We propose and analyze a low-complexity channel estimator for multiuser multicarrier code division multiple access (MC-CDMA) downlink in time-variant frequency-selective channel. MC-CDMA is based on orthogonal frequency multiplexing (OFDM). The estimated individually every flat-fading subcarrier, assuming small intercarrier interference. temporal variation of subcarrier over the duration data block upper bounded by Doppler bandwidth determined maximum velocity users. Slepian showed that...

To make transportation safer, more efficient, and less harmful to the environment, traffic telematics services are currently being intensely investigated developed. Such require dependable wireless vehicle-to-infrastructure vehicle-to-vehicle communications providing robust connectivity at moderate data rates. The development of such vehicular communication systems standards requires accurate models propagation channel in all relevant environments scenarios. Key characteristics channels...

Vehicle-to-vehicle (VTV) wireless communications have many envisioned applications in traffic safety and congestion avoidance, but the development of suitable systems standards requires accurate models for VTV propagation channel. In this paper, we present a new wideband multiple-input-multiple-output (MIMO) model channels based on extensive MIMO channel measurements performed at 5.2 GHz highway rural environments Lund, Sweden. The measured characteristics, particular nonstationarity...

Vehicular communication channels are characterized by a non-stationary time- and frequency-selective fading process due to rapid changes in the environment. The can be assuming local stationarity for region with finite extent time frequency. For this wide-sense uncorrelated-scattering (WSSUS) assumption holds approximately we able calculate frequency dependent scattering function (LSF). In paper, estimate LSF from large set of measurements collected DRIVEWAY'09 measurement campaign, which...

<para xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> Future intelligent transportation systems (ITS) will necessitate wireless vehicle-to-infrastructure (V2I) communications. This link can be implemented by several technologies, such as digital broadcasting, cellular communication, or dedicated short-range communication (DSRC) systems. Analyses of the coverage and capacity requirements are presented when each three is used to implement V2I link. We...

In this paper, a deterministic channel model for vehicle-to-vehicle (V2V) communication is compared against measurement results collected during V2V campaign using sounder. Channel metrics such as gain, delay and Doppler spreads, eigenvalue (EV) distribution, antenna correlations are derived from the ray-tracing (RT) simulations well data obtained two different measurements in an urban four-way intersection. The separately line-of-sight (LOS) non-LOS (NLOS) situations. Most power...

We carried out a car-to-infrastructure (C2I) and car-to-car (C2C) 4x4 multiple-input multiple-output (MIMO) radio channel measurement campaign at 5.2GHz in Lund, Sweden. This paper presents first results on pathloss, power-delay profiles, delay-Doppler spectra C2C highway scenario, where both cars were traveling opposite directions. A pathloss coefficient of 1.8 yields the best fit with our mean square sense. The measured Doppler shift line sight path matches exactly theoretical...

The fading process in high speed vehicular traffic telematic applications at 5 GHz is expected to fulfill the wide-sense stationarity uncorrelated scattering (WSSUS) assumption for very short time-intervals only. In order test this we apply concept of a local time- and frequency-variant function, which estimate from measurements vehicle-to-vehicle wave propagation channels by means multi-window spectrogram. obtained temporal sequence functions (LSF) used calculate collinearity measure. We...

This paper deals with channel estimation for orthogonal frequency-division multiplexing (OFDM) in time-variant wireless propagation channels. We particularly consider the challenges of IEEE 802.11p standard, which is worldwide dominant system vehicular communications. For historic reasons, uses a pilot pattern that identical to used 802.11a, was initially designed indoor channels little or no time variations. Therefore, this violates sampling theorem both large delay spread and Doppler...

The assumption of wide-sense-stationarity (WSS) and uncorrelated scattering (US) wireless propagation channels is widespread for the design analysis channels. However, only valid within a limited range. In this paper, we investigate extension range not in time (WSS), but also frequency (US), measured vehicular We do by using collinearity local function, which bounded spectral distance metric, thus allows us to set an indicative threshold, turn enables WSS US test. prove that fading process...

Vehicular communication channels are characterized by a non-stationary time- and frequency-selective fading process due to fast changes in the environment. We characterize distribution of envelope first delay bin vehicle-to-vehicle means its Rician <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="TeX">$K$</tex-math></inline-formula> -factor. analyze time–frequency variability this channel parameter using vehicular...

Ultra-reliable wireless communication links require the utilization of all diversity sources a channel. Hadani et al. propose two dimensional discrete symplectic Fourier transform (DSFT) as orthogonal pre-coder for time-frequency modulation scheme. In this paper we explore general precoding (OP) and its performance in time- frequency-selective channels. We show that iterative parallel interference cancellation (PIC) channel estimation methods can be used detection OP. A scalar signal model...

Car-to-car and car-to-infrastructure (henceforth called C2X) communications are constantly gaining importance for road- safety other applications. In order to design efficient C2X systems, an understanding of realistic propagation channels is required, but currently, only few measurements have been published. This paper presents a description extensive measurement campaign recently conducted in urban scenario, rural on highway. We focused 4 x multiple-input multiple-output (MHVIO) at center...

Connected autonomous vehicles and industry 4.0 production scenarios require ultrareliable low-latency communication links. The varying positions of transmitter, reflecting objects, receiver cause a nonstationary time- frequency-selective fading process. In this paper, we present the necessary hardware architecture signal processing algorithms for real-time geometry-based channel emulator, that is needed testing wireless control systems. We partition process into sequence local stationarity...

The time-variant vehicle-to-vehicle radio propagation channel in the frequency band from 59.75 to 60.25 GHz has been measured an urban street city center of Vienna, Austria. We have a set 30 realizations capture effect overtaking vehicle. Our experiment was designed for characterizing large-scale fading and small-scale depending on vehicle's position. demonstrate that large vehicles boost mean receive power by up 10 dB. analysis reveals two-wave with diffuse (TWDP) model is adequate. By...

Joint time-variant channel estimation and multi-user detection are key building-blocks for wireless broadband communication mobile users at vehicular speed. We propose an iterative receiver a multi-carrier (MC) code division multiple access (CDMA) system in the uplink. Multi-user is implemented through parallel interference cancellation conditional linear minimum mean square error (MMSE) filtering. MC-CDMA based on orthogonal frequency multiplexing (OFDM), thus can be performed every...

In cyber-physical systems where sensors measure the temporal evolution of a given phenomenon interest and radio communication takes place over short distances, energy spent for source acquisition compression may be comparable with that used transmission. Additionally, in order to avoid limited lifetime issues, powered via harvesting thus collect all they need from environment. This work addresses problem allocation acquisition/compression transmission energy-harvesting sensors. At first,...

The paper provides real-word wireless measurement data of the intravehicular channel for both 3-11 GHz and 55-65 frequency bands under similar conditions. By spatially averaging impulse response realizations within a 10 × grid, we obtain power-delay profile (PDP). measured at exhibit significant differences in terms root mean square (RMS) delay spread, number resolvable clusters, variance maximal excess delay. Moreover, evaluate spatial stationarity via Pearson correlation coefficient PDP...

This paper aims to present a simple but robust model characterizing the frequency-dependent transfer function of an in-vehicle ultrawideband (UWB) channel. A large number functions spanning UWB (3–11 GHz) are recorded inside passenger compartment four-seated sedan. It is found that complex can be decomposed into two terms, first term being real-valued long-term trend characterizes frequency dependence with power law and second forming correlative discrete series may represented via...

We report results from real-world millimetre wave vehicle-to-vehicle channel measurements carried out in an urban street environment, down-town Vienna, Austria. Channel have been acquired with a time-domain sounder the frequency band 59.75-60.25 GHz resolution of approximately 5 MHz. estimate local scattering function for sequential stationarity regions time. A multitaper estimator is used to precisely define Doppler and delay resolutions. Estimates profiles are evaluated several overtaking...

In this paper a non-line-of-sight (NLOS) path-loss and fading model developed for vehicle-to-vehicle (V2V) communication at 5.9 GHz is validated with independent realistic measurement data. The reference NLOS claimed to be flexible of low complexity, incorporates specific geometric aspects in closed-form expression. We the accuracy help channel measurements performed selected street intersections city Lund Malmö, Sweden. fits well, few exceptions, measurements. Those are turn made different...

In this paper, we focus on adaptive time-variant channel estimation for vehicle-to-vehicle (V2V) communications in intelligent transportation systems (ITS) using the IEEE 802.11p physical layer. The pilot pattern is identical to that well-known 802.11a/g (WiFi) standard, which was initially designed indoor environments with little or no mobility. However, a V2V drive-by situation, impulse response rapidly changes due high relative velocity between transmitter and receiver, as well scattering...

Inside a tunnel, electromagnetic wave propagation differs strongly from the well understood "open-air" situation. The characterization of tunnel environment is crucial for deploying vehicular communication systems. In this paper we evaluate vehicle-to-vehicle (V2V) radio channel measurements inside tunnel. We estimate time-varying root mean square (rms) delay and Doppler spreads, as excess maximum dispersion. fading process in V2V communications inherently non-stationary. Hence, characterize...