Michal Sybis

• PhD
• Poznań University of Technology

In this letter, we investigate single-slope path loss models complemented with shadowing effects in the context of vehicular communications. We present several models obtained based on extensive measurement campaigns with inter-vehicle transmission conducted at 26.555 GHz in real-traffic experiments, mainly along high-speed roads. Particular attent...

In this letter, we investigate single-slope path loss models complemented with shadowing effects in the context of vehicular communications. We present several models obtained based on extensive measurement campaigns with inter-vehicle transmission conducted at 26.555 GHz in real-traffic experiments, mainly along high-speed roads. Particular attent...

This paper presents the physical layer of a proprietary broadband communication system for CubeSats. The system operates in the C band (5.8 GHz), delivering at least 10 Mbps of the net user throughput. Operation at low elevation angles (and therefore low SNRs) and high Doppler shifts is made possible thanks to a sophisticated synchronization subsys...

High reliability of wireless communications is a rudimentary requirement for guaranteeing safe autonomous driving. This paper discusses the performance of communications between cars within autonomous platoons, with the application of a proposed database-supported successive interference cancellation (SIC) algorithm. By assumption, it utilizes the...

Vehicle platooning is considered as one of the key use cases for vehicle-to-vehicle (V2V) communications. However, its benefits can be realized only with highly reliable wireless transmission. As the 5.9GHz frequency band used for V2V suffers from high congestion, in this paper, we consider the use of the terrestrial TV frequencies for intra-platoo...

In this paper, we propose a distributed Vehicular Dynamic Spectrum Access (VDSA) framework for vehicles operating in platoon formations. Given the potential for significant congestion in licensed frequency bands for vehicular applications such as 5.9 GHz. Our approach proposes to offload part of the intra-platoon data traffic to spectral white-spac...

Vehicle platooning is considered as one of the key use cases for vehicle-to-vehicle (V2V) communications. However, its benefits can be realized only with highly reliable wireless transmission. As the 5.9GHz frequency band used for V2V suffers from high congestion, in this paper, we consider the use of the terrestrial TV frequencies for intra-platoo...

Platooning is considered to be one of the possible prospective implementations of the autonomous driving concept, where the train-of-cars moves together following the platoon leader's commands. However, the practical realization of this scheme assumes the use of reliable communications between platoon members. In this paper, the results of the meas...

In this paper, we consider the use of radio environment maps (REMs) in vehicular dynamic spectrum access (VDSA) for vehicle platooning applications. We propose an algorithm that dynamically allocates the frequency bands and transmission power in the so-called TV white spaces (TVWS) for intra-platoon messaging, intending to maximize the reliability...

This paper presents the improved distance estimation for the purpose of Database-assisted Autonomous Platooning and V2V channel modelling. The proposed approach combines commonly used GPS-based measurements with UWB-based measurements to benefit from both solutions. While GPS allow for unlimited measurement range, the UWB improves accuracy for shor...

The paper is focused on presentation of the fully autonomous observation SkyLab laboratory which was established recently to support research in the field of astronomical instrumentation and surveillance-related surveys. This facility is operated by the Poznan University of Technology. The main purpose of this laboratory is to provide new hardware...

Platooning is a future approach to autonomous driving in which vehicle-to-vehicle and vehicle-to-infrastructure communications play an important role. Tests performed in the past showed that a significant reduction in fuel consumption is possible when cars are traveling in a dense platoon formation. To increase the level of their awareness of the su...

Platooning is one of the prospective applications, where autonomous driving and Vehicle-to-Vehicle and Vehicle-to-Infrastructure communications play a vital role. Various test proved that reduction of inter-car distance withing platoon of trucks results in significant fuel savings. Keeping of such short distance as well as awareness of the platooni...

This paper investigates the ability of modified cooperative adaptive cruise control to support high-density car platooning. We first use a simplistic communication model to study the impact of actuation lag, message periodicity, and communication delay on the minimum feasible inter-car spacing. We then use a detailed IEEE 802.11p simulation model t...

This book constitutes the refereed proceedings of the 14th International Conference on Cognitive Radio-Oriented Wireless Networks, CROWNCOM 2019, held in Poznan, Poland, in June 2019. The 30 revised full papers were selected from 48 submissions and present a large scope of research topic also covering IoT in 5G and how cognitive mechanisms shall he...

Vehicle platooning is a promising technology that allows to improve the traffic efficiency and passengers safety. Platoons that use cooperative adaptive cruise control, however, require a reliable radio link between platoon members to ensure a required distance between the cars within the platoon, thus maintaining platoon safety. Nowadays, the comm...

The focus of this study is the performance of high-density truck platooning achieved with different wireless technologies for vehicle-to-vehicle (V2V) communications. Platooning brings advantages such as lower fuel consumption and better traffic efficiency, which are maximized when the inter-vehicle spacing can be steadily maintained at a feasible...

One of the most important parts of the vehicle-to-vehicle (V2V) and vehicle-to-infrastructure (V2I) communication is reliable transmission that allows the achievement of good throughput in the system. In terms of high system throughput, two issues need to be taken into consideration. First, accurate estimation that is crucial for the successful app...

One of the most important parts of the vehicle-to-vehicle (V2V) and vehicle to infrastructure (V2I) communication is reliable channel estimation. Accurate estimation is crucial for the successful application of equalization and demodulation, since the V2X (common name for V2V and V2I) channels characteristics are very time-varying. This paper prese...

In this paper, a reduced complexity Log-MAP algorithm based on a non-recursive approximation of the max∗ operator is presented and studied for turbo trellis-coded modulation (TTCM) systems. In the algorithm, denoted as AvN Log-MAP, the max∗ operation is generalized and performed on n≥2 arguments. The approximation is derived from the Jensen inequal...

A novel method for approximating the optimal max* operator used in Log- MAP decoding of turbo and turbo trellis-coded modulation (TTCM) codes is proposed being derived from a well-known inequality, which has not been published before. The max* operation is generalized, for the first time, and performed on n > 2 rather than n = 2 arguments, as it is...

A new complexity reducing technique for turbo trellis-coded modulation (TTCM) is presented. The novel technique is investigated in conjunction with Max-Log-MAP decoding algorithm and is evaluated in terms of complexity and bit error rate (BER) performance in an additive white Gaussian noise (AWGN) channel and uncorrelated, i.e. fully interleaved Ra...

A low-complexity decoding algorithm for turbo trellis-coded modulation (TTCM) is proposed. The algorithm is a simple modification of the log-MAP decoding algorithm in which a correcting term is applied only once in calculation of the Jacobian logarithm for more than two arguments. BER performance has been evaluated by simulation for an additive whi...

In the paper, a modified Log-MAP algorithm based on a novel approximation of the max* operator derived from the Jensen inequality is proposed. In this approach, the max* operation is performed on n≥2 arguments, thus the recursive calculations are avoided and significant reduction in the number of operations performed per decoding step, as compared...

A reduced-complexity modified decoding algorithm for turbo trellis-coded modulation (TTCM) is proposed and evaluated in terms of complexity and bit error rate (BER) performance in an additive white Gaussian noise (AWGN) channel. A novel method is derived from the Chebyshev inequality. In this approach, the max* operation is performed on n≥2 argumen...

A novel approach for approximating the max * operator, used in the Log-MAP decoding algorithm, is presented. In this approximation it is not necessary to use any additional correction term, as previous approximation methods require. Several decoding algorithms are obtained for both turbo and turbo trellis-coded modulation (TTCM) codes with optimal...

A novel method for approximating the optimal max* operator in Log-MAP decoding of turbo and turbo trellis-coded modulation (TTCM) codes is presented. The max* operation is performed on n>2 rather than on only two inputs, as it is in the conventional approach. The approximation uses a very simple max operation and a look-up table (LUT) with only eig...

A reduced-complexity modified decoding algorithm for turbo trellis-coded modulation (TTCM) is proposed and evaluated in terms of complexity and bit error rate (BER) performance in an additive white Gaussian noise channel. The algorithm uses an optimal approximation of the Jacobian logarithm, used in the so-called Log-MAP decoding, by means of the m...