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Design and Implementation of a Programmable Digital Pseudo-Random Bit Generator for Applications in Noise RadarAytimur, Cenk 31 October 2013 (has links)
Noise radar systems have become more prevalent over the past couple of decades due to their superior performance over conventional continuous-wave and pulsed-wave radar systems in certain applications. However, one limiting factor of noise radar systems has been the generation of ultrabroadband waveforms. This thesis proposes a novel application of programmable pseudo-random bit generators (PRBGs) for use in noise radar applications. A long-sequence high-speed PRBG was designed using a low-cost and low-power complementary metal oxide semiconductor (CMOS) technology. The proposed circuit has a sequence length of approximately 4.3 Gbits and was designed to operate at 1 GHz providing a data rate of 1 Gbit/s.
This new waveform generation technique would eliminate the requirement of a large variable delay-line (transmission-line) and reduce the power required by noise radar systems. It would allow such systems to become much more compact and create the opportunity for the move towards hand-held devices. It would further allow easier implementation of bistatic radar systems where the transmitting and receiving sites are physically far from one another. In addition, this programmable long-sequence PRBG could have applications in cryptology, communications, and other areas where the generation of high-speed random bit sequences is paramount.
Unfortunately, an ASIC (application specific integrated circuit) design process documentation error rendered the fabricated IC's unusable. The error was caused by not enabling the input pads of the IC, which required an undocumented edit to the gate-level design file generated by Synopsys \textit{Design Vision}. Consequently, the circuit had to be realized on a field-programmable gate array (FPGA), which performed as expected, albeit at a lower frequency of 50 MHz. The PSD of the FPGA implementation created the expected output of a sinc-squared function with the first null at the clock frequency. This result proves that a LFSR PRBG is a viable noise source for use in noise radar systems. / Thesis (Master, Electrical & Computer Engineering) -- Queen's University, 2013-10-31 14:48:27.422
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[en] A PROBABILISTIC APPROACH IN SIGNAL MODELING FOR NOISE RADARS THAT EMPLOY FREQUENCY MODULATED PULSES / [pt] MODELAGEM PROBABILÍSTICA DE SINAIS EM RADARES DE RUÍDO QUE UTILIZAM PULSOS SENOIDAIS MODULADOS EM FREQUÊNCIALEANDRO GUIMARAES PRALON 09 April 2014 (has links)
[pt] Radares são sistemas eletromagnéticos de detecção e localização de objetos
refletores. Sua operação consiste na transmissão de formas de onda e
na detecção e processamento do sinal refletido no alvo, visando extrair algumas
características deste (e.g. posição, velocidade, direção, tipo de alvo).
Radares de ruído, por sua vez, são sistemas que transmitem sinais com forma
de onda aleatória e que, por este motivo, apresentam elevado desempenho
em presença de interferências externas, intencionais ou não, e supressão da
ambiguidade em distância na detecção de alvos. O presente trabalho desenvolve
inicialmente uma modelagem probabilística dos sinais envolvidos em
radares de ruído. Esta modelagem permite a obtenção de expressões fechadas
para funções autocorrelação, densidades espectrais de potência, funções
correlação cruzada e ganhos de processamento associadas aos diversos sinais
envolvidos. Com base nesta modelagem, e feita uma análise comparativa de
radares que utilizam compressão de pulso e integração em sua cadeia de recepção. Mais especificamente, são comparados radares de ruído com radares
tradicionais (que utilizam formas de onda determinísticas - chirps) operando
em cenários que permitem avaliar aspectos como a resolucao em distância,
o nível de lóbulos secundários e a eliminação de ambiguidades. / [en] Radars are electromagnetics systems used for detecting and locating reflecting
objects. Their operation is based on the transmition of waveforms
and on the detection and processing of the reflected signal so that some
targets can be estimated (e.g. position, velocity, direction and type of target).
Noise radars are systems that use random signals as the transmitting
waveform and that for this reason present high performance against external
interference, intentional or not, and the suppression of range ambiguity in
the detection of targets. The present work initially develops a probabilistic
model for the random signals involved in Noise Radars. This model allows for
derivation of closed forms expressions for autocorrelation functions, power
spectral densities, processing gains, and cross-correlation functions of the
random signals involved. Based on this model, a comparison of radars that
employ pulse compression and integration in their receivers. More specifically,
Noise Radars are compared to traditional radars that use deterministic
waveforms (chirps) under different scenarios which are chosen so that some
specific aspects like range resolution, side-lobe levels and range ambiguity
elimination can be evaluated.
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Estimating Channel Identification Quality in Passive Radar Using LMS AlgorithmsCallahan, Michael J. 28 August 2017 (has links)
No description available.
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Random Sequence Encoding with OFDM for Covert Communication and Signal Reuse for LPI/LPD Radar: Theory & ExperimentsKellett, Daniel 01 August 2017 (has links)
No description available.
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LPI-radar. Nys eller nytta? : Studie av den militära nyttan med LPI-radar. / LPI-radar. Gain or pain? : A Study of Military Benefits When Using LPI-radar.Lundströmer, Torbjörn January 2010 (has links)
Sedan radar började användas under första hälften av 1900-talet har duellen mellan radar och signalspaning pågått. Genom att utnyttja radar har alltid en medveten risk tagits, risken att bli upptäckt av motståndarens signalspaning. Duellen gavs möjlighet att ta en paus då radarsystem med låg uteffekt introducerades på marknaden under slutet av 1980-talet, nu fanns plötsligt en möjlighet att använda radar samtidigt som de samtida signalspaningssystemen inte kunde upptäcka dessa radarsystem. I föreliggande magisteruppsats i krigsvetenskap med militärteknisk inriktning undersöks räckviddsförhållanden mellan dessa radarsystem och signalspaningssystem. Genom scenarier i den marina arenan försöker jag värdera de taktiska vinster en användare av radar med låg uteffekt kan göra. Analysen visar på att det fram till dess att signalspaningssystem med förmåga att upptäcka radar som utnyttjar låg uteffekt finns tillgängligt är det möjligt att nå taktiska fördelar med dessa system. / Since the advent of radar during the early 20th century the duel between radar and electronic support measurement systems has been practised. Using radar has always been associated with a risk of being detected by an opponent’s electronic support measurement systems. The duel came to a halt when radar systems using low output power were introduced on the market during the late 1980s, now it was possible to use radar without being detected by contemporary electronic support measurement systems. The present master of science (one year) thesis in war science with specialization in military technology looks into the range relationships between radar and electronic support measurement systems. Through scenarios in the naval domain, I seek to assess the tactical benefits a user of low probability of intercept radar may have. The analysis indicates that until electronic support measurement systems with the ability to detect radar systems using low output power are available it is still possible to gain tactical advantages with such systems.
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Adaptive Radar with Application to Joint Communication and Synthetic Aperture Radar (CoSAR)Rossler, Carl W., Jr 08 August 2013 (has links)
No description available.
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