Investigation of outdoor path loss models for wireless communication in bhuj
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Investigation of outdoor path loss models for wireless communication in bhuj

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Investigation of outdoor path loss models for wireless communication in bhuj Investigation of outdoor path loss models for wireless communication in bhuj Document Transcript

  • International INTERNATIONALCommunication Engineering & Technology (IJECET), ISSN 0976 – Journal of Electronics and JOURNAL OF ELECTRONICS AND6464(Print), ISSN 0976 – 6472(Online) Volume 3, Issue 2, July-September (2012), © IAEME COMMUNICATION ENGINEERING & TECHNOLOGY (IJECET)ISSN 0976 – 6464(Print)ISSN 0976 – 6472(Online)Volume 3, Issue 2, July- September (2012), pp. 171-178 IJECET© IAEME: www.iaeme.com/ijecet.htmlJournal Impact Factor (2012): 3.5930 (Calculated by GISI) ©IAEMEwww.jifactor.com INVESTIGATION OF OUTDOOR PATH LOSS MODELS FOR WIRELESS COMMUNICATION IN BHUJ Pooja Prajesh , Dr. R.K.Singh , Research scholar UTU, OSD (Professor), UTU, Dehradun (India) Dehradun (India) pooja_prajesh78@yahoo.co.in rksinghkec12@rediffmail.com ABSTRACT For designing the Propagation Path Loss model requires knowledge of environment characteristics. There are many propagation models for radio communication system which is chooses according to Terrain characteristics, geographical area and other parameter can vary widely from area to area. Additionally, the changed environment causes the efficiency of the particular path loss model to vary in different design and form for which it was initially prepared. The Kutch Bhuj (Gujarat) geographical and morphological area varies so widely from sea to hills including desert, rann, plains etc. where most models were developed. We have seen that when we compare the measured data with propagation model then they give unsatisfactory result. In this paper we have compared the measured path loss to various path loss prediction models and result shows one of the best fit model in Bhuj are ECC-33 and Okumura- Hata which were closest to measured data. Key words: Path loss models, Propagation, empirical measurement, communication system. I. INTRODUCTION In Wireless communication Propagation models are used for predicting the path loss at a given distance from the transmitter. Path loss is signal attenuation between the transmitter and receiver and hence these models are also used to predict the signal strength for an arbitrary transmitter receiver (T-R) separation. Path loss is helpful as controlling factor for increasing the system performance and achieves best reception. 171
  • International Journal of Electronics and Communication Engineering & Technology (IJECET), ISSN0976 – 6464(Print), ISSN 0976 – 6472(Online) Volume 3, Issue 2, July-September (2012), © IAEMEThese models can be broadly categorized in to three types: Empirical Models, StatisticalModels and Deterministic Models. Deterministic model are accurate model uses Maxwell’sequation with reflection and diffraction law. The second type model is Empirical modelwhich uses the existing equation obtain from measurement data and other parameters. Thelast one Statistical model which is based on deterministic and empirical model . In thispaper, only empirical models are considered. Empirical models use measurement data tomodel a path loss equation. To conceive these models, a correlation was found between thereceived signal strength and other parameters such as antenna heights, terrain profiles, etcthrough the use of extensive measurement and statistical analysis[3].The was collected fromBSNL by suitable equipment and then compared with the simulation result. A. Propagation Path loss calculation:Path loss is derived by the transmission path from a base transreceiver station to the mobilestation. it is shown by asPL(db)= EIRP+GM - PRXPRX = Received Power (dbm)GM = Mobile antenna gainEIRP = PT –Lc + Gbwhere EIRP is the effective isotropic radiated power of the base station, PT is the BStransfer output power, Lc is antenna cable loss and Gb is BS antenna gain[10]. B. Root Mean Squared ErrorThe root mean squared error (RMSE) [9] calculated based on ඥ∑ሺ୔୪୫ି୔୪ሻଶ RMSE = ୒where Plm is measured path loss and Pl is predicted path loss. II. EMPIRICAL MODELS A. Free space path loss modelPath loss in free space FSPL defines how much strength of the signal is lost duringpropagation from transmitter to receiver. FSPL is diverse on frequency and distance. Thecalculation is done by using the following equation[1][8].PL(dB) = 32.4 + 20log(d) + 20log(f)where,f: Frequency (MHz)d: Distance between transmitter and receiver (m)Power is usually expressed in decibels (dBm). B. Okumura-hata modelThe Okumura model [5] is empirical model to measure the radio signal strength in urbanareas. The model was built by the collected data in Tokyo city. This model is applicable for 172
  • International Journal of Electronics and Communication Engineering & Technology (IJECET), ISSN0976 – 6464(Print), ISSN 0976 – 6472(Online) Volume 3, Issue 2, July-September (2012), © IAEMEfrequencies in the range of 150 MHz to 1950 MHz and distance of 1 km to 100 km. it canbe used for the base station antenna heights ranging from 30m to 1Km.To determine pathloss using Okumara’s model, the free space path loss between the points of interest is firstdetermined and then the value of Amu ( f , d) is added to it along with correction factorsaccording to the type of terrain.The expression of the modelPL(dB)=LF+Amn(f,d)−G(hte)−G(hre)−GAERA (1)WherePL is path loss [dB], LF is Free space path loss [dB] Amn (f,d) is Median attenuationrelative to free space [dB], G(hte) is Base station antenna height gain factor [dB], G(hre) isMobile station antenna height gain factor [dB] , GAREA is Gain due to the type ofenvironment [dB], hte: transmitter antenna height [m] hre: Receiver antenna height [m], d isDistance between transmitter and receiver antenna [km]G(hre) = 10 log10 (hre/200) hre < 3mG(hre) = 20 log10 (hre/200) 10m> hre >3mG(hte) =20 log10 (hte /3)Okumura Model is considered to be among the simplest and best in terms of accuracy inpredicting the path loss for early cellular system. The major disadvantages of this model areits slow response to rapid changes in terrain profile. Therefore the model is fairly good inurban and suburban areas, but not good for rural areas[2]. C. Walfisch- Ikegami model:This model is a combination of J. Walfish and F.Ikegami model. The COST 231 project further developed this model. Now it is known as aCOST 231 Walfish-Ikegami (W-I) model. This model ismost suitable for flat suburban and urban areas that have uniform building height. Amongother models like the Hata model, COST 231 W-I model gives a more precise path loss.This is as a result of the additional parameters introduced which characterized the differentenvironments. It distinguishes different terrain with different proposed parameters. Theequation of the proposed model is expressed as,For LOS condition(PL)LOS = 42.6 + 26log(d) + 20log(f) (15)And for NLOS condition(PL)NLOS = {LFSL+ Lrts+ Lmsd } (16) for urban and suburbanThis is the extended version of COST-231 this model consists rooftop losses and buildinglosses[4][7]. 173
  • International Journal of Electronics and Communication Engineering & Technology (IJECET), ISSN0976 – 6464(Print), ISSN 0976 – 6472(Online) Volume 3, Issue 2, July-September (2012), © IAEME D. ECC 33 modelThe ECC-33 model is developed by Electronic communication committee (ECC). This isgenerally used for FWA (Fixed Wireless Access) system. The path loss is defined asPL (dB) = Afs + Abm – Gb – Gr ……..(4)Where,Afs, Abm, Gb and Gr are the free space attenuation, the basic median path loss, the BS heightgain factor and the terminal height gain factor. They are the individually defined as, Afs = 92.4 + 20 log10(D) + 20 log10(f)Abm = 20.41 + 9.83 log10(D) + 7.894 log10(f) + 9.56[log10(f)] 2..…..(5)Gb=log10(hb/200){13.958+ 5.8[log10(D)] 2} …..(6)And for medium city environments,Gr= [42.57+13.7 log10(f)][log10(hr) − 0.585] ….(7)Where f is the frequency in GHz, D is the distance between Transmitter and Receiver in km, hb isthe BS antenna height in meters and hr is the CPE antenna height in meters. Thepredictions using the ECC-33 model with the medium city option are compared with themeasurements taken in suburban and urban environments [6][7]. III. PERFORMANCE ANALYSISA Base station datathe table 1 shows the base station data which is known as base station transmitted power,mobile antenna height, cable loss, freq and others. Table 1: simulation parameters Sr.no. Parameters Values 1 Base station 43 dbm Transmitted power 2 Base station antenna 40m height 3 Mobile antenna 1.5m height 4 Transmitter antenna 18db gain 5 Cable loss 3.9db 6 Penetration Loss 11db 7 Body loss 4db 8 Connector loss 2db 9 Frequency 900MHzPath loss measurement of different model is given in Table 2 this is shown below. 174
  • International Journal of Electronics and Communication Engineering & Technology (IJECET), ISSN0976 – 6464(Print), ISSN 0976 – 6472(Online) Volume 3, Issue 2, July September (2012), © IAEME July-September Table 2Path Free ECC- W-I Oku-loss space 33 model hatamodel/ model model modeldistance1 91.5248 138.44 108.79 124.6771.5 95.0466 144.42 115.48 130.7362 97.545 149.54 120.23 135.0352.5 99.4836 153.92 123.91 138.3693 101.067 158.02 126.92 141.0933.5 102.406 162.28 129.47 143.3974 103.566 165.81 131.67 145.3924.5 104.589 167.93 133.61 147.1525 105.504 170.77 135.35 148.726 IV. RESULTSThe following graphs plot for the 1.5m Mobile receiver antenna height, 40m Base stationantenna height and frequency is 900MHz. The figure 1 shows minimum mean square errorof models. and Fig2 shows graph between the path loss and distance from transmitter toreceiver for Urban Environment. Similarly figure 2 graphs shows Suburban environment. ment. environment Fig 1 Minimum mean square error . 175
  • International Journal of Electronics and Communication Engineering & Technology (IJECET), ISSN0976 – 6464(Print), ISSN 0976 – 6472(Online) Volume 3, Issue 2, July-September (2012), © IAEME Fig 2 Pathloss for Urban area 1.5 m receiver antenna height in urban environment 170 160 150 140 Path loss (dB) 130 120 110 100 free space - o black 90 w-i model - + blue ecc-33 model- * red 80 oku- hata - ... green measured- * blue 70 0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5 Distance between Tx and Rx (km) Fig 3 Path loss for Suburban area 1.5 m receiver antenna height in suburban environment 170 160 150 140 130 Path loss (dB) 120 110 100 freespace o black 90 w-i model + blue ecc-33 model- * red 80 oku- hata - . . green measured * black 70 0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5 Distance between Tx and Rx (km) V. CONCLUSIONIn this paper we compare different types of propagation model with their path loss equationand graphs. Some of them model are used in urban, suburban area but some are in ruralareas. In this paper comparison shows that ECC-33 model is just near by the measured dataand also shows the minimum error so this is the best model for this environment.REFERENCES[1]H.R.Aderson, “Fixed Broadband Wireless system Design” John Wiley & co 2003.[2]Cruzl, R.M.S., F.C.Da Costal, P.F.Bragal, G. Fontgalland , M.A.B. Demeloand R.R.M.Do Valle “A comparison between theoretical propagation models and measurement data to 176
  • International Journal of Electronics and Communication Engineering & Technology (IJECET), ISSN0976 – 6464(Print), ISSN 0976 – 6472(Online) Volume 3, Issue 2, July-September (2012), © IAEMEdistinguish urban, suburban and open aeras in Jodo Pessoa,Brazil” IEEE Microwave andOptoelectronics, 287-291,July 2005. [3]K.Ayyappan, P.Dananjayan, “Propagation model for highway in mobile communicationsystem” may 2007[4] H.K.Sharma, S.Sahu, S.Sharma, “ Enhanced Cost231 W.I. Propagation Model inWireless Network” International Journal of Computer Applications, volume 19- No 6, April20011.[5]T.S.Rappaport, “Wireless Communications”, Pearson Education, pp.150-154, SecondEdition.[6] Abhayawardhana, V.S.,2003, “comparison of Empirical propagation Path loss Modelfor Fixed Wireless Access Systems”. Project funded by Ofcom, UK[7] V. Erceg, K. V. S. Hari., “Channel models for fixed wireless applications,” tech. rep.,IEEE 802.16 Broadband Wireless Access Working b Group, January 2001.[8] V. Erceg, L.J.Greenstein, “An Empirically Path loss model for Wireless channels insuburban environments” IEEE Journal on selected areas of Communications, vol.17,pp.1205-1211, July1999.[9] Josip Milanovic, Rimac-Drlje S, Bejuk K, “Comparison of propagation model accuracyfor WiMAX on 3.5GHz,” 14th IEEE International conference on electronic circuits andsystems, Morocco, pp. 111-114. 2007.[10]Armoogum.V, Soyjaudah.K.M.S, FogartyT.andMohamudallyN.,”Comparative studyof Path loss using existing models for Digital Television Broadcasting for Summer,Mauritius Vol. 4, pp 34-38,May Season in the north of Mauritius”, Proceeding of ThirdAdvanced IEEE International Conference on Telecommunication 2007.AUTHORS PROFILEMrs. Pooja Prajesh was born on 30th June 1978 in Roorkee, Uttrakhand (India). Shereceived her M.Tech degree in Digital Communication from Uttrakhand TechnicalUniversity (U.K.), India. She is a Associate Member of the AMIETE. She has publishedseveral Research papers in national and international journals/conferences. She is presentlyresearch scholar in Uttarakhand Technical University, Dehradun (India) . Her presentresearch interest is in Wireless Communication. 177
  • International Journal of Electronics and Communication Engineering & Technology (IJECET), ISSN0976 – 6464(Print), ISSN 0976 – 6472(Online) Volume 3, Issue 2, July-September (2012), © IAEMEDr. R.K. Singh Professor, KEC, Dwarahat, Almora, He is member of academic staff ofKumaon Engineering College, Dwarahat, Almora, where he is a professor in the departmentof Electronics and Communication Engineering. Dr. Singh has given his contribution to thearea of Microelectronics, Fiber Optic Communications, and Solid State Devices. He haspublished several research papers in seminar/conference and journal papers. He is memberof several institutional and educational and educational bodies. Before joining KumaonEngineering College, Dwarahat, he has worked in Birla Institute of Technology andSciences (BITS), Pilani, and Central Electronics Engineering Research Institute (CEERI)Pilani. At present he is serving as OSD, in newly established Technical University ofUttarakhand known as Uttarakhand Technical University, Dehradun (INDIA). 178