Accurate inter-receiver timing is essential for marine electromagnetic (EM) exploration as synchronisation errors introduce phase errors and reduce the accuracy of EM inversion. However, in deep-towed receiver arrays, conventional Precision Time Protocol (PTP) synchronisation is affected by asymmetric link delays introduced by fibre-optic converters, Long-Reach Ethernet (LRE) switches, and other non-PTP-aware devices. In addition, underwater receiver nodes are typically implemented on resource-constrained microcontrollers, which limits the deployment of computationally intensive real-time estimation algorithms. To address these challenges, this paper presents a PTP-based synchronisation control system for marine deep-towed EM receivers. The proposed system implements data-link-layer PTP hardware timestamping on an MCU platform. A proportional-integral (PI) controller is first used for pre-synchronisation, after which a trigger-based optimised tracking control (OTC) mechanism is activated. The OTC computes the optimal control strategy for the frequency-adjustment unit using feedback matrices cached in SDRAM, thereby improving clock-parameter estimation and tracking performance while reducing the real-time computational burden. Simulation results show that the proposed method achieves better clock-parameter tracking performance than existing optimisation algorithms under different random-delay distributions. Hardware experiments using fibre-optic converters and LRE switches to construct an asymmetric communication link further verify the ability of the proposed system to suppress synchronisation errors caused by link asymmetry. The measured synchronisation offset was approximately 490 ns, with a standard deviation of 53 ns, corresponding to a phase error of about 0.018 degrees at 100 Hz.

In this work, we introduce an electromagnetic source imaging (EMSI) approach utilizing deep learning (DL) techniques, which employs deep convolutional conditional denoising diffusion probabilistic model (DCCDDPM). Conventional EMSI methods often struggle with various challenges, such as low accuracy and ill-posedness. The newly proposed EMSI method, named as DCCDDPM-EMSI, includes the forward diffusion process and the reverse diffusion process. Its diffusion process starts with EM equivalent sources on targets and adds Gaussian noise in a series of steps. On the counterpart, its reverse diffusion process step-by-step predicts the noise by using DL-based noise prediction network combined with the EM scattering measurements as conditional inputs. In contrast to traditional DDPM frame, the proposed DCCDDPM-EMSI introduces model-based loss term, which measures the discrepancy between the true EM sources and those predicted ones, in the diffusion process during its training process. Consequently, the proposed DCCDDPM-EMSI can reconstruct EM equivalent source of targets from the measured EM scattered field data. Unlike conventional EMSI methods, DCCDDPM-EMSI allows for higher fidelity EM source reconstruction without incurring excessive computational cost. Numerical benchmarks demonstrate that DCCDDPM-EMSI cannot only ensure the high accuracy but also the excellent generality, which offers significant advancements for DL-inspired quantitative EM imaging.

Underwater electric field measurement is critical for ship localization in subsea engineering and coastal defense monitoring. Acoustic, optical, and magnetic sensing technologies have each been successfully used for underwater positioning and detection; however, their performance can be affected by environmental factors, including multipath propagation and attenuation for acoustic links, water turbidity and illumination for optical methods, and geomagnetic or platform magnetic interference for magnetic sensors. Shaft-rate electric-field sensing is, therefore, treated here as a complementary signature channel rather than a replacement for mature acoustic methods. Existing electric-field measurement platforms, including seafloor observatories and towed arrays, still face limitations such as environmental-noise sensitivity, deployment cost, and recovery risk. To address these challenges, this study proposes a multi-node wireless drifting electric-field buoy system. It integrates triaxial differential electric-field sensors, low-noise acquisition circuits (<6.8 nV/Hz at 1 Hz), and low-voltage differential signaling transmission, achieving a dynamic range of 118 dB over a DC-20 Hz bandwidth for weak electric-field measurement. GPS PPS timing provides a common timing reference for distributed nodes, while LoRa wireless communication and real-time processing support efficient data transmission. Pool experiments with one complete receiver set successfully captured simulated 5 Hz shaft-rate E-field signals. Short-time Fourier transform analysis showed clear fundamental and harmonic components with high signal-to-noise ratios. The results validate the single-receiver measurement capability and provide a basis for future field tests and multi-buoy synchronization validation in complex aquatic environments.

To investigate the accumulation characteristics of gas hydrates in the Shenhu Area of the South China Sea from a multi-property perspective,we performed a joint interpretation of marine Controlled-Source Electromagnetic (CSEM) and multi-channel seismic data. The four stratigraphic interfaces identified from the 2D constrained inversion resistivity profiles of two marine CSEM lines correlate well with seismic interfaces T1-T4. A deeply-rooted high-resistivity anomaly zone, extending upward over 3 km in width, couples with chaotic seismic reflections. This correlation confirms the development of mud diapirs and indicates a high thermal maturity of deep source rocks, thereby establishing a foundation for thermogenic gas supply. The CSEM resistivity profiles demonstrate significant advantages in delineating gas migration pathways and reservoir boundaries. They reveal that fault systems control the vertical transport of thermogenic gas,directly influencing the spatial distribution of gas hydrate and free gas. This underscores the effectiveness of integrated seismic-electromagnetic interpretation in analyzing the reservoir transport system. Furthermore,the inverted resistivity values are consistent with drilling results: intervals within the gas hydrate stability zone exhibit high-resistivity anomalies (approximately 5 similar to 10 Omega m),whereas sections without hydrate show no such anomalies. The saturation distribution profile, obtained through joint seismic-CSEM inversion, clearly delineates the saturation characteristics of gas hydrate and free gas. The average saturations at wells W02 and W07 are 0.35 and 0.34,respectively,which deviate by less than 10% from the mean log-derived saturation values (0.32 and 0.33). The integration of marine CSEM and multi-channel seismic data significantly enhances the understanding of gas migration and reservoir systems, thereby contributing to reduced drilling risks.

This study presents the first application of a deep-towed transmitter–receiver marine controlled-source electromagnetic (TTR-MCSEM) system for gas hydrate exploration in the Shenhu area of the South China Sea. High-resolution electromagnetic data were acquired along a 13 km transect using dynamic source–receiver offsets and a 500 A transmitter. The results reveal the following: (1) unprecedented near-seafloor resolution (20~100 m) for the precise delineation of hydrate-bearing caprock, surpassing conventional ocean-bottom electromagnetic systems; (2) laterally continuous high-resistivity anomalies (~10 Ω·m) extending from the base of the gas hydrate stability zone to the seafloor, which correlate with seismic bottom-simulating reflector (BSR) distributions and suggest heterogeneous hydrate saturation; and (3) fault-controlled fluid migration pathways that supply hydrate reservoirs and lead to seabed methane seepage at structural highs. Through 2D inversion, we show that the inverted resistivity values (~10 Ω·m) are slightly higher than those obtained from resistivity logs (~5 Ω·m). Saturation values derived from inverted resistivity exhibit remarkable consistency with well-log-based measurements. The high efficiency of the system confirms its potential for the transformative quantitative assessment of hydrate systems, seafloor massive sulfides, and marine geohazards.

This study presents the design of a high-precision, wide dynamic range low-current measurement system that addresses the limitations of traditional devices in terms of accuracy, noise interference, and range flexibility. As the demand for precise low-current measurements increases in applications such as photodetectors, the ability to measure currents from picoamperes (pA) to milliamperes (mA) with high accuracy is crucial. The proposed system features automatic range switching, allowing for seamless detection across a broad current range, from 2 pA to 2 mA. It incorporates high-impedance operational amplifiers, leakage current protection, and electromagnetic shielding to minimize noise and leakage effects. Test results demonstrate that the system achieves an accuracy of less than 1% and a noise power spectral density of 20 fA Hz-1 in the 3-10 Hz frequency range, outperforming existing low-current measurement devices. The system's real-time data acquisition and display capabilities enhance its usability in dynamic environments. Compared to existing technologies, the proposed design offers superior measurement range, accuracy, and noise control, making it an innovative solution for high-precision low-current measurements in a wide range of applications.

The study of cracking analysis algorithms for rock-like materials is an important branch in the development of solid mechanics, and the related results have received extensive attention from researchers around the world. To broaden the generalizability of the phase-field method, an improved double-phase-field (DPF) algorithm based on the Scaled Boundary Finite Element Method (SBFEM) is presented. Firstly, the main governing equations are deduced and interpreted based on the nonlinear SBFEM framework. Secondly, the flexible polygon class library, data structure and solving framework for DPFM are designed by object-oriented programming. Subsequently, the presented algorithm is integrated in the self-developed finite element software GEODYNA. Thirdly, the precision is demonstrated by three classic examples, and its efficiency and practicality for complex mixed-mode fractures are validated with three case studies. Obviously, the tensile and compressive-shear mixed-mode fracture mode can be reproduced realistically, and the efficient quadtree grids can be utilized directly, making the efficiency to be optimized by more than 75% in representative cases. More potential for practical applications would be further elucidated with extending the proposed method to three-dimensional.

This paper proposes a wideband reconfigurable metasurface (WRM) for full-polarization ground-penetrating radar (FP-GPR). By adjusting the switching states of positive intrinsic negative diodes, the WRM can precisely and efficiently control the polarization of radar signals. Additionally, without increasing the number of antennas or altering their positions, the WRM enables complex antenna configurations of FP-GPR. On this basis, we develop an FP-GPR detection system based on the WRM. Simulation and experimental results confirm that WRM enables rapid and accurate polarization switching. By applying Pauli synthesis to the full-polarization data, the system achieves fast detection and high-precision imaging in FP-GPR applications. The proposed WRM, featuring compact size and lightweight characteristics, offers a cost-effective, flexible, and high-degree-of-freedom solution for FP-GPR applications.

The measurement of underwater target electromagnetic (EM) signatures is crucial for enhancing underwater information perception capabilities. Currently, common ship detection technologies include acoustic, laser, infrared, and electric and magnetic field detection. Compared with other technologies, EM detection offers superior signal stability and accurate positioning. However, current underwater EM receivers face several challenges, such as poor measurement accuracy, inability to simultaneously measure alternating and static magnetic fields, and low efficiency in maritime operations. This article describes a compact seafloor EM receiver used for ship detection. It features a spherical structure with acoustic telemetry modem (ATM) circuits for device recovery and a signal-acquisition circuit connected to an Ag-AgCl electric field sensor, an induction coil, and fluxgate sensors. The device supports three-axis electric and six-channel magnetic field signal collection. Deployed for validation experiments in the northern Yellow Sea, it measured signals from artificial sources at various frequencies and performed spectral analysis of the time series, confirming the capture of corresponding EM signals and validating the effectiveness of the device. The background noise levels of the electric, alternating magnetic, and static magnetic fields were 0.1 nV/m/ root Hz at 1 Hz, 0.1 pT/ root Hz at 1 Hz, and 10 pT/ root Hz at 1 Hz, respectively. The device can operate underwater in a data acquisition state for 90 days at a depth of 1000 m with a power consumption of 400 mW. It features the advantages of complete EM signal capture, low power consumption, and high efficiency in maritime operations, making it suitable for the EM detection of ships.

Multirate signal processing and adaptive filtering techniques have been widely employed to mitigate noise contamination and enhance the efficiency of data analysis. In towed electromagnetic (EM) receiver systems, EM motion-induced noise arising from external conductive and radiative interference and instrument vibrations caused by waves and water currents can severely degrade the quality of inversion imaging. To address this challenge, this study proposes a field-programmable-gatearray-based multirate sampling architecture integrated with a motion-related adaptive filter design that supports multistage downsampling and dynamic noise suppression. The impact of this architecture on the recovery of methane resistivity models under noisy conditions is assessed using controlled-source EM inversion analysis. The results of processing real towed electric field data contaminated with superimposed motion-induced noise demonstrate that the proposed system significantly enhances signal quality, improves imaging resolution, and reduces inversion artefacts. Compared with conventional offline processing approaches, the proposed architecture offers superior real-time capability, adaptability, and noise resistance in marine towed environments.

The marine controlled-source electromagnetic (MCSEM) method is widely employed to reveal the electrical structure of shallow media below the seafloor. It is an indispensable geophysical means in the exploration of marine oil, gas, natural gas hydrates and seafloor geological structures. The transmitter and receiver in electromagnetic detection equipment need to maintain a high temporal consistency, typically relying on high-stability pulse-per-second (PPS) signals generated by GPS or BeiDou navigation modules. Coaxial cable is a widely used tow cable, so it is necessary to design a clock synchronization method of the marine controlled-source electromagnetic transmitter using coaxial cable. This paper proposes a method for synchronizing the internal clock of the transmitter with PPS using a ship-borne power supply when coaxial cable is used as a tow cable. In this method, the ship-borne high-voltage power supply outputs a high-voltage alternating current (AC) signal that is synchronized with a 400 Hz signal output from GPS; the coaxial cable transmits AC high-power electrical energy and control commands; and the AC signal transmitted via coaxial cable is converted into a stable and continuous 1 Hz signal by the step-down method, waveform shaping and frequency division for synchronizing the internal time pulses of the transmitter. The test result shows that the 1 Hz signal obtained by this method has a deviation of approximately 504 ns relative to PPS. This deviation meets the MCSEM transmitter's requirement for clock synchronization.

Taking the sea area near the southern part of the Mariana Trench as a typical area is crucial for deep structural research in marine geology and geophysics. The magnetotelluric (MT) method has advantages such as large detection depth, sensitive to low resistance reactions, low cost, and high efficiency. The application of MT in deep water requires instruments with high reliability and stability, low noise, wideband, low power consumption, and miniaturization. The ocean bottom electromagnetic receiver (OBEM), as one of the important instruments for MT in deep water observation, its performance directly affects the quality of detected data. In response to the shortcomings of the existing 6000 m level OBEM, there is an urgent need to develop a 9000 m level hadal OBEM. According to the requirements, we have focused on overcoming the challenges of weak E-field measurement technology, low-power and low-noise M-field measurement technology, low-power underwater acoustic release technology, and water surface large-scale recycling technology. We have achieved lower noise, longer underwater operation time, and efficient operations, providing reliable and stable instruments for hadal MT observation. We have developed a chopper amplifier that matches deep water E-field sensors, analyzed the causes of injected charges, and adopted a scheme that combines peak filtering technology and dead zone technology to suppress residual misalignment generated during the chopper modulation, effectively reducing 1/f noise in the circuit, expanding the input range, and improving input impedance. An orthogonal fundamental mode fluxgate based on digital demodulation is developed. Digital closed-loop real-time processes such as high-precision ADC, digital synchronous demodulation, digital integration, and high-precision large dynamic range DAC are used to reduce the switching charge noise introduced by analog circuits. Developing adaptive closed-loop feedback control algorithms to achieve fast feedback compensation with low noise and large dynamic range can help improve key parameters such as noise bandwidth, and input range of sensors. We adopt a deep-water acoustic release system, pressure-resistant acoustic transducer, and control module prototype. Hydroacoustic communication controls the opening of the constant current source and the electrocorrosion decoupler. This solution reduces the size of the instrument and only relies on a single glass ball to achieve the floating of the instrument. The system integrates commands such as status query, electrocorrosion on and off. The status information includes distance, electrocorrosion status, battery voltage, etc. The propagation distance of acoustic signals is greatly increased, improving the success rate of underwater acoustic communication. The glass ball is equipped with a beacon module, which is controlled by acoustic signals to activate the AIS, achieving real-time transmission of the OBEM position. Besides, high-power LED flashing is controlled to facilitate nighttime recycling and further reduce the cost of offshore operations. In August 2023, 5000 m level test was conducted in the southern South China Sea. It is preliminarily verified the MT measurement, which has been improved in terms of low power consumption, low noise, and adaptability to deep sea. In the future, we will conduct test verification in deeper sea.

With the gradual application of 10 MW offshore wind turbines (OWTs) in the world, it is very important to study the liquefaction response of high power OWTs under multiple fields. In this paper, based on the state-dependent generalized plasticity model, a cross-scale refined analysis model of structure-monopile-liquefied seabed is established, and a method for the analysis of seismic dynamic response of large-diameter monopile offshore wind turbine (MOWT) in liquefiable seabed is developed. The applicability of the proposed method is validated through simulations of existing centrifuge model tests. Using this approach, the dynamic response characteristics of a 10 MW MOWT under combined wind, wave, and seismic loading are systematically investigated. The study reveals the spatial distribution of seabed liquefaction under varying earthquake intensities, elucidates the flow mechanisms, and explores the effects of different loading conditions and relative depth (Rd) of liquefiable sandy soil on the system's response. The results show that: 1. Seismic loads significantly influence seabed liquefaction, while environmental loads primarily cause cumulative rotation in MOWT. 2. As Rd increases, the rate of pore pressure accumulation slows, and liquefaction depth, soil strain around the pile, MOWT deflection, and rotation angle all increase. 3. Liquefaction results in overall subsidence of the soil within a range of one pile diameter (1D, D = 10.375 m) around the pile, while soil flow and heave within a range of 2D behind the pile are the main contributors to foundation rotational failure.

The underwater electric field (UEF) signature of a ship is a key factor in its survivability in marine warfare. Moreover, the study of a ship's UEF using scale models of ships in pools can be useful for the design of electromagnetically stealthy ships. Aiming at the system requirement of measuring and analyzing the UEF of scale models of ships with low noise, many channels, and real-time responsivity, we developed a system consisting of electrode sensors, a measuring device, and a personal computer (PC). Small Ag/AgCl electrodes with low noise and high stability were used. The measuring device was capable of simultaneously amplifying, sampling, and storing 24 channels of UEF data in real-time, and it was connected to the PC via Ethernet to facilitate the transfer of UEF data at high speeds. The PC software could display 24 low-frequency UEF curves in real time and perform spectral analysis and filtering of the UEF signals. In system performance tests, we found that the system had a noise floor lower than 6.34 nV/rt(Hz)@1 Hz and could simultaneously sample 24 channels of UEF signals while storing, displaying, and analyzing the signals in real-time. The primary functions of the system were also validated in a pooled experiment.

Ocean bottom electromagnetic receivers (OBEMs) are invaluable tools for observing seafloor electromagnetic signals, primarily used in magnetotelluric (MT) sounding and marine controlled source electromagnetics (MCSEM). However, the high operational costs of deploying OBEMs require thorough pre-deployment testing to enhance the data reliability and quality. Commercial signal generators used for MT and controlled source electromagnetic (CSEM) testing often fall short of the restricted terms of the frequency range, signal-to-noise ratio, storage depth, time synchronization, and amplitude dynamics. To address these limitations, we developed a specialized marine MT and CSEM signal simulative generator. The generator employs pseudorandom number code-based white noise to simulate MT signals and uses multi-frequency synthesis and amplitude modulation (AM) to generate CSEM signals. The system is developed using a low-power microcontroller unit and a field programmable gate array platform, integrating various circuits such as power, clock, encoding, control, data storage, chopper, and amplification circuits. The generator simultaneously outputs four-channel white noise and AM signals. The white noise feature provides a wide and adjustable frequency band and amplitude, while the AM feature provides a large dynamic amplitude range and multi-frequency synthesis at various carrier frequency points. Comprehensive testing verified the performance of the proposed simulative generator. The test results demonstrate that the MT simulated signals cover a frequency range from 1 E4s to 100 Hz, providing adjustable amplitudes between 10 μVpp and 10 mVpp. The CSEM simulated signals include standard square waves, third harmonic waves, and seventh harmonic waves, with amplitudes adjustable from 10 mVpp to 10 Vpp. The proposed simulative generator enhances the efficiency of OBEM functional testing and provides essential equipment support for maintaining the quality of marine data.

Underwater electric fields have the characteristics of complex field sources, high dynamic range, and broad frequency band, making high-precision observation difficult. They require high requirements for observation methods, measurement sensors, instrument equipment, and signal processing methods. Underwater electric field measurement technology is widely used in various disciplines such as underwater target detection, geophysical exploration, deep geological structure research, and physical oceanography. This article briefly reviews its technological development process; Summarized the current research status of peers at home and abroad, and summarized the key issues and difficulties in the research of underwater electric field measurement technology; Summarized the electric field sensors, chopper amplifiers, underwater measurement equipment, and signal processing methods related to underwater electric field measurement technology; Representative application cases in multiple disciplines such as underwater target detection, geophysical exploration, deep geological structure research, and physical ocean observation were listed separately; Analyzed the problems and shortcomings of current underwater electric fields measurement technology; On this basis, the prospects for technological development were envisioned and some constructive suggestions were put forward.

Marine controlled-source electromagnetics (MCSEM) is an effective method to map the spatial distribution of gas hydrate and calculate gas hydrate saturation. An MCSEM survey is conducted in the Lingnan low uplift (LNLU), Qiongdongnan Basin (QDNB), South China Sea (SCS), and then the measured data are processed to obtain the geoelectric structure. The estimated gas hydrate stability zone (GHSZ) ranges from 0 to 320 mbsf, and shallow high-conductive sediments serving as gas hydrate caps are at depths ranging from 0 to 100 mbsf (meters below the seafloor). The 2D resistivity model reveals multiple high-resistivity bodies at depths ranging from 100 to 320 mbsf, and BSRs are at depths of 240 mbsf to 280 mbsf, indicating a transversely uneven gas hydrate reservoir in the study area. Moreover, two high-resistivity bodies are detected beneath the GHSZ, implying the presence of potential gas transport pathways. The gas hydrate saturation with a variation of 0–68.4% is calculated using the MCSEM resistivity and Archie’s law. According to the resistivity model and geological data, the transversely uneven gas hydrate reservoir may be associated with multiple gas sources, including shallow biogenic gas and deep pyrolytic gas. The shallow biogenic gas is transported to the GHSZ via short-distance migration and free diffusion, and the deep pyrolytic gas is transported to the GHSZ via two microcracks. In addition, this case emphasizes that the dynamic accumulation of gas hydrate is an important factor causing reservoir heterogeneity.

The seafloor vector magnetometer is an effective tool for marine geomagnetic surveys and seafloor magnetotelluric (MT) detection. However, the noise, power consumption, cost, and volume characteristics of existing seafloor vector magnetometers are insufficient for practical use. Therefore, a low-noise, low-power-consumption seafloor vector magnetometer that can be used for data acquisition of deep-ocean geomagnetic vector components is developed and presented. A seafloor vector magnetometer mainly consists of a fluxgate sensor, data acquisition module, acoustic release module, glass sphere, frame, burn-wire release, and anchor. A new low-noise data acquisition module and a fluxgate sensor greatly reduce power consumption. Furthermore, compact size is achieved by integrating an acoustic telemetry module and replacing the acoustic release with an external burn-wire release. The new design and magnetometer characteristics reduce the volume of the instrument and the cost of hardware considerably, thereby improving the integrity and deployment efficiency of the equipment. Theoretically, it can operate for 90 days underwater at a maximum depth of 6 000 m. The seafloor vector magnetometer was tested in the South China Sea and the Philippine Sea and obtained high-quality geomagnetic data. The deep-water environment facilitates magnetic field data measurements, and the magnetometer has an approximate noise level of 10 pT/rt (Hz)@1 Hz, a peak-to-peak value error of 0.2 nT, and approximate power consumption of 200 mW. The fluxgate sensor can measure the magnetic field in the lower frequency band and realize geomagnetic field measurements over prolonged periods.

A novel intelligent extraction method based on time–frequency analysis and deep learning semantic segmentation were proposed for detailing electromagnetic pulse (EMP) sensitive frequency bands of engine digital controllers. In this method, wavelet transformation was performed to convert EMP-coupled signals into image data sets. Two semantic segmentation networks, namely fully convolutional networks and DeepLabV3+, were used to train and verify the obtained image data sets. The performance of the two models was compared using the confusion matrix and Kappa coefficient. Threshold segmentation, binarization, and average pooling operations were sequentially performed on the feature map output of the networks, and EMP characteristic pixel percentage was calculated using the time–frequency map. The original image was segmented by using the result of the binarization of the feature map output by the last layer of the network as a mask. This technique is immune to the interference caused by noise pixels when calculating the spectrum index. The proposed method has improved the EMP feature extraction accuracy of the model, and the overall performance of the DeepLabV3+ network model is proper. It was performed to obtain a theoretical basis for subsequent targeted EMP protection.

The well-known Filtered-x Affine Projection (FxAP) algorithm is usually deemed a better choice than the conventional Filtered-x Least-Mean-Square (FxLMS) algorithm when faster convergence speed is desired in active noise control applications. However, the improvement of its convergence performance is obtained at the expense of increased computational complexity. It is usually unrealistic to regulate multichannel ANC systems using the centralized AP algorithm. Recently, distributed diffusion adaptation schemes over acoustic sensor and actuator networks have been introduced to multichannel ANC systems, such as the Diffusion FxLMS algorithms. Distributed processing based on diffusion cooperation strategy allocates the computation load to the network nodes in a scalable manner. This paper proposes a distributed Diffusion Filtered-x AP (DFxAP) algorithm for multichannel ANC systems. Simulation results and computational complexity analysis show that the DFxAP algorithm outperforms the Diffusion FxLMS algorithm in convergence performance and has lower computational complexity compared to the centralized AP algorithm.