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In this paper, we consider the problem of secure communication in multiuser downlink wiretap networks where there exist a base-station (BS) equipped with multiple antennas, multiple legitimate receivers and a passive eavesdropper. The transmitter simultaneously transmits an information signal and artificial noise (AN) separately to the intended receivers and the eavesdropper, in which way, the secrecy...
Motivated by the risks and costs associated with outdoor experiments, this paper presents a new multi-platform quadrotor simulator. The simulator implements a novel second-order dynamic model for a quadrotor, produced through evolutionary programming, and explained by domain knowledge. The model captures the effects of mechanics, aerodynamics, wind and rotational stabilization control on the flight...
An approach towards a high speed current mode SAR ADC is presented. Even though SAR ADCs based on charge redistribution have been significantly improved in efficiency and operating frequency, they are still limited by the settling requirements of the switched capacitor DAC. To overcome this limitation, we propose the use of a current mode SAR ADC incorporating a current steering DAC operating at 2...
A new design technique for minimally-invasive all-pole analog lowpass filters is introduced. The proposed method has minimal impact on the in-band signal in terms of added noise and nonlinearity, whereas it has comparable performance for out-of-band signals with smaller number of active devices. Simulation results for third and fifth order lowpass filters show good improvement in in-band linearity...
In a server system, the switching voltage regulator (VR) noise coupled to the IO pins of the adjacent memory riser connector through the open air above the base board, and the link performance was impacted by the coupling. A simulation flow was developed to reproduce this EMI phenomenon. The flow first used electromagnetic field solvers to extract the VR related power network and the VR-IO coupling...
In this paper, we propose a compressive spectrum sensing method robust against noise uncertainty. The proposed scheme utilizes relative ratio of residual matrix for signal detection. Simulation results verify that the proposed scheme provides reliable detection performance regardless of noise variance estimation error.
In order to improve spectrum utilization efficiency of Cognitive Radio (CR) systems, it is important for Secondary User (SU) to get knowledge about Primary User(PU)'s behavior when SU exploits opportunity to access spectrum. Radio Environment Database has recently been proposed to provide information about PU. Traditional advanced spectrum database constructed based on spectrum sensing method assumes...
With low Peak to Average Power Ratio (PAPR) and robustness of the multiple carrier, SC-FDMA has become the uplink scheme of many wireless systems. Comparing with the Frequency Domain Linear Equalizer (FD-LE), the Decision Feedback Equalizer (DFE) can eliminate more Inter Symbol Interference (ISI) which is the residual of the FD-LE in SC-FDMA system. But the error propagation has degraded the performance...
Node localization is one of the most challenging issues in large scale sensor networks. Few bearing-only based methods are used to locate nodes in a large scale system. Existing bearing-only based Semidefinite Programming (BOSDP) method consumes a lot of energy and it may not yield good results if the beacons are placed randomly. Moreover, the BOSDP approach cannot estimate the locations and orientations...
This paper makes some remarks concerning model-based estimation methods for the rate of a nonhomogeneous Poisson processes that describes events arising from modeling biological phenomena in which discrete events are measured. We describe an approach based on observers and Kalman filters as well as preliminary simulation results, and compare these to other methods (not model-based) in the literature.
When unmanned aircraft systems operate in urban corridors, navigation accuracy is a priority due to proximity of buildings, obstructions, and other infrastructure. In most environments a Global Positioning System (GPS)/inertial measurement unit combination along with an air data system can provide accurate navigation capability. However, this is not possible in urban corridors where GPS has well-documented...
We present a fully-digital digital-to-analog converter (FD DAC) architecture design for high-speed communication systems. The FD DAC design is based on the ΔΣ modulation. The specifications for the DAC includes a low 1.2 V supply voltage, a high 5 GS/s input sampling rate, and a wide 2.5 GHz bandwidth. We employ a combination of the time-interleaving, parallel, and pipelining techniques to reduce...
This paper presents the development of a new numerical algorithm for statistical inference problems that require sampling from distributions which are intractable. We propose to develop our sampling algorithm based on a class of Monte Carlo methods, Approximate Bayesian Computation (ABC), which are specifically designed to deal with this type of likelihood-free inference. ABC has become a fundamental...
This paper presents a novel multi-frame denoising method for low light images to get a clear shot even under dark conditions. To this end, multiple short-exposure images are aligned and filtered with a temporal-spatial filter to suppress the noise. Simulation results on real low-light scenes show that the proposed method outperforms the state-of-the-art image denoising method both on processing speed...
In this paper, we propose Adaptive Histogram Equalization (AHE) based contrast enhancement algorithm. Most histogram-based contrast enhancement methods have problems such as excessive contrast enhancement, unnatural output images, and the loss of visual information. The proposed method manipulates the slope of the input of the Probability Density Function (PDF) histogram. Our method adaptively enhances...
This paper is concerned with distributed estimation of a scalar parameter using a wireless sensor network (WSN) that employs a large number of sensors operating under limited bandwidth resource. A semi-orthogonal multiple-access channel (MAC), which provides transmission of observations from K sensors to a fusion center (FC) via N (N ≤ N) orthogonal channels, is studied. The K sensors are divided...
In this paper, a low-noise amplifier (LNA) designed for the lower band of the ultra-wideband (UWB) spectrum and implemented in 0.18 μm CMOS process is presented. Post-layout simulations show a power gain (S21) of 11.18 dB with 0.8 dB value variations from 259 MHz to 5 GHz. The input and output return losses, S11 and S22, are below −10 dB from 466.4 MHz to 5.63 GHz, while reverse isolation (S12) is...
The proposed paper is presented the possibilities for generation of discrete time signals with predefined statistic and frequency parameters, corresponding to the real input or noise signals for analog circuits. A method and program implementation in the MathCAD environment is shown. The signals are statistically modeled by three different autocorrelation types of functions (with predefined dispersion,...
The proposed driver circuit provides a new driver scheme for supply noise rejection and uniformity enhancement of AMOLED displays. We propose a new gamma circuit scheme for supply noise rejection improvement and provide a driver circuit with offset voltage zero-crossing detection (OZCD) technology to enhance the uniformity of larger displays. The simulation results show the supply noise rejection...
In this paper, a BGA package having a ARM SoC chip is introduced, which has component-type embedded decoupling capacitors (decaps) for good power integrity performance of core power. To evaluate and confirm the impact of embedded decap on core PDN (power distribution network), two different packages were manufactured with and without the embedded decaps. The self impedances of system-level core PDN...
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