In this paper, we develop a simulation model for the ego-noise of unmanned aerial vehicles (UAVs). The ego-noise is composed of spike noise and background noise. The spike noise is modelled by a finite sum of sinusoids, while the background noise is modelled by a coloured Gaussian stationary process. The main property of our model is that it only depends on physical characteristics of the UAV and it does not need real-time audio inputs to be developed. This model is very useful for training novel noise cancelling algorithms and for evaluating their performance. To validate the proposed model, we compare the statistical properties of the ego-noise simulated using our model with actual ego-noise measurements.

This paper focuses on the modeling, simulation, and experimental verification of wideband single‐input single‐output (SISO) mobile fading channels for indoor propagation environments. The indoor reference channel model is derived from a geometrical rectangle scattering model, which consists of an infinite number of scatterers. It is assumed that the scatterers are exponentially distributed over the two‐dimensional (2D) horizontal plane of a rectangular room. Analytical expressions are derived for the probability density function (PDF) of the angle of arrival (AOA), the PDF of the propagation path length, the power delay profile (PDP), and the frequency correlation function (FCF). An efficient sum‐of‐cisoids (SOC) channel simulator is derived from the nonrealizable reference model by employing the SOC principle. It is shown that the SOC channel simulator approximates closely the reference model with respect to the FCF. The SOC channel simulator enables the performance evaluation of wideband indoor wireless communication systems with reduced realization expenditure. Moreover, the rationality and usefulness of the derived indoor channel model is confirmed by various measurements at 2.4, 5, and 60 GHz.

Using some recent results on asymptotically equivalent sequences of matrices, we present in this paper, a new derivation of the capacity formula given by Brandenburg and Wyner for a discrete-time Gaussian multiple-input-multiple-output channel with memory. In this paper, we tackle not only the case considered by them, where the number of channel inputs and the number of channel outputs are the same, but also when both numbers are different.

In this paper, we present a geometrical scattering model for a typical class of industrial indoor environments. The proposed industrial reference model takes into account scattering components arising from metallic structures and the surrounding walls of the investigated environment. Starting from the geometrical scattering model, we derive the analytical expressions of the probability density function (PDF) of the angle of arrival (AoA), PDF of the time of arrival (ToA), and the autocorrelation function (ACF) in the frequency domain. The obtained results reveal a large difference between industrial channels and other home and office environments. The theoretical results of the reference model are validated by simulation results of a channel simulator designed by employing the sum-of-cisoids (SOC) principle. The proposed channel model is useful for the design and performance evaluation of wireless communication systems operating in industrial environments.

This paper deals with the design of a set of multiple uncorrelated Rayleigh fading waveforms. The Rayleigh fading waveforms are mutually uncorrelated, but each waveform is correlated in time. The waveforms are generated by using the deterministic sum-of-sinusoids (SOS) channel modeling principle. Two new closed-form solutions are presented for the computation of the model parameters. Analytical and numerical results show that the resulting deterministic SOS-based channel simulator fulfills all main requirements imposed by the reference model with given correlation properties derived under two-dimensional isotropic scattering conditions. The proposed methods are useful for the design of simulation models for diversity-combined Rayleigh fading channels, relay fading channels, frequency-selective channels, and multiple-input multiple-output (MIMO) channels.

A finite sum of complex harmonic functions, also known as a sum-of-cisoids (SOC), has been widely applied in the literature for the modeling and simulation of mobile fading channels. In this paper, we focus on the analysis of the stationarity of SOC-based mobile fading channel simulators. An SOC model depends on three kinds of parameters, namely, the gains, the frequencies, and the phases, where each of which can be a collection of random variables or constants. Hence, there exist altogether eight classes of SOC models. Each individual class will systematically be investigated with respect to its stationary properties.

This paper' deals with the modeling, analysis, and simulation of multiple-input multiple-output (MIMO) narrowband fading channels for mobile-to-mobile communications. A stochastic MIMO mobile-to-mobile reference channel model is derived from the geometrical two-ring scattering model under the assumption that both the transmitter and the receiver are surrounded by an infinite number of local scatterers. Using a wave propagation model, the complex channel gains are derived and their statistical properties are studied. General analytical solutions are provided for the three-dimensional (3-D) space-time cross-correlation function (CCF). We show that this function can be expressed as the product of two 2D space-time cross-correlation function (CFs), called the transmit and receive CF. From the non-realizable reference model, a stochastic and a deterministic simulation model are derived using a double sum of complex exponential functions. It is shown how the parameters of the simulation model can be determined for any given distribution of the angle of departure (AOD) and angle of arrival (AOA). In case of isotropic scattering, we present a closed-form solution for the parameter computation problem and illustrate some numerical results concerning the transmit CF. The proposed procedure provides an important framework for designers of future mobile-to-mobile communication systems to verify new transmission concepts employing MIMO techniques under realistic propagation conditions.

Abstract In this paper, we present a reference model for a wideband multiple‐input multiple‐output (MIMO) channel based on the geometric elliptical scattering model. The model takes into account the exact relationship between the angle of departure (AOD) and the angle of arrival (AOA). Based on this relationship, the statistical properties of the reference model are studied. Analytical solutions are presented for the three‐dimensional (3D) space‐time cross‐correlation function (CCF), the temporal autocorrelation function (ACF), the 2D space CCF, and finally the frequency correlation function (FCF). The correlation properties are studied and visualized under the assumption of isotropic as well as non‐isotropic scattering conditions. The proposed reference model can be used as a starting point for the derivation of a frequency‐selective space‐time MIMO channel simulator enabling the performance evaluation of multi‐antenna wideband communication systems. The reference model is also quite useful for studying the MIMO channel capacity under various propagation conditions imposed by the geometry of the underlying scattering model. Copyright © 2007 John Wiley & Sons, Ltd.

This paper deals with some important statistical properties of the multiple-input multiple-output (MIMO) channel capacity. We assume that all the subchannels are uncorrelated. In case of single-input multiple-output (SIMO) and multiple-input single-output (MISO) channels, exact closed-form expressions are derived for the probability density function (PDF), the cumulative distribution function (CDF), the level-crossing rate (LCR), and the average duration of fades (ADF) of the channel capacity. Furthermore, these exact closed-form expressions are extended to characterize the statistical properties of the maximum MIMO channel capacity. The correctness of the derived closed-form expressions is confirmed by simulations.

In this paper, we extend the geometrical one-ring multi-input multi-output (MIMO) channel model with respect to frequency-selectivity. Our approach enables the design of efficient and accurate simulation models for wideband space-time MIMO channels under isotropic scattering conditions. Two methods will be provided to compute the parameters of the simulation model. Especially, the space, time, and frequency correlation properties of the proposed wideband space-time MIMO channel simulator are studied analytically. It is shown that any given discrete or continuous power delay profile (PDP) can be incorporated in the simulation model. The high accuracy of the simulation model is demonstrated by comparing its statistical properties with those of the underlying reference model. Our procedure provides an important framework for developers of future wideband mobile communication systems to test and to verify new high data rate transmission concepts employing, e.g., space-time coded MIMO orthogonal frequency division multiplexing (OFDM) techniques.

This paper deals with the design of a set of multiple uncorrelated Rayleigh fading waveforms. The Rayleigh fading waveforms are mutually uncorrelated, but each waveform is correlated in time. The waveforms are generated by using the sum-of-sinusoids principle. Two new closed-form solutions are presented for the computation of the model parameters. Analytical and numerical results show that the resulting sum-of-sinusoids-based channel simulator fulfills all main requirements imposed by the reference model with given correlation properties derived under two-dimensional isotropic scattering conditions. The proposed methods are useful for the design of simulation models for diversity-combined Rayleigh fading channels, frequency-selective channels, and multiple-input multiple-output (MIMO) channels.

We demonstrate super-orthogonal space-time (ST) trellis codes with rectangular signal constellations for wireless communications with a spectral efficiency of 4 bits/s/Hz. Considering a mobile wireless communications system with two transmit antennas, we form a 4D signal constellation as Cartesian product of two 2D rectangular signal sets, a 4D point being transmitted by the first antenna as two concatenated 2D points in two consecutive channel uses. The 2D symbols transmitted by the second antenna are not independent, but so chosen as to form, together with the symbols transmitted by the first antenna, the entries of a 2 times 2 orthogonal matrix. This can be done in four different ways, resulting in four sets of 2 times 2 orthogonal matrices. To obtain a higher data rate, the union of two of them forms a super-orthogonal signal set. With 2 times 2 orthogonal matrices, we then label the state transitions of a trellis diagram describing the operation of the encoder. We perform simulations using a model that takes into account the Doppler effect as well as the effect of spatial antenna correlation at both the base station (BS) and at the mobile station (MS). The frame error rate (FER) and the bit error rate (BER) performance results show an excellent behaviour of our proposed super-orthogonal ST trellis code, which clearly outperforms all known simple ST trellis codes of same spectral efficiency using 16QAM or 16PSK

In this paper, we propose a multiple-input multiple-output (MIMO) mobile-to-mobile channel simulation model derived from a non-realizable reference model presented in Part I of our paper. The underlying reference model is based on the geometrical two-ring scattering model, where both the transmitter and the receiver are moving. A closed-form solution is provided for the three dimensional (3-D) space-time cross-correlation function (CCF) of the simulation model. An important result is that this CCF is ergodic. Also, our results show that this 3-D function can be expressed as a product of two 2-D space-time CCF, called the transmit and the receive CCE. It is shown that the parameters of the simulation model can be determined for any given space-time CCF describing the reference model. In case of isotropic scattering, we present a closed-form solution of the model parameters and illustrate some numerical results for the transmit and receive CCF. Finally, simulation results show an excellent correspondence between the statistical and time average of the MIMO channel capacity. This supports the hypothesis that the MIMO capacity is ergodic with respect to the mean.

In this paper, we propose a muiltiple-input multiple-output (MIMO) channel model for mobile-to-mobile commmunications. This so-called MIMO mobile-to-mobile channel model is derived from the geometrical two-ring scattering model under the assumption that both the transmitter and the receiver are moving. In Part I of our paper. we focus on the reference model. which is based on the assumption that the transmitter and the receiver are surrounded by an infinite number of local scatterers. From a wave model, the complex channel gains are derived and their statistical properties are studied. General analytical solutions are provided for the three-dimenisional (3-D) space-time cross-correlation function (CCF). We show that this 3-D function cani be expressed as the product of two 2-D space-time CCFs, which are introduced as the transmit arid receive CCF. Especially for the latter CCFs, closed-form expressions and numerical results are presented in case of isotropic scattering. The procedure presented in our paper provides an important framework for designers of future mobile-to-mobile communication systems to verify new transmission concepts under certain propagation conditions.

Simulation results for the capacity of multiple-input multiple-output (MIMO) mobile radio channels are presented in this paper. Our MIMO channel simulation model is based on the so-called one-ring scattering model with two antennas at both the base station (BS) and the mobile station (MS) side. For the capacity study, we have investigated the influence of various model parameters, such as the angle spread at the MS, the mean angle of arrival (AOA), and the orientation of the antenna elements. The Doppler effect is also taken into account. Nonisotropic scattering around the MS is modelled by the von Mises distribution. The presented simulation results show an excellent correspondence between the statistical and the time average of the capacity. Furthermore, it turned out that a large distance between the antenna elements is not a guarantee for high capacity. Simulation results are also provided for the level crossing rate (LCR) and the average duration of fades (ADF) of the MIMO channel capacity.

Abstract This paper introduces a general concept for the design of efficient multi‐input multi‐output (MIMO) narrowband fading channel simulators. The proposed procedure is applied on a reference model for the geometrical one‐ring scattering model consisting of an infinite number of local scatterers laying on a ring around the mobile station (MS). The statistical properties of both the reference model and the simulation model are studied. Closed‐form solutions are presented, for example for the space‐time cross‐correlation function (CCF), the time autocorrelation function (ACF) and the two‐dimensional (2‐D) space CCF. It will be shown, how the parameters of the MIMO channel simulator can be determined for any given space‐time CCF describing the reference model. The excellent performance of the proposed space‐time channel simulator is demonstrated by comparing its temporal and spatial correlation properties with those of the reference model. Moreover, it is demonstrated how the channel simulator can be used to analyze the statistics of the capacity of MIMO channels from time‐domain simulations. Copyright © 2004 John Wiley & Sons, Ltd.