On the Analysis of PM/FM Noise Radar Waveforms Considering Modulating Signals with Varied Stochastic Properties

Abstract

Noise Radar technology is the general term used to describe radar systems that employ realizations of a given stochastic process as transmit waveforms. Originally, carriers modulated in amplitude by a Gaussian random signal, derived from a hardware noise source, were taken into consideration, justifying the adopted nomenclature. With the advances made in hardware as well as the rise of the software defined noise radar concept, waveform design emerges as an important research area related to such systems. The possibility of generating signals with varied stochastic properties increased the potential in achieving systems with enhanced performances. The characterization of random phase and frequency modulated waveforms (more suitable for several applications) has then gained considerable notoriety within the radar community as well. Several optimization algorithms have been proposed in order to conveniently shape both the autocorrelation function of the random samples that comprise the transmit signal, as well as their power spectrum density. Nevertheless, little attention has been driven to properly characterize the stochastic properties of those signals through closed form expressions, jeopardizing the effectiveness of the aforementioned algorithms as well as their reproducibility. Within this context, this paper investigates the performance of several random phase and frequency modulated waveforms, varying the stochastic properties of their modulating signals.

Extração de Parâmetros Intrapulso e Interpulso de um Radar com Modulação Aleatória em Frequência

“…A PSD Γ(f ) da envoltória complexa s(t), com respeito à f o , tem o formato de uma distribuição gaussiana e é dada por [10]…”

“…Radares de ruído são sistemas eletromagnéticos que utilizam sinais aleatórios como formas de onda de transmissão e empregam filtragem casada e integração de pulsos na sua cadeia de recepção. A natureza estocástica das formas de onda com transmissão aleatória são atrativas para aplicações que requerem alto desempenho contra receptores de GE, introduzindo vantagens estratégicas para os sistemas de radar [10].…”

“…Nesse contexto, até aonde pudemos investigar, não foi proposto um método para interceptação e extração dos parâmetros de formas de ondas radar consideradas LPI/LPID com modulação aleatória, ou seja; radares de ruído [9]. Assim, nossas contribuições neste trabalho são: nova metodologia para extração autônoma dos parâmetros intrapulso e interpulso de uma forma de onda modulada em frequência por um processo estocástico gaussiano estacionário em sentido amplo (WSS -wide sense stationary), doravante designada como FM Noise [10]; adaptação da metodologia de processamento de imagem, considerando uma nova abordagem devido à aleatoriedade em frequência; comparação de desempenho entre a técnica proposta e a baseada em processamento de imagem.…”

Joint Radar-Communications Processing from a Dual-Blind Deconvolution Perspective

“…Highly spectrum-efficient waveforms such as OFDM [27] or certain modulating Gaussian radar waveforms [28] satisfy this property.…”

Low-PAPR Waveforms with Shaped Spectrum for Enhanced Low Probability of Intercept Noise Radars

“…In the late 20th century, with the technological advances in microwave and digital electronics, there was a major shift from analog to digital and it became possible to generate random signals and perform correlation processing fully digitally. Over the past three decades, there has been a considerable interest in noise radar technology and significant progress has been made by research communities [8][9][10].…”