Search results for "Computer Science::Information Theory"
showing 10 items of 272 documents
Outage statistics for Beckmann fading channels in non-isotropic scattering environments
2015
In this paper, the outage statistics are studied for non-isotropic Beckmann fading channel model. Non-isotropic scattering generally results in an asymmetrical Doppler power spectral density (PSD). In this context, an expression for the outage probability (OP) (or equivalently the cumulative distribution function (CDF)) of the fading envelope is first derived. Then, the probability density function (PDF) of the rate of change of the fading envelope is investigated. Thereafter, an expression for the average rate of outages (ARO) (or equivalently the level-crossing rate (LCR)) is provided. Finally, by making use of the analytical results of the ARO and OP, an expression for the average durati…
A generalized method for the design of ergodic sum-of-cisoids simulators for multiple uncorrelated rayleigh fading channels
2010
In this paper, we present a new method for the design of ergodic sum-of-sinusoids (SOS) simulation models for multiple uncorrelated Rayleigh fading channels. The method, which is intended for a special class of SOS models, known as sum-of-cisoids (SOC) models, can be used to generate an arbitrary number of uncorrelated Rayleigh fading waveforms with specified Doppler power spectral characteristics. This is in contrast to the SOS simulators currently available in the open literature that have been designed under the isotropic scattering assumption, which are limited to the simulation of uncorrelated channels characterized by Clarke's U-shaped Doppler power spectral density (DPSD). The excell…
Stochastic resonance in a trapping overdamped monostable system.
2009
The response of a trapping overdamped monostable system to a harmonic perturbation is analyzed, in the context of stochastic resonance phenomenon. We consider the dynamics of a Brownian particle moving in a piecewise linear potential with a white Gaussian noise source. Based on linear-response theory and Laplace transform technique, analytical expressions of signal-to-noise ratio (SNR) and signal power amplification (SPA) are obtained. We find that the SNR is a nonmonotonic function of the noise intensity, while the SPA is monotonic. Theoretical results are compared with numerical simulations.
Design of Measurement-Based Stochastic Wideband MIMO Channel Simulators
2009
In this paper, we propose a method for designing measurement-based stochastic models for simulating wideband multiple-input multiple-output (MIMO) wireless channels. The proposed method allows synthesizing channel transfer functions with the spatial-temporal-frequency correlation properties approximating those of real-world radio channels. The parameters of a channel simulator are determined by fitting the space-timefrequency cross-correlation matrix of the simulation model to the estimated space-time-frequency cross-correlation matrix of a physical channel. For this purpose, an iterative parameter computation algorithm has been developed. The proposed design method is verified by creating …
UWB Channel Measurements for Hand-Portable Devices: A Comparative Study
2007
On-body UWB signal propagation is analyzed using two different types of UWB antennas. For the study, measurements of the frequency response by means of a VNA (vector network analyzer) are performed at 2001 discrete frequency points in the 3 to 6 GHz range. Separated measures are taken for four different transmitter positions on the head and six receiver positions on the body. Channel estimation parameters, such as mean excess delay, delay spread and path loss are obtained. Results are similar for both types of antennas regarding path loss exponent and average power delay profiles.
A simple joint estimation-detection technique for OFDM systems
2005
In this work a simple approach for the joint estimation-detection in a frequency selective severe fading environment of OFDM signals adopting PSK constellations is presented. A linear predictor of suitable order is adopted for the channel estimation in the frequency domain. The predictor coefficients are estimated on the basis of a sample estimation of the autocorrelation of the channel frequency response, aided by a preliminary differential decoding, in a blockwise manner. The detection technique proposed here is based on a simple tree search where a small number of best survivor paths are maintained at each step. Despite the simplicity of above detection approach, the simulation results s…
On the error sequences of M-ary FSK modulation schemes over Nakagami-m fading channels
2012
In this paper, we have studied some important statistical properties of error sequences of M-ary orthogonal frequency-shift keying (FSK) modulation schemes over Nakagami-m fading channels. We have derived the joint probability density function (PDF) of error sequences of arbitrary length. From the joint PDF, we have found an analytical solution for the autocorrelation function (ACF) of the error sequences. The correctness of the analytical expression for the ACF of error sequences has been confirmed by simulations, where the simulation results are obtained by using the sum-of-sinusoids principle. The derived joint PDF of error sequences is useful for the development of first-order and highe…
Rayleigh and Rice Channels
2011
This chapter contains sections titled: System Theoretical Description of Multipath Channels Formal Description of Rayleigh and Rice Channels Elementary Properties of Rayleigh and Rice Channels Statistical Properties of Rayleigh and Rice Channels Further Reading Appendix 3.A Derivation of the Jakes Power Spectral Density and the Corresponding Autocorrelation Function Appendix 3.B Derivation of the Autocorrelation Function of the Envelope Appendix 3.C Derivation of the Autocovariance Spectrum of the Envelope Under Isotropic Scattering Conditions Appendix 3.D Derivation of the Level‐Crossing Rate of Rice Processes with Different Spectral Shapes of the Underlying Gaussian Random Processes
A Trajectory-Driven 3D Non-Stationary mm-Wave MIMO Channel Model for a Single Moving Point Scatterer
2021
This paper proposes a new non-stationary three-dimensional (3D) channel model for a physical millimeter wave (mm-Wave) multiple-input multiple-output (MIMO) channel. This MIMO channel model is driven by the trajectory of a moving point scatterer, which allows us to investigate the impact of a single moving point scatterer on the propagation characteristics in an indoor environment. Starting from the time-variant (TV) channel transfer function, the temporal behavior of the proposed non-stationary channel model has been analyzed by studying the TV micro-Doppler characteristics and the TV mean Doppler shift. The proposed channel model has been validated by measurements performed in an indoor e…
"Table 6" of "A search for resonant and non-resonant Higgs boson pair production in the ${b\bar{b}\tau^+\tau^-}$ decay channel in $pp$ collisions at …
2018
Acceptance x efficiency versus resonance mass for both lephad and hadhad channels in the scalar model