Thng tin di ng Ging vin : Ts Trng Tun5/31/20141 Thng tin di ngNhm : Nguyn Tun Linh Nguyn Nam Hiinh Th Cnh 5/31/20142 Contents 1. Phng thc nh s ARFCN cho GSM. 2. Cp pht knh trong GSM. 3. Cc m hnh suy hao5/31/20143 Contents 1. Phng thc nh s ARFCN cho GSM. 2. Cp pht knh trong GSM. 3. Cc m hnh suy hao5/31/20144 1.Phng thc nh s ARFCN cho GSM. ARFCN (absolute radio-frequency channel number) : l mt dng cng thc xc nh cp sng mang truyn nhn trong h thng thng tin di ng mt t gm mt cng thc cho tn hiu ln v mt cng thc cho tn hiu xung. Vi mi h thng khc nhau s cho cng thc tnh ARFCN khc nhau.

5/31/20145 1.Phng thc nh s ARFCN cho GSM. Cng thc tnh ARFCN cho h thng GSM vi rng bng tn knh l 200kHz, offset l 100kHz 5/31/20146 1.Phng thc nh s ARFCN cho GSM. ARFCNfULfDL GSM 900Primary GSM1 n 124890 + 0.2nfup(n) + 45 Extended GSM0 n 124 975 n 1023 890 + 0.2n 890 + 0.2(n-1024) fup(n) + 45 GSM Rail0 n 124 955 n 1023 890 + 0.2n 890 + 0.2(n-1024) fup(n) + 45 GSM1800 GSM1800 (DCS1800) 512 n 8851710.2 + 0.2(n-512) fup(n) + 95 5/31/20147 Contents 1. Phng thc nh s ARFCN cho GSM. 2. Cp pht knh trong GSM. 3. Cc m hnh suy hao5/31/20148 2.Cp pht knh trong GSM GSM 900-E 5/31/20149 2.Cp pht knh trong GSM GSM1800 5/31/201410 2.Cp pht knh trong GSM GSM1900 5/31/201411 Contents 1. Phng thc nh s ARFCN cho GSM. 2. Cp pht knh trong GSM. 3. Cc m hnh suy hao5/31/201412 3.Cc m hnh suy hao 3.1 M hnh khng gian t do. 3.2 M hnh 2 ng. 3.3 M hnh Hata. 3.4 M hnh Cost231 Walfish-Ikegami. 5/31/201413 3.Cc m hnh suy hao 3.1 M hnh khng gian t do. 3.2 M hnh 2 ng. 3.3 M hnh Hata. 3.4 M hnh Cost231 Walfish-Ikegami. 5/31/201414 3.1 M hnh khng gian t do. L(dB) = 32.5+ 20log(f[MHz]) +20log(d[km]). - f:tns. - d :khongcch BTS v MS. 5/31/201415 3.1 M hnh khng gian t do. 5/31/201416 3.Cc m hnh suy hao 3.1 M hnh khng gian t do. 3.2 M hnh 2 ng. 3.3 M hnh Hata. 3.4 M hnh Cost231 Walfish-Ikegami. 5/31/201417 3.2 M hnh 2 ng. L(dB) = 40log(d[km]) 20log(Hb x Hm). -d : khong cch BTS v MS. -Hb : cao anten BTS. -Hm : cao anten MS. 5/31/201418 3.2 M hnh 2 ng. 5/31/201419 3.Cc m hnh suy hao 3.1 M hnh khng gian t do. 3.2 M hnh 2 ng. 3.3 M hnh Hata. 3.4 M hnh Cost231 Walfish-Ikegami. 5/31/201420 3.3 M hnh Hata. L(urb) = 69.55 + 26.16log(f[Mhz]) 13.82log(Hb) a(Hm) + (44.9 6.55log(Hb))log(d). - a(Hm) l h s hiu chnh ca anten MS. Vi thnh ph loi nh v trung bnh :a(Hm) = (1.1log(f)0.7)Hm (1.56log(f) 0.8).

L(sub) = L(urb) 2(log(f/28))2 5.4. L(open) = L(urb) 4.78(log(f))2 + 18.33log(f) 40.49. 5/31/201421 3.3 M hnh Hata. 5/31/201422 3.Cc m hnh suy hao 3.1 M hnh khng gian t do. 3.2 M hnh 2 ng. 3.3 M hnh Hata. 3.4 M hnh Cost231 Walfish-Ikegami. 5/31/201423 3.4 M hnh Cost231 Walfish-Ikegami. M hnh COST231 Walfish-Ikegami l m hnh tnh ton suy hao c xem xt n nh hng ca cc ta nh bao gm cao cc ta nh, khong cch gia cc ta nh v nh hng ca rng ng ph ti ng truyn . M hnh ny thch hp vi cc thnh ph c mt ta nh ln. 5/31/201424 3.4 M hnh Cost231 Walfish-Ikegami. Trong mi trng truyn sng LOS. L = 42.6 + 26log(d) + 20log(f). 5/31/201425 3.4 M hnh Cost231 Walfish-Ikegami. 5/31/201426 Trong mi trng truyn sng NLOS. L = Lf + Lrts + Lms . L = Lf nu Lrts + Lms 0. Trong : - Lf l suy hao trong khng gian t do. - Lrts l suy hao do nhiu x hay tn x bi vt chn. - W l rng ng ph[m]. - Hr, Hm l chiu cao trung bnh ca cc ta nh - MS[m]; -L0 l sai s suy hao nhiu x v tn x[dB] - Lms l suy hao tn x a vt chn. - Lms = Lbsh + Ka + Kdlog(d)+ Kf log(f) 9log(b). b l khong cch gia cc nh dc theo ng truyn 3.4 M hnh Cost231 Walfish-Ikegami. Suy hao trong khng gian t do c tnh theo cng thc :Lf= 32,4 + 20.logd + 20.logfTrong - Lfl gi tr suy hao trong khng gian t do, tnh theo dB - d l khong cch t trm pht n trm thu, tnh theo km - f l tn s hot ng, tnh theo MHz Suy hao do tn x v nhiu x bi vt chn:Lrts = -16,9 10.logW + 10.logf + 20.log(hr hm) + L0 Trong - Lfl gi tr suy hao do tn x v nhiu x bi vt chn, tnh theo dB - W l rng ng ph, tnh theo m - hr l chiu cao trung bnh ca cc to nh, tnh theo m - hml chiu cao anten trm thu, tnh theo m5/31/201427 3.4 M hnh Cost231 Walfish-Ikegami. L0l sai s do suy hao tn x v nhiu x, tnh theo dB L0 = -10 + 0,354. vi 0 35 = 2,5 + 0,075.( - 35) vi 35 55 = 4,0 - 0,114.( - 55) vi 55 90 Suy hao tn x a vt chn tnh theo cng thc : Lms = Lbsh + Ka + Kd .logd+ Kf. logf 9.logbTrong - Lfl gi tr suy hao tn x a vt chn, tnh theo dB - b l khong cch gia cc to nh dc theo ng truyn, tnh theo m - hb l chiu cao trm pht - hr l chiu cao ta nh - d l khong cch t trm pht n trm thu 5/31/201428 3.4 M hnh Cost231 Walfish-Ikegami. Gi tr Lbsh tnh trong cc trng hp - Lbsh = -18log(1 + hb hr ) khi hb > hr - Lbsh = 0 khi hb < hr Gi tr Ka tnh trong cc trng hp - Ka = 54 khi hb > hr - Ka = 54 - 0,8hb khi hb hr v d 500m- Ka = 54 - 1,6(hb hr ).d khi hb hr v d 500m Gi tr Kd tnh trong cc trng hp - Kd = 18khi hb > hr - Kd = 18 15(hb hr )/(hr-hm)khi hb < hr Gi tr Kf tnh trong cc trng hp -Kf = -4 + 0,7(f/925 - 1)i vi thnh ph trung bnh v vng ngoi c mt cy trung bnh- Kf = -4 + 1,5(f/925 - 1)i vi trung tm thnh ph 5/31/201429 3.4 M hnh Cost231 Walfish-Ikegami. 5/31/201430 Tng hp cc m hnh 5/31/201431 Tng hp cc m hnh Nhn xt :Cc m hnh u c c im l gim mnh bn knh nh sau tc gim nh dn M hnh 2 ng () th hin mt sai s kh ln khi m suy gim (dB) trong vng bn knh 5Km u < 0dB Ngoi tr m hnh 2 ng th cc m hnh khc u cho suy gimln hn ca m hnh khng gian t do Trong m hnh hata ta c th thy r suy gim thnh th > ngoi thnh > nng thn Trong m hnh cos231, suy gim tn hiu LOS gn trng mi suy gim m hnh hata vng nng thn suy gim tn hiu trong cos231 ti vng trung tm v vng ngoi kh ging nhau v u cao hn suy giam trong thnh th ca m hnh hata 5/31/201432