Combining the advantages of both the genetic algorithm(GA) and the chase decoding algorithm, a novel improved decoding algorithm of the block turbo code(BTC) with lower computation complexity and more rapid decoding s...Combining the advantages of both the genetic algorithm(GA) and the chase decoding algorithm, a novel improved decoding algorithm of the block turbo code(BTC) with lower computation complexity and more rapid decoding speed is proposed in order to meet the developing demands of optical communication systems. Compared with the traditional chase decoding algorithm, the computation complexity can be reduced and the decoding speed can be accelerated by applying the novel algorithm. The simulation results show that the net coding gain(NCG) of the novel BTC decoding algorithm is 1.1 dB more than that of the traditional chase decoding algorithm at the bit error rate(BER) of 10-6. Therefore, the novel decoding algorithm has better decoding correction-error performance and is suitable for the BTC in optical communication systems.展开更多
Along with the proliferating research interest in semantic communication(Sem Com),joint source channel coding(JSCC)has dominated the attention due to the widely assumed existence in efficiently delivering information ...Along with the proliferating research interest in semantic communication(Sem Com),joint source channel coding(JSCC)has dominated the attention due to the widely assumed existence in efficiently delivering information semantics.Nevertheless,this paper challenges the conventional JSCC paradigm and advocates for adopting separate source channel coding(SSCC)to enjoy a more underlying degree of freedom for optimization.We demonstrate that SSCC,after leveraging the strengths of the Large Language Model(LLM)for source coding and Error Correction Code Transformer(ECCT)complemented for channel coding,offers superior performance over JSCC.Our proposed framework also effectively highlights the compatibility challenges between Sem Com approaches and digital communication systems,particularly concerning the resource costs associated with the transmission of high-precision floating point numbers.Through comprehensive evaluations,we establish that assisted by LLM-based compression and ECCT-enhanced error correction,SSCC remains a viable and effective solution for modern communication systems.In other words,separate source channel coding is still what we need.展开更多
Multiple functional metasurfaces with high information capacity have attracted considerable attention from researchers.This study proposes a 2-bit tunable spin-decoupled coded metasurface designed for the terahertz ba...Multiple functional metasurfaces with high information capacity have attracted considerable attention from researchers.This study proposes a 2-bit tunable spin-decoupled coded metasurface designed for the terahertz band,which utilizes the tunable properties of Dirac semimetals(DSM)to create a novel multilayer structure.By incorporating both geometric and propagating phases into the metasurface design,we can effectively control the electromagnetic wave.When the Fermi level(EF)of the DSM is set at 6 meV,the electromagnetic wave is manipulated by the gold patch embedded in the DSM film,operating at a frequency of 1.3 THz.When the EF of the DSM is set at 80 meV,the electromagnetic wave is manipulated by the DSM patch,operating at a frequency of 1.4 THz.Both modes enable independent control of beam splitting under left-rotating circularly polarized(LCP)and rightrotating circularly polarized(RCP)wave excitation,resulting in the generation of vortex beams with distinct orbital angular momentum(OAM)modes.The findings of this study hold significant potential for enhancing information capacity and polarization multiplexing techniques in wireless communications.展开更多
A novel Reed Solomon （RS） block turbo code （BTC） coding scheme of RS（63,58）xRS（63,58） for optical communications is proposed. The simulation results show that the net coding gain （NCG） of this scheme at the ...A novel Reed Solomon （RS） block turbo code （BTC） coding scheme of RS（63,58）xRS（63,58） for optical communications is proposed. The simulation results show that the net coding gain （NCG） of this scheme at the sixth iteration is more than that of other coding schemes at the third iteration for the bit error rate （BER） of 10~2. Furthermore, the novel RS BTC has shorter component code and rapider encoding and decoding speed. Therefore, the novel RS BTC coding scheme can be better used in high-speed long-haul optical communication systems, and the novel RS BTC can be regarded as a candidate code of the super forward error correction （super-FEC） code~ Moreover, the encoding/decoding design and implementation of the novel RS BTC are also presented.展开更多
Aiming at the problem that the bit error rate(BER)of asymmetrically clipped optical orthogonal frequency division multiplexing(ACO-OFDM)space optical communication system is significantly affected by different turbule...Aiming at the problem that the bit error rate(BER)of asymmetrically clipped optical orthogonal frequency division multiplexing(ACO-OFDM)space optical communication system is significantly affected by different turbulence intensities,the deep learning technique is proposed to the polarization code decoding in ACO-OFDM space optical communication system.Moreover,this system realizes the polarization code decoding and signal demodulation without frequency conduction with superior performance and robustness compared with the performance of traditional decoder.Simulations under different turbulence intensities as well as different mapping orders show that the convolutional neural network(CNN)decoder trained under weak-medium-strong turbulence atmospheric channels achieves a performance improvement of about 10^(2)compared to the conventional decoder at 4-quadrature amplitude modulation(4QAM),and the BERs for both 16QAM and 64QAM are in between those of the conventional decoder.展开更多
Existing orthogonal space-time block coding(OSTBC)schemes for backscatter communication systems cannot achieve a full transmission code rate when the tag is equipped with more than two antennas.In this paper,we propos...Existing orthogonal space-time block coding(OSTBC)schemes for backscatter communication systems cannot achieve a full transmission code rate when the tag is equipped with more than two antennas.In this paper,we propose a quasi-orthogonal spacetime block code(QOSTBC)that can achieve a full transmission code rate for backscatter communication systems with a four-antenna tag and then extend the scheme to support tags with 2i antennas.Specifically,we first present the system model for the backscatter system.Next,we propose the QOSTBC scheme to encode the tag signals.Then,we provide the corresponding maximum likelihood detection algorithms to recover the tag signals.Finally,simulation results are provided to demonstrate that our proposed QOSTBC scheme and the detection algorithm can achieve a better transmission code rate or symbol error rate performance for backscatter communication systems compared with benchmark schemes.展开更多
Semantic secure communication is an emerging field that combines the principles of source-channel coding with the need for secure data transmission.It is of great significance in modern communications to protect the c...Semantic secure communication is an emerging field that combines the principles of source-channel coding with the need for secure data transmission.It is of great significance in modern communications to protect the confidentiality and privacy of sensitive information and prevent information leaks and malicious attacks.This paper presents a novel approach to semantic secure communication through the utilization of joint source-channel coding,which is based on the design of an automated joint source-channel coding algorithm and an encryption and decryption algorithm based on semantic security.The traditional and state-of-the-art joint source-channel coding algorithms are selected as two baselines for different comparison purposes.Experimental results demonstrate that our proposed algorithm outperforms the first baseline algorithm,the traditional source-channel coding,by 61.21%in efficiency under identical channel conditions(SNR=15 dB).In security,our proposed method can resist 2 more types of attacks compared to the two baselines,exhibiting nearly no increases in time consumption and error rate compared to the state-of-the-art joint source-channel coding algorithm while the secure semantic communication is supported.展开更多
A broadband polarization-independent terahertz multifunctional coding metasurface based on topological optimization using liquid crystal(LC)is proposed.The metasurface can achieve reconfigurability for beam steering a...A broadband polarization-independent terahertz multifunctional coding metasurface based on topological optimization using liquid crystal(LC)is proposed.The metasurface can achieve reconfigurability for beam steering and vortex beam generation within a frequency range of 0.68 THz–0.72 THz.Firstly,the metasurface unit is topologically optimized using the non-dominant sequencing genetic algorithms(NSGA-II)multi-objective optimization algorithm.By applying the LC’s electrically tunable refractive index properties,the metasurface unit enables polarization-independent 2-bit coding within a frequency range of 0.68 THz–0.72 THz.Then,based on the designed metasurface unit,the array arrangement of the metasurface is reverse-designed to achieve beam steering and vortex beam generation.The results show that,for beam steering,not only can polarization-independent steering of both single-and multi-beam be achieved within the 35°elevation angle range,but also independent control of the target angle of each beam in the multi-beam steering.For vortex beam generation,the metasurfaces can achieve the generation of single-and multi-vortex beams with topological charges l=±1,±2 within the 35elevation angle range,and the generation angles of each vortex beam in the multi-vortex beam can be independently controlled.This provides flexibility and diversity in the generation of vortex beams.Therefore,the proposed terahertz LC metasurface can realize flexible control of reconfigurable functions and has certain application prospects in terahertz communication,phased array radar,and vortex radar.展开更多
Structural colors based on metasurfaces have very promising applications in areas such as optical image encryption and color printing.Herein,we propose a deep learning-enabled reverse design of polarization-selective ...Structural colors based on metasurfaces have very promising applications in areas such as optical image encryption and color printing.Herein,we propose a deep learning-enabled reverse design of polarization-selective structural color based on coding metasurface.In this study,the long short-term memory(LSTM)neural network is presented to enable the forward and inverse mapping between coding metasurface structure and corresponding color.The results show that the method can achieve 98%accuracy for the forward prediction of color and 93%accuracy for the inverse design of the structure.Moreover,a cascaded architecture is adopted to train the inverse neural network model,which can solve the nonuniqueness problem of the polarization-selective color reverse design.This study provides a new path for the application and development of structural colors.展开更多
Efficient elastic wave focusing is crucial in materials and physical engineering.Elastic coding metasurfaces,which are innovative planar artificial structures,show great potential for use in the field of wave focusing...Efficient elastic wave focusing is crucial in materials and physical engineering.Elastic coding metasurfaces,which are innovative planar artificial structures,show great potential for use in the field of wave focusing.However,elastic coding lenses(ECLs)still suffer from low focusing performance,thickness comparable to wavelength,and frequency sensitivity.Here,we consider both the structural and material properties of the coding unit,thus realizing further compression of the thickness of the ECL.We chose the simplest ECL,which consists of only two encoding units.The coding unit 0 is a straight structure constructed using a carbon fiber reinforced composite material,and the coding unit 1 is a zigzag structure constructed using an aluminum material,and the thickness of the ECL constructed using them is only 1/8 of the wavelength.Based on the theoretical design,the arrangement of coding units is further optimized using genetic algorithms,which significantly improves the focusing performance of the lens at different focus and frequencies.This study provides a more effective way to control vibration and noise in advanced structures.展开更多
Metasurfaces offer exceptional capabilities for controlling electromagnetic waves,enabling the realization of unique electromagnetic properties.As communication technology continues to evolve,metasurfaces present prom...Metasurfaces offer exceptional capabilities for controlling electromagnetic waves,enabling the realization of unique electromagnetic properties.As communication technology continues to evolve,metasurfaces present promising applications in wireless communications.This paper reviews the latest advancements in metasurface research within the communication sector,explores metasurface-based wireless relay technologies,and summarizes various wireless communication methods employing different types of metasurfaces across diverse modulation schemes.This paper provides a detailed discussion on the design of wireless communication systems based on coding metasurfaces to simplify transmitter architecture,as well as the development of intelligent coding metasurfaces in the communication field.It also elaborates on the application of vector vortex light fields in metasurface communication.Finally,it offers a forward-looking perspective on wireless communication systems that incorporate coded metasurfaces.This review aims to furnish researchers with a thorough understanding of the current state and future directions of coded metasurface applications in communications.展开更多
To address the contradiction between the explosive growth of wireless data and the limited spectrum resources,semantic communication has been emerging as a promising communication paradigm.In this paper,we thus design...To address the contradiction between the explosive growth of wireless data and the limited spectrum resources,semantic communication has been emerging as a promising communication paradigm.In this paper,we thus design a speech semantic coded communication system,referred to as Deep-STS(i.e.,Deep-learning based Speech To Speech),for the lowbandwidth speech communication.Specifically,we first deeply compress the speech data through extracting the textual information from the speech based on the conformer encoder and connectionist temporal classification decoder at the transmitter side of Deep-STS system.In order to facilitate the final speech timbre recovery,we also extract the short-term timbre feature of speech signals only for the starting 2s duration by the long short-term memory network.Then,the Reed-Solomon coding and hybrid automatic repeat request protocol are applied to improve the reliability of transmitting the extracted text and timbre feature over the wireless channel.Third,we reconstruct the speech signal by the mel spectrogram prediction network and vocoder,when the extracted text is received along with the timbre feature at the receiver of Deep-STS system.Finally,we develop the demo system based on the USRP and GNU radio for the performance evaluation of Deep-STS.Numerical results show that the ac-Received:Jan.17,2024 Revised:Jun.12,2024 Editor:Niu Kai curacy of text extraction approaches 95%,and the mel cepstral distortion between the recovered speech signal and the original one in the spectrum domain is less than 10.Furthermore,the experimental results show that the proposed Deep-STS system can reduce the total delay of speech communication by 85%on average compared to the G.723 coding at the transmission rate of 5.4 kbps.More importantly,the coding rate of the proposed Deep-STS system is extremely low,only 0.2 kbps for continuous speech communication.It is worth noting that the Deep-STS with lower coding rate can support the low-zero-power speech communication,unveiling a new era in ultra-efficient coded communications.展开更多
Deep learning-based Joint Source-Channel Coding(JSCC)is a crucial component in semantic communication,and recent research has made significant progress in adapting to different channels.In this paper,we propose a mult...Deep learning-based Joint Source-Channel Coding(JSCC)is a crucial component in semantic communication,and recent research has made significant progress in adapting to different channels.In this paper,we propose a multi-stage progressive technique called Deep learning based Progressive Joint Source-Channel Coding(DP-JSCC).This approach partitions the source into multiple stages and transmits the signals continuously.The receiver gradually enhances the quality of image reconstruction by progressively receiving the signals,offering greater flexibility compared to existing dynamic rate transmission methods.The model adopts a lightweight architectural design,where we introduce an efficient module called the Inverted Shuffle Attention Bottleneck(ISAB)and incorporate self-attention mechanisms in the encoding and decoding process to capture signal correlations and establish long-range dependencies.Additionally,we introduce the Progressive Focus Weight Allocation(PFWA)method to improve the image reconstruction capability in progressive transmission tasks.These design enhance the expressive capacity of the model.Simulation results demonstrate that DP-JSCC can flexibly adjust the transmission rate according to requirements without the need for retraining or deployment,enabling continuous optimization of signals at different rates.Furthermore,compared to stateof-the-art JSCC methods,DP-JSCC exhibits advantages in terms of computational complexity,parameter count,and reconstruction performance.展开更多
The code of the list of sea and island problems is the unique identification code of the regulatory files,which is accompanied by the whole life cycle of the regulatory"discovery,verification and disposal".S...The code of the list of sea and island problems is the unique identification code of the regulatory files,which is accompanied by the whole life cycle of the regulatory"discovery,verification and disposal".Standardized coding of problems found by supervision and tracking and recording the whole life cycle of supervision can quickly guide supervisors to find problems,identify problems,initiate responses and carry out follow-up disposal,which is a reflection of whole-process management of supervision.Combining with sea and island regulatory systems and mechanisms,combed the supervision business flow,divides the supervision link,based on the existing coding system,from the Angle of supervision refinement,puts forward a whole lifetime oriented regulatory system of sea and island issues list for coding,coding through to find and stop and disposal of the three links all process application scenarios,The implementation of the whole business"one code"association,the whole process of"one code"management,practice verification shows the effectiveness of the method,compared with the original coding rules for the supervision of all links and results reflect more intuitive,comprehensive,can be better applied to the practice of supervision.展开更多
基金supported by the National Natural Science Foundation of China(Nos.61371096 and 61275077)the Natural Science Foundation of CQ CSTC(No.2010BB2409)the Program for the Innovation Team Building at Institutions of Higher Education in Chongqing
文摘Combining the advantages of both the genetic algorithm(GA) and the chase decoding algorithm, a novel improved decoding algorithm of the block turbo code(BTC) with lower computation complexity and more rapid decoding speed is proposed in order to meet the developing demands of optical communication systems. Compared with the traditional chase decoding algorithm, the computation complexity can be reduced and the decoding speed can be accelerated by applying the novel algorithm. The simulation results show that the net coding gain(NCG) of the novel BTC decoding algorithm is 1.1 dB more than that of the traditional chase decoding algorithm at the bit error rate(BER) of 10-6. Therefore, the novel decoding algorithm has better decoding correction-error performance and is suitable for the BTC in optical communication systems.
基金supported in part by the National Key Research and Development Program of China under Grant No.2024YFE0200600the Zhejiang Provincial Natural Science Foundation of China under Grant No.LR23F010005the Huawei Cooperation Project under Grant No.TC20240829036。
文摘Along with the proliferating research interest in semantic communication(Sem Com),joint source channel coding(JSCC)has dominated the attention due to the widely assumed existence in efficiently delivering information semantics.Nevertheless,this paper challenges the conventional JSCC paradigm and advocates for adopting separate source channel coding(SSCC)to enjoy a more underlying degree of freedom for optimization.We demonstrate that SSCC,after leveraging the strengths of the Large Language Model(LLM)for source coding and Error Correction Code Transformer(ECCT)complemented for channel coding,offers superior performance over JSCC.Our proposed framework also effectively highlights the compatibility challenges between Sem Com approaches and digital communication systems,particularly concerning the resource costs associated with the transmission of high-precision floating point numbers.Through comprehensive evaluations,we establish that assisted by LLM-based compression and ECCT-enhanced error correction,SSCC remains a viable and effective solution for modern communication systems.In other words,separate source channel coding is still what we need.
文摘Multiple functional metasurfaces with high information capacity have attracted considerable attention from researchers.This study proposes a 2-bit tunable spin-decoupled coded metasurface designed for the terahertz band,which utilizes the tunable properties of Dirac semimetals(DSM)to create a novel multilayer structure.By incorporating both geometric and propagating phases into the metasurface design,we can effectively control the electromagnetic wave.When the Fermi level(EF)of the DSM is set at 6 meV,the electromagnetic wave is manipulated by the gold patch embedded in the DSM film,operating at a frequency of 1.3 THz.When the EF of the DSM is set at 80 meV,the electromagnetic wave is manipulated by the DSM patch,operating at a frequency of 1.4 THz.Both modes enable independent control of beam splitting under left-rotating circularly polarized(LCP)and rightrotating circularly polarized(RCP)wave excitation,resulting in the generation of vortex beams with distinct orbital angular momentum(OAM)modes.The findings of this study hold significant potential for enhancing information capacity and polarization multiplexing techniques in wireless communications.
基金supported by the National Natural Science Foundation of China(Nos.61071117and61003256)the Natural Science Foundation of Chongqing CSTC(No.2010BB2409)the Science and Technology Foundation of Chongqing Municipal Education Commission(No.KJ110519)
文摘A novel Reed Solomon （RS） block turbo code （BTC） coding scheme of RS（63,58）xRS（63,58） for optical communications is proposed. The simulation results show that the net coding gain （NCG） of this scheme at the sixth iteration is more than that of other coding schemes at the third iteration for the bit error rate （BER） of 10~2. Furthermore, the novel RS BTC has shorter component code and rapider encoding and decoding speed. Therefore, the novel RS BTC coding scheme can be better used in high-speed long-haul optical communication systems, and the novel RS BTC can be regarded as a candidate code of the super forward error correction （super-FEC） code~ Moreover, the encoding/decoding design and implementation of the novel RS BTC are also presented.
基金supported by the National Natural Science Foundation of China(No.12104141).
文摘Aiming at the problem that the bit error rate(BER)of asymmetrically clipped optical orthogonal frequency division multiplexing(ACO-OFDM)space optical communication system is significantly affected by different turbulence intensities,the deep learning technique is proposed to the polarization code decoding in ACO-OFDM space optical communication system.Moreover,this system realizes the polarization code decoding and signal demodulation without frequency conduction with superior performance and robustness compared with the performance of traditional decoder.Simulations under different turbulence intensities as well as different mapping orders show that the convolutional neural network(CNN)decoder trained under weak-medium-strong turbulence atmospheric channels achieves a performance improvement of about 10^(2)compared to the conventional decoder at 4-quadrature amplitude modulation(4QAM),and the BERs for both 16QAM and 64QAM are in between those of the conventional decoder.
基金supported by Beijing Municipal Natural Science Foundation(L222002)the Natural Science Foundation of China(U22B2004).
文摘Existing orthogonal space-time block coding(OSTBC)schemes for backscatter communication systems cannot achieve a full transmission code rate when the tag is equipped with more than two antennas.In this paper,we propose a quasi-orthogonal spacetime block code(QOSTBC)that can achieve a full transmission code rate for backscatter communication systems with a four-antenna tag and then extend the scheme to support tags with 2i antennas.Specifically,we first present the system model for the backscatter system.Next,we propose the QOSTBC scheme to encode the tag signals.Then,we provide the corresponding maximum likelihood detection algorithms to recover the tag signals.Finally,simulation results are provided to demonstrate that our proposed QOSTBC scheme and the detection algorithm can achieve a better transmission code rate or symbol error rate performance for backscatter communication systems compared with benchmark schemes.
基金supported in part by the National Key R&D Program of China under Grant 2022YFB3103500in part by the National Natural Science Foundation of China under Grant 62302195.
文摘Semantic secure communication is an emerging field that combines the principles of source-channel coding with the need for secure data transmission.It is of great significance in modern communications to protect the confidentiality and privacy of sensitive information and prevent information leaks and malicious attacks.This paper presents a novel approach to semantic secure communication through the utilization of joint source-channel coding,which is based on the design of an automated joint source-channel coding algorithm and an encryption and decryption algorithm based on semantic security.The traditional and state-of-the-art joint source-channel coding algorithms are selected as two baselines for different comparison purposes.Experimental results demonstrate that our proposed algorithm outperforms the first baseline algorithm,the traditional source-channel coding,by 61.21%in efficiency under identical channel conditions(SNR=15 dB).In security,our proposed method can resist 2 more types of attacks compared to the two baselines,exhibiting nearly no increases in time consumption and error rate compared to the state-of-the-art joint source-channel coding algorithm while the secure semantic communication is supported.
基金Project supported by the Open Fund of Wuhan National Research Center for Optoelectronics(Grant No.2022WNLOKF012)the National College Students Innovation Innovation and Entrepreneurship Training Program(Grant No.2023102930147).
文摘A broadband polarization-independent terahertz multifunctional coding metasurface based on topological optimization using liquid crystal(LC)is proposed.The metasurface can achieve reconfigurability for beam steering and vortex beam generation within a frequency range of 0.68 THz–0.72 THz.Firstly,the metasurface unit is topologically optimized using the non-dominant sequencing genetic algorithms(NSGA-II)multi-objective optimization algorithm.By applying the LC’s electrically tunable refractive index properties,the metasurface unit enables polarization-independent 2-bit coding within a frequency range of 0.68 THz–0.72 THz.Then,based on the designed metasurface unit,the array arrangement of the metasurface is reverse-designed to achieve beam steering and vortex beam generation.The results show that,for beam steering,not only can polarization-independent steering of both single-and multi-beam be achieved within the 35°elevation angle range,but also independent control of the target angle of each beam in the multi-beam steering.For vortex beam generation,the metasurfaces can achieve the generation of single-and multi-vortex beams with topological charges l=±1,±2 within the 35elevation angle range,and the generation angles of each vortex beam in the multi-vortex beam can be independently controlled.This provides flexibility and diversity in the generation of vortex beams.Therefore,the proposed terahertz LC metasurface can realize flexible control of reconfigurable functions and has certain application prospects in terahertz communication,phased array radar,and vortex radar.
基金supported by the National Natural Science Foundation of China(Grant Nos.62375137 and 62175114).
文摘Structural colors based on metasurfaces have very promising applications in areas such as optical image encryption and color printing.Herein,we propose a deep learning-enabled reverse design of polarization-selective structural color based on coding metasurface.In this study,the long short-term memory(LSTM)neural network is presented to enable the forward and inverse mapping between coding metasurface structure and corresponding color.The results show that the method can achieve 98%accuracy for the forward prediction of color and 93%accuracy for the inverse design of the structure.Moreover,a cascaded architecture is adopted to train the inverse neural network model,which can solve the nonuniqueness problem of the polarization-selective color reverse design.This study provides a new path for the application and development of structural colors.
基金Project supported by the National Natural Science Foundation of China(Grant No.12404531)the Natural Science Foundation of the Higher Education Institutions of Jiangsu Province,China(Grant No.23KJB140011)。
文摘Efficient elastic wave focusing is crucial in materials and physical engineering.Elastic coding metasurfaces,which are innovative planar artificial structures,show great potential for use in the field of wave focusing.However,elastic coding lenses(ECLs)still suffer from low focusing performance,thickness comparable to wavelength,and frequency sensitivity.Here,we consider both the structural and material properties of the coding unit,thus realizing further compression of the thickness of the ECL.We chose the simplest ECL,which consists of only two encoding units.The coding unit 0 is a straight structure constructed using a carbon fiber reinforced composite material,and the coding unit 1 is a zigzag structure constructed using an aluminum material,and the thickness of the ECL constructed using them is only 1/8 of the wavelength.Based on the theoretical design,the arrangement of coding units is further optimized using genetic algorithms,which significantly improves the focusing performance of the lens at different focus and frequencies.This study provides a more effective way to control vibration and noise in advanced structures.
基金supported in part by National Natural Science Foundation of China(U24A20307 and 62175224)in part by the science and technology innovation leading talent project of special support plan for high-level talents in Zhejiang Province(2021R52032)+2 种基金in part by the China Jiliang University Basic Research ExpensesZhejiang University Students Science and Technology Innovation Activity Plan-New Talent Plan(2024R409C054)in part by the Natural Science Foundation of Zhejiang Province under Grant(ZCLZ25F0502).
文摘Metasurfaces offer exceptional capabilities for controlling electromagnetic waves,enabling the realization of unique electromagnetic properties.As communication technology continues to evolve,metasurfaces present promising applications in wireless communications.This paper reviews the latest advancements in metasurface research within the communication sector,explores metasurface-based wireless relay technologies,and summarizes various wireless communication methods employing different types of metasurfaces across diverse modulation schemes.This paper provides a detailed discussion on the design of wireless communication systems based on coding metasurfaces to simplify transmitter architecture,as well as the development of intelligent coding metasurfaces in the communication field.It also elaborates on the application of vector vortex light fields in metasurface communication.Finally,it offers a forward-looking perspective on wireless communication systems that incorporate coded metasurfaces.This review aims to furnish researchers with a thorough understanding of the current state and future directions of coded metasurface applications in communications.
基金supported in part by National Natural Science Foundation of China under Grants 62122069,62071431,and 62201507.
文摘To address the contradiction between the explosive growth of wireless data and the limited spectrum resources,semantic communication has been emerging as a promising communication paradigm.In this paper,we thus design a speech semantic coded communication system,referred to as Deep-STS(i.e.,Deep-learning based Speech To Speech),for the lowbandwidth speech communication.Specifically,we first deeply compress the speech data through extracting the textual information from the speech based on the conformer encoder and connectionist temporal classification decoder at the transmitter side of Deep-STS system.In order to facilitate the final speech timbre recovery,we also extract the short-term timbre feature of speech signals only for the starting 2s duration by the long short-term memory network.Then,the Reed-Solomon coding and hybrid automatic repeat request protocol are applied to improve the reliability of transmitting the extracted text and timbre feature over the wireless channel.Third,we reconstruct the speech signal by the mel spectrogram prediction network and vocoder,when the extracted text is received along with the timbre feature at the receiver of Deep-STS system.Finally,we develop the demo system based on the USRP and GNU radio for the performance evaluation of Deep-STS.Numerical results show that the ac-Received:Jan.17,2024 Revised:Jun.12,2024 Editor:Niu Kai curacy of text extraction approaches 95%,and the mel cepstral distortion between the recovered speech signal and the original one in the spectrum domain is less than 10.Furthermore,the experimental results show that the proposed Deep-STS system can reduce the total delay of speech communication by 85%on average compared to the G.723 coding at the transmission rate of 5.4 kbps.More importantly,the coding rate of the proposed Deep-STS system is extremely low,only 0.2 kbps for continuous speech communication.It is worth noting that the Deep-STS with lower coding rate can support the low-zero-power speech communication,unveiling a new era in ultra-efficient coded communications.
文摘Deep learning-based Joint Source-Channel Coding(JSCC)is a crucial component in semantic communication,and recent research has made significant progress in adapting to different channels.In this paper,we propose a multi-stage progressive technique called Deep learning based Progressive Joint Source-Channel Coding(DP-JSCC).This approach partitions the source into multiple stages and transmits the signals continuously.The receiver gradually enhances the quality of image reconstruction by progressively receiving the signals,offering greater flexibility compared to existing dynamic rate transmission methods.The model adopts a lightweight architectural design,where we introduce an efficient module called the Inverted Shuffle Attention Bottleneck(ISAB)and incorporate self-attention mechanisms in the encoding and decoding process to capture signal correlations and establish long-range dependencies.Additionally,we introduce the Progressive Focus Weight Allocation(PFWA)method to improve the image reconstruction capability in progressive transmission tasks.These design enhance the expressive capacity of the model.Simulation results demonstrate that DP-JSCC can flexibly adjust the transmission rate according to requirements without the need for retraining or deployment,enabling continuous optimization of signals at different rates.Furthermore,compared to stateof-the-art JSCC methods,DP-JSCC exhibits advantages in terms of computational complexity,parameter count,and reconstruction performance.
文摘The code of the list of sea and island problems is the unique identification code of the regulatory files,which is accompanied by the whole life cycle of the regulatory"discovery,verification and disposal".Standardized coding of problems found by supervision and tracking and recording the whole life cycle of supervision can quickly guide supervisors to find problems,identify problems,initiate responses and carry out follow-up disposal,which is a reflection of whole-process management of supervision.Combining with sea and island regulatory systems and mechanisms,combed the supervision business flow,divides the supervision link,based on the existing coding system,from the Angle of supervision refinement,puts forward a whole lifetime oriented regulatory system of sea and island issues list for coding,coding through to find and stop and disposal of the three links all process application scenarios,The implementation of the whole business"one code"association,the whole process of"one code"management,practice verification shows the effectiveness of the method,compared with the original coding rules for the supervision of all links and results reflect more intuitive,comprehensive,can be better applied to the practice of supervision.
