Integrated data and energy transfer(IDET)is capable of simultaneously delivering on-demand data and energy to low-power Internet of Everything(Io E)devices.We propose a multi-carrier IDET transceiver relying on superp...Integrated data and energy transfer(IDET)is capable of simultaneously delivering on-demand data and energy to low-power Internet of Everything(Io E)devices.We propose a multi-carrier IDET transceiver relying on superposition waveforms consisting of multi-sinusoidal signals for wireless energy transfer(WET)and orthogonal-frequency-divisionmultiplexing(OFDM)signals for wireless data transfer(WDT).The outdated channel state information(CSI)in aging channels is employed by the transmitter to shape IDET waveforms.With the constraints of transmission power and WDT requirement,the amplitudes and phases of the IDET waveform at the transmitter and the power splitter at the receiver are jointly optimised for maximising the average directcurrent(DC)among a limited number of transmission frames with the existence of carrier-frequencyoffset(CFO).For the amplitude optimisation,the original non-convex problem can be transformed into a reversed geometric programming problem,then it can be effectively solved with existing tools.As for the phase optimisation,the artificial bee colony(ABC)algorithm is invoked in order to deal with the nonconvexity.Iteration between the amplitude optimisation and phase optimisation yields our joint design.Numerical results demonstrate the advantage of our joint design for the IDET waveform shaping with the existence of the CFO and the outdated CSI.展开更多
Recently, integrated Satellite-Terrestrial(S-T) communication system, especially the integration of satellite communication with 5G/6G, is regarded as a research hotpot. Future integrated S-T communication systems are...Recently, integrated Satellite-Terrestrial(S-T) communication system, especially the integration of satellite communication with 5G/6G, is regarded as a research hotpot. Future integrated S-T communication systems are demanding a more compatible and robust physical layer waveform. Considering physical layer access waveform design, this paper proposed a novel Spread Spectrum Generalized Frequency Division Multiplexing(SS-GFDM) scheme for integrated S-T communication system. Traditional GFDM has many advantages such as excellent adaptability and low out-ofband(OOB) radiation. However, because of intrinsic inter carrier interference(ICI) and low signal-to-noise ratio(SNR), the multiple access performance is degraded. In this paper, we introduced CDMA technology into GFDM. Two different spread spectrum modes, Cyclic Code Shift Keying(CCSK) soft spread spectrum and Direct Sequence Spread Spectrum(DSSS), are considered and compared in this paper to illustrate the benefits of GFDM-CDMA in low SNR scenario. Moreover, this scheme integrates the slot-ALOHA protocol with GFDM-CDMA, which extends access freedom in frequency, time and code domain. The simulation and analysis results show that the proposed GFDM-CDMA scheme reduces the performance degradation caused by interference. It is effective in typical satellite channel with low complexity. Meanwhile, the peak-average-power-ratio(PAPR) and access performance has been enhanced significantly.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
针对双功能雷达通信(Dual-Functional Radar-Communication,DFRC)系统中雷达峰均比(Peak-to-Average Power Ratio,PAPR)导致的通信误码率高及通信信号的调制方式导致的雷达分辨率降低的问题,在总功率和PAPR约束下对下行链路多用户通信...针对双功能雷达通信(Dual-Functional Radar-Communication,DFRC)系统中雷达峰均比(Peak-to-Average Power Ratio,PAPR)导致的通信误码率高及通信信号的调制方式导致的雷达分辨率降低的问题,在总功率和PAPR约束下对下行链路多用户通信与目标探测的双功能雷达通信一体化波形设计进行了简要介绍。首先,以总功率与PAPR为约束条件,以多用户干扰(Multi-User Interference,MUI)能量与雷达波形相似度加权和为目标函数,并引入加权因子ρ动态调整通信雷达性能偏好。其次,采用标准交替方向乘子(Alternating Direction Multiplier Method,ADMM)算法,并引入增广拉格朗日函数,通过变量分裂实现优化求解。最后,对所提方法的通信误码率和雷达分辨率等性能进行了仿真。结果表明,所提方法相较于传统方法实现了动态场景下通信和速率的提升,且与恒模约束相比和速率增幅达4.5%,雷达探测概率在低信噪比时达到0.8以上,并最终趋于稳定值1。展开更多
针对现有抗噪声调频干扰相位编码波形设计算法存在计算复杂度高、难以满足实时处理需求的问题,本文提出了一种基于频域坐标下降的高效优化算法。首先,将时域联合优化目标函数转换至频域,建立相位编码波形的频域优化模型。该转换不仅有...针对现有抗噪声调频干扰相位编码波形设计算法存在计算复杂度高、难以满足实时处理需求的问题,本文提出了一种基于频域坐标下降的高效优化算法。首先,将时域联合优化目标函数转换至频域,建立相位编码波形的频域优化模型。该转换不仅有效规避了时域优化过程中大规模矩阵运算带来的高计算代价,还使得优化问题结构更为简洁,便于后续的算法设计。随后,在交替方向乘子法(Alternating Direction Method of Multipliers,ADMM)框架下引入频域坐标下降法(Frequency-domain Coordinate Descent Method,FCDM),形成了ADMMFCDM算法。该算法将复杂的高维优化问题分解为多个可独立并行处理的一维子问题,通过推导波形频域序列元素的闭式解,不仅大幅降低了单次迭代的计算量,还显著提升了全局优化效率。最后,本文引入快速傅里叶变换(Fast Fourier Transform,FFT)技术对ADMM-FCDM进行简化,得到了交替方向乘子法框架下结合快速傅里叶变换的频域坐标下降算法(Frequency-domain Coordinate Descent Method with Fast Fourier Transform under Alternating Direction Method of Multipliers Framework,ADMM-FFT-FCDM)。FFT的引入极大程度地降低了时域与频域之间变换所需的计算时间,进一步提升了算法的运算效率。仿真实验表明,较于现有算法,本文提出的ADMM-FFTFCDM算法在保证雷达抗干扰性能和探测性能的同时,运算速度获得显著提升。展开更多
Aiming at solving the problems existing in the landscape planning of waterfront areas in Yichang City,such as the contradiction of traffic organization,the waste of historical space resources and the insufficient util...Aiming at solving the problems existing in the landscape planning of waterfront areas in Yichang City,such as the contradiction of traffic organization,the waste of historical space resources and the insufficient utilization of hydrological characteristics,systematic renewal strategies were proposed.Through empirical research and spatial behavioral analysis,a renewal paradigm of“ecological restoration-cultural inheritance-spatial creation”was constructed according to topographic texture and hydrological characteristics.The innovation lies in proposing a renewal model of vertical corridors that integrates“transportation,ecology and landscape”,as well as a three-dimensional transportation scheme for separating pedestrians and vehicles based on the theory of alleviating spatial ownership contradictions.This study provides a technical path for improving the functions of high-density urban waterfront areas and optimizing their spatial efficiency,and has a practical value for enhancing citizens’water-friendly experiences and promoting cultural and tourism economy.展开更多
The utilization of optical fiber in fronthaul transmission within radio access networks(RANs)offers significant advantages in terms of high quality,stability,and long-reach capabilities.Simultaneously,distributed acou...The utilization of optical fiber in fronthaul transmission within radio access networks(RANs)offers significant advantages in terms of high quality,stability,and long-reach capabilities.Simultaneously,distributed acoustic sensing(DAS)enables network surveillance and human activity detection through environmental monitoring.However,the implementation of large-scale strain measurement remains a challenge.In this paper,we propose a novel linear frequency modulated(LFM)pilot-aided radio OFDM fronthaul waveform specifically designed for integrated sensing and communication over fiber(ISACoF).The continuous LFM pilots facilitate the demodulation process at the communication side and serve as sensing probes to detect vibrations along the fiber using pulse compression techniques.Furthermore,by leveraging the large bandwidth of OFDM radio signals,the frequency-demodulated DAS enabled by multiple LFM pilots overcomes the limitations of traditional phase-demodulated DAS in scenarios involving large dynamic vibrations.We experimentally demonstrate the transmission of OFDM radio signals through a 10-km fiber and a 4-m free-space channel,assisted by 128 LFM pilots.By utilizing millimeter-wave(MMW)radio signals operating within a frequency range of 27.2 GHz to 29 GHz and a bandwidth of 1.8 GHz,dynamic vibration measurements of up to 6μεare achieved.Additionally,by optimizing the power ratio between OFDM payloads and LFM pilots,we achieve a sensing sensitivity of 0.81.and a demodulated signal-to-noise ratio of over 20 dB for 64-QAM-OFDM.Various modulation formats and vibration waveforms are validated via experiments,thereby confirming the feasibility of implementing the proposed ISACoF system in practical RAN design.展开更多
基金financial support of Natural Science Foundation of China(No.61971102,62132004)MOST Major Research and Development Project(No.2021YFB2900204)+1 种基金Sichuan Science and Technology Program(No.2022YFH0022)Key Research and Development Program of Zhejiang Province(No.2022C01093)。
文摘Integrated data and energy transfer(IDET)is capable of simultaneously delivering on-demand data and energy to low-power Internet of Everything(Io E)devices.We propose a multi-carrier IDET transceiver relying on superposition waveforms consisting of multi-sinusoidal signals for wireless energy transfer(WET)and orthogonal-frequency-divisionmultiplexing(OFDM)signals for wireless data transfer(WDT).The outdated channel state information(CSI)in aging channels is employed by the transmitter to shape IDET waveforms.With the constraints of transmission power and WDT requirement,the amplitudes and phases of the IDET waveform at the transmitter and the power splitter at the receiver are jointly optimised for maximising the average directcurrent(DC)among a limited number of transmission frames with the existence of carrier-frequencyoffset(CFO).For the amplitude optimisation,the original non-convex problem can be transformed into a reversed geometric programming problem,then it can be effectively solved with existing tools.As for the phase optimisation,the artificial bee colony(ABC)algorithm is invoked in order to deal with the nonconvexity.Iteration between the amplitude optimisation and phase optimisation yields our joint design.Numerical results demonstrate the advantage of our joint design for the IDET waveform shaping with the existence of the CFO and the outdated CSI.
基金sponsored by National Natural Science Foundation of China (No. 61871422, No. 61801319)Chinese ministry funds (No.6140518050316, No.6141B06290101)
文摘Recently, integrated Satellite-Terrestrial(S-T) communication system, especially the integration of satellite communication with 5G/6G, is regarded as a research hotpot. Future integrated S-T communication systems are demanding a more compatible and robust physical layer waveform. Considering physical layer access waveform design, this paper proposed a novel Spread Spectrum Generalized Frequency Division Multiplexing(SS-GFDM) scheme for integrated S-T communication system. Traditional GFDM has many advantages such as excellent adaptability and low out-ofband(OOB) radiation. However, because of intrinsic inter carrier interference(ICI) and low signal-to-noise ratio(SNR), the multiple access performance is degraded. In this paper, we introduced CDMA technology into GFDM. Two different spread spectrum modes, Cyclic Code Shift Keying(CCSK) soft spread spectrum and Direct Sequence Spread Spectrum(DSSS), are considered and compared in this paper to illustrate the benefits of GFDM-CDMA in low SNR scenario. Moreover, this scheme integrates the slot-ALOHA protocol with GFDM-CDMA, which extends access freedom in frequency, time and code domain. The simulation and analysis results show that the proposed GFDM-CDMA scheme reduces the performance degradation caused by interference. It is effective in typical satellite channel with low complexity. Meanwhile, the peak-average-power-ratio(PAPR) and access performance has been enhanced significantly.
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.
文摘针对双功能雷达通信(Dual-Functional Radar-Communication,DFRC)系统中雷达峰均比(Peak-to-Average Power Ratio,PAPR)导致的通信误码率高及通信信号的调制方式导致的雷达分辨率降低的问题,在总功率和PAPR约束下对下行链路多用户通信与目标探测的双功能雷达通信一体化波形设计进行了简要介绍。首先,以总功率与PAPR为约束条件,以多用户干扰(Multi-User Interference,MUI)能量与雷达波形相似度加权和为目标函数,并引入加权因子ρ动态调整通信雷达性能偏好。其次,采用标准交替方向乘子(Alternating Direction Multiplier Method,ADMM)算法,并引入增广拉格朗日函数,通过变量分裂实现优化求解。最后,对所提方法的通信误码率和雷达分辨率等性能进行了仿真。结果表明,所提方法相较于传统方法实现了动态场景下通信和速率的提升,且与恒模约束相比和速率增幅达4.5%,雷达探测概率在低信噪比时达到0.8以上,并最终趋于稳定值1。
文摘针对现有抗噪声调频干扰相位编码波形设计算法存在计算复杂度高、难以满足实时处理需求的问题,本文提出了一种基于频域坐标下降的高效优化算法。首先,将时域联合优化目标函数转换至频域,建立相位编码波形的频域优化模型。该转换不仅有效规避了时域优化过程中大规模矩阵运算带来的高计算代价,还使得优化问题结构更为简洁,便于后续的算法设计。随后,在交替方向乘子法(Alternating Direction Method of Multipliers,ADMM)框架下引入频域坐标下降法(Frequency-domain Coordinate Descent Method,FCDM),形成了ADMMFCDM算法。该算法将复杂的高维优化问题分解为多个可独立并行处理的一维子问题,通过推导波形频域序列元素的闭式解,不仅大幅降低了单次迭代的计算量,还显著提升了全局优化效率。最后,本文引入快速傅里叶变换(Fast Fourier Transform,FFT)技术对ADMM-FCDM进行简化,得到了交替方向乘子法框架下结合快速傅里叶变换的频域坐标下降算法(Frequency-domain Coordinate Descent Method with Fast Fourier Transform under Alternating Direction Method of Multipliers Framework,ADMM-FFT-FCDM)。FFT的引入极大程度地降低了时域与频域之间变换所需的计算时间,进一步提升了算法的运算效率。仿真实验表明,较于现有算法,本文提出的ADMM-FFTFCDM算法在保证雷达抗干扰性能和探测性能的同时,运算速度获得显著提升。
文摘Aiming at solving the problems existing in the landscape planning of waterfront areas in Yichang City,such as the contradiction of traffic organization,the waste of historical space resources and the insufficient utilization of hydrological characteristics,systematic renewal strategies were proposed.Through empirical research and spatial behavioral analysis,a renewal paradigm of“ecological restoration-cultural inheritance-spatial creation”was constructed according to topographic texture and hydrological characteristics.The innovation lies in proposing a renewal model of vertical corridors that integrates“transportation,ecology and landscape”,as well as a three-dimensional transportation scheme for separating pedestrians and vehicles based on the theory of alleviating spatial ownership contradictions.This study provides a technical path for improving the functions of high-density urban waterfront areas and optimizing their spatial efficiency,and has a practical value for enhancing citizens’water-friendly experiences and promoting cultural and tourism economy.
文摘The utilization of optical fiber in fronthaul transmission within radio access networks(RANs)offers significant advantages in terms of high quality,stability,and long-reach capabilities.Simultaneously,distributed acoustic sensing(DAS)enables network surveillance and human activity detection through environmental monitoring.However,the implementation of large-scale strain measurement remains a challenge.In this paper,we propose a novel linear frequency modulated(LFM)pilot-aided radio OFDM fronthaul waveform specifically designed for integrated sensing and communication over fiber(ISACoF).The continuous LFM pilots facilitate the demodulation process at the communication side and serve as sensing probes to detect vibrations along the fiber using pulse compression techniques.Furthermore,by leveraging the large bandwidth of OFDM radio signals,the frequency-demodulated DAS enabled by multiple LFM pilots overcomes the limitations of traditional phase-demodulated DAS in scenarios involving large dynamic vibrations.We experimentally demonstrate the transmission of OFDM radio signals through a 10-km fiber and a 4-m free-space channel,assisted by 128 LFM pilots.By utilizing millimeter-wave(MMW)radio signals operating within a frequency range of 27.2 GHz to 29 GHz and a bandwidth of 1.8 GHz,dynamic vibration measurements of up to 6μεare achieved.Additionally,by optimizing the power ratio between OFDM payloads and LFM pilots,we achieve a sensing sensitivity of 0.81.and a demodulated signal-to-noise ratio of over 20 dB for 64-QAM-OFDM.Various modulation formats and vibration waveforms are validated via experiments,thereby confirming the feasibility of implementing the proposed ISACoF system in practical RAN design.
