Level-crossing rate and average duration of fades of the envelope of mobile-to-mobile fading channels in K-parallel dual-hop relay networks

This paper studies the fading behavior of narrowband mobile-to-mobile (M2M) fading channels in dual-hop distributed cooperative multi-relay systems under non-line-of-sight (NLOS) propagation conditions. M2M fading channels considered here are associated with amplify-and-forward relay networks, where K mobile relays are connected in parallel between the source mobile station and the destination mobile station. Such M2M fading channels are referred to as K-parallel dual-hop relay M2M fading channels. We study the fading behavior of these channels by analyzing the level-crossing rate (LCR) and the average duration of fades (ADF) of the received signal envelope. We derive analytical integral expressions of the aforementioned quantities along with the cumulative distribution function (CDF) of the envelope. These statistical quantities are derived assuming that the underlying stochastic processes are independent but not necessarily identically distributed. In addition, the statistical analysis pertaining to the special case of independent and identically distributed (i.i.d.) processes is also presented in this paper. The validity of the presented expressions is confirmed by simulations. Our results are very beneficial for future performance analysis of overall dual-hop distributed cooperative multi-relay systems

Statistical analysis of the capacity of mobile radio channels

Doktorgradsavhandling i informasjons- og kommunikasjonsteknologi, Universitetet i Agder, Grimstad, 201

Modeling of fading dynamics for the indoor microwave channel

This report outlines the multipath fading phenomenon and its relationship to wireless system design. The work was conducted for the academic year of 1996. This report provides the reader with an insight into the phenomenon called fading and its relevance when designing wireless systems. Fading is an important consideration when wireless systems are to be designed. Because fading is very unpredictable and it cannot to totally eliminated in a wireless system, systems engineers have a hard time trying to design and commission efficient communication systems for a particular environment. Over the years, there has been a existing need worldwide to design wireless systems which perform efficiently under fading conditions which is introduced into the propagation channel. As Wireless Local Area Networks (WLAN) and Wireless Private Branch Exchanges (WPBX) have become increasingly popular, along with a whole other range of wireless systems such as Personal Communication Systems and cellular systems, the need to provide effective and efficient systems which perform well under fading conditions and also other conditions which degrade a system, has been the utmost challenge faced by systems and communications engineers. With all this research going into designing efficient systems for communication being conducted worldwide, when the opportunity was presented by my supervisor to conduct similar research into indoor wireless systems within the microwave region. I was very excited as to the prospect of conducting research in these field of interest. This report outlines the background theory, which the reader will find most helpful and then presents the measurements conducted, and finally the results and analysis of the conducted measurements and its important relationship to wireless systems design within the ISM band of 2.4 to 2.5 GHz. This study investigates the various aspects of fading which affect a wireless channel under the introduction of controlled motion for a set measurement period. The empirical data base consists of twenty five 20 second recordings of the continuos wave envelope fading waveforms with both antennas in a stationary position. Measurements were conducted in a cluttered laboratory setting at 2.4 GHz with two quarter wave monopole antennas with transmitter and receiver separation ranging from 2 to 5 meters. Effects of controlled degrees of motion with 2 individuals walking briskly around the antennas was investigated. The report results are presented with statistical properties such a the number of crossings at a particular level, the level crossings rates and the average duration of fades being investigated on the fading envelopes of the measurements. These results and statistical analysis can be used in designing wireless computer communication applications, such as WLAN\u27s and also the results can be used to simulate wireless channels which use intelligent antenna systems to reduce fading

Statistical properties of the capacity of double Nakagami-m channels

paper presented at the 2010 5th IEEE International Symposium on Wireless Pervasive Computing (ISWPC), Modena, Italy. (c) 2010 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other users, 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 components of this work in other works. Paper also available from the publisher: http://dx.doi.org/10.1109/ISWPC.2010.5483776In this article, we have presented an extensive statistical analysis of the capacity of double1 Nakagami-m channels. The double Nakagami-m channel model has applications in keyhole channels and amplify-and-forward relay based dualhop communication systems in cooperative networks. We have derived exact analytical expressions 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 capacity of double Nakagami-m channels. Moreover, the influence of severity of fading on the statistical properties of the channel capacity has been studied. It is observed that an increase in the severity of fading in one or both links in dualhop communication systems decreases the mean channel capacity, while it results in an increase in the ADF of the channel capacity. Moreover, this effect decreases the LCR of the channel capacity at lower signal levels. The results presented in this paper also reveal that an increase in the maximum Doppler frequencies of the wireless nodes in a dualhop communication system increases the LCR of the channel capacity, while it has an opposite influence on the ADF of the channel capacity. The results presented in this article are useful for mobile communication system engineers for the design and optimization of dualhop communication systems

Mobile to mobile channel modelling for wireless communications

Wireless communication has been experiencing many recent advances in mobile to mobile (M2M) applications. M2M communication systems differ from conventional fixed to mobile systems by having both transmitter and receiver in low elevation and in motion. This raises the need to come up with new channel models and perform statistical analysis on M2M communication channels looking from a different perspective. This need motivated us to perform the research outlined in this thesis. In reviewing the literature we found that though in general the M2M channel models are sparse, a major gap exists in the non geometrical stochastic based mathematical channel models. In filling this gap, we develop a novel mathematical non geometrical stochastic multiple input multiple output (MIMO) M2M channel model for two dimensional (2D) and three dimensional (3D) scattering environments. This model is based on the underlying physics of free space wave propagation and can be used as a framework for any environment by selecting suitable complex scattering gain functions. In addition, we extend this novel model to multicarrier M2M which is the first multicarrier channel model in the non geometrical stochastic M2M category. Based on our novel M2M channel model, we carry out an extensive analysis in space-time correlation, space-frequency correlation and second order channel statistics. With the choice of suitable parameters, this analysis and channel model can be used for any wireless environment. Thus, we claim that our novel channel model together with the analysis performed in this thesis can be taken as a generalized framework. A significant contribution of our analysis is the consideration of the impact of transmitter and receiver speed to space-time and space-frequency correlation, which is not available in the literature. Using a von Mises-Fisher distribution as the angular power distribution, the usefulness of the derived temporal correlation function is discussed. The simulation results corroborate the fact that both space-time and space-frequency correlations are reduced when transmitter or receiver speed increases. The rate of reduction of space-time correlation in von Mises-Fisher distribution scattering environment is more than in the isotropic environment. Under second order channel statistics, we consider Rice, Rayleigh and Nakagami fading channels in four different non-isotropic scattering environments with angle of departure (AoD) and angle of arrival (AoA) distributions given by (i) separable Truncated Gaussian, (ii) separable von-Mises, (iii) truncated Gaussian bivariate and (iv) truncated Laplacian bivariate distributions. We show that the major second order statistics, namely, the level crossing rate (LCR) and the average fade duration (AFD), in different fading channels can be expressed in terms of known scattering coefficients of the AoD and AoA distributions. As the channel models and their respective measurements provide reliable knowledge of the channel for the design and analysis of M2M systems, the proposed channel model and the corresponding analysis will be useful for the design, testing and performance evaluation of future M2M communication systems

On the Statistical Properties of Selection Combining Cooperative Diversity over Double Rice Fading Channels

Abstract-This paper investigates the statistical properties of selection combining (SC) cooperative diversity over double Rice narrow-band fading channels under the transparent or amplifyand-forward (AF) strategy. It is assumed that the source, the destination, and relay stations are all equipped with single antenna. The Doppler power spectral density, associated with each of the double Rice fading processes, is considered to be symmetrical about the carrier frequency. Under the above conditions, analytical integral expressions are derived for the probability density function (PDF) and the cumulative distribution function (CDF) of the SC fading envelopes. Also, expressions for the level crossing rate (LCR) as well as the average duration of fades (ADF) are determined. For some cases, the integral expressions are shown to be approximated using the Laplace's method of integration. The approximations are verified to be accurate when the number of relay stations is large. The obtained results include those corresponding to the double Rayleigh and combined Rayleigh×Rice models as special cases of the double Rice fading channel. The validity of all the presented theoretical results are checked by computer simulations. Index Terms-Double Rice fading channels, selection combining (SC) cooperative diversity, probability density function (PDF), cumulative distribution function (CDF), level crossing rate (LCR), average duration of fades (ADF)

Second Order Statistics of -Fisher-Snedecor Distribution and Their Application to Burst Error Rate Analysis of Multi-Hop Communications

An advantage of using the composite fading models (CFMs) is their ability to concurrently address the impact of multi-path and shadowing phenomena on the system performance in wireless communications. A Fisher-Snedecor (FS) F CFM has been recently proposed as an experimentally verified and tractable fading model that can be efficiently applied for 5G and beyond 5G wireless communication systems. This paper provides second-order (s-order) performance analysis of the product of N independent but not identically distributed (i.n.i.d) FS F random variables (RVs). In particular, accurate and closedform approximations for level crossing rate (LCR) and average fade duration (AFD) of the product of N i.n.i.d FS F(N-FS F) RVs are successfully derived by exploiting a general property of a Laplace approximation method for evaluation of the N -folded integral-form LCR expression. Based on the obtained s-order statistical results, the burst error rate and maximum symbol rate of the N -FS F distribution are addressed and thoroughly examined. The numerical results of the considered performance measures are discussed in relation to the N-FS F multi-path and shadowing severity parameters. Moreover, the impact of the number of hops (N) of the N -FS F CFM on the s-order metrics, the burst error rate and maximum symbol rate are numerically evaluated and investigated. The derived s-order statistical results can be used to address the cooperative relay-assisted (RA) communications for vehicular systems. Monte-Carlo (M - C) simulations for the addressed statistical measures are developed in order to confirm the provided theoretical results.This work was supported in part by UC3M and the European Union's Horizon 2020 Programme under the Marie Sklodowska-Curie Grant through the CONEX-Plus Project under Agreement 801538; in part by the IRENE-EARTH Project under Grant PID2020-115323RB-C33/AEI/10.13039/501100011033; in part by ERDF and the Spanish Government Projects under Grant PID2019-106808RA-I00 AEI/FEDER, UE; in part by CDTI Cervera Project INTEGRA under Grant CER-20211031; in part by the Secretaria d'Universitats i Recerca de la Generalitat de Catalunya under Project 2017-SGR-00376 and Project Fem IoT under Grant 001-P-001662; in part by the European Commission Project CPSoSaware; and in part by the Cost Actions under Grant CA19111, Grant CA20120, and Grant CA16220.Publicad

Factors affecting the bit error rate performance of the indoor radio propagation channel for 2.3-2.5 GHz frequency band

The use of wireless in buildings based on microwave radio technology has recently become a viable alternative to the traditional wired transmission media. Because of the portable nature of radio transceivers, the need for extensive cabling of buildings with either twisted pair, coaxial, or optical fibre cable is eliminated. This is particularly desirable where high user mobility occurs and existing wiring is not in place, or buildings are heritage in nature and extensive cabling is seen as intrusive. Economic analysis bas also shown that significant labour cost savings can result by using a radio system or a hybrid mix of cable and radio for personal communication. The use of wireless systems within buildings introduces a new physical radio wave propagation medium, namely the indoor radio propagation channel. This physical medium has significantly different characteristics to some of the other forms of radio channels where elevated antennas, longer propagation path distances, and often minimally obstructed paths between transmit and receive antenna are common. Radio waves transmitted over the indoor channel at microwave frequencies behave much like light rays, they are blocked, scattered, and reflected by objects in the environment. As a direct result of this several phenomena unique to this form of physical medium become apparent, and they must be accounted for in the design and modelling of the indoor radio propagation channel transmission performance. In this thesis we analyse and characterise the indoor radio channel as a physical medium for data transmission. The research focuses on the influence of the radio physics aspects of an indoor microwave channel on the data transmission quality. We identify the associated statistical error performance for both time varying and temporally stationary indoor channels. Together with the theoretical analysis of the channel, a series of propagation measurements within buildings are completed to permit empirical validation of the theoretical predictions of how the indoor microwave channel should perform. The measurements are performed in the frequency range 2.3-2.5 GHz, which includes the 2.4-2.4835 GHz band allocated by spectrum management authorities for industrial scientific and medical radio use, (ISM band). As a direct result of our measurements, statistics related to channel noise, fading, and impulse response for the indoor microwave channel are obtained. The relationship between data transmission error statistics and the aforementioned phenomena is quantified and statistically analysed for the indoor radio channel and phase shift keyed (PSK) modulation. The results obtained from this research provide input data for the development of a simulation model of an indoor wireless mobile channel. Our measurements identify microwave ovens as a channel noise source of sufficient magnitude to corrupt data transmission in the ISM band, and an in depth analysis of the effect of noise emissions from operational microwave ovens on PSK modulation is presented in this thesis. As a result of this analysis, the estimated data error rates are calculated. Channel fading measurements provide results that will be used as the input data for the design of antennas for use on the indoor microwave channel. We also show that a data rate of eight megabits/second is possible over the typical indoor radio channel, with no requirement for adaptive delay equalisation to counter multipath signal delay spread