Optimal Sampling Period and Required Number of Samples for OSTBC-MIMO Rayleigh Fading Channel Capacity Simulators

The purpose of this paper is to contribute to the performance assessment of channel capacity simulators. Here, we consider the instantaneous capacity (also referred to as the mutual information) in orthogonal space-time block code (OSTBC) transceiver systems over multiple-input multiple-output (MIMO) Rayleigh fading channels. To ensure that the level-crossing rate (LCR) of the instantaneous capacity can efficiently and accurately be simulated, we derive closed-form approximate solutions to the optimal sampling period and the required number of samples to be generated. Several numerical examples will be presented to illustrate the usefulness of our procedure. It will also be shown that the d…

A Trajectory-Driven SIMO mm-Wave Channel Model for a Moving Point Scatterer

In this paper, we propose a trajectory-based three-dimensional (3D) non-stationary channel model for a millimeter wave (mm-Wave) single-input multiple-output (SIMO) system. The proposed channel model is designed to capture the mobility of a moving point scatterer in an indoor environment. We derive the expression of the time-variant (TV) channel transfer function (CTF). We study the TV Doppler characteristics of the channel, such as the TV Doppler power spectrum and the TV mean Doppler shift. To validate the proposed channel model, we performed a measurement campaign in an indoor environment using a software defined radar operating at 24 GHz. As a moving object, we consider a single swingin…

The Transfer Function of Non-Stationary Indoor Channels and its Relationship to System Functions of LFMCW Radars

This paper studies the relationship between the time-variant (TV) channel transfer function (CTF) of non-stationary indoor channels and the system functions of linear frequency modulated continuous waves (LFMCW) radars. To do so, we consider a moving person/object in indoor environments, which is modelled by a cluster of moving point scatterers. It is shown that the TVCTF can be obtained from the beat signal of LFMCW radar systems. Analytical expressions are derived for the TV demodulated radar response, the complex channel gain, and the TV Doppler-delay profile. A relationship between the presented results and existing non-stationary indoor channel models assuming pulsed wave systems is al…

Estimation of the Velocity of a Walking Person in Non-Stationary Indoor Environments from the Received RF Signal

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 …

Performance Analysis of M-DPSK Modulation over Fast-Hoyt Fading Channels under Non-Isotropic Scattering Conditions

In this paper, we analyze the symbol error probability (SEP) performance of M-ary differential phase shift keying (M-DPSK) modulation schemes over frequency-flat fast-varying Hoyt multipath fading channels. Assuming general non-isotropic scattering conditions, we first derive a finite-range integral expression for the probability density function (PDF) of the phase difference between two non-isotropic Hoyt vectors perturbed by additive white Gaussian noise (AWGN). Based upon the theory of M-DPSK modulation and the obtained PDF formula, the SEP of M-DPSK and its corresponding asymptotic behavior in non-isotropic fast-Hoyt fading channels are derived. Specifically, a double semi-finite range …

A Trajectory-Driven 3D Non-Stationary mm-Wave MIMO Channel Model for a Single Moving Point Scatterer

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…

Estimation of the Time-Variant Velocity of a Single Walking Person in Two-Dimensional Non-Stationary Indoor Environments Using Radio-Frequency Techniques

Accurate estimation of the time-variant (TV) velocity of moving persons/objects in indoor spaces is of crucial importance for numerous wireless indoor applications. This article introduces a novel iterative procedure to estimate the TV velocity, i.e., TV speed and TV angle-of-motion (AOM), of a single moving person in 2D indoor environments by using radio-frequency (RF) techniques. The indoor area is equipped with a distributed 2 × 2 multiple-input multiple-output (MIMO) system. The proposed method is divided into two parts. In the first part, we estimate the path gains and the instantaneous Doppler frequencies by fitting the exact spectrograms of the complex channel gains of a 2D no…

A Geometry-Based Underwater Acoustic Channel Model Allowing for Sloped Ocean Bottom Conditions

This paper proposes a new geometry-based channel model for shallow-water ocean environments, in which the ocean bottom can slope gently down/up. The need for developing such an underwater acoustic (UWA) channel model is driven by the fact that the standard assumption of a flat ocean bottom does not hold in many realistic scenarios. Starting from a geometrical model, we develop a stochastic channel model for wideband single-input single-output vehicle-to-vehicle UWA channels using the ray theory assuming smooth ocean surface and bottom. We investigate the effect of the ocean-bottom slope angle on the distribution of the channel envelope, instantaneous channel capacity, temporal autocorrelati…

A New Iterative Procedure for the Localization of a Moving Object/Person in Indoor Areas from Received RF Signals

This paper presents a new iterative estimation method to localize a single moving object or person in non-stationary 3-dimensional (3D) indoor environments from received radiofrequency (RF) signals. The moving object/person is modelled by a moving single point scatterer. The indoor space is equipped with a multiple-input multiple-output (MIMO) communication system. This work starts by introducing a new geometrical channel model which considers the effects of the line-of-sight (LOS) component, the fixed objects located in a room, and the moving object (point scatterer). Then, we present an iterative estimation technique for computing the time-variant (TV) coordinates of the moving scatterer.…

Estimation of the Velocity of a Walking Person in Indoor Environments from mmWave Signals

The present work is motivated by the growing interest in using millimeter-wave (mmWave) bands in future wireless indoor communications. For a variety of wireless indoor applications, such as remote medical care, healthcare services, and human-machine interaction, it is of crucial importance to estimate the velocity of walking persons in indoor environments with high precision. In this paper, we present a novel procedure for estimating the velocity of a walking person in indoor environments by using mmWave signals. The indoor environment is considered to be equipped with a distributed $2\times 2$ multiple-input multiple-output (MIMO) system operating in the 60 GHz band. The proposed approach…

An RF-Based Positioning Method for Tracing a Cluster of Moving Scatterers in Non-Stationary Indoor Environments

Author's accepted manuscript © 2021 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works. This letter presents a novel iterative positioning method for tracing the body segments of a person moving indoors using radio-frequency (RF) signals. The indoor space is equipped with a multiple-input multiple-output (MIMO) communication system. The person is modelled by a cluster of …

A non-stationary relay-based 3D MIMO channel model with time-variant path gains for human activity recognition in indoor environments

AbstractExtensive research showed that the physiological response of human tissue to exposure to low-frequency electromagnetic fields is the induction of an electric current in the body segments. As a result, each segment of the human body behaves as a relay, which retransmits the radio-frequency (RF) signal. To investigate the impact of this phenomenon on the Doppler characteristics of the received RF signal, we introduce a new three-dimensional (3D) non-stationary channel model to describe the propagation phenomenon taking place in an indoor environment. Here, the indoor space is equipped with a multiple-input multiple-output (MIMO) system. A single person is moving in the indoor space an…

On the Statistical Properties of Capacity Outage Intervals in OSTBC-MIMO Rayleigh Fading Channels

This paper deals mainly with the study of the asymptotic probability density functions (PDFs) of the outage durations of the instantaneous capacity of orthogonal space-time block code (OSTBC) multiple-input multiple-output (MIMO) systems over Rayleigh channels. Drawing upon known statistical properties for the asymptotic behavior of chi-squared processes at low levels, we provide approximate solutions for the PDF, the cumulative distribution function (CDF), and the $k$ th-order moments of the outage intervals of the underlying capacity processes. Then, as an application of the derived PDF, the performance assessment of capacity simulators is reported. Following this, we introduce the newly …

A study on the distribution of the envelope and the capacity of underwater acoustic channels

This paper deals with the statistical analysis of the instantaneous capacity of shallow underwater acoustic communication (UWAC) channels under the assumption that the scatterers are randomly distributed on the surface and bottom of the ocean. We start by deriving exact closed-form expressions for the probability density function (PDF) of the total propagation path length from which the PDF of the path gains is obtained. Then, we study the distributions of the channel envelope and the capacity under line-of-sight (LOS) conditions. By performing the chi-square goodness-of-fit test, it is shown that the channel envelope is Rice distributed. Moreover, we investigate the effect of the ocean dep…

A New Iterative Estimation Procedure for the Localization of Passive Stationary Objects from Received RF Signals in Indoor Environments

This paper deals with the localization of passive stationary objects from the received radio- frequency (RF) signals in 3-dimensional (3D) indoor environments. Each object located in the 3D indoor environment is modelled by a single point scatterer. The propagation space is equipped with a multiple-input multiple-output (MIMO) wireless communication system. The employed channel model is flexible and allows to have a line-of-sight (LOS) component as well as single- and double- bounce scattering components. Here, we present a new accurate iterative estimation technique for computing the optimal coordinates as well as the number of the main stationary objects (scatterers) in indoor areas. The …

An asymptotic approximate solution to the distribution of the capacity outage intervals in OSTBC-MIMO Rayleigh fading channels

This paper deals with the study of asymptotic probability density functions (PDFs) of the outage durations of the instantaneous capacity (also referred to as the mutual information) in orthogonal space-time block code (OSTBC) transceiver systems over multiple-input multiple-output (MIMO) Rayleigh fading channels. The Rayleigh fading subchannels are assumed to be frequency-nonselective and mutually uncorrelated, whereas the associated Doppler power spectral density is supposed to be symmetric about the origin. In addition, the channel state information (CSI) is considered to be available only at the receiver side. Taking these assumptions into account, and drawing upon known statistical prop…

On the Estimation of the Radial Distance of a Moving Person in Indoor Environments from the Demodulated Response of LFMCW Radars

Estimation of the Velocity of Multiple Moving Persons in Non-Stationary Indoor Environments from Received RF Signals

This paper presents a new accurate iterative procedure to estimate the time-variant (TV) velocity, i.e., TV speed, TV vertical angle-of- motion (VAOM), and TV horizontal angle-of-motion (HAOM), of multiple moving objects/persons in three-dimensional (3D) non-stationary indoor propagation environments. The indoor space is assumed to be equipped with a distributed 3x3 multiple-input multiple-output (MIMO) system. The proposed procedure focuses on estimating the TV speed, TV VAOM, and TV HAOM by matching the spectrogram of the complex channel gain of a non- stationary indoor channel model to the spectrogram obtained from received radio frequency (RF) signals. Together with the velocity …

A Trajectory-Driven SISO mm-Wave Channel Model for a Human Activity Recognition

Statistical Analysis of the Channel Capacity Outage Intervals in Massive MIMO Systems with OSTBC over Rayleigh Fading Channels

This paper studies approximate solutions for the statistical properties of the outage intervals of the instantaneous capacity in massive multiple- input multiple- output (MIMO) sys- tems with orthogonal space-time block code (OSTBC) over Rayleigh fading channels. We take advantage from the fact that the probability density function (PDF) of the channel power gain can be approximated by a left-truncated Gaussian distribution if the number of transmit and receive antennas is large. Assuming a symmetrical Doppler power spectral density (PSD), a closed- form expression is presented for the Rice probability function of the outage durations. This function, in general, approximates the PDF of the …

On the statistical properties of the capacity of sparse multipath fading channels

Most existing works in wireless communications assume rich scattering. However, there is growing experimental evidence that physical wireless channels can exhibit a sparse structure. By assuming an asymmetric Doppler power spectral density (PSD), we can model and simulate sparse channels by using a finite sum of weighted complex harmonic functions, also called sum of cisoids (SOC). In this paper, we focus on the analysis of the statistical properties of the instantaneous capacity of sparse SOC-based multipath fading channels under line-of-sight (LOS) conditions. The probability density function (PDF), the cumulative distribution function (CDF), the level-crossing rate (LCR), and the average…