Mimo - Ofdm1(Full)

7/31/2019 Mimo - Ofdm1(Full)

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TRNG I HC PHNG NGKHOA CNG NGH THNG TIN

TIPHN TCH V KHC PHC NHIU TRONG H

THNG THNG TIN V TUYN, DI NG S

DNG CNG NGH MIMO V GHP KNH OFDM1. Trn Th Chang

Nhm nghin cu: 2. ng Ngc Hng

3. H ng PhLp: 508102TVTKhoa: Cng ngh thng tin

Ngi HDKH: PGS.TS PHAN HU HUN

H N i 03/2012


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TITng quan v

nhiu trongh thngthng tinv tuyn

M hnh knh vtuyn v phn

tch nhiu ISI, ICItrong h thng

MIMO - OFDM

c lng knhv s tritnhiu trongh thng

MIMO OFDM.


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163

TNG QUAN

NhiungknhCCI

Nhiutrng

Nhiuknh

gn kACI

Nhiuxuynk tISI

Nhiuxuynknh

ICI

N h i u

T nhin Nhn to


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Knhh(t)

x(t)Tn hiu pht

y(t)Tn hiu thu

Nhiun(t)

M hnh knh thng tin c nhiu

Tn hiu thu: y(t) = x(t) * h(t) + n(t)


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2. Tnh ton t s cng sut C/I

3. Xc nh mi quan h gia C/I v S/Ihoc xc sut li Pc

1.Tnh ton hoc c lng mt cng sut nhiu

4. Xc nh quan h gia S/I hoc Pcv hiu nng h thng

5. Xc nh quan h gia hiu nng v mc thay itham s ca h thng

6. S dng t s C/I nh l php o ti uha s cp pht ti nguyn v cht lng

7.Khai thc k thut, cc tiu chun gim nhiu vxc nh nh hng ca nhiu

Phng

php

phn

tch

nhiu


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Tn hiu

Tng t

(analog)S

(digital)

Xy dng

quan h

ton hc

Tnh t s

cng sut

sng mang

C/I

Tnh t s C/I v S/I

+ H thng PSK

+ H thng di ngt bo


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Knh v tuyn

Suy haong truyn

Phadinga ng

Theong bao

Theop ngtn s

Knh truynkhng

chn lc

tn s(phng)

Knhtruyn

chn lctn s

Knhbin i

nhanh

Knhbin i

chm

Knh

Rayleigh

Knh

Rician

Dchdoppler


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M HNHMIMO Khngtng quan

MIMOTng quan

MonteCarlo

M hnh

m phngngu nhin

Bng hp Bng rng

M hnhtham chiu

NPhn t

L phn mnh

Niphn t

phn tn


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PHN TCHNHIUI S I I C I

Donh hngcc k hiu

trc v sautrong cng

sng mang

diGI

khng

m bo

di GIkhng

m bo di GI

m bo

T I C T V C T I C T V C


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CLNGKNH

Bn m(SemiBlind)

M(Blind)

+Pha thu bit trc v pha v bin +So snh tn hiu nhn cV pilot nguyn thy

=>Tn hiu chun hay khng khi phc

+ Pha thu khng bit vtn hiu pht v p ngxung knh+ Tn hiu: ngu nhin

hoc tin nh+ Bin i theogian chm

+ Ci thin tc

hi t+ Cp nht hs, cn bngknh+ Tch knh

ph thuc

Pilot(PSAM)


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PILOTMin

Thi gian

B lc bnh phng ti thiu (LS)

Min

Tn s

Cn bng tn hiu cho h thng MIMO - OFDM


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Bcn

bngknh

MIMO-

OFDM

Bphnknhhocmha

STBC

Tnh

tonphn bICI

Tnhton

phn bICI

iuch li

Giiiuch

iuch li

Gii

iuch

Tr mtmu tn

hiu

OFDM

Tnhtonthnh

phnnhiu ISI

Tr mtmu tn

hiuOFDM

Tnhtonthnhphn

nhiu ISI

Bphnknhhocmha

STBC

Bcn

bngknhMIMO-OFDM

TritISI

B ICI

CSI

CSI

a:(I=1)

b:(I>1)

B

A S TRIT NHIU (MIMO OFDM)


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Chn pha ban u

Cn bng knh cho h thng MIMO - OFDM

K thut iu bin v gii iu bin

ng dng thng tin v trng thi knh CSI

Chun b cho ln lp tip theo

Tnh ton phn bICI

Tnh ton nhiuISI

Trit nhiu ISI

B ICI

Thut ton


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MIMO&

OFDM

Kim v Stuber

Suyama

Trn min thi gianTnh nhiu ISI v phn b ICI

Dng IFFT

Trn min tn sTnh nhiu ISI v nhiu ICI

Dng FFT chuyn i

Dng MAP tnh nhiuhiu nng cao nhng

phi c lng knh ttv ph thuc GI

K thut c lng knhGii php v GI Khi phc chnh xc knh truyn

S dng hiu qu bng thng.


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Trong h thng thng tinhin nay, vic x l bng thngrng vi tc cao ang l xu

hng chung. l nhng vn quan trng lin quan n vic

nh hng v gii quyttrit nhiu.

KT LUN

Bng vic vn dng cc kin thc hc, ti liu tham kho v p

dng mt s thnh tu khoa hc k thut, nhm chng em

thc hin nghin cu

ti Phn tch v khc phcnhiu trong h thng

thng tin v tuyn, di ng sdng cng ngh MIMOv ghp knh OFDM.


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Mimo - Ofdm1(Full)

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