Jorg Nuckelt

Bio: Jorg Nuckelt is an academic researcher from Braunschweig University of Technology. The author has contributed to research in topics: Communication channel & Communications system. The author has an hindex of 10, co-authored 13 publications receiving 359 citations.

Simulation and Measurement-Based Vehicle-to-Vehicle Channel Characterization: Accuracy and Constraint Analysis

Abstract: In this paper, a deterministic channel model for vehicle-to-vehicle (V2V) communication is compared against channel measurement results collected during a V2V channel measurement campaign using a channel sounder. Channel metrics such as channel gain, delay and Doppler spreads, eigenvalue (EV) distribution, and antenna correlations are derived from the ray-tracing (RT) simulations as well as from the measurement data obtained from two different measurements in an urban four-way intersection. The channel metrics are compared separately for line-of-sight (LOS) and non-LOS (NLOS) situations. Most power contributions arise from the LOS component (if present) as well as from multipaths with single bounce reflections. Measurement and simulation results of the received power show a very good agreement in the presence of LOS, as most of the received power is carried by the LOS component. In NLOS, the difference is large because the ray-tracer is unable to capture some of the channel characteristics due to the underlying limitations of our ray-based propagation model. Despite the limitations, the model is suitable to characterize some, but not all, of the channel properties in a sufficient manner. We find that the diffuse scattering and multibounced nonspecular reflections must be considered for an accurate prediction of the channel in such a rich scattering environment.

Vehicle-to-Vehicle IEEE 802.11p performance measurements at urban intersections

Abstract: During the last few years, vehicle-to-vehicle (V2V) wireless communication has become a key objective for enabling future cooperative safety applications, such as intersection collision warning. In this paper, we present the results of a 5.9 GHz V2V performance measurement campaign at four different urban intersections under NLOS conditions using commercial off-the-shelf wireless interface cards which meet the 802.11p and ITS-G5 specifications. Particularly, we quantify the packet delivery ratio (PDR) and received signal strength indication (RSSI) levels associated with different scenario conditions with respect to vehicle positioning, intersection geometry and traffic density. We determine reliable communication ranges which constitute an important metric for V2V collision avoidance applications.

Comparison of Ray Tracing and Channel-Sounder Measurements for Vehicular Communications

Abstract: This paper presents the results of an accuracy assessment of a deterministic channel model for vehicle-to-vehicle (V2V) communications. Channel simulations obtained from the ray-tracing model developed by TU Braunschweig are compared to data gathered during the DRIVEWAY V2V channel measurement campaign at 5.6 GHz in the city of Lund in summer 2009. The analysis focuses on PDP and channel gains in an urban four-way intersection scenario. Despite some implementation-based limitations of the ray-tracing model, a very good agreement between simulation and measurement results is achieved. Most relevant power contributions arising from multiple-bounce specular reflections as well as from single-bounce non-specular reflections are captured by the deterministic model. We also discuss the question to what extent roadside obstacles like traffic signs, parked cars or lamp posts have to be considered when characterizing the V2V channel.

Deterministic and stochastic channel models implemented in a physical layer simulator for Car-to-X communications

Abstract: . This paper presents a physical (PHY) layer simulator of the IEEE 802.11p standard for Wireless Access in Vehicular Environments (WAVE). This simulator allows the emulation of data transmission via different radio channels as well as the analysis of the resulting system behavior. The PHY layer simulator is part of an integrated simulation platform including a traffic model to generate realistic mobility of vehicles and a 3D ray-optical model to calculate the multipath propagation channel between transmitter and receiver. Besides deterministic channel modeling by means of ray-optical modeling, the simulator can also be used with stochastic channel models of typical vehicular scenarios. With the aid of this PHY layer simulator and the integrated channel models, the resulting performance of the system in terms of bit and packet error rates of different receiver designs can be analyzed in order to achieve a robust data transmission.

Physical Layer Performance Comparison of LTE and IEEE 802.11p for Vehicular Communication in an Urban NLOS Scenario

Abstract: In this paper, a physical (PHY) layer performance comparison for 3GPP Long Term Evolution (LTE) and IEEE 802.11p in a realistic urban street intersection scenario is presented. For this approach standard compliant link level simulation tools in combination with ray-optical channel modeling are utilized. Results are analyzed with respect to an intersection collision warning application where a suitable performance metric is derived to analyze the individual performances with respect to the packet error ratio in the downlink. In the absence of a line of sight (LOS) path for a Vehicle-to-Vehicle (V2V) link, the results show promising potential of LTE to outperform a dedicated IEEE 802.11p based communication link even when considering full buffer intercell-interference condition.

A Survey of 5G Channel Measurements and Models

Abstract: The fifth generation (5G) mobile communication systems will be in use around 2020. The aim of 5G systems is to provide anywhere and anytime connectivity for anyone and anything. Several new technologies are being researched for 5G systems, such as massive multiple-input multiple-output communications, vehicle-to-vehicle communications, high-speed train communications, and millimeter wave communications. Each of these technologies introduces new propagation properties and sets specific requirements on 5G channel modeling. Considering the fact that channel models are indispensable for system design and performance evaluation, accurate and efficient channel models covering various 5G technologies and scenarios are urgently needed. This paper first summarizes the requirements of the 5G channel modeling, and then provides an extensive review of the recent channel measurements and models. Finally, future research directions for channel measurements and modeling are provided.

Challenges Toward Wireless Communications for High-Speed Railway

Abstract: High-speed railway (HSR) brings convenience to peoples' lives and is generally considered as one of the most sustainable developments for ground transportation. One of the important parts of HSR construction is the signaling system, which is also called the “operation control system,” where wireless communications play a key role in the transmission of train control data. We discuss in detail the main differences in scientific research for wireless communications between the HSR operation scenarios and the conventional public land mobile scenarios. The latest research progress in wireless channel modeling in viaducts, cuttings, and tunnels scenarios are discussed. The characteristics of nonstationary channel and the line-of-sight (LOS) sparse and LOS multiple-input-multiple-output channels, which are the typical channels in HSR scenarios, are analyzed. Some novel concepts such as composite transportation and key challenging techniques such as train-to-train communication, vacuum maglev train techniques, the security for HSR, and the fifth-generation wireless communications related techniques for future HSR development for safer, more comfortable, and more secure HSR operation are also discussed.

On the Performance of IEEE 802.11p and LTE-V2V for the Cooperative Awareness of Connected Vehicles

Abstract: To improve safety on the roads, next-generation vehicles will be equipped with short-range communication technologies. Many applications enabled by such communication will be based on a continuous broadcast of information about the own status from each vehicle to the neighborhood, often referred as cooperative awareness or beaconing. Although the only standardized technology allowing direct vehicle-to-vehicle (V2V) communication has been IEEE 802.11p until now, the latest release of long-term evolution (LTE) included advanced device-to-device features designed for the vehicular environment (LTE-V2V) making it a suitable alternative to IEEE 802.11p. Advantages and drawbacks are being considered for both technologies, and which one will be implemented is still under debate. The aim of this paper is thus to provide an insight into the performance of both technologies for cooperative awareness and to compare them. The investigation is performed analytically through the implementation of novel models for both IEEE 802.11p and LTE-V2V able to address the same scenario, with consistent settings and focusing on the same output metrics. The proposed models take into account several aspects that are often neglected by related works, such as hidden terminals and capture effect in IEEE 802.11p, the impact of imperfect knowledge of vehicles position on the resource allocation in LTE-V2V, and the various modulation and coding scheme combinations that are available in both technologies. Results show that LTE-V2V allows us to maintain the required quality of service at even double or more the distance than IEEE 802.11p in moderate traffic conditions. However, due to the half-duplex nature of devices and the structure of LTE frames, it shows lower capacity than IEEE 802.11p if short distances and very high vehicle density are targeted.

On Indoor Millimeter Wave Massive MIMO Channels: Measurement and Simulation

Abstract: The millimeter wave (mmWave) communications and massive multiple-input multiple-output (MIMO) are both widely considered to be the candidate technologies for the fifth generation mobile communication system. It is thus a good idea to combine these two technologies to achieve a better performance for large capacity and high data-rate transmission. However, one of the fundamental challenges is the characterization of mmWave massive MIMO channel. Most of the previous investigations in mmWave channel only focus on single-input single-output links or MIMO links, whereas the research of massive MIMO channels mainly focus on a frequency band below 6 GHz. This paper investigates the channel behaviors of massive MIMO at a mmWave frequency band around 26 GHz. An indoor mmWave massive MIMO channel measurement campaign with 64 and 128 array elements is conducted, based on which, path loss, shadow fading, root-mean-square (RMS) delay spread, and coherence bandwidth are extracted. Then, by using our developed ray-tracing simulator calibrated by the measurement data, we make the extensive ray-tracing simulations with 1024 antenna elements in the same indoor scenario, and get insights into the variation tendency of mean delay and the RMS delay with different array elements. It is observed that the measurement and the ray-tracing-based simulation results have reached a good agreement.

On Millimeter Wave and THz Mobile Radio Channel for Smart Rail Mobility

Abstract: As a widely acknowledged efficient and green transportation model, rail traffic is expected to evolve into a new era of “smart rail mobility” whereby infrastructure, trains, and travelers will be interconnected to achieve optimized mobility, higher safety, and lower costs. Thus, a seamless high-data rate wireless connectivity with up to dozens of gigahertz bandwidth is required. Such a huge bandwidth requirement motivates the exploration of the underutilized millimeter (mm) wave and terahertz (THz) bands. In this paper, the motivations for developing millimeter wave and THz communications for railway are clarified by first defining the applications and scenarios required for smart rail mobility. Ray-tracing simulations at 100 GHz imply that to form high-gain directional antenna beams, dynamic beamforming strategies and advanced handover design are critical for the feasibility of THz communications to enable smart rail mobility.