UAV data link has been considered as an important part of UAV communication system, through which the UAV could communicate with warships. However, constant coding and modulation scheme that UAV adopts does not make f...UAV data link has been considered as an important part of UAV communication system, through which the UAV could communicate with warships. However, constant coding and modulation scheme that UAV adopts does not make full use of the channel capacity when UAV communicates with warships in a good channel environment. In order to improve channel capacity and spectral efficiency, adaptive coded modulation technology is studied. Based on maritime channel model, SNR estimation technology and adaptive threshold determination technology, the simulation of UAV data link communication is carried out in this paper. Theoretic analysis and simulation results show that according to changes in maritime channel state, UAV can dynamically adjust the adaptive coded modulation scheme on the condition of meeting target Bit-Error-Rate (BER), the maximum amount of data transfer is non-adaptive systems three times.展开更多
Based on the M-ary spread spectrum （M-ary-SS）, direct sequence spread spectrum （DS-SS）, and orthogonal frequency division multiplex （OFDM）, a novel anti-jamming scheme, named orthogonal code time division multi-...Based on the M-ary spread spectrum （M-ary-SS）, direct sequence spread spectrum （DS-SS）, and orthogonal frequency division multiplex （OFDM）, a novel anti-jamming scheme, named orthogonal code time division multi-subchannels spread spectrum modulation （OC-TDMSCSSM）, is proposed to enhance the anti-jamming ability of the unmanned aerial vehicle （UAV） data link. The anti-jamming system with its mathematical model is presented first, and then the signal formats of transmitter and receiver are derived. The receiver＇s bit error rate （BER） is demonstrated and anti-jamming performance analysis is carded out in an additive white Ganssian noise （AWGN） channel. Theoretical research and simulation results show the anti-jamming performance of the proposed scheme better than that of the hybrid direct sequence frequency hopping spread spectrum （DS/FH SS） system. The jamming margin of the OC-TDMSCSSM system is 5 dB higher than that of DS/FH SS system under the condition of Rician channel and full-band jamming, and 6 dB higher under the condition of Rician channel environment and partial-band jamming.展开更多
In order to test the anti-interference ability of an Unmanned Aerial Vehicle(UAV) data link in a complex electromagnetic environment,a method for simulating the dynamic electromagnetic interference of an indoor wirele...In order to test the anti-interference ability of an Unmanned Aerial Vehicle(UAV) data link in a complex electromagnetic environment,a method for simulating the dynamic electromagnetic interference of an indoor wireless environment is proposed.This method can estimate the relational degree between the actual face of an UAV data link in an interface environment and the simulation scenarios in an anechoic chamber by using the Grey Relational Analysis(GRA) theory.The dynamic drive of the microwave instrument produces a real-time corresponding interference signal and realises scene mapping.The experimental results show that the maximal correlation between the interference signal in the real scene and the angular domain of the radiation antenna in the anechoic chamber is 0.959 3.Further,the relational degree of the Signal-toInterference Ratio(SIR) of the UAV at its reception terminal indoors and in the anechoic chamber is 0.996 8,and the time of instrument drive is only approximately 10 μs.All of the above illustrates that this method can achieve a simulation close to a real field dynamic electromagnetic interference signal of an indoor UAV data link.展开更多
收发组合作为无人机数据链系统的核心部件,其抗电磁干扰能力直接影响机载通信安全。为检验核电磁脉冲(HEMP)辐照条件下某型无人机数据链系统的可靠性,基于快沿电磁脉冲模拟系统建立了无人机HEMP效应试验平台,以典型"失锁"效...收发组合作为无人机数据链系统的核心部件,其抗电磁干扰能力直接影响机载通信安全。为检验核电磁脉冲(HEMP)辐照条件下某型无人机数据链系统的可靠性,基于快沿电磁脉冲模拟系统建立了无人机HEMP效应试验平台,以典型"失锁"效应作为受干扰判别依据,开展了无人机数据链系统辐照效应研究,分析了无人机数据链"失锁"效应机理。结果表明:核电磁脉冲场强达到72 k V/m时能够对飞机数据链测试系统产生干扰,导致地面监视系统回报通信链路全部失锁、飞行控制模拟器黑屏,且收发组合放置姿态改变基本不影响数据链系统干扰阈值。通过电磁仿真分析发现,飞行控制模拟器端接电缆耦合外界强场信号使收发组合供电瞬时中断,进而导致数据链测试系统产生干扰。排除数据链测试系统中飞行控制模拟器,在辐照场强<90 k V/m情况下,无人机下行遥测链路不会出现失锁。展开更多
为有针对性地根据不同干扰类型选择正确的抗干扰措施,有必要对无人机数据链所处环境的干扰信号进行分析和分类识别;文章以变换域通信系统(transform domain communication system,TDCS)为载体,对无人机数据链常面临的干扰类型的自动识...为有针对性地根据不同干扰类型选择正确的抗干扰措施,有必要对无人机数据链所处环境的干扰信号进行分析和分类识别;文章以变换域通信系统(transform domain communication system,TDCS)为载体,对无人机数据链常面临的干扰类型的自动识别进行研究,采用时域、频域、时频联合分析的方法,提出了一组对干信比变化不敏感的特征参数,并利用这组参数提出一种基于决策树理论的干扰分类识别方法,仿真结果表明,该方法能够快速准确地识别出干扰类型,具有很好的鲁棒性,并且在干信比和干噪比在0dB以上时,正确识别率均在90%以上。展开更多
文摘UAV data link has been considered as an important part of UAV communication system, through which the UAV could communicate with warships. However, constant coding and modulation scheme that UAV adopts does not make full use of the channel capacity when UAV communicates with warships in a good channel environment. In order to improve channel capacity and spectral efficiency, adaptive coded modulation technology is studied. Based on maritime channel model, SNR estimation technology and adaptive threshold determination technology, the simulation of UAV data link communication is carried out in this paper. Theoretic analysis and simulation results show that according to changes in maritime channel state, UAV can dynamically adjust the adaptive coded modulation scheme on the condition of meeting target Bit-Error-Rate (BER), the maximum amount of data transfer is non-adaptive systems three times.
基金Aeronautical Science Foundation of China (2007ZC53030)
文摘Based on the M-ary spread spectrum （M-ary-SS）, direct sequence spread spectrum （DS-SS）, and orthogonal frequency division multiplex （OFDM）, a novel anti-jamming scheme, named orthogonal code time division multi-subchannels spread spectrum modulation （OC-TDMSCSSM）, is proposed to enhance the anti-jamming ability of the unmanned aerial vehicle （UAV） data link. The anti-jamming system with its mathematical model is presented first, and then the signal formats of transmitter and receiver are derived. The receiver＇s bit error rate （BER） is demonstrated and anti-jamming performance analysis is carded out in an additive white Ganssian noise （AWGN） channel. Theoretical research and simulation results show the anti-jamming performance of the proposed scheme better than that of the hybrid direct sequence frequency hopping spread spectrum （DS/FH SS） system. The jamming margin of the OC-TDMSCSSM system is 5 dB higher than that of DS/FH SS system under the condition of Rician channel and full-band jamming, and 6 dB higher under the condition of Rician channel environment and partial-band jamming.
基金supported by a certain Ministry Foundation under Grant No.20212HK03010
文摘In order to test the anti-interference ability of an Unmanned Aerial Vehicle(UAV) data link in a complex electromagnetic environment,a method for simulating the dynamic electromagnetic interference of an indoor wireless environment is proposed.This method can estimate the relational degree between the actual face of an UAV data link in an interface environment and the simulation scenarios in an anechoic chamber by using the Grey Relational Analysis(GRA) theory.The dynamic drive of the microwave instrument produces a real-time corresponding interference signal and realises scene mapping.The experimental results show that the maximal correlation between the interference signal in the real scene and the angular domain of the radiation antenna in the anechoic chamber is 0.959 3.Further,the relational degree of the Signal-toInterference Ratio(SIR) of the UAV at its reception terminal indoors and in the anechoic chamber is 0.996 8,and the time of instrument drive is only approximately 10 μs.All of the above illustrates that this method can achieve a simulation close to a real field dynamic electromagnetic interference signal of an indoor UAV data link.
文摘收发组合作为无人机数据链系统的核心部件,其抗电磁干扰能力直接影响机载通信安全。为检验核电磁脉冲(HEMP)辐照条件下某型无人机数据链系统的可靠性,基于快沿电磁脉冲模拟系统建立了无人机HEMP效应试验平台,以典型"失锁"效应作为受干扰判别依据,开展了无人机数据链系统辐照效应研究,分析了无人机数据链"失锁"效应机理。结果表明:核电磁脉冲场强达到72 k V/m时能够对飞机数据链测试系统产生干扰,导致地面监视系统回报通信链路全部失锁、飞行控制模拟器黑屏,且收发组合放置姿态改变基本不影响数据链系统干扰阈值。通过电磁仿真分析发现,飞行控制模拟器端接电缆耦合外界强场信号使收发组合供电瞬时中断,进而导致数据链测试系统产生干扰。排除数据链测试系统中飞行控制模拟器,在辐照场强<90 k V/m情况下,无人机下行遥测链路不会出现失锁。
文摘为有针对性地根据不同干扰类型选择正确的抗干扰措施,有必要对无人机数据链所处环境的干扰信号进行分析和分类识别;文章以变换域通信系统(transform domain communication system,TDCS)为载体,对无人机数据链常面临的干扰类型的自动识别进行研究,采用时域、频域、时频联合分析的方法,提出了一组对干信比变化不敏感的特征参数,并利用这组参数提出一种基于决策树理论的干扰分类识别方法,仿真结果表明,该方法能够快速准确地识别出干扰类型,具有很好的鲁棒性,并且在干信比和干噪比在0dB以上时,正确识别率均在90%以上。
