wherein, The transmitting end is used to receive the original transmission signal sent by the terminal and convert the original transmission optical signal into the optical signal carrying the transmission data; The receiving end is used to convert the optical signal into an electrical signal and perform signal preprocessing on the electrical signal to obtain the original transmission signal.

3. The system according to claim 2, characterized in that The transmitting end includes an LED signal source, and the LED signal source is used to convert the original transmission optical signal into the optical signal carrying transmission data, and transmit the optical signal to the receiving end.

4. The system according to claim 3, characterized in that The LED signal source includes one or more of an ultraviolet LED, a phosphor LED, and a tricolor LED.

5. The system according to claim 2, characterized in that The receiving end includes: a concentrator, a photoelectric detector, and a signal processor; wherein, The concentrator is used to receive the optical signal transmitted by the transmitting end, and send the optical signal to the photoelectric detector in a centralized manner; The photoelectric detector is used to collect the optical signal and perform photoelectric conversion on the optical signal to obtain the electrical signal; The signal processor is used to perform at least one signal preprocessing of equalization, demodulation and decoding on the electrical signal to obtain the original transmission signal.

6. The system according to claim 1, wherein: The outdoor communication subsystem includes a channel capacity calculation module and a channel capacity allocation module; wherein, The channel capacity calculation module is used to calculate the total channel capacity required for the original transmission signal; The channel capacity allocation module is used to perform allocation prediction on the total channel capacity according to the Markov algorithm to obtain the first channel capacity and the second channel capacity.

7. The system according to claim 6, characterized in that The channel capacity calculation module includes at least one of the following calculation units: Channel gain calculation unit, condenser gain calculation unit, spectrum efficiency calculation unit, signal-to-noise ratio calculation unit.

8. The system according to claim 6, characterized in that The first channel refers to the terahertz transmission channel.

9. The system according to claim 6, characterized in that The second channel refers to the visible light communication VLC channel.

10. A communication system link optimization method, applied to the communication system according to any one of claims 1 to 9, wherein the communication system comprises an indoor communication subsystem, an outdoor communication subsystem, and a terahertz transmission channel connected between the indoor communication subsystem and the outdoor communication subsystem; The method comprises: The indoor communication subsystem acquires an optical signal carrying transmission data; Restoring the optical signal to an original transmission signal, and transmitting the signal to the outdoor communication subsystem by using the terahertz transmission channel; The outdoor communication subsystem receives the original transmission signal output by the indoor communication subsystem and allocates a first channel capacity and a second channel capacity to the original transmission signal, so that the original transmission signal is transmitted to a ground satellite receiving facility based on the first channel capacity and the second channel capacity.

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