基于单快拍的快速迭代插值DOA(Direction of Arrival)估计方法,有效地消除了频谱泄漏,实现了多源DOA的无偏估计。但是该算法需要提前确定信源的个数,且运算量大,因此在工程应用中受限。本文提出一种新方案,利用传统角度域FFT提供粗略角...基于单快拍的快速迭代插值DOA(Direction of Arrival)估计方法,有效地消除了频谱泄漏,实现了多源DOA的无偏估计。但是该算法需要提前确定信源的个数,且运算量大,因此在工程应用中受限。本文提出一种新方案,利用传统角度域FFT提供粗略角度估计,然后通过迭代插值法细化角度,最终基于对消残差功率和信息论准则进行信源个数估计。该方案无需预知信源个数,且文中提出的基于残差变化率的收敛策略大大减少了细化估计的迭代次数,从而有效地降低了原算法的计算量。通过仿真结果验证了该方案的有效性,在估计精度及分辨率方面性能接近快速迭代插值波束形成算法,优于子空间类算法。展开更多
We propose and demonstrate a simple method to accomplish arbitrary free spectral range(FSR)control of optical frequency combs(OFC).The approach is based on the combination of an optical tapped delay line(OTDL)structur...We propose and demonstrate a simple method to accomplish arbitrary free spectral range(FSR)control of optical frequency combs(OFC).The approach is based on the combination of an optical tapped delay line(OTDL)structure and a phase modulator(PM).The OTDL structure is utilized to multiply the FSR of input OFC,and the PM is used to divide the FSR of the consequent OFC.We illustrate that the proposed method allows one to divide or multiply the FSR of original OFC by any anticipated integer or fractional factor.Numerical simulation results match well with our theoretical analysis.展开更多
An approach for generating optical frequency comb(OFC)with tunable free spectral range(FSR)is proposed.Two Mach-Zehnder modulators(MZMs)driven by phase-shifted sinusoidal signals are cascaded to generate OFC with plen...An approach for generating optical frequency comb(OFC)with tunable free spectral range(FSR)is proposed.Two Mach-Zehnder modulators(MZMs)driven by phase-shifted sinusoidal signals are cascaded to generate OFC with plentiful comb lines and the FSR controlled by the drive frequency.Subsequently,a linearly chirped fiber Bragg grating(LCFBG)and a phase modulator(PM)are used to increase the comb FSR by a particular integer multiple.Therefore,by simultaneously controlling the drive frequency of MZMs,the dispersion amount of the LCFBG and the drive signal of the PM,an OFC with desired FSR can be achieved.展开更多
文摘基于单快拍的快速迭代插值DOA(Direction of Arrival)估计方法,有效地消除了频谱泄漏,实现了多源DOA的无偏估计。但是该算法需要提前确定信源的个数,且运算量大,因此在工程应用中受限。本文提出一种新方案,利用传统角度域FFT提供粗略角度估计,然后通过迭代插值法细化角度,最终基于对消残差功率和信息论准则进行信源个数估计。该方案无需预知信源个数,且文中提出的基于残差变化率的收敛策略大大减少了细化估计的迭代次数,从而有效地降低了原算法的计算量。通过仿真结果验证了该方案的有效性,在估计精度及分辨率方面性能接近快速迭代插值波束形成算法,优于子空间类算法。
基金supported by the Fundamental Research Funds for the Central Universities(No.2019JBM010)the National Natural Science Foundation of China(Nos.61775015 and 61827817)。
文摘We propose and demonstrate a simple method to accomplish arbitrary free spectral range(FSR)control of optical frequency combs(OFC).The approach is based on the combination of an optical tapped delay line(OTDL)structure and a phase modulator(PM).The OTDL structure is utilized to multiply the FSR of input OFC,and the PM is used to divide the FSR of the consequent OFC.We illustrate that the proposed method allows one to divide or multiply the FSR of original OFC by any anticipated integer or fractional factor.Numerical simulation results match well with our theoretical analysis.
基金supported partially by the National Natural Science Foundation of China(Nos.62101027 and 61775015)the Fundamental Research Funds for the Central Universities(No.2019JBM010)。
文摘An approach for generating optical frequency comb(OFC)with tunable free spectral range(FSR)is proposed.Two Mach-Zehnder modulators(MZMs)driven by phase-shifted sinusoidal signals are cascaded to generate OFC with plentiful comb lines and the FSR controlled by the drive frequency.Subsequently,a linearly chirped fiber Bragg grating(LCFBG)and a phase modulator(PM)are used to increase the comb FSR by a particular integer multiple.Therefore,by simultaneously controlling the drive frequency of MZMs,the dispersion amount of the LCFBG and the drive signal of the PM,an OFC with desired FSR can be achieved.
