Low sidelobe waveform can reduce mutual masking between targets and increase the detection probability of weak targets.A low sidelobe waveform design method based on complementary amplitude coding(CAC)is proposed in t...Low sidelobe waveform can reduce mutual masking between targets and increase the detection probability of weak targets.A low sidelobe waveform design method based on complementary amplitude coding(CAC)is proposed in this paper,which can be used to reduce the sidelobe level of multiple waveforms.First,the CAC model is constructed.Then,the waveform design problem is transformed into a nonlinear optimization problem by constructing an objective function using the two indicators of peak-to-sidelobe ratio(PSLR)and integrated sidelobe ratio(ISLR).Finally,genetic algorithm(GA)is used to solve the optimization problem to get the best CAC waveforms.Simulations and experiments are conducted to verify the effectiveness of the proposed method.展开更多
To resolve problems of complicated clutter, fast-varying scenes, and low signal-clutterratio （SCR） in application of target detection on sea for space-based radar （SBR）, a target detection approach based on adapti...To resolve problems of complicated clutter, fast-varying scenes, and low signal-clutterratio （SCR） in application of target detection on sea for space-based radar （SBR）, a target detection approach based on adaptive waveform design is proposed in this paper. Firstly, complicated sea clutter is modeled as compound Gaussian process, and a target is modeled as some scatterers with Gaussian reflectivity. Secondly, every dwell duration of radar is divided into several sub-dwells. Regular linear frequency modulated pulses are transmitted at Sub-dwell 1, and the received signal at this sub-dwell is used to estimate clutter covariance matrices and pre-detection. Estimated matrices are updated at every following sub-dwell by multiple particle filtering to cope with fast-varying clutter scenes of SBR. Furthermore, waveform of every following sub-dwell is designed adaptively according to mean square optimization technique. Finally, principal component analysis and generalized likelihood ratio test is used for mitigation of colored interference and property of constant false alarm rate, respectively. Simulation results show that, considering configuration of SBR and condition of complicated clutter, 9 dB is reduced for SCR which reliable detection requires by this target detection approach. Therefore, the work in this paper can markedly improve radar detection performance for weak targets.展开更多
Transmit waveform optimization is critical to radar system performance. There have been a fruit of achievements about waveform design in recent years. However, most of the existing methods are based on the assumption ...Transmit waveform optimization is critical to radar system performance. There have been a fruit of achievements about waveform design in recent years. However, most of the existing methods are based on the assumption that radar is smart and the target is dumb, which is not always reasonable in the modern electronic warfare. This paper focuses on the waveform design for radar and the extended target in the environment of electronic warfare. Three different countermeasure models between smart radar and dumb target, smart target and dumb radar, smart radar and smart target are proposed. Taking the signal-to-interferenceplus-noise ratio(SINR) as the metric, optimized waveforms for the first two scenarios are achieved by the general water-filling method in the presence of clutter. For the last case, the equilibrium between smart radar and smart target in the presence of clutter is given mathematically and the optimized solution is achieved through a novel two-step water-filling method on the basis of minmax theory. Simulation results under different power constraints show the power allocation strategies of radar and target and the output SINRs are analyzed.展开更多
In order to improve detection and estimation performance of distributed OrthogonalFrequency-Division Multiplexing（OFDM） Multiple-Input Multiple-Output（MIMO） radar system in multi-target scene, we propose a novel a...In order to improve detection and estimation performance of distributed OrthogonalFrequency-Division Multiplexing（OFDM） Multiple-Input Multiple-Output（MIMO） radar system in multi-target scene, we propose a novel approach of Adaptive Waveform Design（AWD） based on a constrained Multi-Objective Optimization（MOO）. The sparse measurement model of this radar system is derived, and the method based on decomposed Dantzig selectors is applied for the sparse recovery according to the block structures of the sparse vector and the system matrix. An AWD approach is proposed, which optimizes two objective functions, namely minimizing the upper bound of the recovery error and maximizing the weakest-target return, by adjusting the complex weights of the emitting waveform amplitudes. Several numerical simulations are provided and their results show that the detection and estimation performance of the radar system is improved significantly when this MOO-based AWD approach is applied to the distributed OFDM MIMO radar system. Especially, we verify the effectiveness of our AWD approach when the available samples are reduced severally and the technique of compressed sensing is introduced.展开更多
Orthogonal waveform design is quite an important issue for waveform diversity systems. A chaos based method for the orthogonal discrete frequency coding waveform （DFCW） design is proposed to increase the insufficien...Orthogonal waveform design is quite an important issue for waveform diversity systems. A chaos based method for the orthogonal discrete frequency coding waveform （DFCW） design is proposed to increase the insufficient orthogonal waveform number and their finite coding length. Premises for chaos choosing and the frequency quantification method are discussed to obtain the best correlation properties. Simulation results show the validity of the theoretic analysis.展开更多
Waveform or code design is an important topic in many applications,which has continuously attracted attention during the past several decades.The development of waveform design has been significantly advanced since th...Waveform or code design is an important topic in many applications,which has continuously attracted attention during the past several decades.The development of waveform design has been significantly advanced since the emergence of multiple-input multiple-output(MIMO)technique.Compared to the single-waveform design for conventional radars,the multi-waveform design enables extra degrees of freedom(DOFs)for modern radars,which therefore triggers a series of relevant studies on MIMO radar.In this paper,we provide an overview on the main techniques of MIMO radar waveform designs developed in recent years,wherein the state-of-the-art methods are reviewed in terms of different designing criteria,including the minimization of auto-and cross-correlation levels(or equivalently,the integrated sidelobe level),the information theoretic,ambiguity function shaping,and signal-to-interference-plus-noise ratio maximization-based criteria,etc.Moreover,we give detailed comments on the main issues of different waveform designs,and also provide the possibly emerging directions toward the research on MIMO radar waveform design and potential challenges.展开更多
Multiple-input multiple-output(MIMO)systems which deploy one-bit DACs are at-tractive in many fields,such as wireless communications and radar.In this paper,the problem of transmit waveform design in MIMO radar system...Multiple-input multiple-output(MIMO)systems which deploy one-bit DACs are at-tractive in many fields,such as wireless communications and radar.In this paper,the problem of transmit waveform design in MIMO radar system with one-bit DACs is investigated.By appropri-ately designing the transmitted QPSK signal waveforms,the majority of radiated energy can be fo-cused into the mainlobe region(s)by minimizing the integrated sidelobe to mainlobe ratio(ISMR)of beampattern,such that the intensity of backscattered signals from targets can be enhanced.However,the resulting optimization problem which consists of constrained fractional quadratic problem(CFQP)is noconvex.To tackle this problem,a block-sparse semidefinite relaxation meth-od is first utilized to reformulate the CFQP into a reduced convex semidefinite programming(SDP).Further,a customized interior point algorithm(IPA)is developed to solve the small-scale SDP.Finally,the desirable one-bit transmit waveform sequence can be properly synthesized by us-ing Gaussian randomization method.Numerical simulation results demonstrate that the proposed method offer better performance than the state-of-the-art algorithms.展开更多
In order to provide a judicious pulse waveform design required for ultra-wideband(UWB)communication to enable the UWB spectral mask compatible and coexistent with other existing wireless communication systems,a semi-d...In order to provide a judicious pulse waveform design required for ultra-wideband(UWB)communication to enable the UWB spectral mask compatible and coexistent with other existing wireless communication systems,a semi-definite programming(SDP)based pulse waveform design method for UWB radios is introduced and a further analysis is given in this paper.By using Sedumi and Yalmip toolboxes of Matlab,the procedure of solving the SDP problem is simplified.Simulation results show that this SDP based pulse waveform design method can be used to design pulses that fulfill the Federal Communications Commission(FCC)spectral mask strictly and optimize the power efficiency at the same time.This paper also analyzes the influences of the power efficiency duing to the changes of sampling interval and the number of combined pulses,and then the optimal sampling interval that maximizes the transmission power can be found.展开更多
For the issue of deterioration in detection performance caused by dynamically changing environment in ultra-wideband（UWB） multiple input multiple output（MIMO） radar, this paper proposes a novel adaptive waveform d...For the issue of deterioration in detection performance caused by dynamically changing environment in ultra-wideband（UWB） multiple input multiple output（MIMO） radar, this paper proposes a novel adaptive waveform design which is aimed to improve the ability of discriminating target and clutter from the radar scene. Firstly, a sequence of Morlet wavelet pulses with frequency hopping and pulse position modulation by Welch-Costas array is designed. Then a waveform optimization solution is proposed which is achieved by applying the minimization mutual-information（MI） strategy. After that, with subsequent iterations of the algorithm, simulation results demonstrate that the optimal waveform design method brings an improvement in the target detection ability in the presence of noise and clutter.展开更多
An effective numerical approach is developed for orthogonal waveform design for Multiple-Input Multiple-Output (MIMO) radar. The Doppler shift tolerance is considered in the design cost function. The design results in...An effective numerical approach is developed for orthogonal waveform design for Multiple-Input Multiple-Output (MIMO) radar. The Doppler shift tolerance is considered in the design cost function. The design results indicate that the Doppler? tolerance of the designed orthogonal waveforms is markedly improved.展开更多
Distributed precision jamming(DPJ)is a novel blanket jamming concept in electronic warfare,which delivers the jamming resource to the opponent equipment precisely and ensures that friendly devices are not affected.Rob...Distributed precision jamming(DPJ)is a novel blanket jamming concept in electronic warfare,which delivers the jamming resource to the opponent equipment precisely and ensures that friendly devices are not affected.Robust jamming performance and low hardware burden on the jammers are crucial for practical DPJ implementation.To achieve these goals,we study the robust design of wideband constant modulus(CM)discrete phase waveform for DPJ,where the worst-case combined power spectrum(CPS)of both the opponent and friendly devices is considered in the objective function,and the CM discrete phase constraints are used to design the wideband waveform.Specifically,the resultant mathematical model is a large-scale minimax multi-objective optimization problem(MOP)with CM and discrete phase constraints.To tackle the challenging MOP,we transform it into a single-objective minimization problem using the Lp-norm and Pareto framework.For the approximation problem,we propose the Riemannian conjugate gradient for CM discrete phase constraints(RCG-CMDPC)algorithm with low computational complexity,which leverages the complex circle manifold and a projection method to satisfy the CM discrete phase constraints within the RCG framework.Numerical examples demonstrate the superior robust DPJ effectiveness and computational efficiency compared to other competing algorithms.展开更多
In this paper,we formulate the precoding problem of integrated sensing and communication(ISAC)waveform as a non-convex quadratically constrained quadratic programming(QCQP),in which the weighted sum of communication m...In this paper,we formulate the precoding problem of integrated sensing and communication(ISAC)waveform as a non-convex quadratically constrained quadratic programming(QCQP),in which the weighted sum of communication multi-user interference(MUI)and the gap between dual-use waveform and ideal radar waveform is minimized with peak-toaverage power ratio(PAPR)constraints.We propose an efficient algorithm based on alternating direction method of multipliers(ADMM),which is able to decouple multiple variables and provide a closed-form solution for each subproblem.In addition,to improve the sensing performance in both spatial and temporal domains,we propose a new criteria to design the ideal radar waveform,in which the beam pattern is made similar to the ideal one and the integrated sidelobe level of the ambiguity function in each target direction is minimized in the region of interest.The limited memory Broyden-Fletcher-Goldfarb-Shanno(LBFGS)algorithm is applied to the design of the ideal radar waveform which works as a reference in the design of the dual-function waveform.Numerical results indicate that the designed dual-function waveform is capable of offering good communication quality of service(QoS)and sensing performance.展开更多
In this paper,we present a novel unimodular sequence design algorithm based on the coordinate descent(CD)algorithm,aimed at countering electronic surveillance(ES)systems based on cyclostationary analysis.Our algorithm...In this paper,we present a novel unimodular sequence design algorithm based on the coordinate descent(CD)algorithm,aimed at countering electronic surveillance(ES)systems based on cyclostationary analysis.Our algorithm not only provides resistance against cyclostationary analysis(CSA)but also maintains low integrated sidelobe(ISL)characteristics.Initially,we derive the expression of the cyclostationary feature(CSF)detector and simplify it into an iterative quadratic form.Additionally,we derive a quadratic form to ensure the similarity of the autocorrelation sidelobes.To balance the minimization of the detection probability and the ISL values,we introduce a Pareto scalar that transforms the multiobjective optimization problem into a convex combination of objective functions.This approach allows us to find an optimal trade-off between the two objectives.Finally,we propose a monotonic algorithm based on the CD algorithm to counter CSA analysis.This algorithm efficiently solves the optimization problem mentioned earlier.Numerical experiments are conducted to validate the correctness and effectiveness of our proposed algorithm.展开更多
For the waveform design and research of wireless powered and backscatter hybrid communication system,it is crucial to balance energy harvesting with ensuring communication rate performance.Considering the communicatio...For the waveform design and research of wireless powered and backscatter hybrid communication system,it is crucial to balance energy harvesting with ensuring communication rate performance.Considering the communication needs of traditional users in the hybrid communication system is particularly practical.In this paper,we study the model of wireless powered and backscatter hybrid communication system,while also taking the traditional orthogonal frequency division multiplexing(OFDM)user system into account.We jointly design the transmitting signal waveform and the backscatter signal waveform to ensure the communication performance of the traditional user while simultaneously enhancing the communication and energy transmission performance of the hybrid communication system.We maximize the signal-to-noise ratio(SNR)at the receiver by jointly optimizing the amplitude and phase of the transmitted signal waveform from the radio frequency(RF)source and the reflection coefficient of the backscatter device(BD).Furthermore,we use geometric programming methods to solve the problem.The simulation results confirm the effectiveness of the proposed scheme.展开更多
Extended target detection performance can be enhanced by using phase-modulated waveform designs in band-limited radar systems. Unlike waveforms designed for the total energy constraint, phase-modulated waveforms can f...Extended target detection performance can be enhanced by using phase-modulated waveform designs in band-limited radar systems. Unlike waveforms designed for the total energy constraint, phase-modulated waveforms can fully exploit the transmit power in the pulse duration, which is more suit- able for practical radar systems. An alternating iterative algorithm was developed to optimize the phase-modulated baseband waveform by maximizing the signal-to-noise ratio （SNR） at the receiver filter output. The output SNR increases continuously with the number of iterations and the algorithm is guaran- teed to converge. Simulations validate the effectiveness of this approach. The waveforms designed by this method outperform other commonly used waveforms for extended target detection.展开更多
The problems of joint adaptive waveform design and baseline range design for bistatic radar to maximize the practical radar resolution were considered.Distinguishing from the conventional ambiguity function(AF)-based ...The problems of joint adaptive waveform design and baseline range design for bistatic radar to maximize the practical radar resolution were considered.Distinguishing from the conventional ambiguity function(AF)-based resolution which is only related with the transmitted waveform and bistatic geometry and could be regarded as the potential resolution of a bistatic radar system,the practical resolution involves the effect of waveform,signal-to-noise ratio(SNR)as well as the measurement model.Thus,it is more practical and will have further significant application in target detection and tracking.The constraint optimization procedure of joint adaptive waveform design and baseline range design for maximizing the practical resolution of bistatic radar system under dynamic target scenario was devised.Simulation results show that the range and velocity resolution are enhanced according to the adaptive waveform and bistatic radar configuration.展开更多
Integrated sensing and communication(ISAC)is a spectrum and energy efficient approach to realizing dual functions by a unified hardware platform.In this paper,we consider a multiple-input multiple-output(MIMO)ISAC sys...Integrated sensing and communication(ISAC)is a spectrum and energy efficient approach to realizing dual functions by a unified hardware platform.In this paper,we consider a multiple-input multiple-output(MIMO)ISAC system,where the transmitted waveform consisting of communication signals and dedicated sensing signal is optimized for dual purposes of estimating targets and serving downlink single-antenna users.Specifically,the sensing interference and multi-user interference are exploited,rather than suppressed,by the waveform design scheme.The joint waveform design problem is formulated by maximizing the constructive interference(CI)while ensuring the power budget and waveform similarity error with the benchmark signal,which limits the sensing estimation accuracy.To obtain the benchmark signal which achieves the optimal estimation performance,we propose a semidefinite relaxation based algorithm to solve the optimization problem.For clarity,we derive the real representation of the complex joint waveform design problem and prove its convexity.Numerical results verify the superiority of the proposed CI-based waveform design when the interference was efficiently exploited as a useful signal source achieving favorable symbol error ratio performance.Moreover,the dedicated sensing signal provides more degree of freedom for waveform design.展开更多
A novel method called the general waterfilling,which is suitable when clutter is not negligible,is proposed to solve the waveform design problem of broadband radar for the recognition of multiple extended targets.The ...A novel method called the general waterfilling,which is suitable when clutter is not negligible,is proposed to solve the waveform design problem of broadband radar for the recognition of multiple extended targets.The uncertainty of the target’s radar signatures is decreased via maximizing the mutual information between a random extended target and the received signal.Then,the general water-filling method is employed to the waveform design problem for multiple extended targets identification to increase the separability of multiple targets.Experimental results evaluated the efficiency of the proposed method.Compared to chirp signal and water-filling signal,our method improves the classification rates and even performs better at low signal-to-interference-plus-noise ratio(SINR).展开更多
The problem of sonar signal waveform design to detect a high-speed small target in an underwater environment is discussed. From theoretical analysis, time-frequency hop signal is regarded as the most suitable signal w...The problem of sonar signal waveform design to detect a high-speed small target in an underwater environment is discussed. From theoretical analysis, time-frequency hop signal is regarded as the most suitable signal waveform in this application. To get precise target parameter estimation ability, the signal should have high range-Doppler resolution performance. The results of signal analysis show that hop signal with frequency serial coding as Costas array has sharp ambiguity characteristic, so it can be used in an active sonar system to detect a high speed small target. A scheme of frequency coding is also presented.展开更多
This paper presents a complex design of frequency modulated interrupted continuous wave (FMICW) and frequency-coded pulses (FCP) for detection of aircraft and ship targets. Here, FMICW is used to satisfy requirements ...This paper presents a complex design of frequency modulated interrupted continuous wave (FMICW) and frequency-coded pulses (FCP) for detection of aircraft and ship targets. Here, FMICW is used to satisfy requirements of aircraft detection and FCP is used to satisfy requirements of ship detection for the differences in maneuverability and scatter characteristics of targets and interference background. The design of such a complex waveform for detection of aircraft and ship targets by a HF radar is discussed in detail with different considerations for better performance.展开更多
基金supported by the National Natural Science Foundation of China(62001481,61890542)the Natural Science Foundation of Hunan Province(2021JJ40686).
文摘Low sidelobe waveform can reduce mutual masking between targets and increase the detection probability of weak targets.A low sidelobe waveform design method based on complementary amplitude coding(CAC)is proposed in this paper,which can be used to reduce the sidelobe level of multiple waveforms.First,the CAC model is constructed.Then,the waveform design problem is transformed into a nonlinear optimization problem by constructing an objective function using the two indicators of peak-to-sidelobe ratio(PSLR)and integrated sidelobe ratio(ISLR).Finally,genetic algorithm(GA)is used to solve the optimization problem to get the best CAC waveforms.Simulations and experiments are conducted to verify the effectiveness of the proposed method.
基金supported by the National Defense Pre-Research Foundation of China
文摘To resolve problems of complicated clutter, fast-varying scenes, and low signal-clutterratio （SCR） in application of target detection on sea for space-based radar （SBR）, a target detection approach based on adaptive waveform design is proposed in this paper. Firstly, complicated sea clutter is modeled as compound Gaussian process, and a target is modeled as some scatterers with Gaussian reflectivity. Secondly, every dwell duration of radar is divided into several sub-dwells. Regular linear frequency modulated pulses are transmitted at Sub-dwell 1, and the received signal at this sub-dwell is used to estimate clutter covariance matrices and pre-detection. Estimated matrices are updated at every following sub-dwell by multiple particle filtering to cope with fast-varying clutter scenes of SBR. Furthermore, waveform of every following sub-dwell is designed adaptively according to mean square optimization technique. Finally, principal component analysis and generalized likelihood ratio test is used for mitigation of colored interference and property of constant false alarm rate, respectively. Simulation results show that, considering configuration of SBR and condition of complicated clutter, 9 dB is reduced for SCR which reliable detection requires by this target detection approach. Therefore, the work in this paper can markedly improve radar detection performance for weak targets.
基金supported by the National Natural Science Foundation of China(61302153)the Aeronautical Science Foundation of China(20160196001)
文摘Transmit waveform optimization is critical to radar system performance. There have been a fruit of achievements about waveform design in recent years. However, most of the existing methods are based on the assumption that radar is smart and the target is dumb, which is not always reasonable in the modern electronic warfare. This paper focuses on the waveform design for radar and the extended target in the environment of electronic warfare. Three different countermeasure models between smart radar and dumb target, smart target and dumb radar, smart radar and smart target are proposed. Taking the signal-to-interferenceplus-noise ratio(SINR) as the metric, optimized waveforms for the first two scenarios are achieved by the general water-filling method in the presence of clutter. For the last case, the equilibrium between smart radar and smart target in the presence of clutter is given mathematically and the optimized solution is achieved through a novel two-step water-filling method on the basis of minmax theory. Simulation results under different power constraints show the power allocation strategies of radar and target and the output SINRs are analyzed.
基金supported by the National Basic Research Program of China(No.613205212)
文摘In order to improve detection and estimation performance of distributed OrthogonalFrequency-Division Multiplexing（OFDM） Multiple-Input Multiple-Output（MIMO） radar system in multi-target scene, we propose a novel approach of Adaptive Waveform Design（AWD） based on a constrained Multi-Objective Optimization（MOO）. The sparse measurement model of this radar system is derived, and the method based on decomposed Dantzig selectors is applied for the sparse recovery according to the block structures of the sparse vector and the system matrix. An AWD approach is proposed, which optimizes two objective functions, namely minimizing the upper bound of the recovery error and maximizing the weakest-target return, by adjusting the complex weights of the emitting waveform amplitudes. Several numerical simulations are provided and their results show that the detection and estimation performance of the radar system is improved significantly when this MOO-based AWD approach is applied to the distributed OFDM MIMO radar system. Especially, we verify the effectiveness of our AWD approach when the available samples are reduced severally and the technique of compressed sensing is introduced.
基金supported by the Hunan Province Distinguished Ph.D. Innovation Fund (CX2012B018)the National University of Defense Technology Distinguished Ph.D. Innovation Fund (B120403)
文摘Orthogonal waveform design is quite an important issue for waveform diversity systems. A chaos based method for the orthogonal discrete frequency coding waveform （DFCW） design is proposed to increase the insufficient orthogonal waveform number and their finite coding length. Premises for chaos choosing and the frequency quantification method are discussed to obtain the best correlation properties. Simulation results show the validity of the theoretic analysis.
基金supported in part by the National Natural Science Foundation of China(No.61901041)。
文摘Waveform or code design is an important topic in many applications,which has continuously attracted attention during the past several decades.The development of waveform design has been significantly advanced since the emergence of multiple-input multiple-output(MIMO)technique.Compared to the single-waveform design for conventional radars,the multi-waveform design enables extra degrees of freedom(DOFs)for modern radars,which therefore triggers a series of relevant studies on MIMO radar.In this paper,we provide an overview on the main techniques of MIMO radar waveform designs developed in recent years,wherein the state-of-the-art methods are reviewed in terms of different designing criteria,including the minimization of auto-and cross-correlation levels(or equivalently,the integrated sidelobe level),the information theoretic,ambiguity function shaping,and signal-to-interference-plus-noise ratio maximization-based criteria,etc.Moreover,we give detailed comments on the main issues of different waveform designs,and also provide the possibly emerging directions toward the research on MIMO radar waveform design and potential challenges.
基金the National Natural Science Found-ation of China(No.62171292)the Guangdong Basic and Applied Basic Research Foundation(No.2020A1515010410)。
文摘Multiple-input multiple-output(MIMO)systems which deploy one-bit DACs are at-tractive in many fields,such as wireless communications and radar.In this paper,the problem of transmit waveform design in MIMO radar system with one-bit DACs is investigated.By appropri-ately designing the transmitted QPSK signal waveforms,the majority of radiated energy can be fo-cused into the mainlobe region(s)by minimizing the integrated sidelobe to mainlobe ratio(ISMR)of beampattern,such that the intensity of backscattered signals from targets can be enhanced.However,the resulting optimization problem which consists of constrained fractional quadratic problem(CFQP)is noconvex.To tackle this problem,a block-sparse semidefinite relaxation meth-od is first utilized to reformulate the CFQP into a reduced convex semidefinite programming(SDP).Further,a customized interior point algorithm(IPA)is developed to solve the small-scale SDP.Finally,the desirable one-bit transmit waveform sequence can be properly synthesized by us-ing Gaussian randomization method.Numerical simulation results demonstrate that the proposed method offer better performance than the state-of-the-art algorithms.
基金the National Natural Science Foundation of China (Grant No.60432040)Program for New Century Excellent Talents in University(Grant No.NCET-04-0332)
文摘In order to provide a judicious pulse waveform design required for ultra-wideband(UWB)communication to enable the UWB spectral mask compatible and coexistent with other existing wireless communication systems,a semi-definite programming(SDP)based pulse waveform design method for UWB radios is introduced and a further analysis is given in this paper.By using Sedumi and Yalmip toolboxes of Matlab,the procedure of solving the SDP problem is simplified.Simulation results show that this SDP based pulse waveform design method can be used to design pulses that fulfill the Federal Communications Commission(FCC)spectral mask strictly and optimize the power efficiency at the same time.This paper also analyzes the influences of the power efficiency duing to the changes of sampling interval and the number of combined pulses,and then the optimal sampling interval that maximizes the transmission power can be found.
基金supported by the National Natural Science Foundation of China(6107114561271331)
文摘For the issue of deterioration in detection performance caused by dynamically changing environment in ultra-wideband（UWB） multiple input multiple output（MIMO） radar, this paper proposes a novel adaptive waveform design which is aimed to improve the ability of discriminating target and clutter from the radar scene. Firstly, a sequence of Morlet wavelet pulses with frequency hopping and pulse position modulation by Welch-Costas array is designed. Then a waveform optimization solution is proposed which is achieved by applying the minimization mutual-information（MI） strategy. After that, with subsequent iterations of the algorithm, simulation results demonstrate that the optimal waveform design method brings an improvement in the target detection ability in the presence of noise and clutter.
文摘An effective numerical approach is developed for orthogonal waveform design for Multiple-Input Multiple-Output (MIMO) radar. The Doppler shift tolerance is considered in the design cost function. The design results indicate that the Doppler? tolerance of the designed orthogonal waveforms is markedly improved.
基金supported by the National Natural Science Foundation of China(No.62301581)the Postgraduate Scientific Research Innovation Project of Hunan Province,China(No.CX20230045)。
文摘Distributed precision jamming(DPJ)is a novel blanket jamming concept in electronic warfare,which delivers the jamming resource to the opponent equipment precisely and ensures that friendly devices are not affected.Robust jamming performance and low hardware burden on the jammers are crucial for practical DPJ implementation.To achieve these goals,we study the robust design of wideband constant modulus(CM)discrete phase waveform for DPJ,where the worst-case combined power spectrum(CPS)of both the opponent and friendly devices is considered in the objective function,and the CM discrete phase constraints are used to design the wideband waveform.Specifically,the resultant mathematical model is a large-scale minimax multi-objective optimization problem(MOP)with CM and discrete phase constraints.To tackle the challenging MOP,we transform it into a single-objective minimization problem using the Lp-norm and Pareto framework.For the approximation problem,we propose the Riemannian conjugate gradient for CM discrete phase constraints(RCG-CMDPC)algorithm with low computational complexity,which leverages the complex circle manifold and a projection method to satisfy the CM discrete phase constraints within the RCG framework.Numerical examples demonstrate the superior robust DPJ effectiveness and computational efficiency compared to other competing algorithms.
基金supported in part by the National Natural Science Foundation of China under Grant 62271142in part by the Key Research and Development Program of Jiangsu Province BE2023021+2 种基金in part by the Jiangsu Key Research and Development Program Project under Grant BE2023011-2in part by the Young Scholar Funding of Southeast Universityin part by the Fundamental Research Funds for the Central Universities 2242022k60001。
文摘In this paper,we formulate the precoding problem of integrated sensing and communication(ISAC)waveform as a non-convex quadratically constrained quadratic programming(QCQP),in which the weighted sum of communication multi-user interference(MUI)and the gap between dual-use waveform and ideal radar waveform is minimized with peak-toaverage power ratio(PAPR)constraints.We propose an efficient algorithm based on alternating direction method of multipliers(ADMM),which is able to decouple multiple variables and provide a closed-form solution for each subproblem.In addition,to improve the sensing performance in both spatial and temporal domains,we propose a new criteria to design the ideal radar waveform,in which the beam pattern is made similar to the ideal one and the integrated sidelobe level of the ambiguity function in each target direction is minimized in the region of interest.The limited memory Broyden-Fletcher-Goldfarb-Shanno(LBFGS)algorithm is applied to the design of the ideal radar waveform which works as a reference in the design of the dual-function waveform.Numerical results indicate that the designed dual-function waveform is capable of offering good communication quality of service(QoS)and sensing performance.
基金support of the National Natural Science Foundation of China under grant numbers 62101570 and 61901494financial support has played a crucial role in the successful completion of this research.
文摘In this paper,we present a novel unimodular sequence design algorithm based on the coordinate descent(CD)algorithm,aimed at countering electronic surveillance(ES)systems based on cyclostationary analysis.Our algorithm not only provides resistance against cyclostationary analysis(CSA)but also maintains low integrated sidelobe(ISL)characteristics.Initially,we derive the expression of the cyclostationary feature(CSF)detector and simplify it into an iterative quadratic form.Additionally,we derive a quadratic form to ensure the similarity of the autocorrelation sidelobes.To balance the minimization of the detection probability and the ISL values,we introduce a Pareto scalar that transforms the multiobjective optimization problem into a convex combination of objective functions.This approach allows us to find an optimal trade-off between the two objectives.Finally,we propose a monotonic algorithm based on the CD algorithm to counter CSA analysis.This algorithm efficiently solves the optimization problem mentioned earlier.Numerical experiments are conducted to validate the correctness and effectiveness of our proposed algorithm.
基金supported in part by Sichuan Major Research and Development Project under Grant 2022YFQ0090in part by the Stable Supporting Fund of National Key Laboratory of Underwater Acoustic Technology.
文摘For the waveform design and research of wireless powered and backscatter hybrid communication system,it is crucial to balance energy harvesting with ensuring communication rate performance.Considering the communication needs of traditional users in the hybrid communication system is particularly practical.In this paper,we study the model of wireless powered and backscatter hybrid communication system,while also taking the traditional orthogonal frequency division multiplexing(OFDM)user system into account.We jointly design the transmitting signal waveform and the backscatter signal waveform to ensure the communication performance of the traditional user while simultaneously enhancing the communication and energy transmission performance of the hybrid communication system.We maximize the signal-to-noise ratio(SNR)at the receiver by jointly optimizing the amplitude and phase of the transmitted signal waveform from the radio frequency(RF)source and the reflection coefficient of the backscatter device(BD).Furthermore,we use geometric programming methods to solve the problem.The simulation results confirm the effectiveness of the proposed scheme.
基金Supported by the National Natural Science Foundation of China(No. 60901057)the National Key Basic Research and Devel-opment (973) Program of China (No. 2010CB731901)
文摘Extended target detection performance can be enhanced by using phase-modulated waveform designs in band-limited radar systems. Unlike waveforms designed for the total energy constraint, phase-modulated waveforms can fully exploit the transmit power in the pulse duration, which is more suit- able for practical radar systems. An alternating iterative algorithm was developed to optimize the phase-modulated baseband waveform by maximizing the signal-to-noise ratio （SNR） at the receiver filter output. The output SNR increases continuously with the number of iterations and the algorithm is guaran- teed to converge. Simulations validate the effectiveness of this approach. The waveforms designed by this method outperform other commonly used waveforms for extended target detection.
基金Project supported by the Program for New Century Excellent Talents in University,ChinaProject(61171133)supported by the National Natural Science Foundation of China+2 种基金Project(11JJ1010)supported by the Natural Science Fund for Distinguished Young Scholars of Hunan Province,ChinaProject(61101182)supported by the National Natural Science Foundation for Young Scientists of ChinaProject(20124307110013)supported by the Doctoral Program of Higher Education of China
文摘The problems of joint adaptive waveform design and baseline range design for bistatic radar to maximize the practical radar resolution were considered.Distinguishing from the conventional ambiguity function(AF)-based resolution which is only related with the transmitted waveform and bistatic geometry and could be regarded as the potential resolution of a bistatic radar system,the practical resolution involves the effect of waveform,signal-to-noise ratio(SNR)as well as the measurement model.Thus,it is more practical and will have further significant application in target detection and tracking.The constraint optimization procedure of joint adaptive waveform design and baseline range design for maximizing the practical resolution of bistatic radar system under dynamic target scenario was devised.Simulation results show that the range and velocity resolution are enhanced according to the adaptive waveform and bistatic radar configuration.
基金This work is supported in part by Shanghai Municipal Science and Technology Major Project under Grant 2021SHZDZX0102.
文摘Integrated sensing and communication(ISAC)is a spectrum and energy efficient approach to realizing dual functions by a unified hardware platform.In this paper,we consider a multiple-input multiple-output(MIMO)ISAC system,where the transmitted waveform consisting of communication signals and dedicated sensing signal is optimized for dual purposes of estimating targets and serving downlink single-antenna users.Specifically,the sensing interference and multi-user interference are exploited,rather than suppressed,by the waveform design scheme.The joint waveform design problem is formulated by maximizing the constructive interference(CI)while ensuring the power budget and waveform similarity error with the benchmark signal,which limits the sensing estimation accuracy.To obtain the benchmark signal which achieves the optimal estimation performance,we propose a semidefinite relaxation based algorithm to solve the optimization problem.For clarity,we derive the real representation of the complex joint waveform design problem and prove its convexity.Numerical results verify the superiority of the proposed CI-based waveform design when the interference was efficiently exploited as a useful signal source achieving favorable symbol error ratio performance.Moreover,the dedicated sensing signal provides more degree of freedom for waveform design.
文摘A novel method called the general waterfilling,which is suitable when clutter is not negligible,is proposed to solve the waveform design problem of broadband radar for the recognition of multiple extended targets.The uncertainty of the target’s radar signatures is decreased via maximizing the mutual information between a random extended target and the received signal.Then,the general water-filling method is employed to the waveform design problem for multiple extended targets identification to increase the separability of multiple targets.Experimental results evaluated the efficiency of the proposed method.Compared to chirp signal and water-filling signal,our method improves the classification rates and even performs better at low signal-to-interference-plus-noise ratio(SINR).
文摘The problem of sonar signal waveform design to detect a high-speed small target in an underwater environment is discussed. From theoretical analysis, time-frequency hop signal is regarded as the most suitable signal waveform in this application. To get precise target parameter estimation ability, the signal should have high range-Doppler resolution performance. The results of signal analysis show that hop signal with frequency serial coding as Costas array has sharp ambiguity characteristic, so it can be used in an active sonar system to detect a high speed small target. A scheme of frequency coding is also presented.
文摘This paper presents a complex design of frequency modulated interrupted continuous wave (FMICW) and frequency-coded pulses (FCP) for detection of aircraft and ship targets. Here, FMICW is used to satisfy requirements of aircraft detection and FCP is used to satisfy requirements of ship detection for the differences in maneuverability and scatter characteristics of targets and interference background. The design of such a complex waveform for detection of aircraft and ship targets by a HF radar is discussed in detail with different considerations for better performance.
