为了提高BPM短波数据服务性能,一种有效的途径是研究合理的数据调制方式。针对现有BPM短波授时系统的时码发播实验方案存在数据传输率低、易受干扰等问题,在不影响现有系统信号格式的基础上,提出一种可应用于BPM短波授时系统的高速率OFD...为了提高BPM短波数据服务性能,一种有效的途径是研究合理的数据调制方式。针对现有BPM短波授时系统的时码发播实验方案存在数据传输率低、易受干扰等问题,在不影响现有系统信号格式的基础上,提出一种可应用于BPM短波授时系统的高速率OFDM(orthogonal frequency division multiplexing)数据调制方式。给出了一种兼容性设计方案,分析了基带OFDM系统模型,提出了一种基于频率分集的OFDM数据调制方式以抵抗短波信道的频率选择性衰落。通过理论分析与几种具有代表性的参数设计方案的仿真实验,初步验证了提出的数据调制方式的有效性,同时针对实际工程应用给出了一些有参考价值的结论与建议。展开更多
Signal modulation is an essential design factor for proximity detectors and directly affects the system's potential performance.In order to achieve the advantages of chaotic codes bi-phase modulation(CCBPM)and lin...Signal modulation is an essential design factor for proximity detectors and directly affects the system's potential performance.In order to achieve the advantages of chaotic codes bi-phase modulation(CCBPM)and linear frequency modulation(LFM) simultaneously,this paper designed a waveform which combined chaotic codes bi-phase modulation and linear frequency modulation(CCBPM-LFM) for proximity detectors.The CCBPM-LFM waveform was analyzed in the aspect of time delay resolution(TDR) and Doppler tolerance(DT) based on ambiguity function(AF).Then,a ranging method,which we called instant correlation harmonic demodulation(ICHD),was presented for the detector using the CCBPM-LFM waveform.By combining time domain instant correlation with harmonic demodulation,the ICHD solved the problem caused by combination modulation and made the most of the linear frequency modulation(LFM) harmonics and the correlation of chaotic codes.Finally,a prototype was implemented and ranging experiments were carried out.From the theoretical analysis and experimental results,the proximity detector used the CCBPM-LFM waveform has an outstanding detection performance.展开更多
文摘为了提高BPM短波数据服务性能,一种有效的途径是研究合理的数据调制方式。针对现有BPM短波授时系统的时码发播实验方案存在数据传输率低、易受干扰等问题,在不影响现有系统信号格式的基础上,提出一种可应用于BPM短波授时系统的高速率OFDM(orthogonal frequency division multiplexing)数据调制方式。给出了一种兼容性设计方案,分析了基带OFDM系统模型,提出了一种基于频率分集的OFDM数据调制方式以抵抗短波信道的频率选择性衰落。通过理论分析与几种具有代表性的参数设计方案的仿真实验,初步验证了提出的数据调制方式的有效性,同时针对实际工程应用给出了一些有参考价值的结论与建议。
基金supported by the State Key Program of Basic Research of China under Grant No.613196the National Natural Science Foundation of China under Grant No.61673066。
文摘Signal modulation is an essential design factor for proximity detectors and directly affects the system's potential performance.In order to achieve the advantages of chaotic codes bi-phase modulation(CCBPM)and linear frequency modulation(LFM) simultaneously,this paper designed a waveform which combined chaotic codes bi-phase modulation and linear frequency modulation(CCBPM-LFM) for proximity detectors.The CCBPM-LFM waveform was analyzed in the aspect of time delay resolution(TDR) and Doppler tolerance(DT) based on ambiguity function(AF).Then,a ranging method,which we called instant correlation harmonic demodulation(ICHD),was presented for the detector using the CCBPM-LFM waveform.By combining time domain instant correlation with harmonic demodulation,the ICHD solved the problem caused by combination modulation and made the most of the linear frequency modulation(LFM) harmonics and the correlation of chaotic codes.Finally,a prototype was implemented and ranging experiments were carried out.From the theoretical analysis and experimental results,the proximity detector used the CCBPM-LFM waveform has an outstanding detection performance.
