Wireless network weak broadband interference resistant communication method and system based on differentiated lead codes

Abstract

The invention relates to the technical field of industrial wireless communication, in particular to a wireless network weak broadband interference resistant communication method and system based on differentiated lead codes, and the method comprises the steps that access point equipment collects the channel state information of each sub-channel, and distributes different lead code sequence configurations for each sub-channel according to the channel state; sending the configuration to the terminal equipment through the management frame; after the terminal equipment analyzes the configuration, preamble detection is executed on each sub-channel in parallel, timing synchronization is performed by using a corresponding L-STF sequence, and channel estimation is performed by using an L-LTF sequence; and screening available sub-channels according to a detection result and completing data receiving demodulation. The system correspondingly comprises a channel state information acquisition module, a lead code sequence configuration distribution module, a management frame sending and analyzing module, a lead code detection module, a sub-channel screening module and a data receiving demodulation module. According to the method, detection performance coupling between sub-channels is broken through differential sequence design, and the communication robustness in a weak broadband interference environment is improved by utilizing a dynamic negotiation and parallel detection mechanism.

Description

Technical Field

[0001] This invention relates to the field of industrial wireless communication technology, and in particular to a wireless network anti-weak broadband interference communication method and system based on differentiated preamble codes. Background Technology

[0002] In modern high-throughput wireless communication systems (such as IEEE 802.11ac / ax / be), channel bonding technology is commonly used to improve spectral efficiency, aggregating multiple adjacent 20MHz sub-channels into a wideband (such as 80MHz or 160MHz) for data transmission. In the physical layer frame structure, the transmitter needs to replicate the same traditional preamble (including L-STF, L-LTF, L-SIG, etc.) on each 20MHz sub-channel and apply a fixed phase rotation only to each sub-channel to reduce phase discontinuities at sub-channel boundaries, meet spectral transmission mask requirements, and support detection by traditional devices. The receiver relies on the preamble to perform critical operations such as timing synchronization, frequency offset correction, and channel estimation. However, interference is unavoidable in real-world wireless environments, especially when the system operates in industrial, smart home, or high-density deployment scenarios, often simultaneously exhibiting strong narrowband interference (such as Bluetooth and radar) and weak wideband interference (such as remote WiFi, Zigbee, or thermal noise rise).

[0003] All sub-channels use the exact same preamble sequence, resulting in consistent correlation characteristics in the frequency domain. However, when weak broadband interference (i.e., interference power density slightly lower than the received signal, typically above -85dBm, but with a coverage bandwidth exceeding 40MHz, such as remote WiFi leakage, Zigbee clustering, and harmonics from industrial equipment) exists, the signal-to-interference-plus-noise ratio (SINR) of the preambles in each sub-channel deteriorates synchronously. The receiver struggles to distinguish between valid signals and noise, significantly increasing the probability of preamble detection failure. Furthermore, under weak interference, multiple sub-channels may simultaneously generate similar but erroneous correlation peaks, causing the receiver to misjudge the synchronization position or channel state, leading to subsequent demodulation failures and wasting bandwidth resources. Figure 1 As shown, existing technologies, such as preamble punching, are only suitable for skipping strong interference sub-channels, but cannot improve the detection reliability of weak interference sub-channels. Although the dual-channel preamble detection mechanism can avoid strong interference in the main channel, in weak broadband interference scenarios, if both the main and backup channels use the same sequence, the detection results of the two channels are highly correlated, the diversity gain is limited, and they are still prone to simultaneous failure.

[0004] Therefore, there is an urgent need for a communication method that can improve the robustness of preamble detection in weak broadband interference environments. This method can enhance the preamble differences between sub-channels, achieve frequency diversity and interference decoupling, and thus maintain the stability of high-bandwidth communication.

[0005] Existing technologies employ a homogeneous preamble plus phase rotation architecture, which is essentially designed to meet spectrum compliance and backward compatibility requirements, without considering the heterogeneity of interference between sub-channels and the need for detection decoupling. Summary of the Invention

[0006] To address the shortcomings of existing technologies, this invention provides a wireless network anti-weak broadband interference communication method and system based on differentiated preambles. This solves the technical problem that high-bandwidth wireless communication systems use the same preamble sequence in all sub-channels in complex electromagnetic environments such as industrial wireless and high-density WiFi, resulting in highly coupled and easily synchronized failures in preamble detection performance under weak broadband interference, leading to communication link interruptions.

[0007] To solve the above-mentioned technical problems, the specific contents of the present invention are as follows:

[0008] In a first aspect, the present invention provides a wireless network anti-weak broadband interference communication method based on differentiated preamble codes, comprising:

[0009] Step 1: The access point device collects channel state information of multiple sub-channels in the aggregated channel to obtain channel state information including at least one of received signal strength, frame error rate and air interface occupancy rate.

[0010] Step 2: The access point device uses the collected channel state information to assign different preamble sequence configurations to each sub-channel in the aggregated channel, generating a preamble sequence configuration including L-STF sequence identifiers and L-LTF sequence identifiers;

[0011] Step 3: The access point device sends the allocated preamble sequence configuration to the terminal device via a management frame;

[0012] Step 4: The terminal device receives the management frame sent by the access point device, and parses the management frame to obtain the preamble sequence configuration corresponding to each sub-channel;

[0013] Step 5: When the terminal device detects an RF signal, it uses the preamble sequence obtained from the management frame to configure and performs preamble detection in parallel on each sub-channel. Each sub-channel uses the corresponding L-STF sequence for timing synchronization and the corresponding L-LTF sequence for channel estimation.

[0014] Step 6: Based on the preamble detection results, the terminal device filters out the successfully detected sub-channels from multiple sub-channels and marks them as available sub-channels.

[0015] Step 7: The terminal device completes the reception and demodulation of data frames on the marked available sub-channels.

[0016] Furthermore, in the wireless network anti-weak broadband interference communication method based on differentiated preamble described in this invention, step 2 includes:

[0017] The access point device selects orthogonal or quasi-orthogonal L-STF sequence variants and L-LTF sequence variants from a predefined preamble sequence library;

[0018] The access point equipment determines the sequence allocation order based on the position index of the sub-channel in the aggregate bandwidth, with the position index numbered sequentially from left to right.

[0019] The access point device uses the collected channel state information to assess the interference level of the sub-channels and allocates sequence variants with higher processing gain to sub-channels with interference levels higher than a preset threshold.

[0020] When allocating sequence variants, the access point device maintains the sub-channel boundary phase rotation parameters in accordance with the spectrum emission mask requirements.

[0021] Furthermore, in the wireless network anti-weak broadband interference communication method based on differentiated preamble described in this invention, step 3 includes:

[0022] The access point device constructs a Beacon frame and adds an extended preamble configuration element to the Beacon frame;

[0023] The access point device sets the main channel index field to indicate the main channel position, sets the bandwidth indicator field to identify the aggregate bandwidth, sets the counter field to realize synchronization control, and sets the sub-channel configuration list to record the sequence configuration of the sub-channel in the extended preamble configuration element;

[0024] The access point device adopts a multi-frame transmission mechanism, carrying the same extended preamble configuration element in multiple consecutive Beacon frames;

[0025] The access point device controls the timing of the preamble sequence configuration by decrementing the counter field.

[0026] Furthermore, in the wireless network anti-weak broadband interference communication method based on differentiated preamble described in this invention, step 4 includes:

[0027] The terminal device listens for Beacon frames in the channel and captures Beacon frames including extended preamble configuration elements;

[0028] The terminal device parses the extended preamble configuration elements in the captured Beacon frames and extracts the main channel index, aggregate bandwidth, and sub-channel configuration list.

[0029] The terminal device determines when the configuration takes effect based on the current value of the counter field in the extended preamble configuration element. When the counter value is zero, the new preamble sequence configuration is enabled.

[0030] If the terminal device does not receive a Beacon frame during the counter decrement process, the terminal device will wait to receive subsequent Beacon frames to complete the configuration update.

[0031] Furthermore, in the wireless network anti-weak broadband interference communication method based on differentiated preamble described in this invention, step 5 includes:

[0032] The terminal device is configured according to the acquired preamble sequence and loads the corresponding L-STF sequence and L-LTF sequence for the sub-channel;

[0033] The terminal device performs sliding correlation calculations simultaneously on the sub-channel to obtain the correlation peak value between the received signal and the local sequence;

[0034] The terminal device compares the correlation peak of the sub-channel with the adaptive threshold to determine whether the preamble detection is successful.

[0035] For successfully detected sub-channels, the terminal device uses the configured L-LTF sequence to perform channel estimation and frequency offset correction.

[0036] Furthermore, in the wireless network anti-weak broadband interference communication method based on differentiated preamble described in this invention, step 6 includes:

[0037] The terminal device establishes a sub-channel status table to record the detection status, channel estimation quality, and signal-to-noise ratio information of the sub-channel;

[0038] The terminal device uses the sub-channel status table and prioritizes selecting the sub-channels that have been successfully detected in the main channel.

[0039] When the primary channel detection fails, the terminal device selects a backup channel;

[0040] The terminal device sorts the remaining sub-channels according to the channel estimation quality and selects the sub-channel with the best channel estimation quality as a supplement;

[0041] The terminal device updates the sub-channel status table, marking available and unavailable sub-channels.

[0042] Furthermore, in the wireless network anti-weak broadband interference communication method based on differentiated preambles described in this invention, the preamble sequence configuration in step 2 includes the STF repetition count and the LTF repetition count;

[0043] Access point equipment uses channel state information to dynamically configure the STF repetition count and LTF repetition count for sub-channels;

[0044] For sub-channels with poor channel conditions, the access point device allocates a higher number of repetitions;

[0045] For sub-channels with good channel conditions, the access point device allocates a lower number of repetitions to reduce overhead.

[0046] Furthermore, the wireless network anti-weak broadband interference communication method based on differentiated preamble described in this invention also includes:

[0047] Access point equipment periodically updates channel status information;

[0048] When the access point device detects a channel state change exceeding a threshold value, the access point device triggers a reconfiguration process;

[0049] The access point device reconfigures the preamble sequence for the sub-channels and generates updated configuration information.

[0050] The access point device sends the updated configuration information to the terminal device through management frames.

[0051] Furthermore, in the wireless network anti-weak broadband interference communication method based on differentiated preamble described in this invention, step 7 includes:

[0052] The terminal device constructs a combined channel response based on the channel estimation results of the available sub-channels;

[0053] The terminal device uses the combined channel response to perform frequency domain equalization on the received signal to compensate for channel distortion.

[0054] The terminal device skips the frequency band corresponding to the sub-channel that failed detection and demodulates data symbols on the available sub-channel;

[0055] The terminal device uses an error correction decoding algorithm to recover the original data bit stream.

[0056] Secondly, the present invention provides a wireless network anti-weak broadband interference communication system based on differentiated preamble, applied to the wireless network anti-weak broadband interference communication method based on differentiated preamble as described above, comprising:

[0057] The channel state information acquisition module is used by the access point device to acquire channel state information of multiple sub-channels in the aggregated channel, and obtain channel state information including at least one of received signal strength, frame error rate and air interface occupancy rate;

[0058] The preamble sequence configuration allocation module is used by the access point device to use the collected channel state information to allocate different preamble sequence configurations to each sub-channel in the aggregated channel, and generate a preamble sequence configuration including L-STF sequence identifier and L-LTF sequence identifier;

[0059] The management frame sending module is used by the access point device to send the allocated preamble sequence configuration to the terminal device via a management frame.

[0060] The management frame parsing module is used by the terminal device to receive management frames sent by the access point device and parse the management frames to obtain the preamble sequence configuration corresponding to each sub-channel.

[0061] The preamble detection module is used to configure the preamble sequence obtained from the management frame when the terminal device detects the radio frequency signal. It performs preamble detection in parallel on each sub-channel, wherein each sub-channel uses the corresponding L-STF sequence for timing synchronization and the corresponding L-LTF sequence for channel estimation.

[0062] The sub-channel filtering module is used by the terminal device to filter out the successfully detected sub-channels from multiple sub-channels based on the preamble detection results and mark them as available sub-channels.

[0063] The data receiving and demodulation module is used by the terminal device to receive and demodulate data frames on the marked available sub-channels.

[0064] Beneficial effects of this invention;

[0065] This invention significantly improves communication robustness under weak broadband interference. In existing technologies, all sub-channels use the same preamble sequence. Under weak broadband interference (such as remote WiFi, Zigbee, motor harmonics, etc.), multiple sub-channels degrade synchronously, resulting in a high preamble detection failure rate. This solution, through differentiated preamble sequence design, enables each sub-channel to have independent frequency domain characteristics. Even if adjacent sub-channels are interfered with, reception can still be successfully initiated through undisturbed or lightly interfered sub-channels, avoiding waste of bandwidth resources.

[0066] This invention achieves sub-channel level frequency diversity gain. Different sub-channels use orthogonal or quasi-orthogonal L-STF / L-LTF sequence variants to break the correlation of receiving performance. In scenarios with frequency selective fading or interference in some frequency bands, it provides natural frequency diversity gain. The measured channel estimation error is reduced by 4–6 dB, and the preamble detection success rate is improved by more than 35%.

[0067] This invention supports dynamic interference adaptation and precise configuration. Through the extended preamble configuration element in the Beacon frame, the AP can independently allocate the optimal sequence ID and extension multiple to each sub-channel according to the real-time channel status (RSSI, error rate, occupancy rate). A 5-frame redundant synchronization mechanism is adopted to ensure that the STA can reliably update the configuration and avoid reception failure due to Beacon loss. Attached Figure Description

[0068] To more clearly illustrate the technical solution of the present invention, the drawings used in the embodiments will be briefly introduced below. Obviously, for those skilled in the art, other drawings can be obtained based on the drawings without creative effort.

[0069] Figure 1 This is a schematic diagram of a wireless network anti-weak broadband interference communication method based on differentiated preamble provided by the present invention. Detailed Implementation

[0070] To make the technical solution of the present invention clearer, the present invention will be clearly and completely described below with reference to specific embodiments and corresponding drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention. The present invention provided by various embodiments will be described in detail below with reference to the accompanying drawings. To better understand the purpose of the present invention, the present invention will be described in further detail below.

[0071] In a first aspect, the present invention provides a wireless network anti-weak broadband interference communication method based on differentiated preamble codes, comprising:

[0072] Step 1: The access point device collects channel state information of multiple sub-channels in the aggregated channel to obtain channel state information including at least one of received signal strength, frame error rate and air interface occupancy rate.

[0073] Step 2: The access point device uses the collected channel state information to assign different preamble sequence configurations to each sub-channel in the aggregated channel, generating a preamble sequence configuration including L-STF sequence identifiers and L-LTF sequence identifiers;

[0074] Step 3: The access point device sends the allocated preamble sequence configuration to the terminal device via a management frame;

[0075] Step 4: The terminal device receives the management frame sent by the access point device, and parses the management frame to obtain the preamble sequence configuration corresponding to each sub-channel;

[0076] Step 5: When the terminal device detects an RF signal, it uses the preamble sequence obtained from the management frame to configure and performs preamble detection in parallel on each sub-channel. Each sub-channel uses the corresponding L-STF sequence for timing synchronization and the corresponding L-LTF sequence for channel estimation.

[0077] Step 6: Based on the preamble detection results, the terminal device filters out the successfully detected sub-channels from multiple sub-channels and marks them as available sub-channels.

[0078] Step 7: The terminal device completes the reception and demodulation of data frames on the marked available sub-channels.

[0079] In industrial wireless communication or high-density WiFi deployment scenarios, wireless channels are often challenged by weak broadband interference, such as remote WiFi leakage or broadband noise generated by Zigbee devices. To improve the reliability of the communication link, the access point device first collects channel state information of multiple sub-channels in the aggregated channel. The access point device periodically scans each 20MHz sub-channel, measuring parameters such as received signal strength, frame error rate, and air interface occupancy rate, thereby comprehensively evaluating the interference level and channel quality of each sub-channel. This scanning mechanism allows the access point device to capture channel state changes in real time, providing a data foundation for subsequent dynamic configuration.

[0080] Based on the acquired channel state information, the access point device (APD) assigns a different preamble sequence configuration to each sub-channel in the aggregated channel. The preamble sequence configuration includes L-STF sequence identifiers and L-LTF sequence identifiers. The APD selects orthogonal or quasi-orthogonal L-STF and L-LTF sequence variants from a predefined preamble sequence library. The sequence allocation process considers the sub-channel's position index within the aggregated bandwidth, with position indices numbered sequentially from left to right. The APD uses the channel state information to assess the interference level of the sub-channels and allocates sequence variants with higher processing gain to sub-channels with interference levels exceeding a preset threshold. When allocating sequence variants, the APD ensures that the sub-channel boundary phase rotation parameters conform to the spectral emission mask requirements, guaranteeing backward compatibility.

[0081] The access point device (APD) sends the allocated preamble sequence configuration to the terminal device via management frames. The management frames use the Beacon frame format, and the APD adds extended preamble configuration elements to these Beacon frames. These extended preamble configuration elements include a main channel index field, a bandwidth indicator field, a counter field, and a sub-channel configuration list. The APD employs a multi-frame transmission mechanism, carrying the same extended preamble configuration elements in multiple consecutive Beacon frames. The counter field is used for synchronization control, decrementing the count to control when the preamble sequence configuration takes effect. This redundant transmission method improves the reliability of configuration updates and avoids communication interruptions due to single-frame loss.

[0082] The terminal device receives management frames sent by the access point device and parses the extended preamble configuration elements within them. The terminal device listens for Beacon frames in the channel and captures Beacon frames including the extended preamble configuration elements. The terminal device extracts the main channel index, aggregate bandwidth, and configuration list for each sub-channel. The terminal device determines when the configuration takes effect based on the current value of the counter field in the extended preamble configuration element; when the counter value is zero, a new preamble sequence configuration is initiated. If the terminal device does not receive a Beacon frame during the counter decrement process, it waits to receive subsequent Beacon frames to complete the configuration update, ensuring the integrity of configuration synchronization.

[0083] When the terminal device detects an RF signal, it uses the preamble sequence configuration obtained from the management frame to perform preamble detection in parallel on each sub-channel. The terminal device loads the corresponding L-STF and L-LTF sequences for each sub-channel. Simultaneously, the terminal device performs sliding correlation calculations on the sub-channel to obtain the correlation peak between the received signal and the local sequence. The terminal device compares the correlation peak of the sub-channel with an adaptive threshold to determine whether the preamble detection was successful. For successfully detected sub-channels, the terminal device uses the configured L-LTF sequence for channel estimation and frequency offset correction, preparing conditions for data demodulation.

[0084] Based on the preamble detection results, the terminal device filters out successfully detected sub-channels from multiple sub-channels and marks them as available sub-channels. The terminal device establishes a sub-channel status table, recording the detection status, channel estimation quality, and signal-to-noise ratio (SNR) information of each sub-channel. Using the sub-channel status table, the terminal device prioritizes successfully detected sub-channels from the primary channel. When the primary channel detection fails, the terminal device selects a backup channel. The terminal device sorts the remaining sub-channels according to their channel estimation quality and selects the sub-channel with the best estimation quality as a supplement. The terminal device updates the sub-channel status table, explicitly marking available and unavailable sub-channels, providing a basis for subsequent data reception.

[0085] The terminal device receives and demodulates data frames on the marked available sub-channels. It constructs a combined channel response based on the channel estimation results of the available sub-channels. The terminal device uses the combined channel response to perform frequency domain equalization on the received signal to compensate for channel distortion. It skips the frequency bands corresponding to sub-channels that failed detection and demodulates data symbols on the available sub-channels. The terminal device employs an error correction decoding algorithm to recover the original data bitstream, achieving efficient and reliable data transmission. This process, through differentiated preamble sequence design and dynamic configuration, effectively addresses weak broadband interference and improves system performance in complex environments.

[0086] In step 2, the access point device selects orthogonal or quasi-orthogonal L-STF and L-LTF sequence variants from a predefined preamble sequence library. Each sequence variant is optimized to exhibit low cross-correlation in the frequency domain, thereby providing frequency diversity gain in industrial wireless scenarios to address weak broadband interference such as motor harmonics or remote WiFi leakage. The access point device determines the sequence allocation order based on the sub-channel's position index in the aggregated bandwidth, with the position index numbered sequentially from left to right, ensuring that the sequence allocation naturally aligns with the physical frequency band layout. The interference level of the sub-channel is assessed using the collected channel state information. For sub-channels with higher interference levels, sequence variants with higher processing gain are allocated, such as by increasing the sequence length or employing anti-interference coding to improve detection reliability. During the allocation process, the access point device maintains the sub-channel boundary phase rotation parameters in accordance with the spectrum emission mask requirements to support coexistence with traditional equipment and meet regulatory compliance.

[0087] In step 3, the access point device constructs a Beacon frame and embeds an extended preamble configuration element. This element includes a main channel index field to identify the main channel location, a bandwidth indication field to specify the aggregate bandwidth range, a counter field for synchronization control, and a sub-channel configuration list to record the sequence parameters of each sub-channel. The access point device employs a multi-frame transmission mechanism, repeatedly carrying the same configuration element in multiple consecutive Beacon frames, and managing the timing of configuration activation by decrementing the counter field. This redundant transmission method effectively addresses channel collisions or frame loss issues in high-density WiFi deployments, enabling terminal devices to complete configuration synchronization through subsequent frames even if they miss receiving some Beacon frames.

[0088] In step 4, the terminal device continuously listens for Beacon frames in the channel, captures frames including extended preamble configuration elements, parses their contents, and extracts key information such as the main channel index, aggregated bandwidth, and sub-channel configuration list. The terminal device determines when the configuration takes effect based on the current value of the counter field; when the counter reaches zero, the new configuration is immediately enabled. If a Beacon frame is not received during the counter's decrement, the terminal device waits for subsequent frames to arrive to complete the update. This mechanism avoids configuration synchronization issues caused by temporary channel degradation in dynamic industrial environments.

[0089] In step 5, the terminal device loads the corresponding L-STF and L-LTF sequences for each sub-channel according to the preamble sequence configuration, and performs sliding correlation calculations in parallel on all sub-channels to obtain the correlation peak value between the received signal and the local sequence. The terminal device compares the correlation peak value of each sub-channel with an adaptive threshold, which is dynamically adjusted based on historical detection statistics, thereby accurately determining whether the preamble detection was successful. For successfully detected sub-channels, the terminal device uses the configured L-LTF sequence to perform fine-grained channel estimation and frequency offset correction, laying the foundation for subsequent data demodulation.

[0090] In step 6, the terminal device establishes a sub-channel status table to record information such as detection status, channel estimation quality, and signal-to-noise ratio, and prioritizes successfully detected sub-channels from the main channel to maintain link stability. When the main channel fails, the terminal device automatically switches to the backup channel, and simultaneously sorts the remaining sub-channels according to their channel estimation quality, selecting the best-quality one as a supplement. Finally, the sub-channel status table is updated and available frequency bands are marked, thereby achieving intelligent bandwidth aggregation in complex interference environments.

[0091] The preamble sequence configuration of claim 2 further includes STF repetition count and LTF repetition count, with the access point device dynamically adjusting each parameter based on channel state information. For sub-channels experiencing heavy interference, the repetition count is increased to improve processing gain, while for sub-channels in good condition, the repetition count is reduced to decrease overhead. This flexible configuration effectively balances reliability and efficiency in industrial IoT scenarios.

[0092] The invention also includes the access point device periodically updating channel state information, triggering a reconfiguration process when a change in interference level or bit error rate exceeds a threshold. The access point device recalculates the preamble sequence configuration for each sub-channel and sends the update via management frames, enabling the terminal device to adapt to channel changes in real time and improving the system's resilience in dynamic environments.

[0093] In step 7, the terminal device constructs a combined channel response based on the channel estimation results of the available sub-channels, and uses this response for frequency domain equalization to compensate for channel distortion. The terminal device skips the frequency bands corresponding to the sub-channels that failed to be detected, demodulates data symbols only on each available sub-channel, and finally applies an error correction decoding algorithm to recover the original data stream.

[0094] This application provides an anti-interference preamble transmission and detection method for high-bandwidth wireless communication systems, applicable to wireless protocols employing channel-bonding architectures (such as IEEE 802.11ac / ax / be, WIA-FA, etc.). This method significantly improves the system's communication robustness in scenarios with weak broadband interference or cross-channel coupling interference by introducing differentiated preamble sequence design, a dynamic sequence negotiation mechanism, and a multi-sequence parallel detection architecture. Specifically, it includes the following three core components:

[0095] Differentiated preamble sequence design

[0096] This application abandons the homogeneous preamble mode of existing technologies that "replicates the same L-STF / L-LTF sequence on all 20MHz sub-channels," and proposes a transmission mechanism that allocates differentiated preamble sequences according to sub-channels. In high-bandwidth (≥40MHz) transmission, the transmitter independently configures L-STF and L-LTF sequences for each 20MHz sub-channel, specifically including:

[0097] Define a set of orthogonal or quasi-orthogonal preamble sequence variants {S0,S1,…,SN-1} and {T0,T1,…,TN-1}, which correspond to L-STF and L-LTF, respectively;

[0098] Where N is the number of 20MHz sub-channels included in the current aggregated bandwidth (e.g., N=4 for 80MHz, N=8 for 160MHz);

[0099] The transmitting end sets the L-STF of sub-channel i to Si and the L-LTF to Ti according to the sub-channel's position index i in the aggregate bandwidth (numbered from 0 to N-1 from left to right);

[0100] At the same time, the sub-channel boundary phase rotation specified in the standard is retained to ensure spectrum mask compliance and compatibility with legacy devices.

[0101] The core advantage of this design lies in breaking the isomorphism of preambles between sub-channels. In scenarios with weak broadband interference (such as motor harmonics or remote WiFi leakage), even if the interference covers multiple adjacent sub-channels (e.g., sub-channels 1, 2, and 3 in an 80MHz bandwidth), they will not fail synchronously because each sub-channel uses a different sequence and has different cross-correlation characteristics with the interference. For example, sub-channel 2 may fail to detect S2 / T2 correctly due to strong interference; however, sub-channel 1 uses S1 / T1, and sub-channel 3 uses S3 / T3, whose sequence spectral characteristics are different from the interference, allowing synchronization and channel estimation to still be achieved. The system can then skip the disturbed sub-channel, maintaining data transmission in the remaining bandwidth and avoiding full-link interruption due to localized interference.

[0102] Dynamic sequence negotiation mechanism

[0103] To achieve interference adaptation and network coordination, this application introduces a dynamic preamble configuration negotiation mechanism based on Beacon frames.

[0104] Access points (APs) or network coordination nodes periodically (e.g., every 2 seconds) scan the channel status of each 20MHz sub-channel, including Received Signal Strength (RSSI), Frame Check Sequence (FCS) error rate, air interface occupancy, etc. Based on the evaluation results, the AP dynamically selects the optimal preamble sequence ID and extension factor for each sub-channel and sends it to all associated STAs through the Extended Preamble Configuration Element in the Beacon frame.

[0105] The element has the following format:

[0106] Primarychannelindex: The index of the primary channel within the aggregate bandwidth.

[0107] Bandwidth: Indicates bandwidth

[0108] Send_cnt: Indicates the number of messages to send. After Send_cnt reaches 0, the terminal device switches the preamble sequence.

[0109] Per-Subchannelconfiglist: Configuration for each subchannel.

[0110] STF_NUM: The number of STFs used in the current subchannel

[0111] LTF_NUM: The number of LTFs used in the current subchannel

[0112] STF_Sequence_id: The ID of the STF sequence used by the current sub-channel.

[0113] LTF_Sequence_id: The ID of the LTF sequence used in the current sub-channel.

[0114] To avoid packet reception failure due to preamble mismatch caused by receiving Beacon, the dynamic sequence negotiation mechanism adopts a synchronous reliability design, using 5 redundant Beacon frames to send the same configuration (Send_cnt from 5 to 0). Even if the terminal device misses 1 to 2 Beacon frames, the configuration synchronization can still be completed in subsequent frames.

[0115] Receiver-side multi-sequence detection architecture;

[0116] After receiving a Beacon frame, the terminal device (STA) parses the extended preamble configuration element and loads the preamble sequence and extended parameters of each sub-channel into the physical layer receiver engine.

[0117] During the receiving process:

[0118] When radio frequency energy is detected, the STA performs preamble detection in parallel on each 20MHz sub-channel;

[0119] For sub-channel i, L-STF timing synchronization, L-LTF channel estimation and frequency offset correction are performed using the configured Si and Ti sequences, respectively;

[0120] If the preamble correlation peak value of a certain sub-channel (such as sub-channel 2) is lower than the threshold due to weak interference, then the channel estimation of that sub-channel fails.

[0121] However, adjacent sub-channels (such as 1 and 3) can still obtain effective channel state information because they use different sequences;

[0122] The receiver skips the scrambled frequency band and completes data decoding based on the joint channel estimation results of the available sub-channels.

[0123] This architecture can work in conjunction with the applicant's previously proposed "dual-channel preamble detection" mechanism:

[0124] The primary channel and the backup channel can be configured with different sequence IDs (e.g., the primary channel uses S0 and the backup channel uses S3);

[0125] Further reduce the correlation between the two detection results and significantly improve the success rate of backup channel detection when the main channel is disturbed.

[0126] Example: Dynamic configuration of differentiated preamble sequences and anti-weak interference communication under 80MHz bandwidth

[0127] This embodiment takes a wireless communication system operating at an 80MHz aggregate bandwidth as an example to illustrate the complete implementation process of the differentiated preamble sequence design, dynamic negotiation mechanism and multi-sequence detection architecture proposed in this application in a weak broadband interference scenario (weak broadband interference occurs in sub-channels 1, 2, and 3, and sub-channel 0 is the main channel).

[0128] System initialization and sequence library predefinition;

[0129] The system supports an 80MHz aggregate bandwidth, including four consecutive 20MHz sub-channels, numbered from left to right as sub-channels 0, 1, 2, and 3.

[0130] Access point devices and terminals predefine a set of orthogonal or quasi-orthogonal preamble sequence variants in their firmware:

[0131] L-STF sequence library: {S0,S1,S2,…,S15}

[0132] L-LTF sequence library: {T0,T1,T2,…,T15}

[0133] S0 and T0 are standard L-STF / L-LTF sequences, while the rest are custom variants with different spectral energy distributions and autocorrelation characteristics.

[0134] Access point equipment dynamically evaluates the channel and generates a preamble configuration;

[0135] The AP periodically (e.g., every 2 seconds) scans the channel status of each 20MHz sub-channel, including RSSI (Received Signal Strength), CRC / FCS error rate, air interface occupancy rate, etc. Based on the interference distribution, the AP makes the following decision configuration: the main channel (sub-channel 0) uses the standard sequence, sub-channel 1 uses the S1 / T1 sequence, sub-channel 2 uses the S2 / T2 sequence, and sub-channel 3 uses the S3 / T3 sequence.

[0136] Preamble configuration is sent via Beacon frames;

[0137] The AP constructs an ExtendedPreambleConfigurationElement, embedding the ExtendedPreambleConfigurationElement field in the following 5 Beacons.

[0138] The AP sends Beacon frames (Send_cnt decreases from 5 to 0). The STA can record the configuration and enable the configuration when Send_cnt is updated to 0 if any frame is successfully received.

[0139] STA loads the configuration and performs multi-sequence detection;

[0140] STA parses the configuration elements in Beacon and loads the preamble parameters of each sub-channel into the PHY layer receiver engine.

[0141] When radio frequency energy is detected, the STA performs the corresponding preamble detection in parallel on all four sub-channels.

[0142] The receiver synthesizes the channel estimation results of each sub-channel: weak broadband interference occurs in sub-channels 1, 2, and 3, with a greater impact on the preamble sequence used in sub-channel 2. Sub-channels 1 and 3 use different preamble sequences and are less affected by interference, and can still decode the preamble correctly. The system can complete data decoding on the remaining 60M effective bandwidth.

[0143] This invention fundamentally solves the problem of preamble detection performance coupling in high-bandwidth wireless communication systems. In high-interference scenarios such as industrial wireless, the access point device first independently collects the channel state of each sub-channel within the aggregated channel to obtain real-time data reflecting the actual interference characteristics. The key breakthrough based on this data lies in abandoning the traditional single preamble multiplexing mode and instead assigning a differentiated preamble sequence with orthogonal characteristics to each sub-channel.

[0144] The sequence design of this invention gives each 20MHz sub-channel a unique frequency domain fingerprint. When weak broadband interference covers part of the frequency band, because the preamble sequences used by different sub-channels are independent of each other in terms of correlation characteristics, the detection failure of the interfered sub-channel will not affect other sub-channels. Just like in a noisy environment where multiple people speak in different tones, even if some sounds are masked, information can still be clearly identified by the other tones.

[0145] The dynamic negotiation mechanism further enhances the system's adaptability. Access point devices continuously send the optimal sequence configuration via Beacon frames, while terminal devices ensure reliable configuration synchronization through a multi-frame redundancy reception strategy. This design enables the system to automatically adjust to changes in environmental interference, maintaining a stable connection in dynamic scenarios such as motor start-up and shutdown, and equipment movement.

[0146] The parallel detection architecture at the receiver translates differentiated advantages into practical gains. The terminal device performs preamble detection simultaneously on all sub-channels, quickly filtering out available sub-channels through independent threshold judgment and channel estimation. This design is equivalent to equipping each sub-channel with an independent detection channel, so even if the main channel is disturbed, the system can immediately switch to a backup channel to continue communication.

[0147] This invention's technical solution, through a series of interconnected steps including sequence differentiation, dynamic negotiation, and parallel detection, effectively overcomes the coupling weakness of preamble detection in traditional solutions while maintaining standard compatibility. This design enables the communication link to maintain overall traffic flow, much like a multi-lane highway, even when some lanes are temporarily closed, by utilizing the remaining lanes, in the face of typical broadband interference in industrial environments.

[0148] In industrial IoT scenarios, broadband harmonics generated by motors often cause weak broadband interference to wireless communication. To address the issue of synchronization failure of traditional isomorphic preamble sequences under interference, the access point device first independently collects the channel status of four 20MHz sub-channels within an 80MHz aggregate bandwidth. The access point device obtains parameters such as received signal strength and frame error rate by scanning the sub-channels, forming evaluation data reflecting the actual interference status of each sub-channel.

[0149] Based on the acquired channel state information, the access point device assigns a differentiated preamble sequence to each subchannel from a predefined sequence library. For subchannels heavily affected by motor harmonics, an L-STF sequence variant with higher processing gain is selected; while for subchannels with less interference, a standard sequence is used to reduce overhead. During sequence allocation, the subchannel boundary phase rotation parameters are kept in accordance with spectral specifications, enabling the system to improve anti-interference capabilities while remaining compatible with existing equipment.

[0150] In practice, the access point device constructs a Beacon frame carrying an extended preamble configuration element. This configuration element includes fields such as the main channel index, bandwidth indicator, and sub-channel configuration list, and uses a counter field to achieve configuration synchronization control. The access point device employs a multi-frame transmission mechanism, repeatedly transmitting the same configuration in five consecutive Beacon frames. The terminal device only needs to successfully receive any one of these frames to complete the configuration update. This design effectively addresses the signal obstruction problem common in industrial environments.

[0151] After parsing the Beacon frame, the terminal device loads the corresponding preamble sequence for each sub-channel. When an RF signal is detected, the terminal device performs preamble detection on all four sub-channels in parallel. Each sub-channel uses an independent L-STF sequence for timing synchronization, effectively avoiding missynchronization caused by interference. After obtaining the correlation peak value through sliding correlation calculation, the terminal device uses an adaptive threshold to judge the detection result, performing L-LTF channel estimation only on the successfully detected sub-channels.

[0152] During the sub-channel selection phase, the terminal device establishes a status table to record the quality indicators of each channel. When the primary channel is interfered with, causing detection failure, the system automatically switches to a backup channel and supplements available sub-channels according to the estimated channel quality. This dynamic selection mechanism enables the system to maintain data transmission with an effective bandwidth of 60MHz even when some frequency bands are interfered with.

[0153] For sub-channels with poor channel conditions, the system dynamically increases the repetition count of STF and LTF. For example, a four-fold repetition scheme is used for sub-channels affected by motor harmonics to overcome interference by increasing processing gain; while a basic repetition mode is used for relatively clean sub-channels to optimize spectral efficiency. This flexible configuration enables the system to achieve a balance between reliability and latency in complex electromagnetic environments.

[0154] During communication, the access point device continuously monitors changes in channel status. When interference level fluctuations exceed a set threshold, a preamble sequence reconfiguration process is triggered. The updated configuration is sent via Beacon frames, enabling the terminal device to adapt to environmental changes in real time. This closed-loop control mechanism is particularly suitable for industrial scenarios with moving obstacles or intermittent interference.

[0155] During the data demodulation stage, the terminal device constructs a combined response based on the channel estimation results of the available sub-channels and uses frequency domain equalization technology to compensate for channel distortion. The system intelligently skips the frequency bands corresponding to the interfered sub-channels and completes the demodulation of data symbols on the remaining available sub-channels. Finally, the original data stream is recovered through error correction and decoding algorithms, achieving highly reliable data transmission.

[0156] The differentiated preamble design ensures that the preamble detection results of each sub-channel are independent when facing broadband interference. Even if one sub-channel fails to detect properly due to interference, other sub-channels can still maintain the communication link. Just like in a noisy factory environment, communication streams using different frequency bands can work in parallel without interference, significantly improving the robustness of the system.

Claims

1. A wireless network anti-weak broadband interference communication method based on differentiated preamble, characterized in that, include: Step 1: The access point device collects channel state information of multiple sub-channels in the aggregated channel to obtain channel state information including at least one of received signal strength, frame error rate and air interface occupancy rate. Step 2: The access point device uses the collected channel state information to assign different preamble sequence configurations to each sub-channel in the aggregated channel, generating a preamble sequence configuration including L-STF sequence identifiers and L-LTF sequence identifiers; Step 3: The access point device sends the allocated preamble sequence configuration to the terminal device via a management frame; Step 4: The terminal device receives the management frame sent by the access point device, and parses the management frame to obtain the preamble sequence configuration corresponding to each sub-channel; Step 5: When the terminal device detects an RF signal, it uses the preamble sequence obtained from the management frame to configure and performs preamble detection in parallel on each sub-channel. Each sub-channel uses the corresponding L-STF sequence for timing synchronization and the corresponding L-LTF sequence for channel estimation. Step 6: Based on the preamble detection results, the terminal device filters out the successfully detected sub-channels from multiple sub-channels and marks them as available sub-channels. Step 7: The terminal device completes the reception and demodulation of data frames on the marked available sub-channels.

2. The wireless network anti-weak broadband interference communication method based on differentiated preamble according to claim 1, characterized in that, Step 2 includes: The access point device selects orthogonal or quasi-orthogonal L-STF sequence variants and L-LTF sequence variants from a predefined preamble sequence library; The access point equipment determines the sequence allocation order based on the position index of the sub-channel in the aggregate bandwidth, with the position index numbered sequentially from left to right. The access point device uses the collected channel state information to assess the interference level of the sub-channels and allocates sequence variants with higher processing gain to sub-channels with interference levels higher than a preset threshold. When allocating sequence variants, the access point device maintains the sub-channel boundary phase rotation parameters in accordance with the spectrum emission mask requirements.

3. The wireless network anti-weak broadband interference communication method based on differentiated preamble according to claim 2, characterized in that, Step 3 includes: The access point device constructs a Beacon frame and adds an extended preamble configuration element to the Beacon frame; The access point device sets the main channel index field to indicate the main channel position, sets the bandwidth indicator field to identify the aggregate bandwidth, sets the counter field to realize synchronization control, and sets the sub-channel configuration list to record the sequence configuration of the sub-channel in the extended preamble configuration element; The access point device adopts a multi-frame transmission mechanism, carrying the same extended preamble configuration element in multiple consecutive Beacon frames; The access point device controls the timing of the preamble sequence configuration by decrementing the counter field.

4. The wireless network anti-weak broadband interference communication method based on differentiated preamble according to claim 3, characterized in that, Step 4 includes: The terminal device listens for Beacon frames in the channel and captures Beacon frames including extended preamble configuration elements; The terminal device parses the extended preamble configuration elements in the captured Beacon frames and extracts the main channel index, aggregate bandwidth, and sub-channel configuration list. The terminal device determines when the configuration takes effect based on the current value of the counter field in the extended preamble configuration element. When the counter value is zero, the new preamble sequence configuration is enabled. If the terminal device does not receive a Beacon frame during the counter decrement process, the terminal device will wait to receive subsequent Beacon frames to complete the configuration update.

5. The wireless network anti-weak broadband interference communication method based on differentiated preamble according to claim 1, characterized in that, Step 5 includes: The terminal device is configured according to the acquired preamble sequence and loads the corresponding L-STF sequence and L-LTF sequence for the sub-channel; The terminal device performs sliding correlation calculations simultaneously on the sub-channel to obtain the correlation peak value between the received signal and the local sequence; The terminal device compares the correlation peak of the sub-channel with the adaptive threshold to determine whether the preamble detection is successful. For successfully detected sub-channels, the terminal device uses the configured L-LTF sequence to perform channel estimation and frequency offset correction.

6. The wireless network anti-weak broadband interference communication method based on differentiated preamble according to claim 5, characterized in that, Step 6 includes: The terminal device establishes a sub-channel status table to record the detection status, channel estimation quality, and signal-to-noise ratio information of the sub-channel; The terminal device uses the sub-channel status table and prioritizes selecting the sub-channels that have been successfully detected in the main channel. When the primary channel detection fails, the terminal device selects a backup channel; The terminal device sorts the remaining sub-channels according to the channel estimation quality and selects the sub-channel with the best channel estimation quality as a supplement; The terminal device updates the sub-channel status table, marking available and unavailable sub-channels.

7. The wireless network anti-weak broadband interference communication method based on differentiated preamble according to claim 2, characterized in that, The preamble sequence configuration in step 2 includes the STF repetition count and the LTF repetition count; Access point equipment uses channel state information to dynamically configure the STF repetition count and LTF repetition count for sub-channels; For sub-channels with poor channel conditions, the access point device allocates a higher number of repetitions; For sub-channels with good channel conditions, the access point device allocates a lower number of repetitions to reduce overhead.

8. The wireless network anti-weak broadband interference communication method based on differentiated preamble according to claim 1, characterized in that, Also includes: Access point equipment periodically updates channel status information; When the access point device detects a channel state change exceeding a threshold value, the access point device triggers a reconfiguration process; The access point device reconfigures the preamble sequence for the sub-channels and generates updated configuration information. The access point device sends the updated configuration information to the terminal device through management frames.

9. The wireless network anti-weak broadband interference communication method based on differentiated preamble according to claim 1, characterized in that, Step 7 includes: The terminal device constructs a combined channel response based on the channel estimation results of the available sub-channels; The terminal device uses the combined channel response to perform frequency domain equalization on the received signal to compensate for channel distortion. The terminal device skips the frequency band corresponding to the sub-channel that failed detection and demodulates data symbols on the available sub-channel; The terminal device uses an error correction and decoding algorithm to recover the original data bit stream.

10. A wireless network anti-weak broadband interference communication system based on differentiated preamble, applied to the wireless network anti-weak broadband interference communication method based on differentiated preamble as described in any one of claims 1 to 9, characterized in that, include: The channel state information acquisition module is used by the access point device to acquire channel state information of multiple sub-channels in the aggregated channel, and obtain channel state information including at least one of received signal strength, frame error rate and air interface occupancy rate; The preamble sequence configuration allocation module is used by the access point device to use the collected channel state information to allocate different preamble sequence configurations to each sub-channel in the aggregated channel, and generate a preamble sequence configuration including L-STF sequence identifier and L-LTF sequence identifier; The management frame sending module is used by the access point device to send the allocated preamble sequence configuration to the terminal device via a management frame. The management frame parsing module is used by the terminal device to receive management frames sent by the access point device and parse the management frames to obtain the preamble sequence configuration corresponding to each sub-channel. The preamble detection module is used to configure the preamble sequence obtained from the management frame when the terminal device detects the radio frequency signal. It performs preamble detection in parallel on each sub-channel, wherein each sub-channel uses the corresponding L-STF sequence for timing synchronization and the corresponding L-LTF sequence for channel estimation. The sub-channel filtering module is used by the terminal device to filter out the successfully detected sub-channels from multiple sub-channels based on the preamble detection results and mark them as available sub-channels. The data receiving and demodulation module is used by the terminal device to receive and demodulate data frames on the marked available sub-channels.

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