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-9 dB时性能已接近克拉美-罗(CRLB)下限。
The Nyquist folding receiver (NYFR) is a new interception architecture which is able to intercept wideband signals in multi-Nyquist 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.
[1] Zhang J J, Wu J, Liu W Y, et al. Clock study of high speed interleaving/multiplexing data-acquisition system. Journal of University of Science and Technology of China, 2006, 36(3): 281-284. (in Chinese) 张俊杰, 武杰, 刘尉悦, 等. 高速交替/并行数据采集系统时钟研究.中国科学技术大学学报, 2006, 36(3): 281-284.
[2] Velazquez S R, Nguyen T Q, Broadstone S R. Design of hybrid filter banks for analog/digital conversion. IEEE Transactions on Signal Processing, 1998, 46(4): 956-967.
[3] Namgoong W. A channelized digital ultrawideband receiver. IEEE Transactions on Wireless Communications, 2003, 2(3): 502-510.
[4] Hoyos S, Sadler B M, Arce G R. Ultra-wideband analog-to-digital conversion via signal expansion. IEEE Transaction on Vehicular Technology, 2005, 54(5): 1609-1622.
[5] Donoho D L. Compressed sensing. IEEE Transactions on Information Theory, 2006, 52(4): 1289-1306.
[6] Chi Y J, Scharf L L, Pezeshki A, et al. Sensitivity to basis mismatch in compressed sensing. IEEE Transactions on Signal Processing, 2011, 59(5): 2182-2195.
[7] Migliore M D. A compressed sensing approach for array diagnosis from a small set of near-field measurements. IEEE Transactions on Antennas and Propagation, 2011, 59(6): 2127-2133.
[8] Laska J N, Kirolos S, Duarte M F, et al. Theory and implementation of an analog-to-information converter using random demodulation. IEEE International Symposium on Circuits and Systems. USA: University of Louisiana at Lafayette, 2007: 1959-1962.
[9] Tropp J A, Wakin M B, Duarte M F, et al. Random filters for compressive sampling and reconstruction. IEEE International Conference on Acoustics, Speech and Signal Processing. France: IEEE, 2006: 872-875.
[10] Fudge G L, Bland R E, Chivers M A, et al. A Nyquist folding analog-to-information receiver. 42nd Asilomar Conference on Signals, Systems and Computers. USA: ATK Mission Research, 2008: 541-545.
[11] Odejide O O, Akujuobi C M, Annamalai A, et al. Application of analytic wavelet transform for signal detection in Nyquist folding analog-to-information receiver. IEEE International Conference on Communications. Germany: IEEE, 2009: 1-5.
[12] Shea P O. A new technique for instantaneous frequency rate estimation. IEEE Signal Processing Letters, 2002, 9(8): 251-252.
[13] Li L, Si X C, Zhang W W, et al. Improved estimation algorithm of multi-component LFM signal parameters and its fast implementation. Systems Engineering and Electronics, 2009, 31(11): 2560-2562. (in Chinese) 李利, 司锡才, 张雯雯,等. 改进的多分量LFM信号参数估计算法及其快速实现. 系统工程与电子技术, 2009, 31(11): 2560-2562.
[14] Liu Y. Fast dechirp algorithm. Journal of Data Acquisition & Processing, 1999, 14(2): 175-178. (in Chinese) 刘渝. 快速解线性调频技术. 数据采集与处理, 1999, 14(2): 175-178.
[15] Aboutanios E, Mulgrew B. Iterative frequency estimation by interpolation on Fourier coefficients. IEEE Transactions on Signal Processing, 2005, 53(4): 1237-1242.
[16] Tang S G, Gong K, Pang C Y, et al. Time domain compensation of I/Q imbalance in digital receivers. Journal of Tsinghua University: Science and Technology, 2007, 47(1): 49-52. (in Chinese) 唐世刚, 龚克, 潘长勇, 等. 数字接收机I/Q 支路不平衡的时域补偿. 清华大学学报:自然科学版, 2007, 47(1): 49-52.
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