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Study of Broadband Wireless Communication in Urban Environment

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Thesis-Portsmouth Uni

  1. 1. M582 MASTER THESIS Study of Broadband Wireless Communication in Urban Environment Submitted By: Saif Al-Shoker Supervised By: Manish Malik (M.Sc)
  2. 2. Study Broadband Wireless Communication in Urban Environment University of Portsmouth Portsmouth/United Kingdom Master ThesisStudy of Broadband Wireless Communication in Urban Environment Submitted By SAIF AL-SHOKER Supervised by MANISH MALIK (M.Sc) June 2012 In partial fulfillment of the requirements For the degree of Master of Science Page | 2
  3. 3. Study Broadband Wireless Communication in Urban Environment Page | 3
  4. 4. Study Broadband Wireless Communication in Urban EnvironmentList of ContentsList of Contents 4List of Figures and Tables 6Acknowledgements 7Chapter One - Introduction 91.1 Introduction 91.2 Project scope 101.3 Aim of mobile systems 101.4 Introduction to Cellular Communications 11 1.4.1 Cellular network architecture: 11 1.4.2 Cellular concept: 12 1.4.3 Time line of modern wireless cellular systems: 14Background Research and Related Work 151.5 Free space propagation model: 151.6 Radio wave propagation mechanisms: 151.7 Reflection: 16 1.7.1 Reflection from dielectrics: 16 1.7.2 Reflection from perfect conductors: 181.8 Path Loss Model: 181.9 Fresnel zone and Huygen’s Principle: 191.10 Cellular Coverage area: 201.11 Outdoor Propagation Models: 22 1.11.1 Ray Tracing: 23 1.11.2 Two – Ray Model: 23 1.11.3 Okumura Model: 24 1.11.4 Hata Model: 26 1.11.5 Lee Model: 281.12 Multipath and fading in radio channels: 29 1.12.1 Doppler shift: 29 1.12.2 Influence of mobile unit velocity on data transfer and impulse response: 30 1.12.3 Power delay profile: 32 Page | 4
  5. 5. Study Broadband Wireless Communication in Urban Environment 1.12.4 Evaluation of transmission performance of mobile communication systems in urban environments: 33 1.12.5 Microwave propagation characteristics in the presence of vehicles and pedestrians: 36 1.12.6 Ray tracing 37Chapter Two - Methodology 412.1 Introduction 412.2 Simulation overview 422.3 Environmental classification and test route 422.4 Measurement Scenario 432.5 Structure Characteristics: 44 2.5.1 Dependency on distance 45 2.5.2 Dependency on the Variability of terrain elevation 45 2.5.3 Dependency on the closest surrounding buildings height with respect to the mobile receiver. Error! Bookmark not defined.Chapter Three - Simulation 493.1 Simulation of models 493.2 Path loss in low-rise environment 503.3 Comparison of simulation results with cost COST 231 Walfish-Ikegami Model 574.1 Analysis of simulation outcomes 614.2 conclusion 61works cited Error! Bookmark not defined.Appendices 65 Page | 5
  6. 6. Study Broadband Wireless Communication in Urban EnvironmentList of Figures and TablesChapter One1 Figure (1.1) Basic cellular network [4]. ............................................................................ 112 Figure (1.2) Illustration of common used cellular reuse clusters [6] ............................ 133 Figure (1.3) Illustration of cellular frequency reuse concept [5]. ............................... 134 Figure (1.4) Geometry for the calculation of the reflection coefficients betweentwo dielectrics [5]. ................................................................................................................. 175 Figure (1.5) shape of constant received power [4]...................................................... 216 Figure (1.6) Path loss, shadowing and multipath against distance [4]. .................... 227 Figure (1.7) two ray Model [4].......................................................................................... 248 Figure (1.8), shows motion of the car and the direction of arrival of the wave ........ 309 Figure (1.9) shows the total amount of data being transferred at velocity shown intable (1), calculated without overhead packets [10]. .................................................... 3110 Figure (1.10) ....................................................................................................................... 3411 Figure (1.11) ...................................................................................................................... 3512 Figure (1.12) shows the path-loss characteristics during daytime [12] ..................... 3613 Figure (1.13) shows the path-loss characteristics during midnight [12] ................... 3714 Figure (1.14) shows a distribution of buildings, vehicles and trees in an urbanenvironment [14] ................................................................................................................... 3815 Figure (1.15) ...................................................................................................................... 39Chapter Two16 Figure (2.1) Staircase zigzag (transverse + lateral) and LOS test routes relative tothe street grid ......................................................................................................................... 4317 Figure (2.2) Model considering homogeneous height and terrain variation ......... 4618 Figure (2.3) Main rays considered by COS231 model ..Error! Bookmark not defined. Page | 6
  7. 7. Study Broadband Wireless Communication in Urban EnvironmentAcknowledgementsThroughout this thesis, I learned patience and dedication. Now I really knowmyself, and I know my voice. First and foremost, I would like to express mygratitude to the two most caring and loving parents in the world, my preciousfather Faris Al-Shoker and my mother Aayad for their love, affection andsupport. I thank you both for giving me strength and courage to chase mydreams and to become the man I am today. My sister, my two brothersdeserve my wholehearted thanks as well.I would like to sincerely thank my supervisor Mr. Manish Malik for sharing withme his experience and patience. His comments and questions were veryinvaluable for completing this thesis.Finally, I would like to leave the remaining space to thank everyone aroundme, my friends and work colleagues, who supported me all the way throughwriting this thesis. Page | 7
  8. 8. Study Broadband Wireless Communication in Urban EnvironmentCHAPTER 1Introduction Page | 8
  9. 9. Study Broadband Wireless Communication in Urban EnvironmentChapter One - Introduction1.1 IntroductionThe cellular mobile communications system has grown rapidly as the usage ofmobile services and its applications is increasing, co-channel and adjacentinterference are becoming more significant, many efforts are underway andbecome a challenge of many engineers and researchers to develop newmethods, undertake new experiments to find the best way possible to fit inmore users efficiently [1]. “The multipath fading experienced by the signal inurban environments results in an irreducible error rate due to the interferencecaused by the overlapping of time delayed replicas” [1], as well as differentantennas height and antennas with different down tilting and high gainantennas play an important role for microcellular applications. [2] Thecharacterization of the urban microcellular channel has been the mainworking area of many researchers, radio cellular systems need to be assessedand evaluated according to the environment of working area, the selectionof multipath propagation parameters needed for the design andimplementation of such systems, is determined according to statistical modelor results of actual implementation [3]. Page | 9
  10. 10. Study Broadband Wireless Communication in Urban Environment1.2 Project scopeThe main objectives of this project are as follows: To undertake a literature review of research conducted illustrating the impact of radio communication channels on different urban environment areas and to find a mathematical formulation for modeling these types of communication channels. Propose a method to predict the effect of vehicular and pedestrian traffic on the characteristics of path loss and delay spread. To develop a simulation tool to predict those channels and compare it with available data analysis.1.3 Aim of mobile systems To provide good outdoor coverage in different urban areas. To provide indoor coverage area inside buildings, parks, tunnels and etc... Capacity is needed to accommodate more users. Insure a high quality of service. No dropped and blocking calls during high speed mobility (e.g., when driving a car at high speed). Need of higher data rates for customer satisfaction. Page | 10
  11. 11. Study Broadband Wireless Communication in Urban Environment1.4 Introduction to Cellular Communications 1.4.1 Cellular network architecture: Cellular systems are extremely important worldwide, two-way and data communication are carried out by cellular phones; this concept was initially designed to communicate with mobile terminals in vehicles. After the evolution of these systems, they become more sophisticated to support lightweight devices known as (cellular phones) which can operate inside buildings and outside, in open areas and urban environments, at different speeds [4], the figure (1.1) shows a basic cellular network: Base station Internet Mobile Telephone Switching Office Public Switched Telephone Network Cellular phone Figure (1.1) Basic cellular network [4] Page | 11
  12. 12. Study Broadband Wireless Communication in Urban Environment1.4.2 Cellular concept:In the past, the idea of telephone mobile system infrastructure wasdesigned like television broadcasting by providing a high antennatransmitter covering a wide area surrounding the antenna, but this ideahad limitations in terms of user capacity and spectral congestion [4].The cellular concept was introduced to overcome this major problem byreplacing the high power antenna transmitter with many low powertransmitters (cells), each cell is required to cover a small area andassigned a small portion of the total channels, neighboring cells, will beassigned different groups of channels to keep the interference as low aspossible between cells and mobile users and by systematically spacingcells and their channel groups. This concept was a huge turn since itenables the reuse of the same channels by different cells distributed by acertain minimum distance to avoid co channel interference betweenthem as shown in figure 1.2, each letter which represents a cell is assigneda different group of channels and in figure 1.3, cells with the same letteruse the same group of frequency and in this way, will cover more areaand increases capacity usage [5]. Page | 12
  13. 13. Study Broadband Wireless Communication in Urban Environment G A F B A D AC B E C B C D3-Cell 4-Cell 7-CellFigure (1.2) Illustration of common used cellular reuse clusters [6] Figure (1.3) Illustration of cellular frequency reuse concept [5] Page | 13
  14. 14. Study Broadband Wireless Communication in Urban Environment1.4.3 Time line of modern wireless cellular systems: First Generation Cellular SystemsIn early 1980s The world witnessed the deployment of first mobile radiosystems, in fact many countries launched first generation cellular systemsafter the world allocation Radio Conference (WARC) Signed the approvalof frequency allocations for cellular telephones operating in the 800/900MHz, starting a new era of cellular systems, based on Frequency divisionmultiple access (FDMA) [6]. Second Generation Cellular SystemsAfter launching the first generation cellular systems, many efforts weremade by researchers and engineers to convert all speech into digitalcode and in fact, it came into existence by launching the world’s firstdigital cellular system (GSM) in late 1992, with higher signal quality.Many versions of GSM were deployed later on to operate on higherfrequency bands and introducing new features like messaging, voice mailand caller ID [6]. Third Generation Cellular SystemsCompared to first and second generation, third generation cellularsystems was a turning point in cellular systems history. Internet access, Callsusing VoIP over Internet protocol, unparalleled network capacity,downloading data, starting web sessions are some of the new featuresthat 3G offers in a single cellular phone [5]. Page | 14
  15. 15. Study Broadband Wireless Communication in Urban EnvironmentBackground Research and Related Work1.5 Free space propagation model:It can be defined as radio signals propagate in the medium from atransmitter antenna to the receiver antenna without the presence ofinterfering terrain and atmospheric anomalies along their path ofpropagation [7], a good example of this is the propagation occurred inspace.The free space loss can be predicted from the well-known equation (1): (1)(Where is in km and f is in MHz) [7].1.6 Radio wave propagation mechanisms:Radio signals as they propagate in medium, through space usually don’texperience any reflection, diffraction or scattering but when it comes toradio signals propagating in urban environments, where there is no line ofsight [5], then they can be attributed to the basic propagation mechanismswhich effect the signal characteristics of the wave, generally speaking canbe defined as follows:A. Absorption. Can be defined as the decrease in the power level of a radio wave caused by partial conversion of the energy in radio wave to matter in the propagation [8]. Page | 15
  16. 16. Study Broadband Wireless Communication in Urban EnvironmentB. Scattering. Is the process in which a wave is diffused by collisions with particles they exist in the medium as the wave goes through it [8].C. Refraction. Is the process in which electromagnetic waves, are deflected when the waves go through a substance. The wave generally changes direction due to the variations in the refractive index of the medium [8].1.7 Reflection:It occurs when the radio wave travels from one medium to another mediumdifferent in electrical properties and reflection causes changes in thedirection, magnitude, phase and polarization of the incident wave,depending on the reflection coefficient [5]: 1.7.1 Reflection from dielectrics: When an electromagnetic wave is incident to a perfect dielectric at an angle it causes the energy to be partially reflected to the original media and partially refracted into the second media at an angle and the value of reflection coefficient varies depending on either the e plane or h plane is parallel to the reflecting plane. The figure below (1.4), illustrates the electromagnetic waves as it propagates between two dielectrics media with subscripts i, r, t refer to the incident, reflected and transmitted fields, respectively [5]. Page | 16
  17. 17. Study Broadband Wireless Communication in Urban Environment (a). E- field in the plane of incident [5] (b). E- Field normal to the plane of incident [5] Figure (1.4) Geometry for the calculation of the reflection coefficients between two dielectrics [5]The reflection coefficients for the previous two cases at the boundary oftwo dielectrics are given by the equations (2) and (3) [5]: (2) E- Field in the plane of incident. (3) E- Field normal to the plane of incident. Page | 17
  18. 18. Study Broadband Wireless Communication in Urban Environment Is the intrinsic impedance of the Th medium [5]. 1.7.2 Reflection from perfect conductors: When it comes to reflection by a perfect conductor the electromagnetic waves cannot pass through it and the electromagnetic waves will completely and the incident and reflected waves by a perfect conductor must be equal in magnitude and it can be summarized as follows [5]: (4) (5) (6)1.8 Path Loss Model:Most of the prediction models depend on the following path loss equations(7) and (8) [2]:P = (7) = (8)Where:PL is the path loss. is the path loss exponent. Page | 18
  19. 19. Study Broadband Wireless Communication in Urban Environment is the wavelength. are the receiver and transmitter gains, respectively [2]. Is the shortest distance at which free space propagation ceases todominate [2].These models assume that the gain of base station antenna is uniformthroughout the coverage area, which is not the case with high gain antennas[2].1.9 Fresnel zone and Huygen’s Principle:When it comes to conditions under free space propagation, Fresnel zonescan be applied to describe propagation path loss. The wavefront can bedivided into a series of concentric rings, known as Fresnel zones [2], and aremostly used for suburban and open areas, as the first Fresnel zone indicatesthe domination of a direct path [2], on the other hand, huygen’s principleexplains the phenomenon of diffraction, Huygens showed that propagationoccurs along a wave front, with Each point on the wavefront acting as asource of a secondary wavefront known as a wavelet, with a new wavefrontbeing created from the combination of the contributions of all the waveletson the Preceding front. Importantly, secondary wavelets radiate in alldirections. However, they radiate strongest in the direction of the wave frontpropagation and diffraction occurs when these secondary waveletspropagate into shadowed region around the obstacle [5].Some facts about using high and low antenna heights in microcellularsystems and can be summarized as follows: Page | 19
  20. 20. Study Broadband Wireless Communication in Urban Environment Increasing antenna height will reduce diffraction path loss and this will be less significant as the distance increases between the transmitter (base station) and receiver [2]. Down tilting and high sites cannot be used effectively without each other [2]. Reduction in system interference can be reached by using high antennas and down tilting, as they can discriminate the boundaries of an intended coverage area [2]. Path loss can be reduced by using high antennas, consequently reduces attenuation [2].1.10 Cellular Coverage area:In urban environments, buildings and blockage of mobiles are the mainobstacles of radio propagation, shadowing caused by these blockages willeffect some locations within the boundaries of the cell (base station) as it isdesigned to cover an area where the minimum received power bythe mobiles should be above SNR for acceptable performance,consequently, some locations within the cell will have received power below and other locations will have above , depending on the effect ofshadowing in these locations [4].All users within the boundaries of a base station cannot receive the samepower level as obstacles by either buildings or being inside a tunnel will causethe received signal to be below the minimum acceptable received power,even though it is enough close to the base station [4]. Page | 20
  21. 21. Study Broadband Wireless Communication in Urban Environment Figure (1.5) shape of constant received power [4]For a combined path loss and shadowing the ratio received to thetransmitted power in dB is given by the equation (9) [4]: (9) is Gauss-distributed random variable with a mean zero, the figure (1.6)below shows that the decreasing in path loss is relatively linear to witha slope of dB/ decade and is the path loss and when it comes toshadowing, the change is more rapid [4]. Page | 21
  22. 22. Study Broadband Wireless Communication in Urban Environment Figure (1.6) Path loss, shadowing and multipath against distance [4]For the combined path-loss and shadowing, the outage probability becomesas in the equation (10) [4]. – (10)And this is the probability of the received power at a given distance to gounder the minimum received power due to path loss and shadowing and itplays a significant role in wireless system design [4].1.11 Outdoor Propagation Models:Estimating the path loss of radio propagation in urban environments varies inaccordance with the terrain profile, the presence of trees, buildings, movableobstacles, cars and other objects have a great impact on radiopropagation, some models have been developed to estimate the path loss Page | 22
  23. 23. Study Broadband Wireless Communication in Urban Environmentand signal strength over different areas, some of them are illustrated below[5]: 1.11.1 Ray Tracing: Radio signals in urban or indoor environments will normally experience reflection, diffraction or scattering and this known to be as multipath signal and it affects the power, delay in time, shift in phase and/ or frequency, this eventually causes distortion in the received signal relative to the transmitted signal [4]. This type of propagation model is retained to be suitable in rural areas, along city streets when the height of the transmitter and receiver is low and close to the ground and in indoor environments, when compared to other empirical models [4]. 1.11.2 Two – Ray Model: Consider a receiver (at a height of ) at a distance d1 from the transmitting antenna (at a height of ) then it can be assumed that the received signal is composed of a direct path (d1) and a reflected path (d2) usually from the ground and this model is useful especially in radio communications of a distance of few kilometers between tall towers and received mobile stations, the figure (1.7) shows a basic two ray model and the equation (11) [5]: Page | 23
  24. 24. Study Broadband Wireless Communication in Urban Environment d Figure (1.7) two ray Model [4] = - (11)And when d is large with respect to , then Taylor approximation canbe applied as in the equation (12) [4]. (12)Finally, the estimated received signal in dB is given by the equation (13)[4]: (13)1.11.3 Okumura Model:It’s a widely used empirical model for signal prediction from 150 MHZ to1920 MHZ in urban areas, this type of model is applicable for distancesranging from (1 km to 100 km) [5]. Page | 24
  25. 25. Study Broadband Wireless Communication in Urban EnvironmentThis model was developed by Okumura who created a set of curvesgiving median attenuation relative to free space over an irregular terrain,between a base station and a mobile antenna, the formula of Okumuraat a distance d can be expressed as in the equation (14) [4]: =( (14)Where: is free space path loss at distance d, is the carrier frequency, is the median attenuation plus the free space path loss in allenvironments, is the height gain factor of the base station, is the hight gain factor of the mobile antenna, is the gain due to the type of environment,Some formulas were derived by Okumura for G( ) and G( ) as in thefollowing equation(15) [4]:G ( ) = 20 , 30 m 1000 m; Page | 25
  26. 26. Study Broadband Wireless Communication in Urban EnvironmentG( )= (15)1.11.4 Hata Model:The Hata Model is an empirical formulation of the graphical path lossprovided by Okumura, it is applicable for the frequencies between 150and 1500 MHZ [4], height of transmitting antenna between 30 m - 200 m,of received antenna between 1 m – 10 m and distance between 1 km to20 km [9], the formula developed by Hata for empirical path loss in urbanareas states that (16) [4]: dB = 69.55 + 26.16 ( 44.9 –6.55 (16)Where: dB is the median path loss for an urban environment expressedin decibels. is the carrier frequency in megahertz. is the transmitting antenna height in meters. is the receiving antenna height in meters.D is the distance between transmitting and receiving antennas inkilometers. Page | 26
  27. 27. Study Broadband Wireless Communication in Urban Environment is a correction factor for mobile unit antenna height.The correction factor of a received antenna height depends on thecoverage area [9] and for a large city it is given by the formula (17) [9] : = (17)For a medium sized city is given by the equation (18) [9]: = (18)This Model also adds some correction factors as for suburban areas isgiven by the equation (19) [9]: dB = dB - - 5.4, (19)And in open rural areas which is given by the equation (20) [9]: dB = dB - – 40.94, (20)Hata model does not provide correction factors for any path, unlikeOkumura Model, but instead it estimates the Okumura model for distancesd for current cellular systems with smaller cellsizes and higher frequencies [4], because it is not enough to include PCSband at 1900 MHz, so an extension to the Hata model was proposed bythe European Cooperative for scientific and Technical Research that willextend its applicability to 2 GHz [9]. Page | 27
  28. 28. Study Broadband Wireless Communication in Urban Environment1.11.5 Lee Model:Lee model is similar to the Okumura and Hata model represented earlierby providing a method to calculate path loss for standardized conditions,supported by correction factors to be applicable for conditions differentfrom the standard. It was developed by members of the Bell Laboratoriestechnical staff, based upon extensive measurements made in thePhiladelphia, Pennsylvania– Camden, New Jersey, area, and in Denville,Newark, and Whippany, New Jersey [9].A standard group of reference conditions and a flat terrain are initiallyassumed by Lee Model, followed by correction factors to be added tocalculate the differences from the standard conditions. Lee model can beapplied for frequencies up to 2 GHz [9].The median received power for Lee model is given by the equation (21)[9]: = 10 (21) is the median received power level in decibels above a mill watt. is the median received power level at the one-mile referencerange in decibels above a milliwatt.v is the path-loss exponent for the specific type of area.d is the total range between the transmitter and receiver antennas. is the reference range of one mile. is the correction factor in decibels for system parameters different fromthe standard. Page | 28
  29. 29. Study Broadband Wireless Communication in Urban Environment1.12 Multipath and fading in radio channels:Fading occurs due to multipath which effects and changes the amplitude,phases, or multipath delays of a signal as it propagates over a short period oftime, the effect of fading can be seen more in urban areas where the heightof mobile antennas are well below the surrounding buildings. The signalreceived by a mobile can experience reflections from the ground andsurrounding objects which will eventually cause the signal to have a largenumber of plane waves with different amplitudes, phase shift and angles [5].Many existing factors have a great impact on fading in radio propagationchannel, multipath propagation due to reflections and scattering, makes thetransmitted signal to have multiple versions at the receiving side, displaced intime and spatial orientation, as well as the motion between the base stationand mobile, leads to random frequency modulation due to Doppler shift [5]. 1.12.1 Doppler shift: It can be defined as the change in frequency of a wave that the mobile receives as it travels from point x to point y having a distance of d and is given by (22) where [5]: = = (22) The previous equation relates “the Doppler shift to the mobile velocity and the special angle between the direction of motion of the mobile and the direction of arrival of the wave” as shown in figure (1.8) [5]. Page | 29
  30. 30. Study Broadband Wireless Communication in Urban Environment The received frequency increases as the mobile moves in the direction of arrival of the wave and decreases as the mobile moves in the opposite direction relative to the direction of arrival of the wave [5].Figure (1.8), shows motion of the car and the direction of arrival of the wave 1.12.2 Influence of mobile unit velocity on data transfer and impulse response: In any urban environment is becoming an issue to predict propagation paths of radio signals, many efforts have been made to come up with new models and improve existent ones to make them more realistic and to assist the design process, many factors must be considered such as the mobility of the mobile unit, mobile speed and the effects of the surroundings in urban environments [10]. One of the most important characteristics of a mobile unit is that it is not stable and changes position continuously and this in turn will affect the amount of data being transferred and received by the mobile unit see Page | 30
  31. 31. Study Broadband Wireless Communication in Urban Environmentfigure (1.9), so it’s vital to consider the possible effects of the receiver unitmovement and its velocity on the amount of data throughput [10].Figure (1.9) shows the total amount of data being transferred at velocity shown in table (1.1), calculated without overhead packets [10] Table (1.1) indicates index to rates of movement table [10]To analyze the performance of such mobile communication systems, theimpulse response is considered to be a useful characterization of thechannel, and a mobile radio channel can be modeled as a linear filterwith time varying impulse response, as the receiver unit moves along theground at a fixed velocity v for a fixed distance d, the channel can bemodeled as a linear time invariant system [5]. Page | 31
  32. 32. Study Broadband Wireless Communication in Urban EnvironmentSince the impulse response of the linear time invariant channel is afunction of the position of the receiver, then the received signal at aposition d can be defined as in the equation (22) [5] below: = = , (22)This is the convolution of the impulse response and the transmitted signal.1.12.3 Power delay profile:Seeking new frequency bands has become very important because ofthe huge growth and growth of mobile communications in terms of voice,image and high data rates which is advancing rapidly and understandingpropagation delay is considered to be essential as the one of the majorproblems that can effect radio signals as they propagate in urbanenvironments is the existence of multipath propagation paths withdifferent and varying time delays.Normally in any urban environment, a transmission is between a fixed basestation and a mobile and the path is usually blocked resulting in scatter orreflection from buildings and surrounding objects along the path.If the mobile unit is moving, it produces a time-varying link and differentDoppler shifts are associated with scatter paths from different angles tothe mobile unit.Multipath characteristics can be obtained by measuring the complexband pass impulse response of the radio link as a function of distance,resulting in delay Doppler power profiles, average power delay profiles, Page | 32
  33. 33. Study Broadband Wireless Communication in Urban Environmentcomplex correlation of transfer function variations as a function offrequency separation, distributions of signal amplitudes at various delaysand different other statistical descriptions of the link which result from themultipath delays.1.12.4 Evaluation of transmission performance of mobile communication systems in urban environments:The transmission performance of broadband mobile communicationsystems operating at megabit-per-second rates is decreased when itcomes to multipath propagation environments due to radio wavesechoes arriving after different delays which interfere the primary radiosignal [11].A way to mitigate such performance degradation (resulting from theintersymbol interference (ISI) caused by radio waves having differentdelay times longer than the symbol duration) is by transmitting at lowerrates, this is achieved by dividing the source information stream intoseveral lower-rate channels that will be transmitted at the same time,using parallel techniques such as orthogonal frequency-divisionmultiplexing (OFDM) and multi-code code-division multiplexing (CDM)[11].To predict the parallel transmission performance in actual environments, itrequires not only the propagation models but also measured impulseresponses and one way to do so is by using equivalent baseband analysis,nevertheless it is considered to be time-consuming to predict suchperformance, since it employs convolution of impulse responses [11]. Page | 33
  34. 34. Study Broadband Wireless Communication in Urban EnvironmentAccording to an experiment conducted by a research group (S.Takahashi, K. Takahashi, H. Masui, K. Kage and T. Kobayashi), theyproposed a theoretical method to estimate the transmission performancein multipath propagation environment in an efficient way. This methodcalculates radio wave-interference probabilities under the assumptionthat the impulse responses have uniform-distribution phases [11]. Figure (1.10)Figure (1.10) [11] shows the dependence of a data rate on transmissionperformance at 3.35 GHz and it gives an indication that bare transmissionperformance decreases at higher data rate, it also shows that the BERexceeds when the distance between the transmitter and receiverexceeds 100 meters and this indicates that anti-multipath techniques arerequired for low BER applications. A better transmission performance canbe obtained by increasing the number of parallel transmission channels asin the previous figure, but the increase requires a wider dynamic rangethat causes the performance to decrease due to marginal symboldetection [11]. Page | 34
  35. 35. Study Broadband Wireless Communication in Urban Environment Figure (1.11)Figure (1.11) [11] shows the BER with parallel transmission in 10 channels at1Mb/s each and compared with BER obtained using bare transmissionand the result is a great reduction in BER with parallel transmissionespecially in the close vicinity to the transmitter, but when the BER withparallel transmission in figure (11) is compared with the bare 1-Mb/sperformance in figure (10), the both BERs are almost the same within arange of 100 meters [11].It can be concluded that the parallel transmission is capable of improvingthe BER, especially at distances less than 100 meters with respect to thetransmitting antenna, which can be retained to be more suitable forbroadband multimedia systems operating at high data rates up to 10Mb/s [11]. Page | 35
  36. 36. Study Broadband Wireless Communication in Urban Environment1.12.5 Microwave propagation characteristics in the presence of vehicles and pedestrians:Traffic condition on the streets has a great impact on the behavior ofradio wave signals. According to an experiment conducted by a researchgroup in an urban area in Tokyo, it shows the effect of vehicles andpeople on the characteristics of path loss and delay spread.The experiment was made in an urban area where the transmitter andreceiver antennas are at low heights, (4) and (2.7, 1.6 two different heightswere considered) m respectively, at two different frequencies of 3.35 GHzand 15.75 GHz in two different scenarios (at daytime and midnight, wherethe number of vehicles passing is less than 1/3 with respect to daytime,and the average number of pedestrians is less than 1/100 with respect todaytime) [12]. 1 Figure (1.12) shows the path-loss characteristics during daytime [12] Page | 36
  37. 37. Study Broadband Wireless Communication in Urban Environment Figure (1.13) shows the path-loss characteristics during midnight [12]The figure (1.12) shows the path-loss characteristics at height of 1.6 m attwo different frequencies (3.35 and 15.75 GHz) during daytime and figure(1.13) shows the path-loss during midnight under the same conditions(without the effect of passing vehicles and pedestrians). After comparingthe results in the previous two figures, it can be noticed that the Breakpoint moves away from the transmitter at midnight due to less trafficconditions in the road [12].1.12.6 Ray tracingRadio signals in urban or indoor environments will normally experiencereflection, diffraction or scattering and this known to be as multipath signaland it affects the power, delay in time, shift in phase and/ or frequency,this eventually causes distortion in the received signal relative to thetransmitted signal [4].This type of propagation model is retained to be suitable in rural areas,along city streets when the height of the transmitter and receiver is low Page | 37
  38. 38. Study Broadband Wireless Communication in Urban Environment and close to the ground and in indoor environments, when compared to other empirical models [4]. A typical urban environment consists of buildings, static and moving vehicles and trees that affect the radio wave propagation. Many papers have been published discussing the propagation loss, delay spread in simple environments using ray tracing technique without taking into account cars, trucks or trees and to obtain a more efficient result, 2D ray tracing is combined with simple 3D geometric considerations as shown in figure (1.14) in order to handle any distribution of buildings, vehicles and trees in an urban environment and their effects [13].Figure (1.14) shows a distribution of buildings, vehicles and trees in an urban environment [14] Page | 38
  39. 39. Study Broadband Wireless Communication in Urban EnvironmentAs shown from the previous figure, buildings, vehicles and group of treesand the behavior of the ray traveling can take different paths, considerthe projection Txp of a transmitting antenna on ground, depending onthe height of the vehicles and trees ( as they maybe higher or lower thanthat of the transmitter), the ray may travel over the top of the vehicles andtrees, may even bounce off the projections of vehicles, trees and buildingsor transmit through the projections of trees and vehicles as shown in figure(1.15), resulting into different reflected scattered waves. Based on thisidea, a binary reflection/transmission tree for a ray tube shot from Txp isconstructed. For each ray tube, the projection Rxp of the receiver Rx ischecked to see if it falls within the ray tube and if it does, a 2D ray from Txpto Rxp can be determined. Once it is established, a third dimension is thentaken to determine if an exact 3D ray from to Exists [14] [13]. Figure (1.15) Page | 39
  40. 40. Study Broadband Wireless Communication in Urban EnvironmentCHAPTER 2Methodology Page | 40
  41. 41. Study Broadband Wireless Communication in Urban EnvironmentChapter Two - Methodology2.1 IntroductionAs mentioned earlier in the preceding topics that the behavior of multipathchannels is becoming more unpredictable as many factors play a big role indefining the nature of these multipath channels along their path, when itcomes to urban environments, signals are affected by buildings, trees, carspassing, pedestrians, interference with other channels as well as the speed ofeither the mobile unit receiver or the objects moving around it. The signalmay bounce of the walls, cars as they pass, penetrate through them andmay take different paths which will cause the signal with different timedelays.As the demand for high speed transfer of data is increasing, thecharacterization of multipath propagation is becoming more difficult and noteasy to measure as it depends mostly on the type of environment, in which alink has been deployed.It can be summarized as follows: 1. Conduct research on different urban environments (possibly through background research) especially in dense areas, where they necessitate higher data rates and find the most suitable multipath propagation parameters to use it as a standard model. 2. Find the impact of multipath on the radio propagation channel in these areas and compare it with available data. 3. Estimate the path loss and delay spread when using high and low antenna heights for microcellular applications. Page | 41
  42. 42. Study Broadband Wireless Communication in Urban Environment 4. Develop a simulation tool using MATLAB to predict the behavior of the channels.2.2 Simulation overviewSeveral steps are considered in providing realistic simulation of radiopropagation channels. The first step is to define the area survey of the urbanregion that is to be simulated, Based on existent data which is provided andthe purpose of this project is to process the same data collected andsimulate it using Matlab software, compare it with actual measurementsobtained during the experiment, the simulation must consider and satisfy allparameters taken into account during the experiment, figure (16) illustratesthe different stages of simulation.According to [15] , measurements were carried out in an urban environment,has shown that it is not necessarily to have a blockage between thetransmitter and receiver path to cause fading, instead, it can introducefrequency selective fading of up to 40 dB and this arises another problemthat the existence of objects in the vicinity of radio wave signal, can still havean effect and cause burst errors in reception.2.3 Environmental classification and test routeExistent models for prediction of radio propagation are commonly classifiedto urban, suburban and rural areas. The latter is characterized with fewerbuildings whose heights range between two to three stories which are widely Page | 42
  43. 43. Study Broadband Wireless Communication in Urban Environmentseparated in comparison to urban and suburban areas. On the other hand,suburban areas can be classified to commercial/residential and suburbanresidential which is a mixture of residential and commercial buildings withheights above four stories normally.2.4 Measurement ScenarioThree different measurement scenarios on site with existent data have beenused for simulation, and later to be compared with real measurements, figure(2.1) depicts the test routs.Figure (2.1) Staircase zigzag (transverse + lateral) and LOS test routes relative to the street grid [16]These measurements were conducted in the San Francisco bay area usingdifferent base station antenna heights which are near or below the Page | 43
  44. 44. Study Broadband Wireless Communication in Urban Environmentsurrounding buildings with operating frequency of 900 and 1900 MHz,following line-of-sight, zigzag and staircase test routes, which are shown infigure (2.1) for the site experiment,. Recalling the importance ofunderstanding the behavior of radio propagation in small cell environmentswhere the antenna height is expected to be a key factor in the design of PCSsystem, three different antenna heights were chosen, the transmittingantennas of 3.2, 8.7 and 13.4 m, while for the receiving antenna, was chosento be at 1.6 m.2.5 Structure Characteristics:The working area which is in this case the sunset District and the MissionDistrict are characterized of attached buildings of quasi-uniform heightstructured on a rectangular street grid with a flat terrain profile, the firstlocation is composed of two-story houses forming a rectangular grid and thesecond location is composed of a mixture of different buildings heights,typically between four to six stories and they were chosen to represent atypical low-rise environment. While to represent high-rise environments,measurements were also conducted in San Francisco downtown,characterized by hills with most buildings being significantly higher than thehighest antenna used. The proposed model was developed as the basemodel for characterizing outdoor signal propagation in low-rise and high-riseenvironments taking into account some urban parameters: distance, mobileheight, Terrain elevation, and propagation over rooftops, diffraction from thelast rooftop to the mobile and finally presence of corners as newcontributions. These factors are explained in details as follows [16]: Page | 44
  45. 45. Study Broadband Wireless Communication in Urban Environment2.5.1 Dependency on distanceIt has been theoretically verified how distance variation can influence theradio propagation, which depends mainly on the topography of theterrain where the model is applied. This parameter is so significant that awrong estimation would result in wrong deductions later [1].2.5.2 Dependency on the Variability of terrain elevationMany researchers have extensively analyzed the effect of mobile heighton the attenuation and considered it a well-known factor in radiopropagation. The proposed model has not considered in details to supportvariation in terrain elevation especially in downtown San Francisco, as theterrain in this area has also hills. In order to have a better understanding onthe effect of the terrain elevation, see figure (2.2), where mobile receiverson low areas are far from the average building height, this in turn willincrease the diffraction angle which would cause the signal to becomelower or higher in case of high areas. Page | 45
  46. 46. Study Broadband Wireless Communication in Urban EnvironmentFigure (2.2) Model considering homogeneous height and terrain variation [18] 2.5.3 Dependency on the closest surrounding buildings height with respect to the mobile receiver For an ideal urban environment where most of its structure is composed of buildings, houses, etc, the usage of the height of the closest building relative to the mobile receiver is theoretically correct. But in some cases it is not accurate due to the existence of other buildings between the last building close to the mobile receiver and the base station which obstacles the line of sight propagation path and causes diffraction. Taking into account all these factors, a correction factor was generated to account for the effect of the closest building height relative to the mobile receiver, so the total path loss was approximated as the sum of , and [18], where: Page | 46
  47. 47. Study Broadband Wireless Communication in Urban Environment is free space loss is the path loss associated due to the diffraction from the last rooftoprelative to the mobile receiver. is the path loss accounted due to the blockage of previous buildingsbefore the mobile receiver. Page | 47
  48. 48. Study Broadband Wireless Communication in Urban EnvironmentCHAPTER 3Simulation Page | 48
  49. 49. Study Broadband Wireless Communication in Urban EnvironmentChapter Three - Simulation3.1 Simulation of modelsA continuous literature review was carried out by the author throughout thewhole project to familiarize the reader with main subject being addressed. Atthe beginning, information was gathered using different sources, mainly frompublished journals and books to establish a solid background and to outlinethe thesis goals at a later stage. Meanwhile and side by side, a focus searchwas conducted mainly on previous published articles proposing the differentmodels that were developed for radio propagation in urban environments.Related work was of great benefit as it was utilized to refine the project scopeand to choose suitable data destined for simulation.As the purpose of this project is to come up with a simulation tool that can beused to predict the performance of radio channel and compare the resultswith experimental measurements, data was chosen from models proposed in[16]. As discussed earlier, test measurements were conducted using threedifferent base station antenna heights with operating frequency of 900 and1900 MHz in urban and suburban areas, the test routes selected were line-of-sight, zigzag and staircase routes. As explained earlier, the Sunset District andthe Mission District were selected to represent low-rise environments while forthe high-rise environment, San Francisco downtown was chosen for testmeasurements.The simulation of the different formulas developed in [16]will be implementedunder the matlab environment as a set of m-files which contain the differentfunctions and procedures. Each will be evaluated and simulated separately.Later in the implementation process, COST 231 W-I model will be computed Page | 49
  50. 50. Study Broadband Wireless Communication in Urban Environmentusing the same set of parameters used during the experimentalmeasurements in [16]. The results are then compared for further analysis.3.2 Path loss in low-rise environmentThe simulation model is deducted using three path-loss formulas: Staircase,Transverse and lateral route developed in [16]with operating frequency at900 and 1900 MHz and these formulas are as follows:For Staircase route (23):(23)For Transverse route (24):For Lateral route (25): Page | 50
  51. 51. Study Broadband Wireless Communication in Urban EnvironmentWhere : Carrier frequency valid for 0.9 < < 2GHz : Distance between the transmitter and receiver valid for -8 < <6m : Average base station height valid for 0.05 < < 3kmIn the previous test analysis, the average height of the surrounding buildingshas been taken as a significant parameter in deriving the different formulasfor path-loss prediction through the relative relation as follows:Base station antenna Height ∆h is defined as∆h = - (26)Taking into account the sunset district which is mainly composed of houseswith average height of two stories, corresponding to an average height of 8m, the measurements undertaken were computed using three base stationantenna heights of the values of -4.8 m, 0.7 m and 5.4 m. while in the Missiondistrict which is mainly composed of three to five story buildings,corresponding to an average height of 11 m, the values -7.8 m, -2.3 m and2.4 m were chosen as base station antenna height for the measurements inthe Mission district. Figure (3.1) and (3.2) show the results obtained in thesimulation process at a distance of 1 km as a function of height as well as thepath loss for a distance up to 2000 meters at operating frequency of 0.9 and1.9 GHz for the previous three formulas of lateral, transverse and staircaserouts. The figure also shows the close result in case of transverse and lateralroutes for the low-raise environment. Page | 51
  52. 52. Study Broadband Wireless Communication in Urban EnvironmentFigure (3.1) illustrates path loss as a function of height and distance at 0.9 GHz. Page | 52
  53. 53. Study Broadband Wireless Communication in Urban EnvironmentFigure (3.2) illustrates path loss as a function of height and distance at 1.9 GHz. Page | 53
  54. 54. Study Broadband Wireless Communication in Urban EnvironmentIt can be noticed from the previous two figures obtained after simulation thatthe path-loss introduced in the lateral route is considerably lower than thepath-loss introduced in the transverse and staircase routes, as in the figure(3.3) below, it can be noticed that which denotes the distance from thelast rooftop to the mobile receiver is large in case of lateral route whereas intransverse and staircase routes are small. In addition, the number of halfscreens and the separation between these screens is different for thedifferent previous routes. It can be seen in [16]that base station antennaheights which are close to rooftops are not sensitive to irregularities so thisleads that average building separation can be applied. Moreover, path-lossvaries according to the equation as: (27)M is equal to the number of screens, so path-loss is not very much dependanton M especially when it is closed to the cell boundary where M is large. Inlight of this, the large value of is considered then to be the main cause forpath loss relative to the lateral route. Figure (3.3) shows the simplified footprint of townhouses [16] Page | 54
  55. 55. Study Broadband Wireless Communication in Urban EnvironmentTo account for the effect introduced by , a theoretical correction factor isused as described in [16]so the distance is taken as 20 m as between thebuilding edge and the center of the street in case of the Sunset and Missiondistricts and using the transverse formula as the standard formula, so thecorrection factor is given as follows: 20/ ) (28)So applying the previous correction factor, so the formula for all non-LOSroutes is given by:40.67−4.57sgn∆hlog1+∆hlogRk+10log⁡(20/rh ) +20log⁡(∆h m/7.8) (29)Where, the average building height in Sunset and Mission districts is 7.8relative to the mobile receiver height of 1.6 m. figure (3.4) and (3.5) illustratethe path loss results obtained after simulation of the previous formula (29) withcorrection factor which is valid for all non-LOS routes and the previous lateralformula in (25) as a function of height at 1 km distance. Page | 55
  56. 56. Study Broadband Wireless Communication in Urban EnvironmentFigure (3.4) Comparison of simulation results at 0.9 GHzFigure (3.5) Comparison of simulation results at 1.9 GHz Page | 56
  57. 57. Study Broadband Wireless Communication in Urban Environment3.3 Comparison of simulation results with cost COST 231 Walfish-Ikegami ModelThe results obtained from formula (29) with correction factors for the Sunsetdistrict is now compared with cost 231 model. This model is a combination ofJ. Walfish and F. Ikegami model which later was developed by The COST 231project [17]. This model among all the other models is more suitable for flatsuburban and urban environments that have almost uniform building heightsas it provides additional parameters and correction factors that can beutilized for different environments. See figure (3.6) below for a typicalenvironment where this model is valid for path loss calculation.(3.6) illustrates a typical urban environment where this model is valid for pathloss calculation Page | 57
  58. 58. Study Broadband Wireless Communication in Urban EnvironmentIn the simulation process, the following data have been use for comparison:Parameters Used for the SimulationBuilding to building distance is 50 mStreet width is 40 mOrientation angle of the street is 40Relative base station height with respect to building height is 5 m Is 18 Is – in the case of urban environment which is valid forSunset district Is 54 which valid for base station antenna height greater than buildingrooftop height.Operating frequency is 900 MHzMobile receiver height is 1.6 mDistance between the transmitter and receiver is 2000 mThe data presented previously was used within the formula of cost 231 modeland taking into account the most suitable parameters that are in closeagreement with data used in the formula found in (29), some of theseparameters were assumed to make the simulation more realistic. As it can beseen from figure (3.7), which illustrates the path loss in dB encountered usingtwo different models, cost 231 which is known to be the most suitable modelfor path loss calculation in urban and suburban and the formula (29) with thecorrection factors added to the latter. The simulation showed differences inpath-loss with discrepancy of around 15-20 dB which is considered to be high. Page | 58
  59. 59. Study Broadband Wireless Communication in Urban Environment(3.7) illustrates the path loss model within the non-LOS formula (29) and cost231 W-I at operating frequency of 0.9 GHz. Page | 59
  60. 60. Study Broadband Wireless Communication in Urban Environment CHAPTER 4Analysis and Conclusion Page | 60
  61. 61. Study Broadband Wireless Communication in Urban Environment 4.1 Analysis of simulation outcomesThe accumulated results obtained from simulation of the proposed formulasin [16] which were derived based on the extensive measurements conductedin field, showed great match as with the three formulas: lateral, transverseand staircase test routes. Lateral formula output showed significant differentwith respect to the transverse and staircase routes, a correction factor hasbeen added to the transverse formula and has been considered for all non-LOS routes in low-rise environment. For comparison purposes, the cost 231model has been simulated using the same set of parameters in accordancewith the formula developed and presented earlier (29). The results obtainafter simulation and comparison as shown in figure (3.7) didn’t show goodagreement, so even the cost 231 model which is considered most suitable forpath-loss prediction in urban and suburban areas, didn’t provide precision inaccordance with the non-LOS formula (29), so hata 231 model cannot beconsidered. 4.2 ConclusionIn light of the background research and related work, it can be noticed thatthe radio propagation takes a different behavior within each differentoperating area and requires the knowledge of its propagation parameters tosuccessfully design a radio cellular system as many factors influence theperformance of such systems, such as multipath fading, path loss, reflectionsfrom buildings, no direct visibility between transmitter and receiver becauseof the low antenna heights compared to the surrounding structures , speedof the mobile and surrounding objects have also a great impact on the radiopropagation behavior. Page | 61
  62. 62. Study Broadband Wireless Communication in Urban EnvironmentAs the urban areas become more populated, capacity becomes moresignificant to accommodate more users and less probability of errors in datarate, this will eventually require more cells to be repositioned and causes co-channel interference to increase and ultimately constrain system capacityfinally, it requires more sophisticated approaches and methods to overcomesuch problems. Page | 62
  63. 63. Study Broadband Wireless Communication in Urban EnvironmentWorks Cited[1] L. D. K. G. B. K. a. P. C. Athansios G. Kanatas, "A UTD propagation Model in Urban Microcellular Environments," IEEE TRANSACTIONS ON VEHICULAR TECHNOLOGY, vol. 46, FEBRUARY 1997.[2] E. B. a. A. B. sesay, "Effects of Antenna Height, Antenna Gain and Pattern Downtilting for Cellular Mobile Radio," IEEE transactions on Vehicular Technology, vol. 45, May 1996.[3] M. S. a. S. Y. Tsutomu Takeuchi, "Multipath delay prediction on a workstation for urban mobile radio environment," vol. 36, 1991.[4] A. Goldsmith, Wireless Communications, Newyork: Cmbridge University Press 2005, 2005.[5] t. s. rappaport, wireless communications principles and practice, second edition ed., 2001.[6] G. L. Stuber, Principles of Mobile Communication, 2nd Edition ed., Georgia: Kluwer Academic Publishers.[7] D. H. Morais, Fixed Broadband Wireless Communications: Principles and Practical Applications.[8] L. J. I. Jr., Satellite Communications Systems Engineering atmospheric Effects, Sattelite Link Design and System Performance, 2008.[9] Bruce A. Black; Philip S. DiPiazza; Bruce A. Ferguson; David R. Voltmer; Frederick C. Berry, Introduction to Wireless Systems, Prentice Hall, 2008.[10] D. D. a. G.-M. M. Tim Casey, "Influence of Mobile User Velocity on Data Transfer in a Multi-Network Wireless Environment," in 9th International Conference on Mobile and Wireless Communications Networks, Cork, Ireland, 2007.[11] K. T. H. M. K. K. a. T. K. Satoshi Takahashi, "Performance of Parallel Transmission Applied to Broadband Mobile Communication Systems in Urban Multipath Environments," IEEE, pp. 1028-1032, 1999.[12] M. I. S. T. H. S. a. T. K. Hironari Masui, "Microwave Propagation Characteristics in an Urban LOS Environment in Different Traffic Conditions," IEEE, pp. 1150-1153, 2000. Page | 63
  64. 64. Study Broadband Wireless Communication in Urban Environment[13] S.-C. J. a. S.-K. Jeng, "A Propagation Modeling for Microcellular Communications in Urban Environments with Vehicles and Trees," IEEE, pp. 1214-1217, 1996.[14] S.-C. J. a. S.-K. Jeng, "A Novel Propagation Modeling for Microcellular Communications in Urban Environments," IEEE TRANSACTIONS ON VEHICULAR TECHNOLOGY, Vols. 46, NO. 4, pp. 1021-1026, November 1997.[15] K. S. S. T. B. V. a. D. S. D. L. Ndzi, "Wideband Sounder for Daynamic and Static wireless channel characterisation: Urban Picocell channel Model," Progress in Electromagnetics Rsearch, vol. 113, pp. 285-312, 2011.[16] Dongsoo Har, Howard H. Xia and Henry Bertoni, "Path-Loss Prediction Model for Microcells," IEEE Transactions on Vehicular Technology, pp. 1-10, 1999.[17] C. A. 231, "cost231," [Online]. Available: http://www.lx.it.pt/cost231/. [Accessed 22 May 2012].[18] Casaravilla J.,Dutra G., Pignataro N. and Acuna J., "Propagation Model for Small Macrocells in Urban Areas". Page | 64
  65. 65. Study Broadband Wireless Communication in Urban EnvironmentAppendicesAppendix AMatlab code for low-rise environment for Lateral, Transverse and staircasetest routes at 900 MHz and distance of 1 km as a function of Height.%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% Lateral, Transverse and Staircase route Simulation %% at 1 km distance Formula for Low-Rise Environment %% as a function of Base Station Antenna Height %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%close all;clear all;clc% Parameters Used in the Simulation f1=0.9; % Frequency at 0.9 GHz I=10; Delta_H =-10.0:0.5:I; % Antenna Range from -10 to 10 meters with stepof 0.5 meter x = sign(Delta_H); % The sign function% Note "Simulation computed at distance of 1 kilometer"%%%%%%%%%%%%%%%%%%%%%%%%%% Lateral Route Path Loss Formula with operatingfrequency of 0.9 GHz %%%%%%%%%%%%%%%%%%%%%%%%%%%%lpmodel=(127.39+31.63.*log10(f1))-(13.05+4.35.*log10(f1))*x.*log10(1+abs(Delta_H))+(29.18-6.70.*x.*log10(1+abs(Delta_H)))*log10(1);%%%%%%%%%%%%%%%%%%%%%%%%%% Transverse Route Path Loss Formula withoperating frequency of 0.9 GHz %%%%%%%%%%%%%%%%%%%%%%%%%%%%Tpmodel=(139.01+42.59.*log10(f1))-(14.97+4.99.*log10(f1))*x.*log10(1+abs(Delta_H))+(40.67-4.57.*x.*log10(1+abs(Delta_H)))*log10(1); Page | 65
  66. 66. Study Broadband Wireless Communication in Urban Environment%%%%%%%%%%%%%%%%%%%%%%%%%% Transverse Route Path Loss Formula withoperating frequency of 0.9 GHz %%%%%%%%%%%%%%%%%%%%%%%%%%%%Spmodel=(137.61+35.16.*log10(f1))-(12.48+4.16.*log10(f1))*x.*log10(1+abs(Delta_H))+(39.46-4.13.*x.*log10(1+abs(Delta_H)))*log10(1);%%%%%%%%%%%%%%%%%%%%%%%%%% Plot %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%plot(Delta_H,lpmodel,b.- ,Delta_H,Tpmodel,r.-,Delta_H, Spmodel,g.-);%%%%%%%%%%%%%%%%%%%%%%%%%% X, Y Axis and Titles %%%%%%%%%%%%%xlabel (Relative Antenna Height Range in Meter);ylabel ( Path Loss In dB);title ( Lateral,Transverse and Staircase route Simulation at 1 kmdistance);h = legend(lateral,Transverse,Staircase,1);set(h,Interpreter,none)text(-8,118,Operating Frequency = 0.9 GHz); Page | 66
  67. 67. Study Broadband Wireless Communication in Urban EnvironmentAppendix BMatlab code for low-rise environment for Lateral, Transverse and staircasetest routes at 1900 MHz and distance of 1 km as a function of Height.%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% Lateral, Transverse and Staircase route Simulation %% at 1 km distance Formula for Low-Rise Environment %% as a function of Base Station Antenna Height %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%close all;clear all;clc% Parameters Used in the Simulation f1=1.9; % Frequency at 1.9 GHz I=10; Delta_H =-10.0:0.5:I; % Antenna Range from -10 to 10 meters with stepof 0.5 meter x = sign(Delta_H); % The sign function% Note "Simulation computed at distance of 1 kilometer"%%%%%%%%%%%%%%%%%%%%%%%%%% Lateral Route Path Loss Formula with operatingfrequency of 0.9 GHz %%%%%%%%%%%%%%%%%%%%%%%%%%%%lpmodel=(127.39+31.63.*log10(f1))-(13.05+4.35.*log10(f1))*x.*log10(1+abs(Delta_H))+(29.18-6.70.*x.*log10(1+abs(Delta_H)))*log10(1);%%%%%%%%%%%%%%%%%%%%%%%%%% Transverse Route Path Loss Formula withoperating frequency of 0.9 GHz %%%%%%%%%%%%%%%%%%%%%%%%%%%%Tpmodel=(139.01+42.59.*log10(f1))-(14.97+4.99.*log10(f1))*x.*log10(1+abs(Delta_H))+(40.67-4.57.*x.*log10(1+abs(Delta_H)))*log10(1);%%%%%%%%%%%%%%%%%%%%%%%%%% Transverse Route Path Loss Formula withoperating frequency of 0.9 GHz %%%%%%%%%%%%%%%%%%%%%%%%%%%% Page | 67
  68. 68. Study Broadband Wireless Communication in Urban EnvironmentSpmodel=(137.61+35.16.*log10(f1))-(12.48+4.16.*log10(f1))*x.*log10(1+abs(Delta_H))+(39.46-4.13.*x.*log10(1+abs(Delta_H)))*log10(1);%%%%%%%%%%%%%%%%%%%%%%%%%% Plot %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%plot(Delta_H,lpmodel,b.- ,Delta_H,Tpmodel,r.-,Delta_H, Spmodel,g.-);%%%%%%%%%%%%%%%%%%%%%%%%%% X, Y Axis and Titles %%%%%%%%%%%%%xlabel (Relative Antenna Height Range in Meter);ylabel ( Path Loss In dB);title ( Lateral,Transverse and Staircase route Simulation at 1 kmdistance);h = legend(lateral,Transverse,Staircase,1);set(h,Interpreter,none)text(-8,130,Operating Frequency = 1.9 GHz); Page | 68
  69. 69. Study Broadband Wireless Communication in Urban EnvironmentAppendix CMatlab code for low-rise environment for Lateral, Transverse and staircasetest routes at 900 MHz for an average antenna height of 5 m as a function ofdistance.%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% Lateral, Transverse and Staircase route Simulation %% Formula for Low-Rise Environment as a function of %% distance %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%close all;clear all;clc% Parameters Used in the Simulation f1=0.9; % Frequency at 900 MHz N=2; d=0.0:0.01:N; % Distance Range from 0 to 2 kilometres Delta_H= 5; % Average Base station Height at 5 meters x = sign(Delta_H); % The sign function%%%%%%%%%%%%%%%%%%%%%%%%%% Lateral Route Path Loss Formula with operatingfrequency of 0.9 GHz %%%%%%%%%%%%%%%%%%%%%%%%%%%%lpmodel=(127.39+31.63.*log10(f1))-(13.05+4.35.*log10(f1))*x.*log10(1+abs(Delta_H))+(29.18-6.70.*x.*log10(1+abs(Delta_H)))*log10(d);%%%%%%%%%%%%%%%%%%%%%%%%%% Transverse Route Path Loss Formula withoperating frequency of 0.9 GHz %%%%%%%%%%%%%%%%%%%%%%%%%%%%Tpmodel=(139.01+42.59.*log10(f1))-(14.97+4.99.*log10(f1))*x.*log10(1+abs(Delta_H))+(40.67-4.57.*x.*log10(1+abs(Delta_H)))*log10(d);%%%%%%%%%%%%%%%%%%%%%%%%%% Transverse Route Path Loss Formula withoperating frequency of 0.9 GHz %%%%%%%%%%%%%%%%%%%%%%%%%%%%Spmodel=(137.61+35.16.*log10(f1))-(12.48+4.16.*log10(f1))*x.*log10(1+abs(Delta_H))+(39.46-4.13.*x.*log10(1+abs(Delta_H)))*log10(d); Page | 69
  70. 70. Study Broadband Wireless Communication in Urban Environment%%%%%%%%%%%%%%%%%%%%%%%%%% Plot %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%plot(d,lpmodel,b.- ,d,Tpmodel,r.-,d, Spmodel,g.-);%%%%%%%%%%%%%%%%%%%%%%%%%% X, Y Axis and Titles %%%%%%%%%%%%%xlabel (Distance between Tx and Rx in kilometers);ylabel ( Path Loss In (dB));title ( Lateral,Transverse and Staircase route Simulation);h = legend(lateral,Transverse,Staircase,1);set(h,Interpreter,none)text(1.0,100,Operating Frequency = 0.9 GHz); Page | 70
  71. 71. Study Broadband Wireless Communication in Urban EnvironmentAppendix DMatlab code for low-rise environment for Lateral, Transverse and staircasetest routes at 1900 MHz for an average antenna height of 5 m as a function ofdistance.%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% Lateral, Transverse and Staircase route Simulation %% Formula for Low-Rise Environment as a function of %% distance %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%close all;clear all;clc% Parameters Used in the Simulation f1=1.9; % Frequency at 1900 MHz N=2; d=0.0:0.01:N; % Distance Range from 0 to 2 kilometers Delta_H= 5; % Average Base station Height at 5 meters x = sign(Delta_H); % The sign function%%%%%%%%%%%%%%%%%%%%%%%%%% Lateral Route Path Loss Formula with operatingfrequency of 0.9 GHz %%%%%%%%%%%%%%%%%%%%%%%%%%%%lpmodel=(127.39+31.63.*log10(f1))-(13.05+4.35.*log10(f1))*x.*log10(1+abs(Delta_H))+(29.18-6.70.*x.*log10(1+abs(Delta_H)))*log10(d);%%%%%%%%%%%%%%%%%%%%%%%%%% Transverse Route Path Loss Formula withoperating frequency of 0.9 GHz %%%%%%%%%%%%%%%%%%%%%%%%%%%%Tpmodel=(139.01+42.59.*log10(f1))-(14.97+4.99.*log10(f1))*x.*log10(1+abs(Delta_H))+(40.67-4.57.*x.*log10(1+abs(Delta_H)))*log10(d);%%%%%%%%%%%%%%%%%%%%%%%%%% Transverse Route Path Loss Formula withoperating frequency of 0.9 GHz %%%%%%%%%%%%%%%%%%%%%%%%%%%%Spmodel=(137.61+35.16.*log10(f1))-(12.48+4.16.*log10(f1))*x.*log10(1+abs(Delta_H))+(39.46-4.13.*x.*log10(1+abs(Delta_H)))*log10(d); Page | 71
  72. 72. Study Broadband Wireless Communication in Urban Environment%%%%%%%%%%%%%%%%%%%%%%%%%% Plot %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%plot(d,lpmodel,b.- ,d,Tpmodel,r.-,d, Spmodel,g.-);%%%%%%%%%%%%%%%%%%%%%%%%%% X, Y Axis and Titles %%%%%%%%%%%%%xlabel (Distance between Tx and Rx in kilometers);ylabel ( Path Loss In (dB));title ( Lateral,Transverse and Staircase route Simulation);h = legend(lateral,Transverse,Staircase,1);set(h,Interpreter,none)text(1.0,100,Operating Frequency = 1.9 GHz); Page | 72
  73. 73. Study Broadband Wireless Communication in Urban EnvironmentAppendix EMatlab code for comparison of lateral formula and non-LOS formula withcorrection factors for the sunset district as a function of height for 1.9 and 0.9GHz at 1 km distance%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% comparison of lateral formula and non-LOS formula with %% correction factors for the sunset district as a function%% of height for 1.9 and 0.9 GHz at 1 km distance %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%close all;clear all;clc% Parameters Used in the Simulationf1 = 0.9; % Frequency at 0.9 GHzf2 = 1.9; % Frequency at 1.9 GHzI=10;Delta_H =-10.0:0.5:I; % Antenna Range from -10 to 10 meters with stepof 0.5 meterx = sign(Delta_H); % The sign function%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% 900 MHz %%%%%%%%%%%%%%%%%%%%%%%%%%%%lpmodel1=(139.01+42.59.*log10(f1))-(14.97+4.99.*log10(f1))*x.*log10(1+abs(Delta_H))+(40.67-4.57.*x.*log10(1+abs(Delta_H)))*log10(1)+ 20*log10( 10./7.8)+10*log10(20./250);lpmodel3=(127.39+31.63.*log10(f1))-(13.05+4.35.*log10(f1))*x.*log10(1+abs(Delta_H))+(29.18-6.70.*x.*log10(1+abs(Delta_H)))*log10(1);%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% 1900 MHz %%%%%%%%%%%%%%%%%%%%%%%%%%%%lpmodel2=(139.01+42.59.*log10(f2))-(14.97+4.99.*log10(f2))*x.*log10(1+abs(Delta_H))+(40.67-4.57.*x.*log10(1+abs(Delta_H)))*log10(1)+ 20*log10( 10./7.8)+10*log10(20./250);lpmodel4=(127.39+31.63.*log10(f2))-(13.05+4.35.*log10(f2))*x.*log10(1+abs(Delta_H))+(29.18-6.70.*x.*log10(1+abs(Delta_H)))*log10(1);figure(1);plot(Delta_H,lpmodel1,b.- ,Delta_H,lpmodel3,r.-);%%%%%%%%%%%%%%%%%%%%%%%%%% X, Y Axis and Titles %%%%%%%%%%%%% Page | 73
  74. 74. Study Broadband Wireless Communication in Urban Environmentxlabel (Relative Antenna Height Range in Meter);ylabel ( Path Loss In dB);title ( comparison of lateral formula and non-LOS formula with correctionfactors);h = legend(lateral,Non-Los,1);set(h,Interpreter,none)text(-8,120,Operating Frequency = 0.9 GHz);figure(2);plot(Delta_H,lpmodel2,b.-,Delta_H,lpmodel4,r.-);xlabel (Relative Antenna Height Range in Meter);ylabel ( Path Loss In dB);title ( comparison of lateral formula and non-LOS formula with correctionfactors);h = legend(lateral,Non-Los,1);set(h,Interpreter,none)text(-8,130,Operating Frequency = 1.9 GHz); Page | 74
  75. 75. Study Broadband Wireless Communication in Urban EnvironmentAppendix FMatlab code for comparison of simulation results with cost COST 231 Walfish-Ikegami Model%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% Comparison of simulation results with cost COST 231 %% Walfish-Ikegami Model %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%close all;clear all;clc%%%%%%%%%%%%%%% COST Walfish-Ikegami (WI) Model%%%%%%%%%%%%%%%distance between buildingsB=50;f = 0.9; % Frequency at 0.9 GHzd =0:0.01:2000; % Distance%street width B/2w=40; % Width of the street%Mobile_Height=h roof-h mobile(15-10/6/3)m we consider h roof is 5 mMobile_Height=1.6; % Antenna height in meter for mobilereceiver%street orientation angel 40 degreetheta=40;Lori_angle=2.5+0.075*(theta-35);Lrts=-16.9-10.*log10(w)+10.*log10(f)+20.*log10(Mobile_Height)+Lori_angle;Lfs=32.45+20.*log10(d)+20.*log10(f);height_base=5;%in urban kf is (-4+1.5((f/925)-1))Lmsd=-18.*log10(1+height_base)+54+18.*log10(d)+(-4+1.5*((f/925)-1)).*log10(f)-9.*log10(B);Path_loss_wl=Lfs+Lrts+Lmsd;Delta_H = 5;x = sign(Delta_H); % The sign functionlpmodel1=(139.01+42.59.*log10(f))-(14.97+4.99.*log10(f))*x.*log10(1+abs(Delta_H))+(40.67-4.57.*x.*log10(1+abs(Delta_H)))*log10(d/1000)+ 20*log10( 10./7.8)+10*log10(20./250);plot(d,lpmodel1,b.-,d,Path_loss_wl,r.-);%%%%%%%%%%%%%%%%%%%%%%%%%% X, Y Axis and Titles %%%%%%%%%%%%%xlabel (Relative Antenna Height Range in Meter);ylabel ( Path Loss In dB);title ( Comparison of simulation results with cost COST 231 Walfish-Ikegami Model);h = legend(Low-Rise (Non-LOS),Cost WI,1);set(h,Interpreter,none)text(200,0,Operating Frequency = 0.9 GHz); Page | 75

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