Indoor location recognition system and its control method

Abstract

This invention provides an indoor location recognition system and a control method thereof. [Solution] The indoor location recognition system may include a camera, a location recognition sensor, a first communication module, a memory for storing at least one instruction, and at least one processor. The at least one processor, by performing at least one instruction, recognizes the location of a vehicle traveling on the road based on the location detection signal of the location recognition sensor and generates location information, recognizes the vehicle license plate information and location of the vehicle traveling on the road based on the input video captured by the camera, encodes the location information using a code-division multiple access (CDMA) scheme with a spreading code generated from the vehicle license plate information, and outputs the encoded location information as a wireless signal through the first communication module.

Description

Technical Field

[0001] The present invention relates to an indoor position recognition system and a control method thereof.

Background Art

[0002] To recognize the position of an object, GNSS (Global Navigation Satellite System) that recognizes the position using satellite signals is widely used. GNSS is a technology for calculating the position information of a receiver based on information received from satellites. GNSS includes, for example, GPS (Global Positioning System) of the United States, GLONASS of Russia, Galileo system (Galileo) of the EU (European Union), Beidou of China, Quasi-Zenith Satellite System (QZSS) of Japan, and IRNSS (Indian Regional Navigation Satellite System) of India.

[0003] Since GNSS uses information received from satellites, there is a limit in grasping the position of a receiver in a GNSS shadowing area where there is an obstacle to line-of-sight (LOS) communication with satellites, such as in underground facilities. Thus, when trying to provide position information using GNSS indoors, it is difficult to provide accurate position information. For example, in systems that involve providing position information inside buildings, underground areas, tunnels, etc., such as bus arrival time notification services and navigation systems inside underground facilities, due to the limitations of GNSS, there is a problem that the quality of useful public services for citizens deteriorates. When a bus is located in an underground transfer center or a long tunnel, GNSS reception becomes impossible, and it is impossible to track the position of the bus, resulting in a problem of a decrease in the accuracy of the position information and the scheduled arrival time of the bus provided by the arrival schedule service.

Summary of the Invention

Problems to be Solved by the Invention

[0004] The problem that this invention aims to solve is to provide an indoor location recognition system and a control method thereof. [Means for solving the problem]

[0005] According to one aspect of one embodiment of the present invention, an indoor location recognition system is provided. The indoor location recognition system may include a camera, a location recognition sensor, a first communication module, a memory for storing at least one instruction, and at least one processor. The at least one processor can recognize the location of a vehicle traveling on a road based on the location detection signal of the location recognition sensor and generate location information by performing the at least one instruction. The at least one processor can also recognize the license plate information and location of the vehicle traveling on the road based on the input video captured by the camera. The at least one processor can encode the location information using a code-division multiplexing (CDMA) scheme with a spreading code generated from the license plate information. The at least one processor can also output the encoded location information as a wireless signal through the first communication module.

[0006] Furthermore, according to one embodiment of the present invention, the indoor location recognition system may include a plurality of detection devices arranged at different locations in an indoor space, a server that communicates with the plurality of detection devices, and a wireless output device located in the indoor space that communicates with the server. Each of the plurality of detection devices may include the camera, the location recognition sensor, and a second communication module that communicates with the server. The server may include the memory and the at least one processor, and may include a third communication module that communicates with the plurality of detection devices and the wireless output device. The wireless output device may include the first communication module that communicates with the server and outputs the wireless signal.

[0007] Furthermore, according to one embodiment of the present invention, the plurality of detection devices can generate the position information based on the position detection signal, generate the vehicle number plate information based on the input video, and transmit the position information and the vehicle number plate information to the server through the second communication module.

[0008] Furthermore, according to one embodiment of the present invention, the server can receive the vehicle license plate information and the location information from the plurality of detection devices through the third communication module, encode the location information in CDMA using the spreading code generated from the vehicle license plate information, and transmit the encoded signal to the wireless output device.

[0009] Furthermore, according to one embodiment of the present invention, the wireless output device can broadcast the wireless signal through the first communication module.

[0010] Furthermore, according to one embodiment of the present invention, the position recognition sensor includes a radar (RADAR: radio detection and ranging) sensor or a lidar (LIDAR: light detection and ranging) sensor, and the at least one processor can generate speed information of the vehicle whose position has been recognized based on the position detection signal by performing the at least one instruction, and output the speed information as the wireless signal.

[0011] Furthermore, according to one embodiment of the present invention, the at least one processor can match the location information generated from the location detection signal with the vehicle license plate information based on the location information generated from the location detection signal and the location of the vehicle recognized by the input video, and can CDMA encode the location information using the spreading code generated from the matched vehicle license plate information.

[0012] Furthermore, according to one embodiment of the present invention, the at least one processor can generate a CDMA-encoded encoded signal for each of the location information of a plurality of vehicles by performing the at least one instruction, sum the encoded signals for each of the location information of the plurality of vehicles to generate a composite signal, and output the composite signal as the wireless signal.

[0013] Furthermore, according to one embodiment of the present invention, the synthesized signal can be received by a client device located inside the vehicle and decoded using a despreading code generated from vehicle identification number information stored in the client device.

[0014] Furthermore, according to one embodiment of the present invention, the at least one processor can hash the vehicle identification number information by performing the at least one instruction, convert the hashed vehicle identification number information into mutually orthogonal (orthogonal) orthogonal codes, and encode the location information in CDMA using the orthogonal codes as the spreading code.

[0015] Furthermore, according to one embodiment of the present invention, the operation of outputting the encoded location information as a wireless signal involves converting the encoded location information into a plurality of data chunks, generating a bit sequence for each frame from the plurality of data chunks, converting the bit sequence for each frame into a QPSK (Quadrature Phase Shift Keying) symbol, upsampling the QPSK symbol using an RC (Raised cosine transmit filter) transmission filter, and outputting the upsampled QPSK symbol as the wireless signal through an AWGN (Additive White Gaussian Noise) channel.

[0016] According to one aspect of one embodiment of the present invention, a method for controlling an indoor location recognition system is provided. The method for controlling an indoor location recognition system may include the steps of: recognizing the location of a vehicle traveling on a road based on a location detection signal from a location recognition sensor and generating location information; recognizing the vehicle license plate information and location of the vehicle traveling on the road based on input video captured by a camera; encoding the location information using a code-division multiple access (CDMA) scheme with a spreading code generated from the vehicle license plate information; and outputting the encoded location information as a wireless signal. [Brief explanation of the drawing]

[0017] The present invention will be readily understood by the following detailed description and accompanying drawings, where reference numerals refer to structural elements. [Figure 1] This is a diagram showing the structure of an indoor location recognition system according to one embodiment of the present invention. [Figure 2] This is a block diagram showing the structure of an indoor location recognition system according to one embodiment of the present invention. [Figure 3] This flowchart shows a method for controlling an indoor location recognition system according to one embodiment of the present invention. [Figure 4] This is a diagram showing the structure of an indoor location recognition system according to one embodiment of the present invention. [Figure 5] This diagram shows the process of encoding and decoding location information using one embodiment of the present invention. [Figure 6] This flowchart shows a method for controlling an indoor location recognition system according to one embodiment of the present invention. [Figure 7] This diagram illustrates the process of generating and transmitting wireless signals using one embodiment of the present invention. [Figure 8]A drawing showing the process of receiving and decoding a wireless signal in a client device according to an embodiment of the present invention. [Figure 9] A drawing showing the process of outputting a wireless signal from a plurality of wireless output devices according to an embodiment of the present invention. [Figure 10] A drawing showing the data structure of a wireless signal according to an embodiment of the present invention.

Mode for Carrying Out the Invention

[0018] This specification clarifies the scope of the claims of the present invention, and explains the principles of the embodiments of the present invention and discloses the embodiments so that those having ordinary knowledge in the technical field to which the embodiments of the present invention belong can implement the embodiments of the present invention. The disclosed embodiments can be embodied in various forms.

[0019] The various embodiments of this specification and the terms used therein are not intended to limit the technical features described in this specification to specific embodiments, but should be understood to include various modifications, equivalents, or alternatives of the embodiments.

[0020] In connection with the description of the drawings, similar or related components may be denoted by the same reference numerals.

[0021] The singular form of a noun corresponding to an item may include one or more of the items, unless clearly indicated otherwise in the relevant context.

[0022] Terms such as "first", "second", or "primary" or "secondary" are merely used to distinguish the component from other components of the same kind, and do not limit the component in other aspects (e.g., importance or order).

[0023] When one component (e.g., the first) is referred to as "combined" or "connected" to another component (e.g., the second) with or without the terms "functionally" or "communically," it means that the first component is connected to the other component directly (e.g., by wire), wirelessly, or through the third component.

[0024] Terms such as “includes” or “has” indicate the presence of features, numbers, steps, operations, components, parts, or combinations thereof described herein, and do not preclude the presence or possibility of adding one or more other features, numbers, steps, operations, components, parts, or combinations thereof.

[0025] When one component is said to be “connected,” “joined,” “supported,” or “in contact” with another component, this includes not only cases where the components are directly connected, joined, supported, or in contact, but also cases where they are indirectly connected, joined, supported, or in contact through a third component.

[0026] Throughout this specification, the same reference numerals refer to the same components. This specification does not describe all elements of the embodiments, and general content in the art to which the embodiments of the present invention belong or overlapping content between embodiments is omitted. The term “part” or “portion” as used in this specification is embodied by software or hardware, and in an embodiment, multiple “parts” may be embodied by a single “unit” or a single “part” may contain multiple elements. Hereinafter, embodiments of the present invention and the principles of operation of the embodiments will be described with reference to the accompanying drawings.

[0027] Figure 1 is a diagram showing the structure of an indoor location recognition system according to one embodiment of the present invention.

[0028] According to one embodiment of the present invention, the indoor location recognition system 100 can recognize the location of a vehicle 150 that is traveling on a road in an indoor space and output location information of the vehicle 150.

[0029] Indoor spaces can correspond to GNSS shadowing areas where satellite signals are not transmitted due to obstacles such as concrete and rebar. Indoor spaces can correspond to, for example, tunnels, underground parking lots, building interiors, and underground spaces. This invention will mainly describe an embodiment in which the indoor space corresponds to a tunnel. However, the embodiments of this invention are not limited to cases in which the indoor space corresponds to a tunnel, and the indoor position recognition system 100 according to the embodiments of this invention can be applied to a variety of indoor spaces, such as underground parking lots.

[0030] The indoor location recognition system 100 may include at least one detection device 110a, 110b, a server 120, and a wireless output device 130. The at least one detection device 110a, 110b may include cameras 112a, 112b and location detection sensors 114a, 114b. In this invention, the at least one detection device 110a, 110b is collectively referred to as identification number 110, the cameras 112a, 112b are collectively referred to as identification number 112, and the location detection sensors 114a, 114b are collectively referred to as identification number 114.

[0031] At least one detection device 110 may be placed at multiple locations within the tunnel. Detection devices 100 may be placed, for example, at 1 km intervals along the tunnel road. Each of the multiple detection devices 110 can communicate with the server 120. The detection devices 110 can communicate with the server 120 by wire or wireless connection.

[0032] The detection device 110 may include a camera 112 and a position detection sensor 114. The camera 112 captures images of a vehicle 150 traveling on a road and generates input video. The detection device 110 can acquire the vehicle number plate information of the vehicle 150 using the input video. The detection device 110 can also detect the location information of the vehicle 150 using the position detection signal from the position detection sensor 114. The detection device 110 can transmit the vehicle number plate information and location information to the server 120.

[0033] Server 120 can encode vehicle identification number information and location information received from at least one detection device 110. In step 122, Server 120 can encode location information using the vehicle identification number information in the CDMA (Code-Division Multiple Access) method. Server 120 can also synthesize the encoded location information of each vehicle 150 to generate a combined signal. Server 120 can transmit the combined signal to the wireless output device 130.

[0034] The wireless output device 130 can be placed at multiple locations within the tunnel. The wireless output device 130 can receive a composite signal received from the server 120 and output it as a wireless signal. The wireless output device 130 can broadcast the wireless signal via Wi-Fi communication.

[0035] The client device 140 may be compatible with electronic devices built into the vehicle 150 or electronic devices used by passengers inside the vehicle 150 (e.g., mobile phones, wearable devices, tablet PCs, laptop PCs, etc.). The client device 140 receives radio signals output from the radio output device 130. The client device 140 pre-installs a program or application to decode location information encoded by the server 120. The client device 140 can pre-store the vehicle number plate information of the vehicle 150. In step 142, the client device 140 can decode the information contained in the radio signal received from the radio output device 130 using the vehicle number plate information of the vehicle 150 and obtain location information.

[0036] According to one embodiment of the present invention, the server 120 encodes the location information of the vehicle 150 using the vehicle identification number information, and the client device 140 decodes the location information contained in the wireless signal using the vehicle identification number information, thereby providing accurate location information for each vehicle 150 in a GNSS shadowing area.

[0037] Figure 2 is a block diagram showing the structure of an indoor location recognition system according to one embodiment of the present invention.

[0038] According to one embodiment of the present invention, the indoor location recognition system 100 may include a camera 112, a location detection sensor 114, a processor 210, a memory 212, and a first communication module 214.

[0039] In Figure 1, an embodiment of the indoor location recognition system 100 including a detection device 110, a server 120, and a wireless output device 130 was described, but the indoor location recognition system 100 can have a variety of system configurations. For example, the detection device 110 and the server 120 can be realized as a single device. As another example, the server 120 and the wireless output device 130 can be realized as a single device. As yet another example, the detection device 110, the server 120, and the wireless output device 130 can be realized as a single device.

[0040] Camera 112 photographs the license plate of vehicle 150 as it travels on the road inside the tunnel. Camera 112 may be positioned to photograph the license plate from the front or rear of vehicle 150. Camera 112 may include a lens and an image sensor. Camera 112 can capture images at a predetermined frame rate to generate input video. The input video may be a still image or a video.

[0041] The position detection sensor 114 is positioned to detect vehicles traveling on a road. The position detection sensor 114 may include, for example, one of the following: a radar (RADAR: radio detection and ranging) sensor or a LiDAR (LIDAR: light detection and ranging) sensor.

[0042] A radar sensor generates electromagnetic waves, outputs them towards an object, and detects the distance and direction of the object through the returning electromagnetic waves. A radar sensor is a type of Time of Flight (ToF) sensor. Radar sensors can detect objects over long distances (approximately 2 km).

[0043] The processor 210 controls the overall operation of the indoor position recognition system 100. The processor 210 may be comprised of one or more processors. The processor 210 executes instructions or commands stored in memory 212 to perform predetermined operations. The processor 210 also controls the operation of components provided in the indoor position recognition system 100. The processor 210 may include a CPU (Central Processing Unit), a microprocessor, a GPU (Graphics Processing Unit), or an NPU (Neural Processing Unit).

[0044] Memory 212 stores various information, data, commands, programs, etc., necessary for the operation of the indoor position recognition system 100.

[0045] Memory 212 may include at least one of volatile memory or non-volatile memory, or a combination thereof.

[0046] Memory 212 may include at least one type of recording medium from among flash memory type, hard disk type, Multimedia card micro type, card type memory (e.g., SD or XD memory), RAM (Random Access Memory), SRAM (Static Random Access Memory), ROM (Read Only Memory), EEPROM (Electrically Erasable Programmable Read-Only Memory), PROM (Programmable Read-Only Memory), magnetic memory, magnetic disk, or optical disk. Memory 212 may also support web storage or cloud servers that perform storage functions over the internet.

[0047] The first communication module 214 can communicate with at least one external device by wire or wireless connection. The first communication module 214 may include a wireless communication module (e.g., a cellular communication module, a short-range wireless communication module, or a GNSS (global navigation satellite system) communication module) or a wired communication module (e.g., a LAN (local area network) communication module, or a power line communication module).

[0048] Furthermore, the first communication module 214 can perform short-range communication and utilize technologies such as Bluetooth®, BLE (Bluetooth Low Energy), Near Field Communication, WLAN (Wi-Fi), Zigbee, infrared (IrDA: infrared Data Association) communication, WFD (Wi-Fi Direct), UWB (ultra wide band), and Ant+ communication.

[0049] Furthermore, for example, the first communication module 214 can perform long-distance communication and communicate with external devices via, for example, a legacy cellular network, a 4G network, a 5G network, a next-generation communication network, the Internet, or a computer network (e.g., LAN or WAN).

[0050] Furthermore, for example, the first communication module 214 can use mobile communication to send and receive wireless signals with at least one of a base station, an external terminal, or a server on a mobile communication network.

[0051] The first communication module 214 can utilize USRP (Universal Software Radio Peripheral).

[0052] Furthermore, the first communication module 214 can be compatible with Wi-Fi communication AP (Access Point) devices.

[0053] The processor 210 recognizes the vehicle number plate information of vehicle 150 from the input video captured by camera 112. The processor 210 can utilize the ANPR (Automatic Number Plate Recognition) algorithm. The processor 210 can recognize vehicle 150 from the input video and perform object tracking on vehicle 150. In addition, the processor 210 can recognize the position of vehicle 150 from the input video.

[0054] Furthermore, the processor 210 can recognize the position of the vehicle 150 traveling on the road based on the position detection signal from the position detection sensor 114 and generate position information. The position information can be defined as coordinate information in a predetermined coordinate system. For example, the coordinate information can be defined as x, y, and z coordinates.

[0055] The processor 210 can match the location information generated from the location detection signal with the vehicle license plate information recognized from the input video, based on the location information generated from the location detection signal and the location information recognized from the input video. In addition, the processor 210 can track the location information corresponding to the vehicle license plate information while tracking the vehicle 150 recognized by the location detection sensor 114.

[0056] The processor 210 can encode location information using the CDMA method. In this process, the processor 210 generates a spreading code from the vehicle license plate information and performs CDMA encoding using the spreading code. CDMA encoding involves multiplying the data by the spreading code during the encoding process to spread bandwidth. The spreading code can correspond to an orthogonal code. The processor 210 can generate an orthogonal code from the vehicle license plate information and use the generated orthogonal code as the spreading code to encode location information using the CDMA method. In this process, the processor 210 can hash the vehicle license plate information using a hash function, convert it to an orthogonal code, and then use the vehicle license plate information converted to an orthogonal code as the spreading code. The processor 210 can generate an encoded signal obtained by CDMA encoding the location information. Furthermore, the processor can generate a composite signal by summing up multiple encoded signals.

[0057] The processor 210 can output a composite signal generated from multiple encoded signals as a wireless signal through the first communication module 214.

[0058] The first communication module 214 can broadcast wireless signals. The first communication module 214 can broadcast wireless signals without establishing a communication channel with a specific client device 140. The first communication module 214 can broadcast wireless signals using Wi-Fi communication. Client devices 140 in the vicinity of the first communication module 214 can receive wireless signals broadcast from the first communication module 214. Client devices 140 can receive broadcast wireless signals even if they have not previously formed a channel with the indoor location recognition system 100. Client devices 140 can receive wireless signals, decode the data contained in the wireless signals, and obtain location information. Client devices 140 can be pre-inputted with license plate information and generate a despreading code from the license plate information. Client devices 140 can decode the received composite signal using the generated despreading code and obtain location information.

[0059] Figure 3 is a flowchart showing a control method for an indoor location recognition system according to one embodiment of the present invention.

[0060] The control method for an indoor location recognition system according to one embodiment of the present invention is performed by the indoor location recognition system 100 according to one embodiment of the present invention. However, the control method for an indoor location recognition system according to one embodiment of the present invention is not limited to the embodiment performed by the indoor location recognition system 100 according to one embodiment of the present invention, but can be performed by a variety of systems including a camera, a lidar sensor, a processor, and a communication module.

[0061] Referring to Figure 3, in S302, the indoor position recognition system 100 generates position information of the vehicle 150 using the position detection signal from the position detection sensor 114. The indoor position recognition system 100 can recognize the vehicle 150 using the position detection signal and generate position information of the vehicle 150. According to one embodiment of the present invention, the indoor position recognition system 100 can generate speed information of the vehicle 150 using the position information of the vehicle 150 over time.

[0062] In S304, the indoor position recognition system 100 recognizes vehicle license plate information from the input video captured by the camera 112. The indoor position recognition system 100 can recognize vehicle license plate information from the input video using algorithms such as license plate recognition or character recognition. The indoor position recognition system 100 also recognizes the position from the input video. The position recognized from the input video is an approximate position of the vehicle 150 and is less accurate than the position information detected from the position detection signal.

[0063] Next, in S306, the indoor location recognition system 100 can encode the location information using the CDMA method with the spreading code generated from the vehicle license plate information. The indoor location recognition system 100 can process the vehicle license plate information with a hash function and convert it into an orthogonal code. The indoor location recognition system 100 can define the vehicle license plate information converted into an orthogonal code as a spreading code.

[0064] The indoor position recognition system 100 can match position information with vehicle license plate information using position information generated from the position recognized from the input video and the position detection signal.

[0065] Next, in S308, the indoor location recognition system 100 outputs the encoded location information as a wireless signal. The indoor location recognition system 100 can generate a composite signal by summing up multiple encoded signals, each generated by CDMA encoding the location information of multiple vehicles. The indoor location recognition system 100 can convert the composite signal into a wireless signal and broadcast the wireless signal for output.

[0066] Figure 4 is a diagram showing the structure of an indoor location recognition system according to one embodiment of the present invention.

[0067] According to one embodiment of the present invention, the indoor location recognition system 100 may include detection devices 110, 110a, 110b, a server 120, and wireless output devices 130, 130a, 130b. The indoor location recognition system 100 may include a plurality of detection devices 110, 110a, 110b. In this invention, the plurality of detection devices 110, 110a, 110b are collectively referred to as 110. Furthermore, the indoor location recognition system 100 may include a plurality of wireless output devices 130, 130a, 130b. In this invention, the plurality of wireless output devices 130, 130a, 130b are collectively referred to as 130.

[0068] Multiple detection devices 110 may be arranged at predetermined intervals in different locations within the tunnel. For example, multiple detection devices 110 may be arranged on the ceiling of the tunnel at intervals of approximately 1 km to 2 km. The detection device 110 may include a camera 112, a position detection sensor 114, a second processor 410, and a second communication module 412.

[0069] The second processor 410 of the detection device 110 can recognize the vehicle 150 from the input video generated by the camera 112 and recognize the vehicle license plate information. The second processor 410 can also recognize the position of the vehicle 150 from the input video.

[0070] Furthermore, the second processor 410 can recognize the vehicle 150 using the position detection signal generated by the position detection sensor 114 and identify the position information of the vehicle 150. The second processor 410 can define the coordinate information of the vehicle 150 in a predetermined coordinate system and generate position information. For example, the coordinate information of the vehicle 150 may be defined by x, y, and z coordinates. In addition, the second processor 410 can generate speed information of the vehicle 150 using the position information over time.

[0071] The second processor 410 can match the vehicle number plate information with the location information generated from the location detection signal. The second processor 410 can transmit the vehicle number plate information and location information to the server 120 via the second communication module 412. The second communication module 412 can transmit the vehicle number plate information and location information to the server 120 via wired or wireless connection. The second processor 410 can transmit the vehicle number plate information and location information together with the detection time information. Furthermore, according to one embodiment of the present invention, the detection device 110 can transmit the input video to the server 120.

[0072] The server 120 can receive vehicle identification number information, location information, and detection time information from the detection device 110 via the third communication module 422. Furthermore, according to one embodiment of the present invention, the server 120 can receive speed information from the detection device 110. The first processor 420 of the server 120 can encode the location information of each vehicle 150 using the vehicle identification number information in a CDMA manner. The first processor 420 can generate a spreading code using the vehicle identification number information and encode the location information using the generated spreading code. The first processor 420 can generate an encoded signal by CDMA encoding the location information.

[0073] The first processor 420 synthesizes multiple encoded signals to generate a combined signal. For example, the first processor 420 can generate a combined signal by summing four encoded signals. The first processor 420 can transmit the combined signal to the wireless output device 130.

[0074] Multiple wireless output devices 130 can be positioned at different locations within the tunnel. Each wireless output device 130 includes a first communication module 214. The wireless output device 130 wirelessly outputs a composite signal through the first communication module 214. The first communication module 214 can broadcast the composite signal via Wi-Fi communication. The server 120 can periodically encode location information, generate a composite signal, and output it to the wireless output device 130. Upon receiving the composite signal, the wireless output device can convert it into a wireless signal and output it.

[0075] The client device 140 can receive wireless signals output from the wireless output device 130.

[0076] The client device 140 may include a third processor 430, a memory 432, and a fourth communication module 434.

[0077] Memory 432 can store vehicle identification number information corresponding to the client device 140.

[0078] The third processor 430 executes a predetermined program or application stored in the memory 432. The third processor 430 can execute the program or application and decode the received radio signal using the vehicle identification number information.

[0079] The third processor 430 can generate a spreading code from the vehicle identification number information. The third processor 430 can process the vehicle identification number information with a hash function, convert the value processed by the hash function into an orthogonal code, and generate a spreading code. The third processor 430 can decode the radio signal with a CDMA decoder using the spreading code. In this case, if the location information contained in the radio signal corresponds to the vehicle identification number information stored in the client device 140, the radio signal can be decoded as a valid value. If the location information contained in the radio signal does not correspond to the vehicle identification number information stored in the client device 140, the location information cannot be decoded as a valid value. Therefore, the client device 140 can obtain its own location information by obtaining the location information decoded as a valid value using the stored vehicle identification number information.

[0080] Multiple client devices 140, 140a, and 140b can store different vehicle identification number information from each other. Therefore, the multiple client devices 140, 140a, and 140b can decode the location information corresponding to the vehicle identification number information stored in the device as a value valid only for the radio signal containing location information, and obtain the location information.

[0081] Figure 5 is a diagram illustrating the process of encoding and decoding location information according to one embodiment of the present invention.

[0082] According to one embodiment of the present invention, the server 120 can encode location information in the CDMA manner using the CDMA encoder 510 and generate an encoded signal. The CDMA encoder 510 may be performed by the first processor 420.

[0083] The CDMA encoder 510 receives vehicle license plate information and location information. The vehicle license plate information is hashed using the hash function 512. The hashed vehicle license plate information can also be converted into an orthogonal code. The orthogonal code can be defined as a spreading code.

[0084] The CDMA encoder 510 can synthesize the spreading code generated using the vehicle identification number information and the location information using the synthesizer 514 to generate encoded signals 516a, 516b, 516c, and 516d.

[0085] The synthesizer 514 can encode location information by using orthogonal codes as spreading codes according to the CDMA standard.

[0086] The CDMA encoder 510 can generate encoded signals 516a, 516b, 516c, and 516d using mutually matched location information and vehicle identification number information. For example, the CDMA encoder 510 can CDMA encode the location information of the first vehicle 150a using a spreading code generated from the vehicle identification number information of the first vehicle 150a to generate a first encoded signal 516a. The CDMA encoder 510 can also CDMA encode the location information of the second vehicle 150b using a spreading code generated from the vehicle identification number information of the second vehicle 150b to generate a second encoded signal 516b. Furthermore, the CDMA encoder 510 can CDMA encode the location information of the third vehicle 150c using a spreading code generated from the vehicle identification number information of the third vehicle 150c to generate a third encoded signal 516c. Furthermore, the CDMA encoder 510 can CDMA encode the position information of the fourth vehicle 150d using a spreading code generated from the vehicle number plate information of the fourth vehicle 150d, and generate the fourth encoded signal 516d.

[0087] Location information for each vehicle 150 can be continuously generated over time. This location information can be generated periodically and encoded by the CDMA encoder 510. For example, location information can be generated at a 1-second interval, and the CDMA encoder 510 can generate encoded signals 516a, 516b, 516c, and 516d for the location information at a 1-second interval.

[0088] The CDMA encoder 510 combines the encoded signals 516a, 516b, 516c, and 516d using the combiner 518 to generate a combined signal 522. The combiner 518 can combine a predetermined number of encoded signals 516a, 516b, 516c, and 516d. For example, the combiner 518 can combine four encoded signals 516a, 516b, 516c, and 516d to generate a combined signal 522. The server 120 can output the combined signal in step 520 through the third communication module 422.

[0089] According to one embodiment of the present invention, the server 120 can generate a composite signal corresponding to QPSK (Quadrature Phase Shift Keying) symbols. QPSK symbols are a method of combining and transmitting four types of digital symbols by changing their phase by 90° increments. The server 120 can convert the composite signal into QPSK symbols and then into a wireless signal.

[0090] Server 120 can output wireless signals through wireless output device 130. Wireless output device 130 can broadcast wireless signals through a Wi-Fi network.

[0091] The client device 140 can receive the broadcasted Wi-Fi signal. In step 530, the client device 140 can receive the combined signal 532.

[0092] The client device 140 may include a CDMA decoder 540. The CDMA decoder 540 may be operated by a third processor 430 of the client device 140.

[0093] In step 542, the client device 140 can decode the encoded signal obtained from the radio signal using the CDMA decoder 540 with a despreading code. The client device 140 can generate a despreading code using the vehicle identification number information stored in the device. The client device 140 can hash the stored vehicle identification number information with a hash function, convert it into an orthogonal code, and define the orthogonal code as the despreading code.

[0094] The CDMA decoder 540 can decode an encoded signal obtained from a radio signal received using a despreading code and generate a plurality of decoded signals 544a, 544b, 544c, and 544d. The decoded signals 544a, 544b, 544c, and 544d may have valid values ​​if they include location information corresponding to the vehicle identification number information stored in the client device 140. If the location information of the decoded signals 544a, 544b, 544c, and 544d does not correspond to the vehicle identification number information stored in the client device 140, the decoded signals 544a, 544b, 544c, and 544d may have invalid values.

[0095] Let us explain using the video 550 shown in Figure 5, which captures a vehicle traveling inside a tunnel, as an example. Assume that the first encoded signal 516a corresponds to the first vehicle 150a, among the first encoded signal 516a, second encoded signal 516b, third encoded signal 516c, and fourth encoded signal 516d included in the composite signal 532. If the CDMA decoder 540 included in the first vehicle 150a decodes the composite signal 532 using a despreading code generated from the vehicle number plate information of the first vehicle 150a, the first decoded signal 544a obtained by decoding the first encoded signal 516a may have a valid value. Furthermore, if the CDMA decoder 540 included in the first vehicle 150a decodes the composite signal 532 using a despreading code generated from the vehicle number plate information of the first vehicle 150a, the second decoded signal 544b, the third decoded signal 544c, and the fourth decoded signal 544d obtained by decoding the second coded signal 516b, the third coded signal 516c, and the fourth coded signal 516d, respectively, may have invalid values.

[0096] Figure 6 is a flowchart showing a control method for an indoor location recognition system according to one embodiment of the present invention.

[0097] Figure 6 illustrates the operation of the detection device 110, server 120, wireless output device 130, and client device 140 of the indoor location recognition system 100 using a flowchart.

[0098] In S602, the detection device 110 generates position information using the position detection signal generated by the position detection sensor 114. Based on the position detection signal, the detection device 110 can generate position information for each vehicle 150 while performing object tracking for each vehicle 150.

[0099] Furthermore, in S604, the detection device 110 can recognize the vehicle 150 from the input video captured by the camera 110 and recognize the vehicle number plate information of the vehicle 150. The detection device 110 can generate the vehicle number plate information using the ANRP algorithm. In addition, the detection device 110 can recognize the position of the vehicle 150 from the input video.

[0100] The detection device 110 matches the location information generated from the location detection signal with the vehicle number plate information. In S606, the detection device 110 can transmit the location information and vehicle number plate information of the vehicle 150 to the server 120.

[0101] In S608, Server 120 generates a spreading code using the vehicle identification number information. Server 120 generates an orthogonal code from the vehicle identification number information. Server 120 can use the generated orthogonal code as a spreading code for CDMA encoding.

[0102] In S610, server 120 encodes location information using a CDMA encoder with a spreading code generated from the vehicle license plate information. Server 120 can generate a CDMA-encoded encoded signal.

[0103] Next, in S612, the server 120 can synthesize multiple encoded signals to generate a combined signal. The multiple encoded signals may correspond to the location information of different vehicles 150. According to one embodiment of the present invention, the server 120 can QPSK modulate four encoded signals using a QPSK modulator to generate a combined signal. The server 120 can also modulate the encoded signals with at least one of the following: BPSK (Biphase Shift Keying), QAM (Quadrature Amplitude Modulation), or OFDMA (Orthogonal Frequency Division Multiple Access) to generate a combined signal.

[0104] Next, in S614, the server 120 transmits the combined signal to the wireless output device 130.

[0105] In S616, the wireless output device 130 broadcasts the synthesized signal. According to one embodiment of the present invention, the wireless output device 130 can broadcast the synthesized signal using UDP (User Datagram Protocol). Furthermore, the wireless output device 130 can transmit the synthesized signal via Wi-Fi communication.

[0106] In S618, the client device 140 can be configured with a predetermined program or application. The program or application executed by the client device 140 is referred to as the client program.

[0107] The client program can be a program that receives and uses location information. The client program can acquire location information by receiving GNSS satellite signals or by receiving broadcasting signals according to one embodiment of the present invention. Outdoors, the client program can acquire location information by receiving GNSS satellite signals, and in GNSS shadowing areas, it can acquire location information by receiving Wi-Fi broadcasting signals.

[0108] The client program can acquire location information from broadcasted Wi-Fi signals if it determines that the area is a GNSS shadowing area where GNSS satellite signals are not received. The client program can support navigation programs, firmware, map programs, location service programs, etc. The client program can be installed during the production of the client device 140 or downloaded and installed from a cloud server while the client device 140 is in use.

[0109] In S620, the client device 140 can register vehicle license plate information. The client device 140 can receive and save vehicle license plate information from the user.

[0110] In S622, the client device 140 generates a despreading code using the vehicle identification number information. The client program of the client device 140 can hash the vehicle identification number information with a hash function, convert the hashed value into an orthogonal code, and define the orthogonal code as the despreading code.

[0111] When the client device 140 receives a broadcasted signal from the wireless output device 130, it can decode the received composite signal using the despreading code in S624. The client device 140 can use broadcasted signals using UDP. The client program can execute a CDMA decoder to decode the composite signal using the despreading code.

[0112] In S626, the client device 140 can acquire location information if the decoded signal decoded by the despreading code has a valid value. The client device 140 can output the acquired location information through the client program or make it available to the client program.

[0113] Figure 7 is a diagram illustrating the process of generating and transmitting a wireless signal according to one embodiment of the present invention. Figure 7 shows the process of generating a wireless signal using QPSK modulation according to one embodiment of the present invention.

[0114] According to one embodiment of the present invention, the indoor location recognition system 100 can convert CDMA encoded data 710 generated by the CDMA encoder 510 into a predetermined number of data chunks 720. The indoor location recognition system 100 can divide the data into predetermined data sizes and generate a plurality of data chunks 720.

[0115] Next, the bit string generator 730 of the indoor position recognition system 100 generates a bit string from the data chunk 720. The bit string generator 730 can generate a bit string for each frame from the data chunk 720. For example, the bit string for each frame may have a size of 2266 × 1.

[0116] Next, the QPSK modulator 740 performs QPSK modulation on the bit string. The QPSK modulator 740 can generate QPSK symbols in units of 1133 × 1 size bit strings. Therefore, two QPSK symbols can be generated from a single bit string.

[0117] Next, the Raised Cosine Transmit Filter (RC) 750 can upsample two QPSK symbols at a time. The RC transmission filter 750 can utilize a rolloff factor of 1 / 2. The RC transmission filter can convert two QPSK symbols into a 2266×1 size radio signal 760 and output it. The radio signal 760 may have in-phase amplitude and quadrature amplitude, for example, as shown in graph 762.

[0118] The wireless signal 760 may be output to the AWGN (Additive White Gaussian Noise) channel 770. The AWGN channel 770 is referred to as the additive white Gaussian noise channel. The AWGN channel 770 is a channel in which white Gaussian noise affects the characteristics of the signal and can be modeled as a stationary random processor. The AWGN channel may have a frequency offset and a variable time delay.

[0119] The bit string generator 730, the QPSK modulator 740, and the RC transmission filter 750 are either provided in either the server 120 or the wireless output device 130, or they are provided separately in the server 120 or the wireless output device 130.

[0120] Figure 8 is a diagram illustrating the process of receiving and decoding a wireless signal from a client device using one embodiment of the present invention. Figure 8 shows the process of converting a QPSK-modulated wireless signal.

[0121] According to one embodiment of the present invention, the client device 140 can receive and decode a radio signal broadcast from the radio output device 130.

[0122] In step 810, the client device 140 receives a wireless signal. The client device 130 can receive the wireless signal via Wi-Fi communication or a mobile communication network such as 4G / 5G. The wireless signal may include 2266×1 size QPSK symbols.

[0123] Next, in step 820, the client device 140 performs automatic gain control. The client device 140 applies a gain to the radio signal received in step 820 and processes it so that the magnitude of the radio signal remains at a constant level. The automatically gain-controlled signal may have a size of 2266 × 1. Through automatic gain control, the client device 140 can ensure that the phase and timing error detectors have a constant gain over time.

[0124] Next, the Raised Cosine Receive Filter (RC) 830 of the client device 140 filters the received signal processed using automatic gain control. For example, the RC receive filter 830 can utilize a rolloff index of 0.5. The signal output from the RC receive filter may have a size of 2266 × 1.

[0125] Next, in step 840, the client device 140 performs coarse frequency compensation processing. Through coarse frequency compensation processing, the client device 140 can estimate and correct the approximate frequency offset of the received radio signal.

[0126] Next, the synchronizer 850 of the client device 140 synchronizes the radio signal and converts it into frames. The synchronizer 850 may include a symbol synchronizer 852, a carrier synchronizer 854, and a frame synchronizer 856. The symbol synchronizer 852 resamples the input signal with a recovered timing strobe so that symbol determination occurs at a suitable sampling instant. The carrier synchronizer 854 can compensate for residual frequency offset and phase offset. The frame synchronizer 856 can align the frame boundary from a known frame header.

[0127] In step 860, the client device 140 decodes the frame-by-frame signal output from the synchronizer 850. In step 860, the client device 140 decodes the signal to have a reference BER (Bit error ratio) value. The client device 140 eliminates the phase uncertainty caused by the carrier synchronizer 854, demodulates the signal, and decodes the original message.

[0128] Next, in step 870, the client device 140 reconstructs the CDMA encoded data. The client device 140 separates the decoded data into data chunks. The client device 140 also generates CDMA encoded data from the data chunks.

[0129] Next, the CDMA decoder 880 of the client device 140 decodes the CDMA encoded data and generates decoded data. The CDMA decoder 880 can decode the data using the despreading code generated using the vehicle identification number information. Figure 9 is a diagram illustrating the process of outputting wireless signals from multiple wireless output devices according to one embodiment of the present invention.

[0130] According to one embodiment of the present invention, the server 120 can broadcast wireless signals through a plurality of wireless output devices 130. The server 120 can be connected to the plurality of wireless output devices 130 via the Internet. The server 120 can transmit signals to be output as wireless signals to the plurality of wireless output devices 130 via the Internet.

[0131] Multiple wireless output devices 130 can be installed at multiple locations within the tunnel. The wireless output devices 130 can be fixed to structures such as the tunnel ceiling and walls. The wireless output devices 130 can be arranged at predetermined intervals, for example, at intervals of 0.5 km to 2 km. The wireless output devices 130 can be compatible with Wi-Fi communication equipment.

[0132] The wireless output device 130 can broadcast Wi-Fi signals. According to one embodiment of the present invention, multiple wireless output devices 130 can output the same wireless signal. Furthermore, the wireless output device 130 can output a wireless signal through a mobile communication network. When using a 4G communication network, the wireless output devices 130 can be arranged at a reference interval between communication base stations (for example, at intervals of approximately 1.6 km). When using a 5G communication network, the wireless output devices 130 can be arranged at a reference interval between communication base stations (for example, at intervals of approximately 500 m).

[0133] A client device 140 inside a vehicle 150 traveling through a tunnel can receive a broadcasted Wi-Fi signal. The client device 140 can extract symbols from the Wi-Fi signal and perform CDMA decoding to extract information such as the vehicle 150's location, speed, and direction of travel.

[0134] Figure 10 is a diagram showing the data structure of a wireless signal according to one embodiment of the present invention.

[0135] According to one embodiment of the present invention, a wireless signal may have a UDP (User Datagram protocol) data structure. A UDP data structure is a TCP / IP layer protocol that transmits data or messages over an IP-based network (e.g., the Internet or an intranet) in an unpredictable manner without any initial agreement between the transmitter and receiver. UDP communication networks can be transmitted as datagrams without sequence numbers or acknowledgment messages. Messages lost during transmission must be recovered by an application layer protocol operating at the UDP top.

[0136] The application layer protocol operating on top of UDP can provide its own dependability service or transmit messages on a fixed or predetermined schedule.

[0137] As shown in Figure 10, a UDP data structure can include a Header Protocol Network Interface, Header IP, Header UDP, UDP Message, and Trailer Protocol Network Interface within a single Frame Protocol Network Interface. The Header IP, Header UDP, and UDP Message can constitute a Datagram Protocol IP. The Header UDP and UDP Message can constitute a Data UDP. CDMA-encoded data may be included in the UDP Message.

[0138] On the other hand, the disclosed embodiments may be embodied in the form of a computer-readable recording medium for storing computer-executable instructions and data. The instructions are stored in the form of program code and, when executed by a processor, can generate a predetermined program module and perform predetermined operations. Furthermore, when executed by a processor, the instructions can perform predetermined operations of the disclosed embodiments.

[0139] A recording medium readable by a device may be provided in the form of a non-transitory recording medium. Here, "non-transitory recording medium" simply means a tangible device that does not contain signals (e.g., electromagnetic waves), and this term does not distinguish between cases where data is stored semi-permanently and cases where it is stored temporarily. For example, a "non-transitory recording medium" may include a buffer in which data is temporarily stored.

[0140] According to one embodiment, the methods according to the various embodiments disclosed herein may be provided in a computer program product. The computer program product may be traded as a commodity between a seller and a buyer. The computer program product may be distributed in the form of a device-readable recording medium (e.g., compact disc read-only memory: CD-ROM), or online (e.g., by download or upload) through an application store or directly between two user devices (e.g., smartphones). In the case of online distribution, at least a portion of the computer program product (e.g., a downloadable app) may be at least temporarily stored or temporarily generated on a device-readable recording medium such as the memory of a manufacturer's server, an application store server, or an intermediary server.

[0141] As described above, the disclosed embodiments have been explained with reference to the accompanying drawings. A person with ordinary skill in the art to which the present invention pertains will understand that the present invention may be carried out in forms different from those disclosed without altering the technical idea or essential features of the present invention. The disclosed embodiments are illustrative and should not be construed as restrictive. [Explanation of symbols]

[0142] 100 Indoor Location Recognition System 110a, 110b detection device 112a, 112b Camera 114a, 114b Position detection sensor 120 servers 122 Location information encoding 130 Wireless output device 140 client devices 150 vehicles

Claims

1. Camera and, A position recognition sensor and First communication module and Memory to store at least one instruction, The system includes at least one processor, and the at least one processor performs the at least one instruction, Based on the position detection signal from the aforementioned position recognition sensor, the position of a vehicle traveling on the road is recognized, and position information is generated. Based on the input video captured by the aforementioned camera, the vehicle license plate information and location of the vehicle traveling on the road are recognized. Using the spreading code generated from the vehicle license plate information, the location information is encoded using the Code-Division Multiple Access (CDMA) method. An indoor location recognition system that outputs the encoded location information as a wireless signal through the first communication module.

2. The aforementioned indoor location recognition system is Multiple detection devices are arranged at different locations within the indoor space, A server that communicates with the aforementioned plurality of detection devices, Includes a wireless output device located within the indoor space and communicating with the server, Each of the aforementioned plurality of detection devices includes the camera, the position recognition sensor, and a second communication module that communicates with the server. The server includes the memory and the at least one processor, and includes a third communication module that communicates with the plurality of detection devices and the wireless output device. The indoor location recognition system according to claim 1, wherein the wireless output device includes a first communication module that communicates with the server and outputs the wireless signal.

3. The plurality of detection devices are, Based on the position detection signal, the position information is generated. Based on the input video, the vehicle number plate information is generated. The indoor location recognition system according to claim 2, wherein the location information and the vehicle license plate information are transmitted to the server via the second communication module.

4. The aforementioned server, The vehicle number plate information and location information are received from the plurality of detection devices through the third communication module. Using the diffusion code generated from the vehicle number plate information, the location information is encoded in CDMA format. The indoor location recognition system according to claim 2, wherein the encoded signal is transmitted to the wireless output device.

5. The aforementioned wireless output device is The indoor location recognition system according to claim 2, wherein the wireless signal is broadcast through the first communication module.

6. The position recognition sensor includes a radar (RADAR: radio detection and ranging) sensor or a lidar (LIDAR: light detection and ranging) sensor. The at least one processor performs the at least one instruction, Based on the position detection signal, speed information of the vehicle whose position has been recognized is generated. The indoor position recognition system according to claim 1, wherein the speed information is output as the wireless signal.

7. The at least one processor is Based on the position information generated from the position detection signal and the position of the vehicle recognized by the input video, the position information generated from the position detection signal and the vehicle number plate information are matched. The indoor location recognition system according to claim 1, wherein the location information is CDMA encoded using the diffusion code generated from the matched vehicle license plate information.

8. The at least one processor performs the at least one instruction, A CDMA-encoded encoded signal is generated for each of the location information of multiple vehicles. The encoded signals for each of the location information of the plurality of vehicles are summed up to generate a composite signal. The indoor location recognition system according to claim 1, wherein the composite signal is output as the wireless signal.

9. The indoor location recognition system according to claim 8, wherein the synthesized signal is received by a client device located inside the vehicle and decoded using a despreading code generated from vehicle identification number information stored in the client device.

10. The at least one processor performs the at least one instruction, The aforementioned vehicle number plate information is hashed, The hashed vehicle identification number information is converted into mutually orthogonal codes. The indoor location recognition system according to claim 1, wherein the orthogonal code is used as the diffusion code to encode the location information in the CDMA format.

11. The operation of outputting the encoded location information as a wireless signal is: The encoded location information is converted into multiple data chunks. A bit sequence for each frame is generated from the aforementioned multiple data chunks, Convert the bit sequence for each frame into a QPSK (Quadrature Phase Shift Keying) symbol, The indoor location recognition system according to claim 1, wherein the QPSK symbols are upsampled using an RC (Raised cosinetransmit filter) transmission filter, and the upsampled QPSK symbols are output as the wireless signal through an AWGN (Additive White Gaussian Noise) channel.

12. The steps include: recognizing the position of a vehicle traveling on a road based on the position detection signal from a position recognition sensor and generating position information; The steps include: recognizing the vehicle number plate information and location of a vehicle traveling on the road based on input video captured by a camera; The steps include: encoding the location information using a spreading code generated from the vehicle license plate information in a Code-Division Multiple Access (CDMA) manner; A method for controlling an indoor location recognition system, comprising the step of outputting the encoded location information as a wireless signal.

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