Jaroslaw Wojtun

• Military University of Technology

Long/short-term memory (LSTM) is a deep learning model that can capture long-term dependencies of wireless channel models and is highly adaptable to short-term changes in a wireless environment. This paper proposes a simple LSTM model to predict the channel transfer function (CTF) for a given transmitter-receiver location inside a bus for the 60 GH...

Fifth generation (5G) new radio is now offering sidelink capability, which allows direct vehicle-to-vehicle (V2V) communication. Millimeter wave (mmWave) enables low-latency mission-critical V2V communications, such as forward crash warning, between two vehicles crossing on a road without dividers. In this article, we present a measurement-based pa...

In this letter, we examine the effect of misalignment angle on cluster-based power delay profile (PDP) modeling for a 60 GHz millimeter-wave uplink. The analysis uses real-world data, where fixed uplink scenarios are realized by placing the transmitter at ground level and the receiver at the building level. Both outdoor-to-indoor (O2I) and outdoor-...

This paper presents a comprehensive measurement campaign aimed at evaluating indoor-to-indoor radio channels in dynamic scenarios, with a particular focus on applications such as autonomous ground vehicles (AGV). These scenarios are characterized by the height of the antennas, addressing the unique challenges of near-ground communication. Our study...

Millimeter wave (mmWave) technology offers high throughput but has a limited radio range, necessitating the use of directional antennas or beamforming systems such as massive MIMO. Path loss (PL) models using narrow-beam antennas are known as directional models, while those using omnidirectional antennas are referred to as omnidirectional models. T...

In this paper, we analyze the spectral efficiency for millimeter wave downlink with beam misalignment in urban macro scenario. For this purpose, we use a new approach based on the modified Shannon formula, which considers the propagation environment and antenna system coefficients. These factors are determined based on a multi-ellipsoidal propagati...

Vegetation significantly affects radio signal attenuation, influenced by factors such as signal frequency, plant species, and foliage density. Existing attenuation models typically address specific scenarios, like single trees, rows of trees, or green spaces, with the ITU-R P.833 recommendation being a widely recognized standard. Most assessments f...

In this paper, we present an empirical verification of the method of determining the Doppler spectrum (DS) from the power angular spectrum (PAS). Measurements were made for the frequency of 3.5 GHz, under non-line-of-sight conditions in suburban areas characteristic of a university campus. In the static scenario, the measured PAS was the basis for...

In the article, we evaluate the possibility of locating modern tactical radio using the Signal Doppler Frequency (SDF) method. Using an acoustic signal, we show how to emulate the Doppler effect in laboratory conditions. We use the L3 Harris AN/PRC-152A tactical radio as a transmitter. The research is carried out on the proposed concept of building...

This paper focuses on testing the suitability of the USRP B200mini platform for radio emitter localization using the Signal Doppler Frequency (SDF) method. We show how to emulate the Doppler effect in laboratory conditions for different scenarios. For each scenario, we estimate the localization accuracy. We compare our measurement results with simu...

In this paper, we examine the effect of misalignment angle on cluster-based power delay profile modeling for a 60 GHz millimeter-wave (mmWave) uplink. The analysis uses real-world data, where fixed uplink scenarios are realized by placing the transmitter at ground level and the receiver at the building level. Both outdoor-to-indoor (O2I) and outdoo...

In this paper, we explore several widely available software-defined radio (SDR) platforms that could be used for locating with the signal Doppler frequency (SDF) method. In the SDF, location error is closely related to the accuracy of determining the Doppler frequency shift. Therefore, ensuring high frequency stability of the SDR, which is utilized...

The occurrence of cross-beam interference in the received signal is one of the main problems that limit the possibilities of massive multiple-input–multiple-output technology (massive-MIMO) in fifth-generation (5G) systems. Thus, the evaluation of the level of this interference is one of the most important procedures in the spatial planning of curr...

Fifth generation new radio (5G NR) is now offering sidelink capability, which allows direct vehicle-to-vehicle (V2V) communication. Millimeter wave (mmWave) enables low-latency mission-critical V2V communications, such as forward crash warning, between two vehicles crossing on a road without dividers. In this article, we present a measurement-based...

In this paper, we present an empirical verification of the method of determining the Doppler spectrum (DS) from the power angular spectrum (PAS). Measurements were made for the frequency of 3.5 GHz, under non-line-of-sight conditions in suburban areas characteristic of a university campus. In the static scenario, the measured PAS was the basis for...

In emerging fifth-generation (5G) networks, millimeter-wave bands will be used. Due to high atmospheric attenuation, the 60 GHz band is planned to be used for indoor and outdoor line-of-sight communication. Numerous uses of this band for vehicle-to-infrastructure (V2I) connectivity are indicated in the literature. In this paper, we propose a novel...

The use of a spatial selection of radio links in 5G networks is conditioned by the assessment of a power angular spectrum (PAS) of received signals. In this paper, we present a simulation procedure that allows the determination of the PAS for various environmental conditions and antenna patterns. The simulation procedure is based on a propagation m...

Steganography is a technique that makes it possible to hide additional information (payload) in the original signal (cover work). This paper focuses on hiding information in a speech signal. One of the major problems with steganographic systems is ensuring synchronization. The paper presents four new and effective mechanisms that allow achievement...

A Wireless Sensor Network (WSN) in definition, is a self-configuring network consisting of small wireless nodes. Sensor nodes are essentially small computers with extremely basic functionality deployed to sense the physical world. The processing unit of each node has limited computational power, a memory and capacity of battery. The WSN are applied...