Piotr Gajewski

Using SDF method for simultaneous location of multiple radio transmitters

The paper is devoted to the subject of simultaneous location of many radio waves emitting sources. The possibility to use the SDF method based on the Doppler effect and spectral analysis of signals received have been presented in it. The evaluation of the location procedure accuracy and time of realisation has been done according to simulation tests carried out.

Dynamic Spectrum Management: A perspective for Polish Armed Forces

The Dynamic Spectrum Management is a key to increase the spectrum efficiency usage in rapidly growing demand for spectrum in military operations. In the paper, the main results of national project concerning DSM proposals for Polish Armed Forces are presented.

Mobile Location Method of Radio Wave Emission Sources

This paper deals with the new location method of radio wave sources, based on the Doppler efiect. In this method, position of the radio signal source is calculated on the basis of momentary frequency measurements taken by mobile receiver. Theoretical and simulating analysis of the presented methodology was made before empirical veriflcation process was intro- duced. General outline of the method on the basis of the Doppler efiect and preliminary empirical veriflcation results are presented. 1. INTRODUCTION Over that last decade, the emerging location service of electromagnetic waves sources has found numerous applications in the commercial as well as the military radio systems. In this paper, we concentrate on location service of a subscriber in radio communication networks. Several methods for subscriber location in radio communication nets have been already presented like (1) ¥ (5): access station identiflcation | so-called Cell ID or Cell of Origin (CoO), Angle of Arrival (AoA), Time of Arrival (ToA), Time Difierence of Arrival (TDoA), Received Signal Strength (RSS), Global Positioning System (GPS). Each of foregoing methods have some advantages and some disadvantages too. Disadvantages of foregoing methods make di-cult for practical utilization. These factors have motivated the development of new location methods based on analytic description of the Doppler efiect. The analytic description of this problem (6) makes it possible to calculate exactly the value of the received signal parameters especially frequency ofiset. In this paper, the theoretical basis as well as empirical veriflcation of frequency ofiset measurement is described. 2. ANALYTIC DESCRIPTION OF THE DOPPLER EFFECT

CDMA systems modelling using OPNET software tool

The paper presents the result of CDMA network modelling using OPNET software. Some results of our model investigation are also described here. Simulation result can be achieved using elaborated computer programs or commercial software tools. OPNET (Optimized Network Engineering Tool) is an example of such commercial software elaborated and delivered by MIL-3.

Prediction of VHF and UHF wave attenuation in urban environment

The analysis of the literature shows that there is lack of attenuation prediction models in the urban environment for frequencies the most often exploited in military communication systems and for geometries of these systems (low hanged antennas). The only model that however require additional experimental verification is the one published in [5]. Therefore the results of measurements carried out in a large urban environment proofing usability of this model have been described in presented paper.

Performance monitoring of cognitive radio mobile ad hoc network with dynamic spectrum access

The paper presents a method of monitoring the basic parameters of cognitive mobile ad hoc network (MANET) with opportunistic access to the spectrum. The collected parameters are based on metrics from different communications layers, combined into single utility function, being a global indicator of the network health. The proposed method was tested and validated using a real time cognitive radio network demonstrator. Results for example test scenario are also presented.

MANET Cognitive Radio realtime testbed for dynamic spectrum access

The paper describes the MANET Cognitive Radio test bed. The proposed architecture consists of a number of CR nodes connected to the RF Switch Matrix, and enables simulation, scenario definition and management. Proposed procedures for Opportunistic Spectrum Access in MANET CR are described as well and chosen results of simulations obtained during laboratory tests are presented. The performance of these solution makes them fit for use in special and military applications.

Performance of distributed clustering with weighted optimization algorithm for MANET Cognitive Radio

Mobile Ad-Hoc networks (MANET) are widely used for data communication between mobile nodes on the digital battlefield. Clustering has evolved as an important research topic in military MANETs in reference to supporting the ability of C4I system reconfiguration in highly dynamic operation. Clustering is a process that divides the network nodes into groups according to the command system. Each cluster has a Cluster Head (CH) as a coordinator within the cluster. For policy-based MANET Cognitive Radio (CR) it is very important to have an appropriate set of policies according to the variety of specific scenarios of the data network usage. A few algorithms have been recently studied and proposed for distributed clustering. The presented algorithm is based on the multi-criteria decision using the weighted function of the main network parameters. An appropriate selection of weights values for each particular scenario is critical for the effectiveness of MANET-CR. As the simulations have shown, the number of clusters within the network and the number of nodes in the clusters determine the ability of CR adaptation according to better usage of the available spectrum resources. The performances of the proposed algorithm has been evaluated through the simulations using OMNeT++ simulator and the results are encouraging.

Software Controlled Generator for Electromagnetic Compatibility Evaluation

This paper presents a concept of a testbed designed for laboratory and field tests of wireless communication equipment and systems. The paper presents also a proposal of its use for evaluation of Quality of Service for defined particular scenarios. One of the testbed elements is a software defined arbitrary generator, that enables generation of both predefined signals and interference.