This paper presents a new chaos-based True Random Number Generator (TRNG) with decreased voltage supply sensitivity. Contrary to the traditionally used sources of randomness it uses well-defined deterministic switched-capacitor circuit that exhibits chaos. The whole design is embedded into commercially available mixed-signal PSoC reconfigurable device without any external components. Proposed design is optimized for reduction of influence of supply voltage to the quality of generated random bit stream. The influence of circuit non-idealities is significantly reduced by the proposed XOR corrector and optimized circuit topology. The ultimate output bit rate of proposed TRNG is 60 kbit/s and quality of generated bit-streams is confirmed by passing standard FIPS and correlation statistical tests performed in the full range of PSoC device supply voltages.

Autonomous robots are intelligent machines capable of performing tasks by themselves, without explicit human control. They can find quit a number of unique applications. Here, their utilisation for surveillance, monitoring and reconnaissance in hostile and dangerous to life environment intent on human being detection and/or static object imaging is up-to-date, promising and challenging as well. The fruitfulness of this application of robot systems is determined by many factors. The effective and reliable sensor system for human being detection and localization and static object imaging under wide variety of scenarios can be rated among them. In the last decade, it has been shown that ultra-wideband (UWB) radars (sensors) can be used with advantage as day and night, and under all-weather conditions sensors for person localization and static object imaging. Taking into account this fact, this paper will be intent on the analyses of UWB sensor applicability as the part of the smart sensor systems of robots to be used at emergency situation solutions. Summarizing the results of theoretical analyses and experiments with UWB sensors presented in the paper, it will be concluded that the short-range UWB radars have the great potential to be used as a standard equipment of surveillance and reconnaissance robot systems of future.

Multiple-input multiple-output (MIMO) techniques and orthogonal frequency-division multiplexing (OFDM) can be combined to obtain a promising candidate for next generation wireless communications. However, like a single- input single output (SISO) systems one main disadvantage of MIMO-OFDM is high sensitivity to nonlinear distortion that results in significant loss in power efficiency and performance. In order to improve overall system performance this paper introduces a new iterative method for the detection of nonlinearly distorted symbols received by the receiver of the space-frequency block coded (SFBC) MIMO-OFDM transmission system. The proposed approach is based on the Bussgang theorem application and consists in iterative estimation and accurate cancellation of the nonlinear distortion due to the high power amplifier of the transmitter. The numerical performance evaluation shows that the proposed scheme can achieve significant performance improvement compared to conventional receivers.

The article gives a brief overview of the ongoing research in the field of the ultra wideband (UWB) front-end circuits for ground penetrating radars (GPRs). The novel concept for GPR front-end circuits exploiting electrically short active antenna is considered. The designed low cost active antenna achieves the wide frequency band of the radar system and minimal dimensions. In the paper, measurement results with designed circuits for the active dipole UWB antenna are presented. The circuits offer enhanced user experience in comparison to currently used conventional GPR systems.

The goal of this paper is to draw attention to the possibility of detecting discarded vegetable oil, used at the fryer, via a UWB integrated reflectometer, which enables wideband sensing from “almost DC” to 9 GHz. An integrated reflectometer allows online monitoring of the differences between pure oil, and oil under measurement. For oil quality sensing, a test was proposed which utilizes a structure consisting of a microstrip sensor, an UWB reflectometer, an UWB radar system with an A/D converter, a source clock signal (CLK) and a computer for processing and evaluating results.