Search results for "Channel models"
showing 7 items of 17 documents
A novel MIMO car-to-car channel model based on the geometrical curved street scattering model
2012
This paper introduces a novel multiple-input multiple-output (MIMO) car-to-car (C2C) channel model, which is based on a geometrical curved street scattering model. Starting from the geometrical model, a MIMO reference channel model is derived under the assumption of a combination of single- and double-bounce scattering in line-of-sight (LOS) and non-LOS (NLOS) propagation environments. The proposed channel model assumes an infinite number of scatterers, which are uniformly distributed on the outer and inner curves of the street. Expressions are presented for the three-dimensional (3D) space-time cross-correlation function (CCF), the temporal autocorrelation function (ACF), and the two-dimen…
Frequency‐Selective Channel Models
2011
Robust Adaptive Modulation and Coding (AMC) selection in LTE systems using reinforcement learning
2014
Adaptive Modulation and Coding (AMC) in LTE networks is commonly employed to improve system throughput by ensuring more reliable transmissions. Most of existing AMC methods select the modulation and coding scheme (MCS) using pre-computed mappings between MCS indexes and channel quality indicator (CQI) feedbacks that are periodically sent by the receivers. However, the effectiveness of this approach heavily depends on the assumed channel model. In addition CQI feedback delays may cause throughput losses. In this paper we design a new AMC scheme that exploits a reinforcement learning algorithm to adjust at run-time the MCS selection rules based on the knowledge of the effect of previous AMC d…
Estimation of the Velocity of a Walking Person in Non-Stationary Indoor Environments from the Received RF Signal
2018
Accurate estimation of the time-variant (TV) velocity, i.e., TV speed and TV direction of motion, of walking persons in indoor environment is of great importance in a variety of wireless indoor applications. This paper presents a novel method for estimating the velocity of a walking person in three-dimensional indoor environments, which are assumed to be equipped with a distributed 3 × 3 multiple-input multiple-output (MIMO) system. The approach estimates the TV speed, TV vertical angle-of-motion (VAOM), and TV horizontal angle-of-motion (HAOM) by fitting the spectrogram of the complex channel gain of a non-stationary indoor channel model to the spectrogram obtained from the received radio …
The effect of body shape and gender on wireless Body Area Network on-body channels
2010
Technological advancements have made possible the emergence of Body Area Networks (BANs). There are numerous on-body channel characterizations in the literature performed on a phantom or a single human subject. In this paper, using multiple subjects, we consider the effect of body shape and gender on the on-body channel. A characterization of a narrowband on-body to on-body channel among different subjects is presented. The paper investigates the relationship between the propagation and the subject's physical characteristics. The investigation is performed at 2360 MHz; the new medical band undergoing FCC approval. Our results show that the path loss in women is less than that in men and the…
Modeling of Vehicle-to-Vehicle Channels in the Presence of Moving Scatterers
2012
In this paper, we derive a vehicle-to-vehicle~(V2V) channel model assuming a typical propagation scenario in which the local scatterers move with random velocities in random directions. The complex channel gain of the proposed V2V channel model is provided. Subsequently, for different scatterer velocity distributions, the corresponding autocorrelation functions~(ACFs) are derived, illustrated, and compared with the classical ACF derived under the assumption of fixed scatterers. Furthermore, under specific conditions, highly accurate approximations for the ACFs are provided in closed form. Since the proposed V2V channel model covers several communication scenarios as special cases, including…
Influence of inelastic couplings on 32S + 24MG sub-barrier fusion
1988
Elastic, inelastic and mutual excitation angular distributions have been measured for 32S+ 24Mg at 65, 75, 56.3, 95 and 110 MeV of 32S incident energy. The data have been analysed by optical model and coupled channel calculations. Energy-dependent optical potentials have been obtained which have been used to describe the 32S + 24Mg fusion data of Berkowitz et al2). Barrier penetration and coupled channel models are compared. It is found that the energy-dependence of the empirical potentials is essential if a consistent simultaneous description of elastic, inelastic an fusion data is required.