A parameter estimation algorithm for LFM/BPSK hybrid modulated signal intercepted by Nyquist folding receiver

Abstract

Nyquist folding receiver (NYFR) is a novel ultra-wideband receiver architecture which can realize wideband receiving with a small amount of equipment. Linear frequency modulated/binary phase shift keying (LFM/BPSK) hybrid modulated signal is a novel kind of low probability interception signal with wide bandwidth. The NYFR is an effective architecture to intercept the LFM/BPSK signal and the LFM/BPSK signal intercepted by the NYFR will add the local oscillator modulation. A parameter estimation algorithm for the NYFR output signal is proposed. According to the NYFR prior information, the chirp singular value ratio spectrum is proposed to estimate the chirp rate. Then, based on the output self-characteristic, matching component function is designed to estimate Nyquist zone (NZ) index. Finally, matching code and subspace method are employed to estimate the phase change points and code length. Compared with the existing methods, the proposed algorithm has a better performance. It also has no need to construct a multi-channel structure, which means the computational complexity for the NZ index estimation is small. The simulation results demonstrate the efficacy of the proposed algorithm.

Parameter Estimation of SAR Signal Based on SVD for the Nyquist Folding Receiver

“…Based on the characteristic above, we define the chirp singular value ratio (CSVR) spectrum [ 23 ] as: …”

Estimation of both Nyquist zone index and code rate for BPSK radar signal intercepted by Nyquist folding receiver

“…The multi‐channel method neglects the known LOS information and it needs to search the peak of the signal spectrum in each channel. In [15], we have proposed a method that has considered the LOS known information. However, it needs squaring process to transform the BPSK signal into a single carrier frequency signal, which leads to the SNR deterioration.…”

“…Considering the parameter estimation under the NYFR architecture, except for the multi‐channel method, another NZ index estimation method has been proposed [15]. However, it requires squaring process to transform the BPSK signal into a single carrier frequency signal, which leads to the signal–noise ratio (SNR) deterioration.…”

A Sub-Nyquist Sampling Digital Receiver System Based on Array Compression

“…Traditional wideband digital receivers for electronic reconnaissance are commonly utilized to sample and process radar signals at the Nyquist sampling rate or the band-pass sampling rate [1][2][3]. However, with the increasing complexity of the electronic environment, bottleneck problems have been encountered with traditional digital receiver systems, such as complex hardware structure and large-volume data processing.…”