CHNG 2: GII THIU V CNG NGH V MC TIU THIT K LTE

2.1 . Gii thiu v cng ngh LTE :

LTE l th h th t tng lai ca chun UMTS do 3GPP pht trin. UMTS th

h th ba da trn WCDMA c trin khai trn ton th gii. m bo tnh cnh tranh cho h thng ny trong tng lai, thng 11/2004 3GPP bt u d n nhm xc nh bc pht trin v lu di cho cng ngh di ng UMTS vi tngi Long Term Evolution (LTE). 3GPP t ra yu cu cao cho LTE, bao gm gim chi ph cho mi bit thng tin, cung cp dch v tt hn, s dng linh hot cc bng tn hin c v bng tn mi, n gin ha kin trc mng vi cc giao tip m v gim ng k nng lng tiu th thit b u cui. c t k thut cho LTE ang c hon tt v d kin sn phm LTE s ra mt th trng trong 2 nm ti. Cc mc tiu ca cng ngh ny l: Tc nh tc thi vi bng thng 20 MHz: o Ti xung: 100 Mbps; Ti ln: 50 Mbps Dung lng d liu truyn ti trung bnh ca mt ngi dng trn 1 MHz so vi mng HSDPA Rel. 6:o Ti xung: gp 3 n 4 ln; Ti ln: gp 2 n 3 ln.

Hot ng ti u vi tc di chuyn ca thu bao l 0 15 km/h. Vn hot ng tt vi tc t 15 120 km/h. Vn duy tr c hot ng khi

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thu bao di chuyn vi tc t 120 350 km/h (thm ch 500 km/h ty bng tn) Cc ch tiu trn phi m bo trong bn knh vng ph sng 5km, gim cht t trong phm vi n 30km. T 30 100 km th khng hn ch.

Hnh 1.1 - Kin trc ca mng LTE

di bng thng linh hot: c th hot ng vi cc bng 1.25 MHz,

1.6 MHz, 2.5 MHz, 5 MHz, 10 MHz, 15 MHz v 20 MHz c chiu ln v xung. H tr c 2 trng hp di bng ln v bng xung bng nhau hoc khng. t c mc tiu ny, s c rt nhiu k thut mi c p dng, trong ni bt l k thut v tuyn OFDMA (a truy cp phn chia theo tn s trc giao), k thut anten MIMO (Multiple Input Multiple Output - a nhp a xut).