Ryszard Studański

DS CDMA Radio Transmissions Detection

This paper presents two methods for detection DS CDMA signals hidden in the noise are described. The proposed methods are based on analysis of an averaged spectrum of the signal and an averaged spectrum of signal raised to the power 2n. These methods are difficult to use when narrowband signals are presented in an analysing frequency band. Influence of narrowband signals for the DS CDMA signals detection is shown. Simulation experimental results are provided to illustrate the approach. Experimental results with filtering interferences in the time domain and the in frequency domain are presented.

Measurement of Hydroacoustic Channel Impulse Response

The article describes the method of determining the hydroacoustic channel impulse response using signals modulated by pseudo-random sequence. Moreover, exemplary impulse responses determined in the laboratory conditions were presented.

Data transmission in the hydroacoustic channel – experimental researches

ABSTRACT The paper presents the results of experimental researches of data transmission in water using Direct Sequence Spread Spectrum technique and the RAKE receiver. The signal with the QPSK modulation was spread by factor of 4, 8 or 16 chips. Researches were made to verify that spread spectrum technique can be used to underwater voice communications. Static studies were conducted in a small laboratory water tank and in a harbour. Propagation properties were evaluated based on the estimated impulse response of the hydroacoustic channel.

Passive fault tolerant control allocation for small unmanned underwater vehicle

ABSTRACT The paper presents methods of control allocation in a multi-thruster propulsion system of a small torpedo-shaped underwater vehicle. It concentrates on finding an optimal thrust distribution among thrusters for demanded values of propulsive forces and moments. The approach is directed towards minimisation of energy expenditures necessary to obtain required control. Special attention is paid to the unconstrained thrust allocation for both a faultless and faulty work of the propulsion system. The developed algorithms are designed to be modular, interchangeable and highly computationally efficient. Illustrative examples are inserted to demonstrate correctness and simplicity of proposed thrust allocation methods.

Modelling of Underwater Robotic Vehicle Motion with Using of Genetic Algorithms

The utilization of underwater robotic vehicles has known an increasing importance in many marine activities. The robotic vehicle is equipped with a propulsion system and controlled by a human operator. To simplify tasks of the operator, a control system guaranteeing the automation of elementary robot’s behaviours is often applied. In the paper, a control system supporting the robot spatial motion along a reference path is presented. A waypoint line-of-sight scheme is incorporated and Genetic Algorithms are applied to calculate command signals. Selected results of computer simulations are inserted to demonstrate quality and correctness of the proposed approach.

The analysis of the DS CDMA transmission — Studies in the environment of real signals

The paper presents a method of the DS CDMA signals with BPSK modulation detection through the examination of the enhanced signal spectrum density. On the base of experiments carried out on the real radio communication signals the impact of a narrowband emission occurring in the examined frequency band on the detection process effectiveness was shown. The results of the experiment aimed at the detection of the satellite navigation system GPS signals are presented.

Digital receiving of OQPSK signals acquired in wide spectrum

In this paper authors present a possible way to receive a narrowband digital signal that was previously registered in a wide spectrum. To begin with a scheme of receiving equipment is shown. Next, the digital signal processing leading to extraction information from narrowband OQPSK signal is described.

Digital Receiving of OQPSK Signals Dedicated for Maritime Mechatronic Systems

In this paper authors present a possible way to receive a narrowband digital signal that was previously registered in a wide spectrum. To begin with a scheme of receiving equipment is shown. Next, the digital signal processing leading to extraction information from narrowband OQPSK signal is described.