Three-frequency WiFi camera system based on FPGA

Abstract

The invention discloses a three-frequency WiFi camera system based on an FPGA, and belongs to the field of cameras, the three-frequency WiFi camera system comprises a camera driving module, a DDR cache module and a WiFi transmission module, the FPGA end detects and analyzes a three-frequency WiFi chip, arbitrates RSSI and SNR of the three-frequency WiFi chip, selects a 5GHz frequency band when the RSSI and the SNR are in an excellent state, uses a 2.4 G frequency band when the RSSI and the SNR are qualified, and transmits the camera driving module to the WiFi transmission module. When the RSSI and the SNR are too low, a transmission error alarm is adopted, and a Sub-1GHz frequency band transmission instruction is adopted; according to the invention, the link communication efficiency can be improved, the dual-mode communication separation instruction and the data transmission frequency band are used at the same time, and compared with an FPGA-based WiFi communication system in the market, the communication efficiency and the communication reliability are higher.

Description

Technical Field

[0001] The present invention relates to the technical field of optical payloads, and particularly to a three-band WiFi camera system based on FPGA. Background Art

[0002] With the rapid development of space technology, space cameras, as key space exploration tools, are playing an increasingly important role in multiple fields such as remote sensing, surveying and mapping, and astronomical observation. However, traditional space camera systems generally adopt a single data transmission method, such as relying only on wired transmission or single-channel wireless transmission, which to a certain extent restricts the data transmission efficiency and the flexibility of the overall system. In recent years, thanks to the continuous progress of wireless communication technology, especially the WiFi technology with its high bandwidth, low latency, and easy deployment, it has begun to stand out in the space field.

[0003] Field Programmable Gate Array (FPGA) has also been widely used in space camera systems due to its high programmability and parallel processing capabilities. FPGA can achieve high-speed data acquisition, processing, and transmission. However, how to effectively combine FPGA and WiFi technology to build an efficient and stable three-band WiFi space camera system is still a technical challenge faced by the current space field. Summary of the Invention

[0004] The purpose of this part is to outline some aspects of the embodiments of the present invention and briefly introduce some preferred embodiments. Some simplifications or omissions may be made in this part, as well as in the abstract and title of the present application, to avoid obscuring the purpose of this part, the abstract, and the title. However, such simplifications or omissions shall not be used to limit the scope of the present invention.

[0005] Therefore, the purpose of the present invention is to provide a three-band WiFi camera system based on FPGA, which improves the quality of image data transmission.

[0006] To solve the above technical problems, according to one aspect of the present invention, the following technical solutions are provided: A three-band WiFi communication system based on FPGA, which includes: a Kintex-7 chip and a three-band WiFi chip; As a preferred solution of the three-band WiFi communication system based on FPGA according to the present invention, wherein, the Kintex-7 chip includes a camera driving module, a DDR buffer module, and a WiFi transmission module. Among them, the FPGA end detects and analyzes the three-band WiFi chip, arbitrates the RSSI (signal strength) and SNR (signal-to-noise ratio) of the three-band WiFi chip. When the RSSI and SNR are in an excellent state, the 5GHz band is selected. When the RSSI and SNR are qualified, the 2.4G band is used.

[0007] As a preferred solution of a triple-band WiFi communication system based on FPGA according to the present invention, wherein the triple-band WiFi chip includes a WiFi communication arbitration module, a WiFi alarm module, and a WiFi instruction receiving module; The WiFi communication arbitration module is used to arbitrate the RSSI and SNR of the triple-band WiFi communication signal. When the RSSI and SNR are high, WiFi uses the 5GHz band. When the RSSI and SNR are poor, WiFi uses the 2.4GHz band; The WiFi alarm module and the WiFi instruction receiving module. When the WiFi chip detects that the RSSI and SNR are abnormal and unable to transmit image data, the WiFi chip uses the Sub-GHz communication and the Sub-1GHz band to transmit an error alarm signal to the space base. At the same time, the WiFi chip enters the C (command) mode and waits for the base instruction, including but not limited to system reset instruction, WiFi chip reset instruction, on-board vehicle return instruction, etc.

[0008] The WiFi chip mode is divided into C (Command) mode and T (Transfer) mode. In the C mode, the WiFi chip uses the Sub-1GHz band to transmit alarm signals to the space base and receive instructions. In the T (Transfer) mode, the 2.4GHz and 5GHz bands are used to transmit image data to the space base.

[0009] As a preferred solution of a triple-band WiFi camera system based on FPGA according to the present invention, wherein the FPGA end includes a WiFi transmission module, a DDR cache module, and a camera driving module; The WiFi transmission module is used to transmit the image data in the data buffer area to the WiFi signal receiving device through the WiFi chip by the TCP / UDP protocol; The DDR cache module is used to store the image data generated by the optical sensor; The camera driving module is used to drive optical sensors including but not limited to optical sensors such as IMX335, IMX415, and OV5640. When the WiFi chip uses the 5GHz band, the transmission image frame rate is 3n Fps / s (n is controlled by parameters such as image pixel values and sensor parameters). When the WiFi chip uses the 2.4GHz band, the frame extraction technology is used to make the transmission image frame rate n Fps / s; As a preferred solution of a triple-band WiFi camera system based on FPGA according to the present invention, wherein in the DDR cache module, the data buffer area adopts a linear storage structure and is implemented through sequential storage logic. The number of data buffer areas is limited by the memory capacity and the size of a single-frame data.

[0010] A method for a dual-channel WiFi communication system based on FPGA, the specific steps are as follows: S1. Use tri-band 2.4GHz and 5GHz WiFi; S2. The WiFi communication arbitration module arbitrates the signal quality of tri-band WiFi. When the RSSI and SNR are high, the 5GHz band is selected. When the RSSI and SNR are qualified, the 5GHz band is selected. When a special transmission error alarm occurs, the Sub-1GHz band is used. S3. Use the T / C WiFi communication mode, that is, the system defaults to the T mode, which is the data transmission mode. When the system is abnormal, the C mode is used to transmit control instructions, and at this time, the data transmission work is suspended.

[0011] S4. During the initialization process, the FPGA end loads the content of the configuration file into the buffer area. After that, all configuration refresh and read operations rely on the buffer area. The buffer area adopts a chained storage structure. The FPGA end changes the content in the chained buffer area according to the configuration instructions, and finally updates the content of the chained buffer area to the configuration file. The FPGA end restarts the system to complete the reconfiguration of WiFi.

[0012] Compared with the prior art, the beneficial effects of the present invention are: 1. The present invention adopts the T / C WiFi communication mode, that is, the data transmission mode is default, and the 5GHz band is used. In the T mode, when the RSSI and SNR drop from excellent to qualified standards, the 2.4GHz band is used instead. When the signal quality is extremely poor, the WiFi Sub-1GHz band is selected to transmit alarm signals to the space base. The present invention can improve the link communication efficiency and use the dual-mode communication to separate the frequency bands of instructions and data transmission, and has higher communication efficiency and communication reliability compared with the existing FPGA-based WiFi communication systems on the market.

[0013] 2. In the design of the DDR cache module, the data buffer area adopts a queue storage structure in the linear table, which is realized through sequential storage logic. The number of data buffer areas is limited by the memory capacity and the size of a single frame of data. This design ensures the best balance between cache efficiency and storage resources. Such a design choice ensures that the DDR cache module can efficiently process data between different cache areas, and also takes into account the reasonable utilization of storage resources and cost-effectiveness. Description of the Drawings

[0014] To more clearly illustrate the technical solutions of the embodiments of the present invention, the present invention will be described in detail below in conjunction with the drawings and detailed embodiments. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings. Among them: Figure 1 It is a schematic structural diagram of a three-band WiFi camera system based on FPGA of the present invention; Figure 2 It is a three-band WiFi configuration flowchart of a three-band WiFi communication system based on FPGA of the present invention; Figure 3 It is a three-band WiFi arbitration flowchart of a three-band WiFi communication system based on FPGA of the present invention. Specific Embodiments

[0015] To make the above objects, features, and advantages of the present invention more obvious and understandable, the specific embodiments of the present invention will be described in detail below in conjunction with the drawings.

[0016] Secondly, the present invention is described in detail in conjunction with the schematic diagrams. When detailing the embodiments of the present invention, for the convenience of description, the cross-sectional views showing the device structure will be enlarged locally out of the general proportion, and the schematic diagrams are only examples and should not limit the scope of protection of the present invention herein. In addition, in actual production, three-dimensional spatial dimensions including length, width, and depth should be included.

[0017] To make the purpose, technical solutions, and advantages of the present invention clearer, the embodiments of the present invention will be further described in detail below in conjunction with the drawings.

[0018] The present invention provides a three-band WiFi camera system based on FPGA, which improves the data transmission efficiency.

[0019] I. System Composition Kintex-7 chip: As the core processing unit of the system, the Kintex-7 chip integrates the following modules: (1) Camera driver module: Responsible for driving optical sensors, such as IMX335, IMX415, OV5640, etc., to realize the acquisition of image data.

[0020] (2) DDR cache module: Used to temporarily store the image data generated by the optical sensor to ensure the continuity and stability of data transmission.

[0021] (3) WiFi transmission module: Responsible for transmitting the image data in the DDR cache module to the WiFi signal receiving device through the TCP / UDP protocol.

[0022] Tri - band WiFi Chip: This chip is responsible for wireless communication and has the following functional modules: (1)WiFi Communication Arbitration Module: Arbitrates the WiFi communication frequency band in real - time according to RSSI (signal strength) and SNR (signal - to - noise ratio).

[0023] (2)WiFi Alarm Module: When communication is abnormal, it uses the Sub - 1GHz frequency band to transmit error alarm signals to the space base.

[0024] (3)WiFi Command Receiving Module: Receives control commands sent by the space base, such as system reset commands, WiFi chip reset commands, etc.

[0025] II. System Operation Steps Step 1: System Initialization After the system is powered on, the FPGA side loads the configuration file to initialize the Kintex - 7 chip and the tri - band WiFi chip. The DDR cache module clears the data and prepares to receive the image data generated by the optical sensor.

[0026] Step 2: Image Data Acquisition The camera driver module drives the optical sensor to acquire image data according to the preset parameters. After the data acquisition is completed, the image data is written into the DDR cache module.

[0027] Step 3: Data Processing in the DDR Cache Module The DDR cache module adopts a linear storage structure and realizes data caching through sequential storage logic. The number of buffer areas is optimally configured according to the memory capacity and the size of a single - frame data. The image data is temporarily stored in the DDR cache module and waits for processing by the WiFi transmission module.

[0028] Step 4: Selection of WiFi Communication Frequency Band The FPGA side detects and analyzes the RSSI and SNR of the tri - band WiFi chip in real - time. According to the detection results, the WiFi communication arbitration module selects the appropriate communication frequency band: when RSSI and SNR are in an excellent state, the 5GHz frequency band is selected; when RSSI and SNR are qualified, the 2.4GHz frequency band is used.

[0029] Step 5: Image Data Transmission The WiFi transmission module reads the image data from the DDR cache module and transmits the data to the WiFi signal receiving device through the TCP / UDP protocol. When using the 5GHz frequency band, the transmission image frame rate is 3n Fps / s; when using the 2.4GHz frequency band, the frame - extraction technology is adopted to make the transmission image frame rate n Fps / s.

[0030] Step 6: Abnormality Handling When the WiFi chip detects abnormal RSSI and SNR and is unable to transmit image data normally, it immediately switches to the Sub-1GHz band and sends an error alarm signal to the space base. At the same time, the WiFi chip enters the C (command) mode and waits to receive control instructions from the space base.

[0031] Step 7: System reset and reconfiguration Based on the received instructions, the FPGA resets the system or reconfigures the WiFi parameters. After the configuration is completed, the system re-enters the data transmission mode and continues to perform image data acquisition, caching, and transmission tasks.

Claims

1. A FPGA-based tri-band WiFi camera system, characterized in that: include: Kintex-7 chip and tri-band WiFi chip; The Kintex-7 chip includes an FPGA end, which detects and analyzes the tri-band WiFi chip, and is specifically set to: arbitrate the communication signal-to-noise ratio of the tri-band WiFi chip signal, use the 5GHz frequency band for communication when the signal-to-noise ratio is good, use the 2.4GHz frequency band for communication when the signal-to-noise ratio is qualified, and use the Sub-1GHz frequency band to broadcast instructions when the signal-to-noise ratio does not meet the communication requirements.

2. The FPGA-based tri-band WiFi camera system according to claim 1, characterized in that: The tri-band WiFi chip includes a WiFi communication arbitration module, a WiFi alarm module and a WiFi command receiving module; The WiFi communication arbitration module is used to arbitrate the signal-to-noise ratio of the tri-band WiFi communication signal, using the 5GHz frequency band for communication; The WiFi alarm module uses the Sub-1GHz frequency band to broadcast alarm instructions to the aerospace base when the signal-to-noise ratio does not meet the communication requirements; The WiFi command receiving module receives commands sent by the aerospace base, including but not limited to system reset commands, WiFi chip reset commands, and satellite vehicle return commands.

3. The FPGA-based tri-band WiFi camera system according to claim 1, characterized in that: The FPGA end includes a WiFi transmission module, a DDR cache module, and a camera driver module.

4. The FPGA-based tri-band WiFi camera system according to claim 3, characterized in that: The WiFi transmission module is used to transmit the image data obtained in the data buffer area to the WiFi signal receiving device through the WiFi chip via the TCP / UDP protocol; the DDR cache module is used to store the image data generated by the optical sensor.

5. The FPGA-based tri-band WiFi camera system according to claim 4, characterized in that: The camera driving module is used to drive optical sensors including IMX335, IMX415, and OV5640 optical sensors. When the WiFi chip uses the 5GHz frequency band, the transmission image frame rate is 3n Fps / s. When the WiFi chip uses the 2.4GHz frequency band, the frame extraction technology is used to make the transmission image frame rate n Fps / s.

6. The FPGA-based tri-band WiFi camera system according to claim 3, characterized in that: In the DDR cache module, the data cache area adopts a queue storage structure in a linear table and is implemented through sequential storage logic. The number of data cache areas is limited by the memory capacity and the size of a single frame of data.

7. A method for a FPGA-based tri-band WiFi camera system, characterized in that: The specific steps are as follows: S1, system initialization; After the system is powered on, the FPGA side loads the configuration file and initializes the Kintex-7 chip and the tri-band WiFi chip; the DDR cache module clears the data and prepares to receive the image data generated by the optical sensor; S2: Image data acquisition; The camera driver module drives the optical sensor to collect image data according to preset parameters; After data acquisition is completed, the image data is written into the DDR cache module; S3, DDR cache module data processing; The DDR cache module adopts a linear storage structure and implements data caching through sequential storage logic; the number of cache areas is optimized according to the memory capacity and the size of single-frame data; the image data is temporarily stored in the DDR cache module and waits for processing by the WiFi transmission module; S4, WiFi communication frequency band selection; The FPGA detects and analyzes the RSSI and SNR of the tri-band WiFi chip in real time. Based on the detection results, the WiFi communication arbitration module selects the appropriate communication frequency band: when the RSSI and SNR are in good condition, the 5GHz frequency band is selected; when the RSSI and SNR are qualified, the 2.4GHz frequency band is used. S5, image data transmission; The WiFi transmission module reads the image data from the DDR cache module and transmits the data to the WiFi signal receiving device through the TCP / UDP protocol; in the 5GHz frequency band, the transmission image frame rate is 3n Fps / s; in the 2.4GHz frequency band, the frame extraction technology is used to make the transmission image frame rate n Fps / s; S6: Exception handling When the WiFi chip detects abnormal RSSI and SNR and cannot transmit image data normally, it immediately switches to the Sub-1GHz frequency band and sends an error alarm signal to the space base. At the same time, the WiFi chip enters C (command) mode and waits to receive control commands from the space base. S7, system reset and reconfiguration; The FPGA resets the system or reconfigures the WiFi parameters according to the received instructions. After the configuration is completed, the system re-enters the data transmission mode and continues to perform image data acquisition, caching and transmission tasks.

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