Internet of Things wireless transmission method based on dynamic arbitrary polarization antenna

Abstract

The present invention provides an Internet of Things wireless transmission method based on a dynamic arbitrary polarization antenna, which belongs to the field of wireless network technology and includes the following steps: a master station finds a slave station to be established for communication by adjusting the antenna polarization direction, and sends a handshake signal to establish communication; after communication is established, the master station periodically sends a judgment signal to the slave station, receives a feedback signal from the slave station, and judges whether the slave station needs to adjust the antenna polarization direction based on the polarization signal quality CQI result of the feedback signal; the slave station judges based on the judgment signal that when the antenna polarization direction needs to be adjusted, switches, and calculates CQI data and feeds it back to the master station. The present invention uses an antenna with adjustable polarization direction, combined with baseband processing and signaling protocol, to enable the master station and the slave station to perform adaptive polarization direction switching, thereby ensuring a reliable, stable and fast communication state.

Description

Technical Field

[0001] The present invention belongs to the technical field of wireless networks, and in particular relates to an Internet of Things wireless transmission method based on a dynamic arbitrary polarization antenna. Background Art

[0002] With the advent of the 5G era, the development of wireless communication in the Internet of Things is very rapid, and it is inevitable that an environment with multiple terminals and multiple wireless communication technologies will be created. Figure 1 As shown in the figure, as signals are transmitted between a master station and multiple groups of slave stations, reflections from objects along the path can cause changes in polarization, introducing multipath effects. Because each station's location and antenna polarization vary, achieving secure and stable transmission in a multi-terminal, multi-antenna environment requires higher standards for transmission technology reliability, stability, and even power consumption.

[0003] Traditional solutions often use multiple antennas and gain compensation to compensate for transmission losses. However, this approach increases power consumption, shortens device lifespan, and introduces new problems. Summary of the Invention

[0004] In order to solve the problems in the prior art, the present invention discloses an Internet of Things wireless transmission method based on a dynamic arbitrary polarization antenna.

[0005] To achieve the above object, the technical solution of the present invention is as follows:

[0006] The method for wireless transmission of the Internet of Things based on a dynamic arbitrary polarization antenna includes the following steps:

[0007] Step 1: The master station adjusts the antenna polarization direction to find the slave station to establish communication and sends a handshake signal to establish communication;

[0008] Step 2: After establishing communication, the master station periodically sends a judgment signal to the slave station, receives a feedback signal from the slave station, and determines whether the slave station needs to adjust the antenna polarization direction based on the polarization signal quality (CQI) result of the feedback signal. The slave station determines when the antenna polarization direction needs to be adjusted based on the judgment signal and switches the direction and calculates the CQI data. When the CQI meets the requirements, it determines the appropriate channel.

[0009] The CQI calculation formula is: CQI = f(BLER) + f(RSSI), where BLER is the block error rate and RSSI is the received signal strength.

[0010] Furthermore, the step 1 specifically includes the following process:

[0011] The master station sets the default polarization direction of the antenna and sends a "handshake" request to the slave station. Then, the master station waits for the slave station to reply. When the slave station replies, the communication is established successfully, and the subsequent steps of sending judgment instructions are started. If no reply is received for a long time, the master station switches the antenna polarization direction and sends the "handshake" request again. When the slave station replies, the establishment is successful, and the subsequent steps of sending judgment instructions are started. If the number of "handshake" requests sent exceeds the limit and no reply is received from the slave station, the master station sends an error.

[0012] Furthermore, when the master station switches the polarization direction, the planned directions of the slave stations that have established communication with the master station are modified.

[0013] Furthermore, the step 2 specifically includes the following sub-steps:

[0014] Step 2-1: The master station sends a judgment signal, which includes: a slave station address, a polarization direction switching instruction, and a test data packet;

[0015] Step 2-2: After receiving the judgment signal, the slave station determines the polarization switching instruction and switches the polarization direction when polarization switching is required; the slave station calculates the CQI and feeds it back to the master station;

[0016] In step 2-3, after the master station receives the feedback signal sent by the slave station, it makes a judgment based on the CQI: when the CQI is greater than the threshold, the master station maintains the judgment signal until the next feedback signal is received; when the CQI is less than the threshold, the master station updates the judgment signal, requiring the slave station to switch the antenna polarization direction, and sends the judgment signal in the next time slot, and repeats this step to receive the feedback signal again and make a judgment based on the CQI result until the channel is determined when the CQI is greater than the threshold.

[0017] Furthermore, when switching the polarization direction, a protection period is set before the switching is implemented. The encoded data in the transmission pipeline is processed during the protection period. The polarization direction is switched after the protection period ends and the old polarization data in the transmission pipeline is processed.

[0018] The beneficial effects of the present invention are:

[0019] The present invention uses an antenna with adjustable polarization direction, combined with baseband processing and signaling protocols, to enable the master station and the slave station to perform adaptive polarization switching, alleviate the multipath effect, ensure reliable, stable and fast communication status, and effectively reduce manual operation costs.

[0020] The method of the present invention avoids overcompensation of gain and can extend the service life of the device (PA).

[0021] The present invention does not require multiple antennas, thus saving costs.

[0022] The method of the present invention adopts a protection period to form a protection mechanism, which can improve communication quality and stability. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 Schematic diagram of signal transmission between the master station and multiple groups of slave stations.

[0024] Figure 2 Schematic diagram of the adjustable antenna structure.

[0025] Figure 3 Schematic diagram of the communication process between the master station and the slave station.

[0026] Figure 4 Schematic diagram of main station monitoring.

[0027] Figure 5 This is a schematic diagram of slave station feedback.

[0028] Figure 6 Schematic diagram of the polarization direction switching stage. DETAILED DESCRIPTION

[0029] The technical solutions provided by the present invention will be described in detail below with reference to specific embodiments. It should be understood that the following specific embodiments are only used to illustrate the present invention and are not used to limit the scope of the present invention.

[0030] The network environment for implementing the solution of the present invention should include at least a master station and several groups of slave stations. Communication is established between the master station and the slave stations, and the antennas of both the master station and the slave stations have adjustable polarization directions. The polarization-adjustable antenna is a single antenna that supports dynamic polarization reconfiguration and supports both transmission and reception. The present invention utilizes dynamic polarization to combat adverse environments such as multipath fading, interference, and signal obstruction, ensuring that the transmitting and receiving antennas have the same polarization direction, achieving high system performance and reducing interference. The baseband chips of the master station and the slave stations are upgraded, and the channel quality (CQI) assessment algorithm and polarization mode selection algorithm are implemented in the baseband processor. In addition, a suitable signaling protocol is required. Reference can be made to the wireless protocol stack. Signaling messages containing channel quality feedback and polarization mode negotiation are used during the wireless link establishment and maintenance process. Data packets transmitted between the master and slave stations are encoded and modulated using an adaptive codec to dynamically adjust transmission parameters based on real-time link quality, further optimizing the utilization efficiency of wireless resources. The slave antenna uses adaptive antenna polarization mode to switch polarization direction: 1. When the CQI of the current polarization mode is detected to be below the preset threshold, it can switch to another polarization mode. 2. When the master station notifies the slave station to switch polarization mode, the slave station switches polarization mode, and the master station should also maintain synchronization with the slave station.

[0031] Adjustable antennas are usually Figure 2The stacked-disk Yagi structure shown consists of a half-wavelength dipole driver, a reflector, and multiple pilots. In contrast, the tunable antenna employed in the present invention utilizes 13 circular metal disks as pilots and a patch antenna as the driving element. This patch antenna also serves as the location where the liquid metal alloy adjusts the polarization direction. The patch antenna structure is essentially a center-fed circular patch. The patch antenna used in this tunable antenna consists of an inner circular patch with a radius of r1 and an outer circular patch with a radius of r2 printed on an RO4350B circular substrate. The relative dielectric constant is 3.48 and the loss tangent is 0.0037. The substrate has a radius of r and a thickness of d. The other side of the substrate is a metal ground. The gap g between the main radiating plates is 0.5 mm. A cylinder with a radius of r4 and a height of d1 is located on top of the patch. It is made of polymethyl methacrylate (PMMA) with a dielectric constant of 3.7. A circular groove with a height of d2 is formed inside the PMMA cylinder using a cutting tool. When this annular groove is located directly above the annular gap g, a microfluidic ring channel is formed. About one-sixth of the channel is filled with a small section of liquid metal, sealed with liquid polytetrafluoroethylene (PTFE). This is injected through two PTFE tubes. The inner and outer patches are short-circuited at the liquid metal rod. The position of the liquid metal rod can be moved by pumping in liquid through a syringe connected to the PTFE tube. This changes the current path in the patch antenna and, therefore, the polarization direction.

[0032] Before installing the parasitic patch, the position of the liquid metal rod is observed under a microscope, and the amount of PTFE injected through the needle is recorded. The parasitic patch and guide are then installed. The antenna polarization direction is controlled by the amount of PTFE injected. It is important to note that a programmable micro-constant current pump and a precise cross-polarization calibration procedure are required to generate a more accurate lookup table that correlates polarization direction with the amount of PTFE injected. A circular copper parasitic patch with a radius r3 and thickness d3 is further stacked on top of the PMMA cylinder to improve impedance matching and bandwidth. The antenna is excited at the center of the patch using a 50Ω semi-rigid coaxial cable. The overall antenna geometry exhibits rotational symmetry, and changes in the position of the liquid metal do not affect the impedance matching. Continuous polarization adjustment over a 180° range can be achieved by adjusting the liquid metal rods along the semicircle.

[0033] Based on the above hardware environment, the present invention provides an Internet of Things wireless transmission method based on a dynamic arbitrary polarization antenna, comprising the following steps:

[0034] Step 1: Initialization

[0035] The master station adjusts the antenna polarization direction and finds the slave station to establish communication by sending a handshake signal. The handshake signal includes: master station address, pointing address, request instruction, etc.

[0036] Specifically, such as Figure 3 As shown in the figure, the direction from the master to the slave is the downlink channel, and the direction from the slave to the master is the uplink channel. The master receives an instruction from the upper layer to communicate with slave a. The master sets the antenna to the default polarization direction and sends a "handshake" request to slave a. The master then waits for a reply from slave a. Upon receiving a reply from slave a, communication is successfully established, and the subsequent step of sending a judgment instruction begins. If no reply is received for an extended period, the master switches the antenna polarization direction and sends a "handshake" request again. Upon receiving a reply from slave a, communication is successfully established, and the subsequent step of sending a judgment instruction begins. If no reply is received from slave a after three "handshake" requests, the master sends an error to the upper layer.

[0037] When the master station establishes communication with another slave station, B, through a "handshake" request, the master station's polarization direction may change again. To maintain the communication quality of slave station A, the polarization direction of slave A needs to be modified to match that of the master station.

[0038] Step 2: Master Station Monitoring

[0039] After establishing communication, the master station periodically sends a judgment signal to the slave station, receives the feedback signal from the slave station, and judges whether the slave station needs polarization direction adjustment based on the CQI result of the feedback signal. The process is as follows: Figure 4 shown.

[0040] (1) First, the master station sends a judgment signal, which includes: the slave station address, the polarization direction switching instruction (such as the polarization direction switching judgment bit), and the test data packet.

[0041] (2) If Figure 5 As shown in the figure, after receiving the judgment signal, the slave's vertically / horizontally polarized antenna determines whether polarization switching and demodulation are required from the master. If no switching is required, the slave maintains operation. If switching is required, the slave switches the antenna polarization direction according to the antenna switching principle. The master and slave stations must agree on a set of polarization mode codes (Zadoff-Chu sequences), including the polarization direction and CQI representation. In this example, the polarization mode uses 1-bit data. A polarization mode of 0 indicates vertical polarization, and a polarization mode of 1 indicates horizontal polarization.

[0042] After calculating the polarization signal quality (CQI Channel Quality Indication) corresponding to the test data through the baseband, the slave station uniformly feeds it back to the master station. The feedback includes the slave station address, the slave station antenna polarization direction information, and the CQI processing result. The CQI reflects the downlink channel quality received by the slave station and serves as the basis for determining whether to switch the antenna polarization mode. The CQI can be obtained from the following data: signal-to-noise ratio (SNR), bit error rate (BER / PER), received signal strength (RSSI), multipath delay spread information, etc. In this example, the CQI is measured and processed by the baseband data, and the calculation formula is as follows:

[0043] CQI = f(BLER) + f(RSSI)

[0044] The BLER value can be obtained under SINR conditions and weighted conversion is performed based on the BLER<10% limit. The RSSI value is compared with the theoretical result under the master-slave direct connection condition and weighted conversion is performed based on the theoretical value.

[0045] The CQI value occupies 4 bits, with a maximum value of 15 (1111). In this example, the judgment threshold is set to >7 (0111). The slave station reports the CQI value periodically (e.g., during each transmission gap) or in a triggered manner. If both reporting methods occur simultaneously, the triggered reporting method prevails. The slave station reports the CQI value via the uplink control channel or the in-band feedback channel.

[0046] (3) The master station receives the feedback signal sent by the slave station and makes a judgment based on the CQI result: when the CQI is greater than the threshold, the master station maintains the judgment signal until the next feedback signal is received; when the CQI is less than the threshold, the master station updates the judgment signal, requires the slave station to switch the antenna polarization direction, and sends the judgment signal in the next time slot, and repeats this step to receive the feedback signal again and make a judgment based on the CQI result until the CQI is greater than the threshold; the channel is determined.

[0047] like Figure 6 As shown, the polarization direction switching is divided into three stages:

[0048] Switching notification: After the master station decides to switch the polarization mode according to the adaptive algorithm, it needs to first notify the slave station of the new polarization mode code to be switched through control signaling.

[0049] Protection period: Immediately switching after notifying the slave station will prevent the receiving station from correctly demodulating. Therefore, it is necessary to protect the encoded data in the transmission pipeline. This protection period is used to protect this data, and switching is not performed during the protection period. This protection mechanism uses a "cache" and then "send" method to ensure that data is not lost during the antenna polarization switch.

[0050] Switching implementation: After the protection period ends and the old polarization data in the transmission pipeline is processed (confirmation is required for completion), the master station and the slave station synchronously switch to the new polarization mode encoding and start using the new polarization mode for data transmission.

[0051] The present invention employs a timing synchronization mechanism for switching: polarization mode switching is performed based on a time slot or frame structure, providing precise control over the switching timing. The master station indicates the specific switching effective timestamp (e.g., the number of the time slot) in the judgment signaling. The slave station adjusts its local timing accordingly, switching the polarization mode at the specified timestamp. The slave station compares the timestamp to determine whether the switching effective time has expired. If the slave station has not switched after the timeout, it is considered out of sync with the master station mode and enters protection mode. In protection mode, the master station demodulates the two polarization modes in parallel and selects the demodulation output with better reception quality. After a period of protection mode operation, if the receiving end detects that the transmitting end has switched, it also switches to the same mode.

[0052] When the master station is monitoring, it no longer actively switches the antenna polarization direction. The master station monitors each slave station independently.

[0053] The present invention can also use artificial intelligence methods to evaluate and decide on polarization channels, thereby achieving better transmission effects.

[0054] It should be noted that the above content merely illustrates the technical idea of ​​the present invention and cannot be used to limit the scope of protection of the present invention. 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 all fall within the scope of protection of the claims of the present invention.

Claims

1. An Internet of Things wireless transmission method based on a dynamic arbitrary polarization antenna is characterized in that: The steps include: Step 1: The master station finds the slave station to be established by adjusting the polarization direction of the antenna and sends a handshake signal to establish communication. The polarization-adjustable antenna is a single antenna that can achieve continuous polarization adjustment within a range of 180°. The specific process includes the following: The master station sets the default polarization direction of the antenna and sends a "handshake" request to the slave station. Then, the master station waits for the slave station to reply. When the slave station replies, the communication is successfully established, and the subsequent steps of sending judgment instructions are started. If no reply is received for a long time, the master station switches the antenna polarization direction and sends the "handshake" request again. When the slave station replies, the establishment is successful, and the subsequent steps of sending judgment instructions are started. If the number of "handshake" requests exceeds the limit and no reply is received from the slave station, the master station sends an error to the upper layer. When the master station switches polarization direction, it modifies the polarization direction of slave stations that have established communication with the master station and switches using a timing synchronization mechanism. Polarization mode switching is performed based on the time slot or frame structure. The master station indicates the specific switch effective timestamp in the judgment signaling. The slave station adjusts its local timing accordingly and switches the polarization mode at the specified timestamp. The slave station checks the timestamp to determine whether the switch effective time has expired. If the slave station has not switched after the timeout, it is considered out of sync with the master station mode and enters protection mode. In protection mode, the master station demodulates the two polarization modes in parallel and selects the demodulation output with better reception quality. After a period of protection mode, if the slave station detects that the master station has switched, it also switches to the same mode. Step 2: After establishing communication, the master station periodically sends a judgment signal to the slave station, receives a feedback signal from the slave station, and determines whether the slave station needs to adjust the antenna polarization direction based on the polarization signal quality (CQI) result of the feedback signal. The slave station determines when the antenna polarization direction needs to be adjusted based on the judgment signal, and calculates the CQI data and feeds it back to the master station. When the CQI meets the requirements, it determines the appropriate channel. The CQI calculation formula is: CQI=f(BLER)+f(RSSI), where BLER is the block error rate and RSSI is the received signal strength.

2. The method for wireless transmission of the Internet of Things based on a dynamic arbitrary polarization antenna according to claim 1, characterized in that: The step 2 specifically includes the following sub-steps: Step 2-1: The master station sends a judgment signal, which includes: a slave station address, a polarization direction switching instruction, and a test data packet; Step 2-2: After receiving the judgment signal, the slave station determines the polarization switching instruction and switches the polarization direction when polarization switching is required; the slave station calculates the CQI and feeds it back to the master station; In step 2-3, after the master station receives the feedback signal sent by the slave station, it makes a judgment based on the CQI: when the CQI is greater than the threshold, the master station maintains the judgment signal until the next feedback signal is received; when the CQI is less than the threshold, the master station updates the judgment signal, requiring the slave station to switch the antenna polarization direction, and sends the judgment signal in the next time slot, and repeats this step to receive the feedback signal again and make a judgment based on the CQI result until the channel is determined when the CQI is greater than the threshold.

3. The method for wireless transmission of the Internet of Things based on a dynamic arbitrary polarization antenna according to claim 1, wherein: When switching polarization direction, a protection period is set before switching is implemented. The encoded data in the transmission pipeline is processed during the protection period. The polarization direction is switched after the protection period ends and the old polarization data in the transmission pipeline is processed.

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