中文摘要：

Nyquist折叠接收机（NYFR）为一种新型侦察接收机结构，可利用单／双片模数转换器（ADC）同时完成多Nyquist区域内的宽频段信号采集。本文对NYFR结构进行了改进，提出了多分量信号的参数估计算法。首先，引入了同步结构，对NYFR进行了改进，得到了同步NYFR（SNYFR）；其次，以本振为周期性线性调频（LFM）为例，分析了多分量信号的输出结果；然后，提出了去斜函数（DF）以用于检测信号的Nyquist区域；最终，根据区域信息完成了信号的各参数估计。计算量分析与仿真表明，所提算法计算量小且在信噪比（SNR）优于-9dB时性能已接近克拉美-罗（CRLB）下限。

英文摘要：

The Nyquist folding receiver （NYFR） is a new interception architecture which is able to intercept wideband signals in multiNyquist zones simultaneously with one or two analog-to-digital converters （ADCs）. This paper presents a parameter estimation algorithm of multicomponent signals intercepted by an improved NYFR. First, the NYFR is improved by introducing a synchronous mechanism, denoted as synchronous NYFR （SNYFR）. Secondly, the periodic linear frequency modulation （LFM） is chosen as the local signal, and the outputs of the SNYFR for multicomponent signals are presented. Then, the dechirp function （DF） is proposed for the detection of Nyquist zones. Finally, the parameter estimations are accomplished according to the Nyquist zones. Simulations show that the parameter estimation accuracy is close to the Cramer Rao lower bound （CRLB） when the signal to noise ratio （SNR） is above -9 dB.