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This paper will present an approach for implementing an airborne radar warning receiver (RWR) pulse data extraction (PDE) and processing technique capable of handling multiple time-coincident radio-frequency (RF) pulse input threat emitter signals received in a dense threat radar signal environment. The pulse data extraction technique is specifically developed to accommodate the RF to video response...
Time of arrival (TOA) based techniques are widely used in many ranging and localization problems. But because their performance highly depends on the accuracy of the TOA estimation of direct-paths, it's challenging to achieve accurate position estimations under dense multipath or Non-Line-of-Sight (NLOS) condition. In this paper, an algorithm which combines Time difference of arrival (TDOA) technique...
This paper designs an audio covert communication system based on spread spectrum (SS) data hiding technology. Considering the characteristics of covert communication, some methods were proposed to solve the key problems in the system. Firstly, the system employed M-ary SS coding combining with return-to-zero base band code to embed hiding data. In addition, the sender embedded the base band clock...
Multipath effects on carrier phase measurements are the major error source for short baseline positioning. Multipath effects impair the precision and reliability of both the ambiguity resolution and estimated site coordinates. Empirical Mode Decomposition (EMD) is a relatively new non-linear technique for adaptively representing non-stationary signals. The method is a fully data driven approach. Noisy...
In this paper, we consider blind interference suppression in IR UWB communication system, and the means of a statistical technique called independent component analysis (ICA), taken as a solution for the coexistence of impulse-radio Ultra-wideband (IR-UWB) systems with other wireless systems was studied. Particularly for the evaluation of the system performance, tone, multiton, and partial-band interference...
A 6th order Chebyshev type I low pass filter applied in zero-IF wireless receivers, implemented in 0.18 ??m CMOS technology is introduced, this filter is realized with leapfrog structure, has an attenuation of 30 dB at 5.25 MHz, less than 1 dB in-band ripple, 25 nV/sqrt(Hz) input referred noise at 5 kHz, and draws 2.6 mA from 1.8 V supply. By employing frequency calibration circuit, the cut-off frequency...
Contemporary proven cryptographic algorithms, like the advanced encryption standard (AES), are used in many secure data storage systems. Cipher data when written or read might be subject to noise. Classical error detection and correction methods are not suitable for encrypted data. In this paper, error detection and correction is performed at the receiver end, without any changes to the encryption...
The compound wiretap channel generalizes the classical problem in broadcast information-theoretic secrecy by allowing a class of potential eavesdroppers. This represents uncertainty in the eavesdropper channel and the characterization of its secrecy capacity is an open question. In this paper we present a new coding scheme that generalizes known approaches to this problem. The scheme prefixes an artificial...
Amplitude probability distribution (APD) statistical parameter measuring technique was approved as a new standard electromagnetic disturbance measurement method in CISPR16-1 Ed.2, but the limits of APD is still under consideration. Based on the constellation diagram, a general method to determine APD limits is presented in this paper. First of all, the smallest Euclidean distance of communication...
We propose a novel parallel mixed-signal compressive spectrum sensing architecture for cognitive radios (CRs) with a detailed study of the signal modeling. The mixed-signal compressive sensing is realized with a parallel segmented compressive sensing (PSCS) architecture, which not only can filter out all the harmonic spurs that leak from the local random generator, but also provides a tradeoff between...
The IEEE 802.15.4a standard for wireless sensor networks is designed for highly accurate ranging with impulse radio Ultra Wideband (UWB) signals. The standard allows a large number of different system parameters for the preamble, which are analyzed in detail for energy detectors. Energy detectors have low complexity and promise low cost and low energy consumption. The focus of this work is on statistical...
We present an accurate SER estimation method for low duty, QPSK modulated, Direct Sequence Impulse Radio (DS-IR) over a frequency selective channel with RAKE reception. The approach is a useful novelty since the existing SER estimation methods for DS-IR are problematic in the low duty case because they are accurate only when the number of pulses per symbol is high. The approach is exploited to study...
This paper presents an energy efficient way to detect a UWB Impulse Radio (UWB-IR) signal relying on a Time Hopping sequence with a non coherent receiver. This detection is performed in a periodic manner, observing the received signal on the mean pulse repetition period basis. It allows to derive a simple requirement on the THSs design, to fit our detection scheme. Compared to a straightforward busy...
Measurement of the background radio noise is very important process being used in survey of radio noise environment, calculating the threshold level for the frequency occupancy measurement and so forth. First step of background radio noise measurement is to select the sample sub-band which is mostly dominated by the background white Gaussian noise (WGN) within the target band. The second step is to...
Linear frequency signal has been used in many domain, especially used in detecting of rebound wave. The thesis uses not only phasic matching theory but also matching filter in order to dispose of noise. Using the new synthesis idea on phasic matching and matched filer, we can get purity signal. Through emulator ,we can get the best effection of needing signal and at the same time remove coherent and...
Intelligent robotic navigation requires precise positioning information. The Global Navigation Satellite System (GNSS) enables such navigation by providing precise timing, velocity and positioning information to any adequately equipped receiver world-wide. A core capability of these receivers is to identify all visible satellites from a snapshot of received signal. This identification process, called...
Contemporary proven block cryptographic algorithms, like the advanced encryption standard (AES), are used for secure transmission of data in many of the communication systems in use. Classical error detection/correction methods are not suitable for such situations due to the randomness property of encryption. A one bit error in an encrypted message will lead to an average of 50% error rate in the...
The Wiener de-convolution algorithm has been used to improve the resolution of images acquired using a coherent terahertz imaging system at 186 GHz. Experimental results have demonstrated that the Wiener algorithm is capable of improving the resolution of images acquired with this system. A testing phantom will be designed and manufactured for quantitative analysis of the improvement in future research.
When talking about data, information, knowledge and wisdom we usually have a vague understanding on the concepts that are described by these terms. However, their relationships and dependencies can-and usually have to-be described from different perspectives in order to cover most of their facets. In this paper, we try to give an overview of some fundamental aspects that we have to consider. This...
This paper considers the problem of secret communication over a two-receiver multiple-input multiple-output (MIMO) Gaussian broadcast channel. The transmitter has two independent messages, each of which is intended for one of the receivers but needs to be kept asymptotically perfectly secret from the other. It is shown that, surprisingly, under a matrix power constraint both messages can be simultaneously...
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