Parameter estimation of LFM signals intercepted by a composite local oscillation SNYFR

Nyquist Folding Receiver (NYFR) is a novel ultrawideband interception receiver architecture, which can sample a large range wideband signal by single Analog-to-Digital Converter (ADC). And the Synchronous Nyquist Folding Receiver (SNYFR) is an improved structure of NYFR. In this paper, a new SNYFR structure based on composite Sinusoidal Frequency Modulated (SFM) Local Oscillator (LO) is proposed. For Linear Frequency Modulated (LFM) signals intercepted by this SNYFR, a Nyquist Zone (NZ) estimation and parameter estimation algorithm based on instantaneous autocorrelation is deduced. The complexity of the algorithm is lower, which reduces the difficulty of resolving the LFM/SFM hybrid modulated signals after the ADC of SNYFR. Computer simulation shows that effective detection of multi-component LFM signals and accurate parameters estimation can be achieved by the proposed algorithm when the signal to noise ratio (SNR) is better than −8dB.