在电力线载波信道特性研究的基础上,提出了一种基于现场可编程门阵列(FPGA)的跨频带电力线载波通信(PLC)信道模拟方法,并完成了模拟器实现。所提出方法能够在150 k Hz^10 MHz的跨频带范围内模拟通过现场测量取得的、或基于模型的电力线...在电力线载波信道特性研究的基础上,提出了一种基于现场可编程门阵列(FPGA)的跨频带电力线载波通信(PLC)信道模拟方法,并完成了模拟器实现。所提出方法能够在150 k Hz^10 MHz的跨频带范围内模拟通过现场测量取得的、或基于模型的电力线载波信道噪声、传输函数,为PLC系统的测试与优化提供了便捷高效的手段。进一步对比现场实际信道与模拟信道条件下的PLC系统测试结果,验证了信道模拟的准确性以及所提出方法的有效性。展开更多
In this article,novel emulation strategies for the sectored multiple probe anechoic chamber(SMPAC)are proposed to enable the reliable evaluation of the massive multiple-input multiple-output(MIMO)device operating at b...In this article,novel emulation strategies for the sectored multiple probe anechoic chamber(SMPAC)are proposed to enable the reliable evaluation of the massive multiple-input multiple-output(MIMO)device operating at beamforming mode,which requires a realistic non-stationary channel environment.For the dynamic propagation emulation,an efficient closed-form probe weighting strategy minimizing the power angular spectrum(PAS)emulation errors is derived,substantially reducing the associated computational complexity.On the other hand,a novel probe selection algorithm is proposed to reproduce a more accurate fading environment.Various standard channel models and setup configurations are comprehensively simulated to validate the capacity of the proposed methods.The simulation results show that more competent active probes are selected with the proposed method compared to the conventional algorithms.Furthermore,the derived closedform probe weighting strategy offers identical accuracy to that obtained with complicated numerical optimization.Moreover,a realistic dynamic channel measured in an indoor environment is reconstructed with the developed methodologies,and 95.6%PAS similarity can be achieved with 6 active probes.The satisfactory results demonstrate that the proposed algorithms are suitable for arbitrary channel emulation.展开更多
As antennas are inherently included recommended in Over-The-Air (OTA) testing, it is important to also consider realistic channel models for the multiple-input multiple-output (MIMO) device performance evaluation. Thi...As antennas are inherently included recommended in Over-The-Air (OTA) testing, it is important to also consider realistic channel models for the multiple-input multiple-output (MIMO) device performance evaluation. This paper aims to emulate realistic multi-Path propagation channels in terms of angles of arrivals (AoA) and cross-polarization ratio (XPR) with Rayleigh fading, inside an anechoic chamber, for antenna diversity measurements. In this purpose, a practical multi-probe anechoic chamber measurement system (MPAC) with 24 probe antennas (SATIMO SG24) has been used. However, the actual configuration of this system is not able to reproduce realistic channels. Therefore, a new method based on the control of the SG24 probes has been developed. At first time, this method has been validated numerically through the comparison of simulated and analytical AoA probability density distributions. At the second time, the performance of an antenna diversity system inside the SG24 has been performed in terms of the correlation coefficient and diversity gain (DG) using an antenna reference system. Simulated and measurements results have shown a good agreement.展开更多
A real-time ray-based hardware emulator for Unmanned Aerial Vehicle(UAV) communication channels which suits for the Three-Dimensional(3D) dynamic scenarios and considers the movements of both terminals is developed in...A real-time ray-based hardware emulator for Unmanned Aerial Vehicle(UAV) communication channels which suits for the Three-Dimensional(3D) dynamic scenarios and considers the movements of both terminals is developed in this paper. The time-variant channel parameters, i.e.,ray delay, ray gain, and ray Doppler frequency are precalculated in the host by using the Ray Tracing(RT) method. Meanwhile, RT simulation dramatically increases the number of valid rays. To address the problem of resource limitation and huge computational burden in the implementation,an efficient ray coefficients generation method based on iteration is proposed and implemented.With the advantages of low cost and high flexibility, a Software Defined Radio(SDR) hardware platform is used to emulate the ray-based UAV channels by utilizing the compact architecture including the Time-Division(TD) scheme and Tapped-Delay Line(TDL) for channel convolution.Finally, hardware measurement results demonstrate that the properties of emulated channel, i.e.,Power Delay Profile(PDP) and Doppler Power Spectrum Density(DPSD) consist with the simulated ones, which verifies the correctness of hardware implementation. The proposed channel emulator provides an efficient way for optimization, verification, and evaluation of UAV communication systems.展开更多
由于无线电波传播环境的复杂性和多样性,无线信道仿真需要兼顾仿真的准确性和实时性,因而需要进行大量高速的数据运算。本文利用美国国家仪器(NI)公司基于软件无线电技术的高性能矢量信号分析仪,FPGA模块以及矢量信号发生器进行了无线...由于无线电波传播环境的复杂性和多样性,无线信道仿真需要兼顾仿真的准确性和实时性,因而需要进行大量高速的数据运算。本文利用美国国家仪器(NI)公司基于软件无线电技术的高性能矢量信号分析仪,FPGA模块以及矢量信号发生器进行了无线信道仿真仪核心部分的设计,并提出了针对经典信道模型和宽带多天线信道模型的硬件仿真实现方法。此外该平台还搭配USRP(Universal Software Radio Peripheral)进行了辅助设计,从而为无线通信系统的半实物仿真和测试提供了较好的实验验证平台。展开更多
多输入多输出(Multiple Input and Multiple Output,MIMO)信道的空间相关性极大程度上影响着MIMO系统的性能.基于相关统计建模的空间相关性MIMO信道模型,通过合理的软硬件划分,设计了一种高资源利用率的MIMO信道实时模拟方案,实现了实时...多输入多输出(Multiple Input and Multiple Output,MIMO)信道的空间相关性极大程度上影响着MIMO系统的性能.基于相关统计建模的空间相关性MIMO信道模型,通过合理的软硬件划分,设计了一种高资源利用率的MIMO信道实时模拟方案,实现了实时MIMO信道模拟器.针对3GPP标准MIMO信道模型进行模拟,硬件模拟结果统计分析表明本方案模拟的MIMO信道特征能够与理论特征很好地吻合,具有良好的模拟精度.可扩展的信道模拟方案能够直接扩展到支持更多天线数目的 MIMO信道的实时模拟.展开更多
Cognitive radio is an effective technology to alleviate the spectrum resource scarcity problem by opportunistically allocating the spare spectrum to unauthorized users. However, a serious denial-of-service(DoS) attack...Cognitive radio is an effective technology to alleviate the spectrum resource scarcity problem by opportunistically allocating the spare spectrum to unauthorized users. However, a serious denial-of-service(DoS) attack,named the ‘primary user emulation attack(PUEA)', exists in the network to deteriorate the system performance. In this paper, we propose a PUEA detection method that exploits the radio channel information to detect the PUEA in the cognitive radio network. In the proposed method, the uniqueness of the channel impulse response(CIR) between the secondary user(SU) and the signal source is used to determine whether the received signal is transmitted by the primary user(PU) or the primary user emulator(PUE). The closed-form expressions for the false-alarm probability and the detection probability of the proposed PUEA detection method are derived. In addition, a modified subspace-based blind channel estimation method is presented to estimate the CIR, in order for the proposed PUEA detection method to work in the scenario where the SU has no prior knowledge about the structure and content of the PU signal. Numerical results show that the proposed PUEA detection method performs well although the difference in channel characteristics between the PU and PUE is small.展开更多
文摘在电力线载波信道特性研究的基础上,提出了一种基于现场可编程门阵列(FPGA)的跨频带电力线载波通信(PLC)信道模拟方法,并完成了模拟器实现。所提出方法能够在150 k Hz^10 MHz的跨频带范围内模拟通过现场测量取得的、或基于模型的电力线载波信道噪声、传输函数,为PLC系统的测试与优化提供了便捷高效的手段。进一步对比现场实际信道与模拟信道条件下的PLC系统测试结果,验证了信道模拟的准确性以及所提出方法的有效性。
基金supported by National Natural Science Foundation of China(No.62090015,No.61821001)BUPT Excellent Ph.D.Students Foundation under Grant(CX2021216)。
文摘In this article,novel emulation strategies for the sectored multiple probe anechoic chamber(SMPAC)are proposed to enable the reliable evaluation of the massive multiple-input multiple-output(MIMO)device operating at beamforming mode,which requires a realistic non-stationary channel environment.For the dynamic propagation emulation,an efficient closed-form probe weighting strategy minimizing the power angular spectrum(PAS)emulation errors is derived,substantially reducing the associated computational complexity.On the other hand,a novel probe selection algorithm is proposed to reproduce a more accurate fading environment.Various standard channel models and setup configurations are comprehensively simulated to validate the capacity of the proposed methods.The simulation results show that more competent active probes are selected with the proposed method compared to the conventional algorithms.Furthermore,the derived closedform probe weighting strategy offers identical accuracy to that obtained with complicated numerical optimization.Moreover,a realistic dynamic channel measured in an indoor environment is reconstructed with the developed methodologies,and 95.6%PAS similarity can be achieved with 6 active probes.The satisfactory results demonstrate that the proposed algorithms are suitable for arbitrary channel emulation.
文摘As antennas are inherently included recommended in Over-The-Air (OTA) testing, it is important to also consider realistic channel models for the multiple-input multiple-output (MIMO) device performance evaluation. This paper aims to emulate realistic multi-Path propagation channels in terms of angles of arrivals (AoA) and cross-polarization ratio (XPR) with Rayleigh fading, inside an anechoic chamber, for antenna diversity measurements. In this purpose, a practical multi-probe anechoic chamber measurement system (MPAC) with 24 probe antennas (SATIMO SG24) has been used. However, the actual configuration of this system is not able to reproduce realistic channels. Therefore, a new method based on the control of the SG24 probes has been developed. At first time, this method has been validated numerically through the comparison of simulated and analytical AoA probability density distributions. At the second time, the performance of an antenna diversity system inside the SG24 has been performed in terms of the correlation coefficient and diversity gain (DG) using an antenna reference system. Simulated and measurements results have shown a good agreement.
基金supported in part by CEMEE State Key Laboratory Fund(No.2020Z0207B)in part by the National Key Scientific Instrument and Equipment Development Project,China(No.61827801)+1 种基金in part by the State Key Laboratory of Integrated Services Networks Fund,China(No.ISN22-11)in part by the Fundamental Research Funds for the Central Universities,China(Nos.NS2020026 and NS2020063)。
文摘A real-time ray-based hardware emulator for Unmanned Aerial Vehicle(UAV) communication channels which suits for the Three-Dimensional(3D) dynamic scenarios and considers the movements of both terminals is developed in this paper. The time-variant channel parameters, i.e.,ray delay, ray gain, and ray Doppler frequency are precalculated in the host by using the Ray Tracing(RT) method. Meanwhile, RT simulation dramatically increases the number of valid rays. To address the problem of resource limitation and huge computational burden in the implementation,an efficient ray coefficients generation method based on iteration is proposed and implemented.With the advantages of low cost and high flexibility, a Software Defined Radio(SDR) hardware platform is used to emulate the ray-based UAV channels by utilizing the compact architecture including the Time-Division(TD) scheme and Tapped-Delay Line(TDL) for channel convolution.Finally, hardware measurement results demonstrate that the properties of emulated channel, i.e.,Power Delay Profile(PDP) and Doppler Power Spectrum Density(DPSD) consist with the simulated ones, which verifies the correctness of hardware implementation. The proposed channel emulator provides an efficient way for optimization, verification, and evaluation of UAV communication systems.
文摘由于无线电波传播环境的复杂性和多样性,无线信道仿真需要兼顾仿真的准确性和实时性,因而需要进行大量高速的数据运算。本文利用美国国家仪器(NI)公司基于软件无线电技术的高性能矢量信号分析仪,FPGA模块以及矢量信号发生器进行了无线信道仿真仪核心部分的设计,并提出了针对经典信道模型和宽带多天线信道模型的硬件仿真实现方法。此外该平台还搭配USRP(Universal Software Radio Peripheral)进行了辅助设计,从而为无线通信系统的半实物仿真和测试提供了较好的实验验证平台。
基金supported by the National Natural Science Foundation of China(Nos.61471318 and 61671410)the Zhejiang Provincial Natural Science Foundation of China(No.LY14F010014)the State Key Laboratory of Complex Electromagnetic Environment Effects on Electronics and Information System,China(No.CEMEE2015Z0202A)
文摘Cognitive radio is an effective technology to alleviate the spectrum resource scarcity problem by opportunistically allocating the spare spectrum to unauthorized users. However, a serious denial-of-service(DoS) attack,named the ‘primary user emulation attack(PUEA)', exists in the network to deteriorate the system performance. In this paper, we propose a PUEA detection method that exploits the radio channel information to detect the PUEA in the cognitive radio network. In the proposed method, the uniqueness of the channel impulse response(CIR) between the secondary user(SU) and the signal source is used to determine whether the received signal is transmitted by the primary user(PU) or the primary user emulator(PUE). The closed-form expressions for the false-alarm probability and the detection probability of the proposed PUEA detection method are derived. In addition, a modified subspace-based blind channel estimation method is presented to estimate the CIR, in order for the proposed PUEA detection method to work in the scenario where the SU has no prior knowledge about the structure and content of the PU signal. Numerical results show that the proposed PUEA detection method performs well although the difference in channel characteristics between the PU and PUE is small.
