A channel access system and method with transmit channel pre-activation

Abstract

A channel access system and method with pre-activated transmit channel is disclosed to achieve efficient and reliable channel access under conditions of limited RF performance of equipment. The system incorporates a compensation backoff module and an RF management module to implement a compensation backoff method. This method involves pre-energizing the RF transmit channel during channel access and shutting it down after transmission. Combined with the system's half-duplex communication mode, this achieves communication without local oscillator leakage, improving the signal-to-noise ratio at the receiver and enabling hardware-constrained equipment to achieve an efficient and reliable channel access mechanism. Furthermore, the invention employs an integrated timer to compensate for the timer value during the backoff process, resolving time slot misalignment caused by processing delays and improving the backoff coordination between different devices.

Description

Technical Field

[0001] This invention relates to the field of communication technology, and more particularly to a channel access system and method for pre-activation of the transmit channel in the field of wireless communication technology. This invention can be used in wireless local area networks to share channels with existing wireless devices, eliminating interference caused by local oscillator leakage in radio frequency-limited systems during channel access. Background Technology

[0002] Because of the diverse device types and lack of a fixed scheduling device in wireless LANs, media access mechanisms based on Distributed Coordination Function (DCF) have become a common channel access mechanism in WLANs. This type of access mechanism performs backoff on a time-slot basis, requiring devices to immediately transmit data after the backoff period. However, the transmission channel of such systems suffers from local oscillator leakage, which degrades the signal-to-noise ratio at the receiver, making it unsuitable for longer-distance and higher-order modulation communications. This invention improves the channel access process, enabling hardware-constrained devices to achieve an efficient channel access method.

[0003] Beijing University of Posts and Telecommunications disclosed a media access method based on distributed coordination function in its patent application "Distributed Media Access Method for Wireless Local Area Networks" (Patent Application No. 201210065672.1, Publication No. CN102625466A). This method adds a random duration to the DCF inter-frame interval, with the random duration being a value between 0 and the time slot size. This allows different users to transmit data at different times after adopting the same backoff duration, avoiding users simultaneously entering a waiting state when adopting the same backoff duration. The shortcomings of this method are: it does not consider factors such as radio frequency transmission delay, reception processing delay, and channel sensing delay existing in the actual system. Overly fine time slot intervals can lead to a decrease in the redundancy of channel sensing in different devices, increasing the collision probability and reducing throughput when multiple devices are accessing the network.

[0004] Beijing Zhongdian Huada Electronic Design Co., Ltd. disclosed a method and apparatus for calibrating the local oscillator leakage of a wireless LAN chip transmitter in its patent application "A Method and Apparatus for Correcting Local Oscillator Leakage of a Wireless LAN Chip Transmitter" (Patent Application No. 201210595908.2, Publication No. CN103916345A). This apparatus corrects the transmitter's local oscillator leakage by adding a compensation circuit to the RF section and estimating the deviation values ​​of the I / Q channels using a digital one-dimensional scanning method. The estimation results are then written into the compensation circuit of the RF section. The drawback of this apparatus is that it requires transmitting a calibration waveform and uses a one-dimensional scanning method for correction. Since the local oscillator leakage changes continuously with time, voltage, temperature, and other conditions, the apparatus needs to be periodically calibrated. During the calibration process, all devices in the channel must not transmit data, otherwise it will interfere with the calibration process. This can lead to the link being unable to operate stably for extended periods when the number of devices in the system increases, reducing the system's channel utilization. Summary of the Invention

[0005] The purpose of this invention is to address the shortcomings of the existing technology by proposing a channel access system and method for pre-activation of the transmission channel. This system is designed to solve problems such as excessive local oscillator leakage leading to high system bit error rate under radio frequency constraints, and collisions caused by different data processing delays and radio frequency transmission delays of different devices.

[0006] The specific approach to achieving the objective of this invention is that the system employs a compensation backoff module and an RF management module to control the power-off and power-on of the transmission channel in real time during channel access. This integrates the channel access process with hardware implementation, achieving communication without local oscillator leakage without affecting the system's half-duplex communication mode. The method of this invention introduces a backoff compensation mechanism, which reduces the risk of transmission collisions during channel access caused by backoff time slot offsets when the channel is busy by compensating for the backoff interval.

[0007] The technical solution for achieving the objective of this invention is as follows.

[0008] The system of this invention includes a channel eavesdropping module, a compensation backoff module, a baseband transmission module, a radio frequency module, a radio frequency management module, a baseband reception module, and a frame acknowledgment module; wherein:

[0009] The channel listening module is used to perform idle channel assessment on the current channel, obtain the busy / idle status of the current channel, and input the busy / idle status of the current channel into the compensation backoff module.

[0010] The compensation backoff module includes a timer initialization unit, a local timer, an integrated timer, an idle timer, an RF control unit, and a data transmission unit. The timer initialization unit updates the values ​​of the initial backoff register and the integrated timer when the channel state changes from busy to idle, and generates a backoff start pulse. The local timer generates a timing pulse signal with a period equal to the minimum backoff interval. The integrated timer records the current backoff time. The idle timer records the current idle duration. The RF control unit generates an RF enable signal according to channel access requirements and inputs the RF enable signal into the RF module. The data transmission unit generates a baseband transmission pulse when the integrated timer value becomes 0, clears the initial register value, and inputs the baseband transmission pulse signal into the baseband transmission module.

[0011] The radio frequency management module is used to control the power-on and power-off of the radio frequency transmission channel based on the values ​​of the channel status signal, the radio frequency enable signal, and the baseband transmission pulse signal.

[0012] The radio frequency module includes a transmitting channel and a receiving channel; the transmitting channel is used to transmit the baseband signal input from the baseband transmitting module to the wireless environment; the receiving channel is used to convert the wireless signal in the wireless environment into a digital signal and input it to the baseband receiving module.

[0013] The baseband transmission module includes a data buffer unit, a modulation unit, and a buffer update unit. The data buffer unit is used to buffer data to be transmitted, and when a baseband transmission pulse signal is received, it inputs the data to be transmitted into the modulation unit. The modulation unit is used to modulate the data to be transmitted into a digital baseband signal and input the digital baseband signal into the radio frequency module. The buffer update unit is used to clear the transmitted data frames from the buffer after receiving a buffer update signal.

[0014] The baseband receiving module includes a demodulation unit and a parsing unit; the demodulation unit is used to demodulate the digital signal input from the radio frequency module to obtain a received data frame, and input the received data frame into the parsing unit; the parsing unit is used to verify the data frame, obtain the verification result, and output a frame confirmation pulse signal when the verification result is correct, and input the frame confirmation pulse signal into the frame confirmation module.

[0015] The frame confirmation module is used to detect the frame confirmation pulse signal, output the radio frequency enable signal, and after waiting for the pre-transmission time slot, send the confirmation frame to the transmitting end through the baseband transmission module and the radio frequency module.

[0016] The specific steps of the channel access method of the present invention include the following:

[0017] Step 1, listen to the channel until the channel is idle:

[0018] The channel sensing module performs idle channel assessment to obtain the current busy / idle status of the channel, and inputs the channel busy / idle status into the compensation backoff module. When the channel status becomes idle, the channel idle signal is input into the compensation backoff module.

[0019] Step 2: Use compensated backoff for channel access.

[0020] Step 2.1: When the initialization unit in the compensation backoff module detects that the channel state has changed from busy to idle, it clears the value of the idle timer to zero. If the value of the initial backoff register is 0, a random number is generated within the current contention window. The random number is multiplied by the time slot interval to obtain the random backoff duration. The value of the initial backoff register is updated to the sum of the random backoff duration and the inter-frame interval. Otherwise, the value of the initial backoff register remains unchanged.

[0021] Step 2.2: Set the value of the integrated timer to the value of the initial register and generate a timing start pulse, then input the timing start pulse into the backoff unit;

[0022] Step 2.3: The local timer of the compensation backoff module periodically generates pulse signals with an interval equal to the shortest backoff period. When the timing pulse is high, if the channel state is idle and the value of the integrated timer is greater than 0, the value of the integrated timer is subtracted from the value of the shortest backoff period, and the value of the idle timer is added to the value of the shortest backoff period. If the channel state is busy and the value of the idle duration timer is greater than the inter-frame interval, the value of the initial backoff register is updated to the result of the current integrated timer value plus the backoff compensation value, and the process returns to step 1. Otherwise, the process directly returns to step 1.

[0023] Step 2.4: When the value of the integrated timer is less than the time it takes for the RF transmit channel to operate stably from power-on, set the RF enable signal to enable; otherwise, set the RF enable signal to disable and input the RF enable signal into the RF management module.

[0024] Step 2.5: When the value of the integrated timer becomes 0, set the value of the initial register to 0, generate the baseband transmit pulse signal, and input the transmit pulse signal into the baseband transmit module;

[0025] Step 3: Power on the RF module's transmit channel in advance:

[0026] The RF management module reads the RF enable signal and the channel status. If the RF enable signal is enabled and the channel status is idle, the RF module's transmit channel is powered on; otherwise, the RF module's transmit channel is powered off.

[0027] Step 4: Complete the transmission of data frames and power off the RF module's transmission channel;

[0028] Step 4.1: When the modulation unit of the baseband transmitter module detects the baseband transmission pulse signal, it encodes and modulates the data to be transmitted in the buffer to obtain the baseband modulation signal. The baseband modulation signal is then input into the radio frequency module. The radio frequency module sends the baseband modulation signal to the wireless environment. When the baseband signal is completely transmitted, it outputs the transmission end pulse signal and inputs the baseband modulation signal and the transmission end pulse signal into the radio frequency module.

[0029] Step 4.2: When the RF management module detects the baseband transmission end signal, it cuts off the power to the RF module's transmission channel.

[0030] Step 5: Demodulate the data frame signal to obtain the original data frame:

[0031] Step 5.1: The radio frequency module of the receiving device acquires the baseband signal sent by the transmitting end in the wireless environment and inputs the received digital baseband signal into the baseband receiving module.

[0032] Step 5.2: The baseband receiving module demodulates the received digital baseband signal input from the RF module to obtain the received data frame, and inputs the received data frame into the frame parsing module;

[0033] Step 6: Parse the original data frame and reply with an acknowledgment frame:

[0034] Step 6.1: The data parsing module of the receiving device parses and verifies the data. If the verification result is correct, it generates an acknowledgment frame and a frame acknowledgment pulse signal, and inputs the frame acknowledgment pulse signal into the frame module.

[0035] Step 6.2: After the frame confirmation module of the receiving device detects the frame confirmation pulse signal, it powers on the transmission channel of the radio frequency module, waits for the pre-transmission time slot, modulates the confirmation frame into a confirmation frame baseband signal through the baseband transmission module, and inputs the confirmation frame baseband signal into the radio frequency module.

[0036] Step 6.3: The radio frequency module sends the confirmation frame baseband signal to the wireless environment. After the confirmation frame baseband signal is sent, the radio frequency module of the receiving station closes the transmission channel.

[0037] Step 7: Complete channel access and clear the transmit buffer:

[0038] Step 7.1: The radio frequency module of the transmitting device obtains the acknowledgment frame baseband signal from the wireless environment and inputs the acknowledgment frame baseband signal into the baseband demodulation module; after the baseband demodulation module finishes demodulating the acknowledgment frame and verifies its correctness, it outputs a buffer clear pulse and inputs the buffer clear pulse into the baseband transmitting module.

[0039] Step 7.2: If no buffer clearing pulse is received within the timeout interval, return to step 1 to retransmit the data; otherwise, clear the transmitted data from the buffer and complete the channel access process.

[0040] Compared with the prior art, the present invention has the following advantages:

[0041] First, because the compensation backoff module and radio frequency management module of the present invention control the power-off and power-on of the radio frequency transmission channel in real time during the channel access process, the local oscillator leakage problem at the transmitter end is eliminated from the root. This overcomes the shortcomings of the existing system where the local oscillator leakage is too large when the radio frequency device is limited, resulting in a low signal-to-noise ratio of the received signal and the inability to properly demodulate the data frame. This reduces the bit error rate of the system under long distance and high-order modulation.

[0042] Secondly, since the method of the present invention uses an integrated timer and an idle timer to realize the backoff process of different time slot intervals, and the integrated timer is decremented and compensated according to the busy and idle state of the channel, systems with different processing delays can use a unified time slot standard for backoff, which overcomes the shortcomings of existing systems where different devices have different processing delays and cause collisions, reduces the probability of collisions when accessing the channel, and improves the throughput of the link when multiple devices access. Attached Figure Description

[0043] Figure 1 This is a schematic diagram of the system modules of the present invention;

[0044] Figure 2 This is a schematic diagram of the compensation retreat module of the present invention;

[0045] Figure 3 This is a flowchart of the method of the present invention;

[0046] Figure 4 The flowchart of the compensation retreat method in this invention. Detailed Implementation

[0047] The present invention will now be further described with reference to the accompanying drawings and embodiments.

[0048] An embodiment of the present invention includes two STA site devices, wherein STA1 sends data frames to STA2 and completes the power-on and power-off of the radio frequency transmission channel and access to the common channel through the method of the present invention.

[0049] Reference Figure 1 The structure of the system of the present invention will be further described.

[0050] The system of this invention includes a channel sensing module, a compensation backoff module, a baseband transmission module, a radio frequency module, a radio frequency management module, a baseband reception module, and a frame confirmation module. Wherein:

[0051] The channel listening module is used to perform idle channel assessment on the current channel, obtain the busy / idle status of the current channel, and input the busy / idle status of the current channel into the compensation backoff module.

[0052] See attached document Figure 2 The compensation and backoff module of the present invention will be further described.

[0053] The compensation backoff module includes a timer initialization unit, a local timer, an integrated timer, an idle timer, an RF control unit, and a data transmission unit. The timer initialization unit updates the values ​​of the initial backoff register and the integrated timer when the channel state changes from busy to idle, and generates a backoff start pulse. The local timer generates a timing pulse signal with a period of 1µs. The integrated timer records the current backoff time. The idle timer records the current idle duration. The RF control unit generates an RF enable signal according to channel access requirements and inputs the RF enable signal into the RF module. The data transmission unit generates a baseband transmission pulse when the integrated timer value becomes 0, clears the initial register value, and inputs the baseband transmission pulse signal into the baseband transmission module.

[0054] The radio frequency management module is used to control the power-on and power-off of the radio frequency transmission channel based on the values ​​of the channel status signal, the radio frequency enable signal, and the baseband transmission pulse signal.

[0055] The radio frequency module includes a transmitting channel and a receiving channel; the transmitting channel is used to transmit the baseband signal input from the baseband transmitting module to the wireless environment; the receiving channel is used to convert the wireless signal in the wireless environment into a digital signal and input it into the baseband receiving module.

[0056] The baseband transmission module includes a data buffer unit, a modulation unit, and a buffer update unit. The data buffer unit is used to buffer data to be transmitted, and when a baseband transmission pulse signal is received, it inputs the data to be transmitted into the modulation unit. The modulation unit is used to modulate the data to be transmitted into a digital baseband signal and input the digital baseband signal into the radio frequency module. The buffer update unit is used to clear the transmitted data frames from the buffer after receiving a buffer update signal.

[0057] The baseband receiving module includes a demodulation unit and a parsing unit; the demodulation unit is used to demodulate the digital signal input from the radio frequency module to obtain a received data frame, and input the received data frame into the parsing unit; the parsing unit is used to verify the data frame, obtain the verification result, and output a frame confirmation pulse signal when the verification result is correct, and input the frame confirmation pulse signal into the frame confirmation module.

[0058] The frame confirmation module is used to detect the frame confirmation pulse signal, output the radio frequency enable signal, and after waiting for the pre-transmission time slot, send the confirmation frame to the transmitting end through the baseband transmission module and the radio frequency module.

[0059] Reference Figure 3 The implementation steps of embodiments of the method of the present invention will be further described below.

[0060] Step 1: Listen to the channel until the channel is idle.

[0061] The channel sensing module performs channel idleness assessment to obtain the current channel busy / idle status, and inputs the channel busy / idle status into the compensation backoff module. When the channel status becomes idle, the channel idle signal is input into the compensation backoff module.

[0062] Step 2: Channel access is performed using the compensation backoff method.

[0063] Reference Figure 4 The retreat compensation method of the present invention will be further described below.

[0064] Step 2.1: When the initialization unit in the random timer detects that the channel state has changed from busy to idle, it clears the value of the idle timer to zero. At the same time, if the value of the initial backoff register is 0, a random number is generated in a window between 0 and 15. This random number is multiplied by the time slot interval of 9us to obtain the random backoff duration. The value of the initial backoff register is updated to the sum of the random backoff duration and the inter-frame interval of 34us. Otherwise, the value of the initial backoff register remains unchanged.

[0065] Step 2.2: Set the value of the integrated timer to the value of the initial register and generate a timing start pulse, then input the timing start pulse into the backoff unit.

[0066] Step 2.3: The local timer of the compensation backoff module unit periodically generates pulse signals at 1µs intervals. When the timing pulse is high, if the channel state is idle, the value of the integrated timer is decremented by 1 and the value of the idle timer is incremented by 1. If the channel state is busy and the value of the idle duration timer is greater than the inter-frame interval (the inter-frame interval is the minimum inter-frame interval plus twice the time slot interval), the initial backoff register is updated to the current integrated timer value plus the backoff compensation value, and the process returns to step 1. Otherwise, the process directly returns to step 1. The backoff compensation value is the remainder obtained by subtracting the current integrated counter value from the inter-frame interval plus the time slot interval.

[0067] Step 2.4: When the value of the integrated timer is less than 10, set the RF enable signal to 1; otherwise, set the RF enable signal to 0 and input the RF enable signal into the RF management module.

[0068] Step 2.5: Wait for the value of the integration timer to become 0, set the value of the initial register to 0, generate the baseband transmit pulse signal, and input the transmit pulse signal into the baseband transmit module.

[0069] Step 3: Power on the RF module's transmission channel in advance.

[0070] The RF management module reads the RF enable signal and channel status. If the RF enable signal is 1 and the channel status is idle, the RF module's transmit channel is powered on; otherwise, the RF module's transmit channel is powered off.

[0071] Step 4: Complete the transmission of data frames and power off the RF module's transmission channel.

[0072] Step 4.1: When the modulation unit of the baseband transmitter module detects the baseband transmission pulse signal, it encodes and modulates the data to be transmitted in the corresponding buffer address according to the input transmission buffer address to obtain the baseband modulation signal. The baseband modulation signal is then input into the radio frequency module, which transmits the baseband modulation signal to the wireless environment. After the baseband signal is transmitted, the module outputs a transmission end pulse signal and inputs the baseband modulation signal and the transmission end pulse signal into the radio frequency module.

[0073] Step 4.2: When the RF management module detects the baseband transmission end signal, it will power off the RF module's transmission channel.

[0074] Step 5: Demodulate the data frame signal to obtain the original data frame.

[0075] Step 5.1: The STA2's radio frequency module converts the signals in the wireless environment into received digital baseband signals and inputs the received digital baseband signals into the baseband receiving module.

[0076] Step 5.2: The baseband receiving module demodulates the received digital baseband signal input from the RF module to obtain the received data frame, and inputs the received data frame into the frame parsing module.

[0077] Step 6: Parse the original data frame and reply with an acknowledgment frame.

[0078] Step 6.1: The data parsing module of STA2 parses and verifies the data. If the verification result is correct, it generates an acknowledgment frame and a frame acknowledgment pulse signal, and inputs the frame acknowledgment pulse signal into the frame acknowledgment module.

[0079] Step 6.2: After the frame confirmation module of STA2 detects the frame confirmation pulse signal, it powers on the transmission channel of the RF module, waits for the pre-transmission time slot, modulates the confirmation frame into a confirmation frame baseband signal through the baseband transmission module, and inputs the confirmation frame baseband signal into the RF module. The pre-transmission interval is greater than the time from power-on to stable operation of the RF channel.

[0080] Step 6.3: The radio frequency module sends the acknowledgment frame baseband signal to the wireless environment. After the acknowledgment frame baseband signal is sent, the transmission channel of the radio frequency module of the receiving station is turned off.

[0081] Step 7: Complete channel access and clear the transmit buffer.

[0082] Step 7.1: The RF module of STA1 extracts the acknowledgment frame baseband signal from the wireless environment and inputs the acknowledgment frame baseband signal into the baseband demodulation module. When the baseband demodulation module finishes demodulating the acknowledgment frame and detects that the frame type is a unicast frame and the frame destination address is the local address, it outputs a buffer clear pulse and inputs the buffer clear pulse into the baseband transmission module.

[0083] Step 7.2: If no buffer clearing pulse is received within the timeout transmission interval, return to step 1 for data retransmission. The timeout interval is a value greater than the sum of the pre-transmission interval and the demodulation delay at the receiving end. Otherwise, clear the transmitted data from the buffer to complete the channel access process.

Claims

1. A channel access system of transmit channel pre-boot, comprising a channel listening module, a baseband sending module, a radio frequency module, a baseband receiving module and a frame confirmation module; characterized in that, It also includes a compensation backoff module and a radio frequency management module; wherein: The channel listening module is used to perform idle channel assessment on the current channel, obtain the busy / idle status of the current channel, and input the busy / idle status of the current channel into the compensation backoff module. The compensation backoff module includes a timer initialization unit, a local timer, an integrated timer, an idle timer, an RF control unit, and a data transmission unit. The timer initialization unit updates the values ​​of the initial backoff register and the integrated timer when the channel state changes from busy to idle, and generates a backoff start pulse. The local timer generates a timing pulse signal with a period equal to the minimum backoff interval. The integrated timer records the current backoff time. The idle timer records the current idle duration. The RF control unit generates an RF enable signal according to channel access requirements and inputs the RF enable signal into the RF module. The data transmission unit generates a baseband transmission pulse when the integrated timer value becomes 0, clears the initial register value, and inputs the baseband transmission pulse signal into the baseband transmission module. The radio frequency management module is used to control the power-on and power-off of the radio frequency transmission channel based on the values ​​of the channel status signal, the radio frequency enable signal, and the baseband transmission pulse signal. The radio frequency module includes a transmitting channel and a receiving channel; the transmitting channel is used to transmit the baseband signal input from the baseband transmitting module to the wireless environment; the receiving channel is used to convert the wireless signal in the wireless environment into a digital signal and input it to the baseband receiving module. The baseband transmission module includes a data buffer unit, a modulation unit, and a buffer update unit. The data buffer unit is used to buffer data to be transmitted, and when a baseband transmission pulse signal is received, it inputs the data to be transmitted into the modulation unit. The modulation unit is used to modulate the data to be transmitted into a digital baseband signal and input the digital baseband signal into the radio frequency module. The buffer update unit is used to clear the transmitted data frames from the buffer after receiving a buffer update signal. The baseband receiving module includes a demodulation unit and a parsing unit; the demodulation unit is used to demodulate the digital signal input from the radio frequency module to obtain a received data frame, and input the received data frame into the parsing unit; the parsing unit is used to verify the data frame, obtain the verification result, and output a frame confirmation pulse signal when the verification result is correct, and input the frame confirmation pulse signal into the frame confirmation module. The frame confirmation module is used to detect the frame confirmation pulse signal, output the radio frequency enable signal, and after waiting for the pre-transmission interval, send the confirmation frame to the transmitting end through the baseband transmission module and the radio frequency module.

2. A channel access method for pre-activation of the transmit channel in the channel access system according to claim 1, characterized in that, Channel access is achieved using a compensated backoff method, and an RF control mechanism is introduced during the channel access process. The RF module's transmission channel is powered on in advance based on the value of the integrated timer, and powered off after transmission is complete. The specific steps of this channel access method are as follows: Step 1, listen to the channel until the channel is idle: The channel sensing module performs idle channel assessment to obtain the current busy / idle status of the channel, and inputs the channel busy / idle status into the compensation backoff module. When the channel status becomes idle, the channel idle signal is input into the compensation backoff module. Step 2: Use compensated backoff for channel access. Step 2.1: When the initialization unit in the compensation backoff module detects that the channel state has changed from busy to idle, it clears the value of the idle timer to zero. If the value of the initial backoff register is 0, a random number is generated within the current contention window. The random number is multiplied by the time slot interval to obtain the random backoff duration. The value of the initial backoff register is updated to the sum of the random backoff duration and the inter-frame interval. Otherwise, the value of the initial backoff register remains unchanged. Step 2.2: Set the value of the integrated timer to the value of the initial register and generate a timing start pulse, then input the timing start pulse into the backoff unit; Step 2.3: The local timer of the compensation backoff module periodically generates pulse signals with the shortest backoff period interval; When the timing pulse is high, if the channel state is idle and the value of the integrated timer is greater than 0, the value of the integrated timer is reduced by the value of the shortest backoff period, and the value of the idle timer is increased by the value of the shortest backoff period; if the channel state is busy and the value of the idle duration timer is greater than the inter-frame interval, the value of the initial backoff register is updated to the result of the current value of the integrated timer plus the backoff compensation value, and the process returns to step 1. Otherwise, return directly to step 1; Step 2.4: When the value of the integrated timer is less than the time it takes for the RF transmit channel to operate stably from power-on, set the RF enable signal to enable; otherwise, set the RF enable signal to disable and input the RF enable signal into the RF management module. Step 2.5: When the value of the integrated timer becomes 0, set the value of the initial register to 0, generate a baseband transmit pulse signal, and input the transmit pulse signal into the baseband transmit module; Step 3: Power on the RF module's transmit channel in advance: The RF management module reads the RF enable signal and the channel status. If the RF enable signal is enabled and the channel status is idle, the RF module's transmit channel is powered on; otherwise, the RF module's transmit channel is powered off. Step 4: Complete the transmission of data frames and power off the RF module's transmission channel; Step 4.1: When the modulation unit of the baseband transmitter module detects the baseband transmission pulse signal, it encodes and modulates the data to be transmitted in the buffer to obtain the baseband modulation signal. The baseband modulation signal is then input into the radio frequency module. The radio frequency module sends the baseband modulation signal to the wireless environment. When the baseband signal is completely transmitted, it outputs the transmission end pulse signal and inputs the baseband modulation signal and the transmission end pulse signal into the radio frequency module. Step 4.2: When the RF management module detects the baseband transmission end signal, it cuts off the power to the RF module's transmission channel. Step 5: Demodulate the data frame signal to obtain the original data frame: Step 5.1: The radio frequency module of the receiving device acquires the baseband signal sent by the transmitting end in the wireless environment and inputs the received digital baseband signal into the baseband receiving module. Step 5.2: The baseband receiving module demodulates the received digital baseband signal input from the RF module to obtain the received data frame, and inputs the received data frame into the frame parsing module; Step 6: Parse the original data frame and reply with an acknowledgment frame: Step 6.1: The data parsing module of the receiving device parses and verifies the data. If the verification result is correct, it generates an acknowledgment frame and a frame acknowledgment pulse signal, and inputs the frame acknowledgment pulse signal into the frame module. Step 6.2: After the frame confirmation module of the receiving device detects the frame confirmation pulse signal, it powers on the transmission channel of the radio frequency module, waits for the pre-transmission interval, modulates the confirmation frame into a confirmation frame baseband signal through the baseband transmission module, and inputs the confirmation frame baseband signal into the radio frequency module. Step 6.3: The radio frequency module sends the confirmation frame baseband signal to the wireless environment. After the confirmation frame baseband signal is sent, the radio frequency module of the receiving station closes the transmission channel. Step 7: Complete channel access and clear the transmit buffer: Step 7.1: The radio frequency module of the transmitting device obtains the acknowledgment frame baseband signal from the wireless environment and inputs the acknowledgment frame baseband signal into the baseband demodulation module; After the baseband demodulation module confirms the end of the demodulation frame and verifies its correctness, it outputs a buffer clear pulse, which is then input to the baseband transmission module. Step 7.2: If no buffer clearing pulse is received within the timeout interval, return to step 1 to retransmit the data; otherwise, clear the transmitted data from the buffer and complete the channel access process.

3. The channel access method according to claim 2, characterized in that, The time slot interval mentioned in step 2.1 is a value greater than the carrier sensing delay.

4. The channel access method according to claim 2, characterized in that, The inter-frame interval mentioned in step 2.1 is the minimum inter-frame interval plus twice the time slot interval.

5. The channel access method according to claim 2, characterized in that, The backoff compensation value mentioned in step 2.3 is the remainder obtained by subtracting the value of the current integration counter from the remainder of the inter-frame interval plus the time slot interval.

6. The channel access method according to claim 2, characterized in that, The shortest backoff period mentioned in step 2.3 is a value greater than the channel listening delay.

7. The channel access method according to claim 2, characterized in that, The verification in step 6.1 is correct if the frame type is a unicast frame and the frame destination address is the local machine's address.

8. The channel access method according to claim 2, characterized in that, The pre-transmission interval mentioned in step 6.2 is greater than the time it takes for the RF channel to go from power-on to stable operation.

9. The channel access method according to claim 2, characterized in that, The timeout interval mentioned in step 7.2 is a value greater than the sum of the pre-transmission interval and the demodulation delay at the receiving end.

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