LTE-Planning Sec04 100509 v01

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©

©Ima Telems & MeiaIma Telems & Meia

OFDM/OFDMA AnD

LTE COnCEpTs

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OFDM/OFDMA and LTE Concepts OFDM/OFDMA and LTE Concepts

ThE L

TE R

ADiO

inTERFA

CE

InTroducTIon To oFdM/oFdMA

44

reqiemets

reqiemets   Me Me cmmiati cmmiati Systems Systems 44

chael

chael Bawith Bawith a a Faig Faig 66

Flat

Flat Faig Faig a a Feqey Feqey Seletive Seletive Faig Faig 66

deig

deig nawba nawba a a Wieba Wieba chaels chaels 88

cheee

cheee Bawith Bawith 1010

Mlti-caie

Mlti-caie Slti Slti 1122

oFdM

oFdM Basi Basi Piiples Piiples 1144

Sb

Sb caie caie othgaliothgality ty 1616

dpple

dpple Shit Shit i i rai rai chaels chaels 1818

cheee

cheee Time Time 1818

cyli

cyli Pex/Ga Pex/Ga Time Time 2020

Peak-t-Aveage

Peak-t-Aveage Pwe Pwe rati rati (PAPr) (PAPr) 2222

Sigle caie – Feqey divisi

Mltiple

Mltiple Aess Aess (Sc-FdMA) (Sc-FdMA) 2424

L

LTE TE PHY PHY Laye Laye Paametes Paametes 2828

L

LTE TE Sb-caie Sb-caie Spaig Spaig 2828

L

LTE TE Timig Timig a a Famig Famig 3030

Fame

Fame TType ype 2, 2, Tdd Tdd 3232

The

The rese rese Blk Blk 3434

cmpais  rese Blks, chael Size

a

a Samplig Samplig rate rate 3636

L

LTE TE chaels chaels a a chael chael Mappig Mappig 3838

L

LTE TE Lgial Lgial chaels chaels 4040

L

LTE TE TTaspt aspt chaels chaels 4242

L

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©

©Ima Telems & MeiaIma Telems & Meia

ThE L

TE R

ADiO

inTERFA

CE

InTroducTIon To oFdM/oFdMA

44

reqiemets

reqiemets   Me Me cmmiati cmmiati Systems Systems 44

chael

chael Bawith Bawith a a Faig Faig 66

Flat

Flat Faig Faig a a Feqey Feqey Seletive Seletive Faig Faig 66

deig

deig nawba nawba a a Wieba Wieba chaels chaels 88

cheee

cheee Bawith Bawith 1010

Mlti-caie

Mlti-caie Slti Slti 1122

oFdM

oFdM Basi Basi Piiples Piiples 1144

Sb

Sb caie caie othgaliothgality ty 1616

dpple

dpple Shit Shit i i rai rai chaels chaels 1818

cheee

cheee Time Time 1818

cyli

cyli Pex/Ga Pex/Ga Time Time 2020

Peak-t-Aveage

Peak-t-Aveage Pwe Pwe rati rati (PAPr) (PAPr) 2222

Sigle caie – Feqey divisi

Mltiple

Mltiple Aess Aess (Sc-FdMA) (Sc-FdMA) 2424

L

LTE TE PHY PHY Laye Laye Paametes Paametes 2828

L

LTE TE Sb-caie Sb-caie Spaig Spaig 2828

L

LTE TE Timig Timig a a Famig Famig 3030

Fame

Fame TType ype 2, 2, Tdd Tdd 3232

The

The rese rese Blk Blk 3434

cmpais  rese Blks, chael Size

a

a Samplig Samplig rate rate 3636

L

LTE TE chaels chaels a a chael chael Mappig Mappig 3838

L

LTE TE Lgial Lgial chaels chaels 4040

L

LTE TE TTaspt aspt chaels chaels 4242

L

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OFDM/OFDMA and LTE Concepts OFDM/OFDMA and LTE Concepts

chael

chael Mappig Mappig 4646

Mappig

Mappig chaels chaels t t the the rese rese Blk Blk 4848

chael

chael Mappig Mappig   a a 10MHz 10MHz chael chael 5050

uplik

uplik Mappig Mappig   Physial Physial chaels chaels 5252

uplik

uplik Mappig Mappig   the the ctl ctl chael chael 5454

oveall

oveall Pite Pite   uL uL Mappig Mappig 5656

Physial

Physial chaels chaels a a Mlati Mlati Shemes Shemes 5858

Syhisati

Syhisati a a reeee reeee Sigals Sigals 6060

Pimay

Pimay a a Seay Seay Syh Syh Seqees Seqees 6262

PSS

PSS a a SS SS i i the the Fame Fame Stte Stte 6464

reeee

reeee Sigals Sigals 6868

L

LTE TE reeee reeee Sigals Sigals 7070

dL

dL cell cell Spei Spei rS rS 7272

dL

dL uE uE Spei Spei rS rS 7744

uL

uL uE uE Spei Spei rS rS 7676

demlati

demlati reeee reeee Sigals Sigals (dM (dM rS) rS) 7676

Sig

Sig reeee reeee Sigals Sigals (SrS) (SrS) 7878

Mlati,

Mlati, chael chael cig cig a a Lik Lik Aaptati Aaptati 8080

chael

chael cig cig 8484

HArQ

HArQ (Hybi (Hybi Atmati Atmati reqest) reqest) 8686

reptig

reptig   uE uE Feebak Feebak 8888

Pwe

Pwe ctl ctl i i LLTE TE 9090

The

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4 ©Ima Telems & Meia

Reqremet o Moder Commcato sytem

reet xe a mbile baba statistis sggest that the ema  ata is ieasig at a eve aeleatig ate. Sevies sh as Faebk, Ytbe a the Web 2.0 type appliatis have taitially bee aesse m xe baba etis, hweve with the isig pplaity  the smat phe, these appliatis ae mvig switly i t the mbile mai. This pts pesse  the peats  mbile etwks t ese thee is siet apaity

 the existig vie ta as well as all the ew mltimeia a sial etwkig appliatis. The ema  high apaity makes the ai egiee lk t the ai hael t 

aitial apaity. I eet yeas the bawith  the hael has gw sigiatly m 200KHz GSM t 5MHz uMTS/HSPA a the mlati a ig shemes have gw steaily me mplex a eiet. Give the et bawith a mplexity  systems like HSPA it wl be ilt t gai me apaity by simply ieasig the hael bawith witht makig the tehlgy phibitively mplex.

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Cael Badwdt ad Fadg

The ge ppsite illstates a typial ba evimet thgh whih ai sigals ppagate. The tasmissi  the sigal m the se t the estiati is aie ve mltiple paths. The mai eas  this is the existee  the biligs, vehiles, a the bstales whih a

efet a satte the tasmitte sigal. The eeive sigal is a smmati  all these sigals m ieet paths. It is appaet that ay eeive will be sbjet t mltiple, time shi te pies  the same sigal.

Flat Fadg ad Freqecy selectve Fadg

Eah  these paths expeiees a ieet dpple shit a egee  atteati. The eqey espse is the epesetati i the eqey mai  the spepsiti  all these paths. With the mltipath seai, whee the tasmitte sigals take plae ve ieet paths, the sigals eeive m eah path will a p at the eeive ipt

The pwe  the eeive sigal will vay as it is epeet p the elatiship betwee the phases  eah eeive mpet; whethe the eslt is sttive  esttive aiti  the phase vales. This is geeally kw as aig

I the tasmitte hael is sietly aw the all the eqey mpets tasmitte i the hael will be atteate by the same amt, this is kw as fat aig

The piiple pblem with ieasig the bawith  the hael t ammate highe apaity is that the hael bemes ieasigly likely t se m eqey seletive

aig. This is whee ly a pat  the veall tasmitte spetm ses m the atteati e t mltipath aig.

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Receiver

Transmitter

P

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Frequency

Expected signal

Actual signal

P

o

w

e

r

Frequency

Expected signal

Actual signal

Fg. 2

a) Tycal Mltat Evromet

b) Flat Fadg

(9)

8

8 ©©Ima Telems & MeiaIma Telems & Meia

Defg narrowbad ad Wdebad Cael

Whethe a hael is etemie t be wie  aw ba epes  the elative magite

 the symbl time a the elay spea haateisti  the hael evimet. Tempal

istti  the sigal is a eet  the mltipath evimet asig the same symbl t be

eeive mltiple times ve a pei  time. The time ieees ae e t the ieig ppagati

elays expeiee  ieet paths.

T

Typial elay sypial elay speas  i apeas  i a t evimets ae shw be t evimets ae shw belw.lw.

I

I – – 40S 40S – – 20S; 20S; 112m 2m – – 60m60m

ot

ot – – 1S 1S – – 20S; 20S; 300m 300m – – 6Km6Km

A hael a be sai t be aw ba whe the symbl time (Ts) is sigiatly lage tha

ay elay spea peset

ay elay spea peset (T)(T)

naw ba – Ts > T

Hweve i the elay spea is sigiatly lage tha the symbl time the the hael may

be siee wieba.

Wieba – T > Ts

Fllwig  m the isssi abve, egaig fat a eqey seletive aig, it a

be sai that a hael that is ee as wieba, it is me likely t se m eqey

seletive aig.

csie w, that the symbl time is a

csie w, that the symbl time is a ti  the hael bati  the hael bawith.with.

Ts = 1/Bw

Theee as the hael bawith ieases the symbl time will eease.

e.g. e.g. Bw Bw = = 1MHz; 1MHz; Ts Ts = = 1S1S Bw = 1 Bw = 10M0MHz; Hz; Ts Ts = 0.= 0.1S1S

It is me pbable theee that high apaity, high bawith ai haels will expeiee

eqey seletive aig.

(10)

Transmitter

Receiver

P

o

w

e

r

Time

RMS delay spread

t5 t5 t4 t4 t3 t3 t2 t2 t1 t1 t0 t0

Narrow band ~ Ts > Td

Wideband ~ Td > Ts

T Tss Td Td

Fg. 3

idoor Delay sread

RMs Delay sread

narrowbad or WdeBad?

(11)

10

Coerece Badwdt

cheee bawith is a statistial mease  the age  eqeies ve whih the hael

a be siee “fat” (i.e., a hael whih passes all spetal mpets with appximately

eqal gai a liea phase). I the ws, heee bawith is the age  eqeies

ve whih tw eqey mpets have a stg ptetial  amplite elati.

cheee bawith is a ti  the elay spea evimet a a be allate

sig the llwig expessi;

1 1 B = B = 2 2πτπτ_ms_ms Whee;

Whee;ττ_ms_ms _{is the ms elay spea  the hael.}_{is the ms elay spea  the hael.}

The table belw shws typial elay speas  vais evimets a thei heee

bawith. Kwig the heee bawith  typial eplymet evimets allws a

estimati  the pbability that eqey seletive aig will  i the hael bawith

 the system is k  the system is kww..

E



v



r

o



m

e



t

T

y





c

a

l

r

m



D

e

l

a

y

C

o



e

r

e



c

e

B

a



d

w



d

t



H Hiilllly y aaeeaa 33--110 0 μμssee 5533KKHHzz--1166KKHHzz u ubbaa 11--33μμssee 116600KKHHzz--5533KKHHzz S Sbbbbaa << 11μμssee >>116600KKHHzz o oppee  aaeeaa < < 22000 0 ssee > > 779955KKHHzz I Iss 1100--550 0 ssee 1166MMHHzz--33..22MMHHzz

(12)

Fg. 4 – Coerece Badwdt

Coherence bandwidth is a statistical measure o the range

o requencies over which the channel can be considered

“fat”

_{(i.e., a channel which passes all spectral components}

with approximately equal gain and linear phase)

1 Bc =

2 πτ

_rms

Evromet

Tycal rm Delay

Coerece Badwdt

Hilly aea 3-10 μse 53KHz-16KHz

uba 1-3 μse 160KHz-53KHz

Sbba < 1μse > 160KHz

opeaea < 200se >795KHz

(13)

Mlt-Carrer solto

Give the pblems tlie abve the slti  tay’s baba wieless systems is t tilise mlti-aie systems kw as oFdM (othgal Feqey divisi Mltiplexig)  oFdMA (othgal Feqey divisi Mltiple Aess).

FDM (Freqecy Dvo Mltle Acce)

Mlti-aie systems split the high spee steam  seial baseba ata i t lwe spee paallel steams. The lwe bit ate  eah sb-aie eslts i a awe ai hael that is esistat t the eqey seletive ae.

OFDM (Ortogoal Freqecy Dvo Mltlexg)

Hweve, these mlti-aie systems ee t exhibit g spetal eiey, eah sb

aie mst be plae lse t its ajaet aie with t asig iteeee. The hael spaig is 1/Ts whee Ts is the symbl time  imati mlate t the aie.

Spaig the haels i this mae eses that the ete  eah aie esps with a ze ssig pit  eah  the eighbig sb-aies. This meas that the ete  the sb-aies a be sample, ee m iteeee  the ajaet sb-aies.

(14)

t1

t2

t3

t4

t5

t6

1/Ts

Fg. 5

Tradtoally saced FDM Cael

Ortogoally saced FDM Cael

(b-carrer)

(15)

OFDM Bac prcle

The blk iagam ppsite shws the basi piiple  a oFdM tasmitte/eeive. The imig ata steam is st vete m seial ata t paallel ata, the mbe  paallel ata steam will epe  the bawith  the veall hael a the mbe  sb-aies available t ay the ata. Eah  the paallel steams  ata is the mlate  t eah sb aie whih the eges a IFFT (Ivese Fast Fie Tasm) whih tasms the eqey mai sigal it a tme mai sigal. The mplex time mai sigal is the ae t pe a mpsite a mplex wavem.

I eeive the sigal mst be sample with siet eqey t ese all the mpsite eqey mpets ae apte. Whee thee ae me sb-aies the eeive sigal mst be sample me eqetly.

The tem FFT (Fast Fie Tasm) pits  samples, ees t the mbe  samples that mst take plae ig a sige FFT symbl, hee the lage mbe  FFT pits  highe bawith haels. The FFT symbl has a time eqivalet t the baseba symbl time bt is the mpsite  all the mlate sb-aies. The apte a sample sigal is tasme t the eqey mai by applyig a FFT. This eetively sepaates the sb-aies s they may be emlate iepeetly.

(16)

(17)

sb Carrer Ortogoalty

Give the vey tight spaig  the sb-aies  the oFdM hael it is vey imptat that the sb-aies emai thgal m eah the. distbaes i the time a eqey mai a ee the thgality  the aies esltig i a iease i BEr a geeally pe pemae.

distti i the eqey mai a me m dpple shit e t uE mvemet  m p syhisati  the uE sb systems t the system lk. The latte pblem a be eslve by havig the enB baast syhisati sigals  a egla basis, allwig the uE t ajst a maitai its syhisati with the enB. This a als ee the eet  dpple shit, hweve the heee time  the hael will pvie a iiati  hw likely the eeive sigals will be aete by dpple shit.

(18)

Demodulated

signal with

frequency offset

causing ICI

Demodulated

signal without

frequency offset

(zero ICI)

Fg. 7 – sb Carrer Ortogoalty

(19)

Doler st  Rado Cael

Feqey set is a imptat sieati, patilaly i oFdM systems. I mbile ai systems the velity  the uE will ase a appaet set m the ete aie  the ai hael, yielig pe pemae a highe BEr. I oFdM systems it will als ase ite sb-aie iteeee.

The llwig expessi may be se t etemie the eqey set e t dpple shit.   = sθ.

.υ

 Whee;

 is the eqey  peati v is the velity  the eeive  is the spee  light

Coerece Tme

A imptat pemae attibte whe sieig the systems sesitivity t eets  eqey set is the heee time. The heee time is a ti  the amt  eqey set peset i the hael a is ee as;

The time ve whih a hael a be assme t be stat. T_ = 2

√

16π9_._2

Theee a system that ses a symbl time whih is less tha the heee time will t be istte by the eets  dpple shit.

e.g.

Fi the heee time  a ai hael peatig at 2.6GHz a a mbile tavellig at 140kph. The agle  aival is 0

140kph = 38 m/s   = sθ. 2.6 x 109 _{. 3.8} 3 x 108  _ = 329.33 Hz T_ = 2

√

16π9_.329.332   = 1.28 x 10-3 ses

(20)

Fg. 8

Coerece Tme

The time over which a channel can be

assumed to be constant

(21)

Cyclc prefx/Gard Tme

The mlti-path evimet thgh whih the ai sigals ae tasmitte eate tempal isttis i the ata aie by the ai hael. The ieig ppagati ati  eah  the mlti-path mpets eate ite-symbl iteeee (ISI). Ite-symbl iteeee i oFdM systems at be tleate sie it ees the thgality betwee the sb-aies a ieases the BEr a ees pemae  the hael. All  the imati

imptat t the FFT (Fast Fie Tasm) is taie withi the symbl time theee it is itial that thee is  istti ig this pei.

Sie the ISI at be elimiate m the hael, the imati mst be ptete m its eet. The slti i oFdM systems is t exte the legth  eah symbl by a at eqivalet t the likely elay spea i the hael. This extesi t the symbl is kw as the yli pex (cP)  ga time.

The cP, whih appeas at the begiig  eah symbl a is atally a py  the last pat  that symbl. The ilsi  the ga pei elimiates the eets  mlti-path ISI at the expese  thgh pt, sie the cP aies  atal imati a is isae at the eeive e the rF sigal has bee sesslly igitise.

(22)

Symbol = 66.7µS Tcp= 4.7µ S

Total T ransmi tted Symbo l = 71.3µS

A B C CP A CP_B CP_C A B CP A CP_B CP_C T d Compete Symbol FF T Sampling Ti me

Fg. 9

Creato o te Cyclc prefx

(23)

peak-to-Average power Rato (pApR)

oFdM es peset sme tehial halleges. The esltig mpsite wavem isplays lage vaiatis i amplite ase by the mbiati  a mbe  iivial sigals.

This is illstate i Fige 11. The eet is simila t that ase by the mltipath evimet – a esltat sigal ftatig i amplite as a eslt  the mbiig  s may sigals with isete phase a amplite ieees.

This esltat mpsite sigal has impliatis  A t d vet a rF amplie esig. The yami age  the amplie mst be able t pe with the smallest a lagest sigal

amplites – patilaly the lagest amplite as it this that l ase ve-ivig  the amplie. ove ivig a amplie ases -liea behavi esltig i the geeati  hamis a Itemlati Pts (IPs) whih will esie withi the wate spetm, bt will ase wate eets. The FFT pess will be egae as it attempts t eal with eqey mpets that shl t be thee, esltig i l st pakets.

(24)

Symbol time 4

Symbol time 3

Symbol time 2

Carrier 1

Carrier 2

Carrier 3

Carrier 4

Composite

signal

(25)

sgle Carrer – Freqecy Dvo Mltle Acce (sC-FDMA)

3GPP has hse Sc-FdMA  the plik. nt spisigly, pwe smpti is a key sieati  uE temials. The high PAPr a elate lss  eiey assiate with oFdMA ae maj es. As a eslt, a alteative t oFdM was sght  se i the LTE plik.

Sc-FdMA is well site t the LTE plik eqiemets. The basi tasmitte a eeive ahitete is vey simila (ealy ietial) t oFdMA, a it es the same egee  mltipath pteti. Mst imptat thgh is that the elyig wavem is essetially sigle-aie, a theee the PAPr is lwe.

The ge ppsite mpaes the oFdMA a Sc-FdMA sttes. F laity this example ses ly  (M) sbaies ve tw symbl peis with the payla ata epesete by qaate phase shit keyig (QPSK) mlati.

data symbls i the time mai ae vete t the eqey mai sig a isete Fie tasm (dFT); the i the eqey mai they ae mappe t the esie lati i the veall hael bawith bee beig vete bak t the time mai sig a ivese FFT (IFFT). Fially, the cP is isete. Bease Sc-FdMA ses this tehiqe, it is smetimes alle isete Fie tasm spea oFdM  (dFT-SoFdM).

The mst bvis ieee betwee the tw shemes is that oFdMA tasmits the  QPSK ata symbls i paallel, e pe sbaie, while Sc-FdMA tasmits the  QPSK ata

(26)

Q

I

QPSK modulating

data symbols

Sequence of QPSK data symbols to be transmitted

1,1

-1,1

1,-1

-1,-1

V V

T i m e T i m e O F D M A s y m b o l O F D M A s y m b o l S C - F D M A s y m b o l S C F - D M A s y m b o l Frequency Frequency fc CP CP fc 15kHz 60kHz Constant subcarrier power during each SC-FDMA symbol period

OFDMA

Data symbols occupy 15kHz for one OFDMA symbol period

SC-FDMA

Data symbols occupy M*15kHz for 1/M SC-FDMA symbol periods

(27)

Sc-FdMA sigal geeati begis with a speial pe-ig pess. The iagam ppsite shws the st steps, whih eate a time-mai wavem  the QPSK ata sb-symbls. usig the  l-e QPSK ata symbls m the pevis iagam, the pess

eates e Sc-FdMA symbl i the time mai by mptig the tajety tae by mvig m e QPSK ata symbl t the ext. This is e at M times the ate  the Sc-FdMA

symbl sh that e Sc-FdMA symbl tais M setive QPSK ata symbls. oe a IQ epesetati  e Sc-FdMA symbl has bee eate i the time mai, the ext step is t epeset that symbl i the eqey mai sig a dFT.

T mplete Sc-FdMA sigal geeati, the pess llws the same steps as  oFdMA. Pemig a IdFT vets the eqey-shite sigal t the time mai a isetig the cP pvies the ametal bstess  oFdMA agaist mltipath. The iagam ppsite shws the stages i mm with oFdM.

(28)

Q

I

V(I)

+1 –1

One SC-FDMA

symbol period

One SC-FDMA

symbol period

V(I)

+1 –1

1,1

-1,1

1,-1

-1,-1

M d a t a b i t s i n Time domain Map data to constellation Generate time domain waveform

Unique to SC-FDMA Common with OFDMA

Perform M-point DFT (time to freq) Map symbols to subcarriers Perform N-point IFFT N > M Upconvert and transmit M d a t a b i t s o u t De-map constellation to data Generate constellation Perform M-point IDFT (time to freq) De-map subcarriers to symbols Perform N-point DFT N > M Receive and downconvert Frequency domain Time domain

Fg. 12

Geeratg te sC-FDMA sgal

(29)

LTE phY Layer parameter

LTE is esige t meet may ieig eqiemets ilig ba, sbba, i a t evimets as well as pig with may ieet mbility itis m statiay t high spee mbility p t 500Kph. cell sizes may als vey m emt t lage al ma. The age  spetm that LTE may be ptetially eply ass is als vey wie, 400MHz –

4GHz, the eplye system bawiths that may be sppt als ages m 1.4MHz t 20MHz. Give the eplymet fexibility  LTE the age  hael itis that it is expete t pem e is extemely wie a vaie. The itial paametes eqie t sppt this ivesity ae the sb-aie spaig a the yli pex.

LTE sb-Carrer sacg

The sb-aie spaig is 15KHz. csie the pevis isssis  heee bawith a esiliee t dpple eets, seleti  sb aie spaig  15KHz  LTE ai

iteae is a mpmise base  the expete peatial evimet a expete levels  pemae.

(30)

Channel spacing = 1/Ts

Ts = 66.7µS

Fs = 1/66.7µS = 15KHz

(31)

LTE Tmg ad Framg

The basi it  time i LTE is Ts, this is ee as 1/(15000*2408) = 32.56S, whee 15000 is the bawith  the sb-aie a 2048 is the maximm mbe  FFTs sppte. Evey elemet  time is sme mltiple  this vale.

The ge ppsite shws the type 1 ame,  Fame Stte 1 (FS1), this is the timig stte se  the plik a wlik  the Fdd (Feqey divisi dplex) haels. oe slt is a 0.5mS pei  time whih tais 7 symbls  66.67 µS. 2 slts make p e 1mS Sb-Fame, the sb-ame is smetimes eee t as the tasmissi time iteval (TTI) patilaly by the highe layes. Thee a 10 sb-ames  20 slts i e 10mS ame. This stte is se i the time mai t map the physial haels. nte that the physial

(32)

0 1 2 3 4 5 6

One subframe

One slot, T

_slot

= 15360, T

_s

= 0.5 ms

One radio frame, T

_f

= 307200, T

_s

= 10 ms

#0

#1

#2

#3

#18

#19

66.67µS Symbols

(33)

Frame Tye 2, TDD

The ge ppsite shws the ame stte se  a Tdd (Time divisi dplex) hael. It has simila veall timig i.e. the veall ame legth is 10mS a 10 sb-ames  1mS eah. Hweve the stte  the sb-ames is i eet.

I the FS2 the sb-ame allws bth a plik a wlik tasmissi/eepti pptity. These ae eee t as the dwPTS (dwlik Pilt Time Slt) a upPTS (uplik Pilt Time Slt),

these ae sepaate i the sb-ame by a ga pei (GP).

The ame has tw ieet swith pits i.e. the pit at whih a ee slt gati begis t epeat, these ae at 5mS a 10mS. I aiti thee ae 7 ieet ame

gatis. I ay  these gatis sb-ame 0 a 6 ay wlik imati ly, a sb-ame aies plik ly. The table ppsite shws the ame gatis.

(34)

Fg. 15 – Frame Tye 2 TDD

Cofgrato swtc-ot

erodcty

sb-rame mber

0

1

2

3

4

5

6

7

8

9

0 5ms d S u u u d S u u u 1 5ms d S u u d d S u u d 2 5ms d S u d d d S u d d 3 10ms d S u u u d d d d d 4 10ms d S u u d d d d d d 5 10ms d S u d d d d d d d 6 10ms d S u u u d S u u d

(35)

Te Reorce Block

Mappig  haels takes plae i the time a eqey mais i LTE. The pimay elemet that sppt the mappig pess is the rese Blk (rB). The rB has a xe size a is mm t all hael bawiths/FFT sizes.

I the time mai the rB is e slt ( 7 x 66.67µS symbls). I the eqey mai thee ae 12 x 15KHz sb-aies. 1 symbl a 1 sb-aie is kw as a ese elemet. Fm the ge ppsite it a bee see that the rB pies 12 x 15KHz = 180KHz  ba with. I a 5MHz ai hael thee will be 300 rB pyig 4.5MHz  spetm. The mbe  FFTs eqie t pess this is 512, assmig sb-aie size  15KHz, 512 x 15KHz = 7.68MHz. 7.68MHz i the spae pie by 512 FFT pits a is t the tasmitte bawith, 7.68MHz is als the samplig eqey eqie t eve imati m the aie t ive the FFT (time mai t eqey mai) i the eeive.

(36)

1 slot

Resource

block

DL or UL

symbol

N

s c R B

=

1

2 (

1

8

0 k

H

z

)

Time

*5 MHz system with frame structure type 1

F

r

e

q

u

e

n

c

y

N

R B

x

N

s c R B

=

3

0

0 (

4 .

5 M

H

z

)

Z

e

r

o

s

Z

e

r

o

s

M

=

5

1

2 (

7 .

6

8 M

H

z

)

(37)

Comaro o Reorce Block, Cael sze ad samlg Rate

The table ppsite shws the mbe  rB eqie  hael bawiths sppte by LTE, it shl be te that the eiti  hael bawith i this table ees t the mial hael size ee by the spetm eglatig by, it is t eessaily the tasmissi bawith. Sie eah rB tais 12 sb-aies the mbe  pie sb-aies a be etemie, mltiplyig the mbe  pie sb-aies by 15KHz will me aately esibe the tasmissi bawith  the vais ptis.

The IdFT/dFT (Ivese diseet Fie Tasm) esibes the mbe  FFT pits eqie t sesslly eve imati m the aie, it is always a vale  2 a etemies the mbe  steps  pesses eqie t stt/e-stt the mpsite oFdMA sigal. The samplig ate a samples pe slt ae etemie m the FFT mbe a the sb-aie 

bawith. E.g. i the 5MHz hael the samplig ate  7.68MHz wl eslt i 3840 samples evey 1mS.

(38)

Fg. 17 – Table o Reorce Block sze ad Cael Badwdt

chael bawith (MHz) 1.4 3 5 10 15 20 nmbe  ese blks (nrB) 6 15 25 50 75 100

nmbe  pie sbaies 72 180 300 600 900 1200 IdFT(Tx)/dFT(rx) size 128 256 512 1024 1536 2048 Sample ate (MHz) 1.92 3.84 7.68 15.36 23.04 30.72 Samples pe sht 960 1920 3840 7680 11520 15360

(39)

LTE Cael ad Cael Mag

Imati, bth sigallig a se, is tasmitte thgh the ptl stak a ve ai sig haels. Thee ae 3 basi types  hael ee, Lgial, Taspt a Physial haels. Eah hael is ee by a set  tis  attibtes whih etemies the halig  the ata ve the ai iteae.

Logcal Cael

Lgial chaels exist betwee the PdcP laye a MAc, they ae piipally ee by the type  imati that they ay. Thee ae lgial haels that ay tl ata, a lgial haels that ay se ta.

Traort Cael

Taspt chaels exist betwee the MAc laye a the Physial Laye a ae ee the mae i whih the ata will be tasee, i.e. the type  hael ig, whethe the ata is ptete m es, size  ata pakets, et. The attibtes  ata tase applie t the ata i the taspt hael is thewise kw as the taspt mat.

pycal Cael

Physial chaels ae the atal implemetati  the taspt haels i the physial laye. The ly exist i the physial laye a epe  the physial laye haateistis, i.e. hael

(40)

Trafﬁc

channel

MAC

PHY

Control

channel

Logical channels

Deﬁned by Type of information

i.e. trafﬁc, control,

e.g. BCCH, PCCH,

CCCH, MCCH, DCCH

Transport channels

Deﬁned by Transport attribute

i.e. channel coding,

CRC, interleaving,

size of radio data packets,

e.g. BCH, PCH, DL-SCH, MCH

Physical channels

Deﬁned by actual physical layer

characteristics, bandwidth,

FFT size, e.g. PDSCH,

PDCCH, PMCH, PBCH…

(41)

LTE Logcal Cael

Thee ae tw types  lgial hael, tl haels a ta haels, they ae esibe belw.

Cotrol Cael

ctl haels ae se  tase  tl plae imati ly. The tl haels ee by MAc ae:

Broadcast Control Channel (BCCH)

A wlik hael  baastig system tl imati. Imati baast  this hael is shae by all the ses i the ell, the imati baast elates t the opeat ietity, ell gati, aess imati et

Paging Control Channel (PCCH)

A wlik hael that tases pagig imati. This hael is se whe the etwk es t kw the lati ell  the uE.

Common Control Channel (CCCH)

chael  tasmittig tl imati betwee uEs a etwk. This hael is se  uEs havig  rrc eti with the etwk. It wl be se ig the ealiest phases  mmiati establishmet.

Multicast Control Channel (MCCH)

A pit-t-mltipit wlik hael se  tasmittig MBMS tl imati m the etwk t the uE,  e  seveal MTcHs. This hael is ly se by uEs that eeive MBMS.

Dedicated Control Channel (DCCH)

A pit-t-pit bi-ietial hael that tasmits eiate tl imati betwee a uE a the etwk. uEs havig a rrc eti will exhage rrc a nAS sigallig, it shl be te that appliati level sigallig (SIP messages m the IMS) is t hale by the dccH.

Trafc Cael

Ta haels ae se  the tase  se plae imati ly. The ta haels ee by MAc ae:

Dedicated Trafc Channel (DTCH)

A deiate Ta chael (dTcH) is a pit-t-pit hael, eiate t e uE,  the tase  se imati. The dTcH will als ay sigallig m the appliati layes, this may be SIP a rTSP sigallig i the EPc sppts IMS (IP Mltimeia Sbsystem) Multicast Trafc Channel (MTCH)

A pit-t-mltipit wlik hael  tasmittig ta ata m the etwk t the uE. This hael is ly se by uEs that eeive MBMS.

(42)

LTE Logical Channels

L

o

g

i

c

a

l

C

o

n

t

r

o

l

C

h

a

n

e

l

s

L

o

g

i

c

a

l

T

r

a

f



c

C

h

a

n

e

l

s

Broadcast Control Channel (BCCH)

•

• System Information MessagesSystem Information Messages

Paging Control Channel (PCCH)

•

• Paging Messages, UE LocationPaging Messages, UE Location

not known

Common Control Channel (CCCH)

•

• Early communication, no RRCEarly communication, no RRC

connection

Multicast Control Channel (MCCH)

•

• Multicast control signallingMulticast control signalling

Dedicated Control Channel (DCCH)

•

• Bi-Directional signalling, RRCBi-Directional signalling, RRC

connection, RRC and NAS Signalling

Dedicated Trafﬁc Channel (DTCH)

•

• Point-Point bi-directional channel,Point-Point bi-directional channel,

User data and application level

signalling (SIP)

Multicast Traf

Multicast Trafﬁc Channel ﬁc Channel (MTCH)(MTCH)

•

• Point-Multi-point channel supportingPoint-Multi-point channel supporting

data transfer for the MMBS service

Fg. 19 – LTE Logcal Cael

(43)

42

LTE Traort Cael

Taspt haels ae lassie i t plik a wlik haels a ae esibe belw.

Broadcat Cael (BCh)

The BcH has a xe a pe-ee taspt mat lagely ee by the eqiemet t

be baast i the etie veage aea  the ell sie the imati aie by this hael

tais system imati.

Dowlk sared Cael (

Dowlk sared Cael (DL-sChDL-sCh))

This hael will ay wlik sigallig a ta a may have t be baast i the

etie ell, give the ate  the ata i this hael it will als sppt  bth yami

a semi-stati ese allati with the pti t sppt  uE istis eepti

(drX) t eable uE pwe savig, E tl is sppte i this hael by meas 

HArQ a yami lik aaptati by vayig the mlati, ig a tasmit pwe.

Spetal eiey a als be iease e t the pssibility  sig beammig atea

tehiqes. The hael als sppts MBMS tasmissis.

pagg Cael (pCh)

This hael is assiate with the PccH a will ay pagig message t uEs t etly

ete t the etwk. The PcH sppts istis eepti (drX) t eable uE

pwe savig whee the sleep yle is iiate by the etwk t the uE. The PcH may als

have t be baast i the etie veage aea  the ell. The PcH is als mappe t

physial eses whih a be se yamially als  ta/the tl haels.

Mltcat Cael (MCh)

The hael is assiate with the mltiast sevies m the ppe layes a as sh thee

is a eqiemet t baast bth tl a se ata ve the etie veage aea  the

ell. It als sppt the Sigle Feqey netwk as semi-stati ese allati

ulk sared Cael

ulk sared Cael (uL-sCh)(uL-sCh)

The uL_ScH aies mm a eiate sigallig as well as eiate ta imati.

It sppts

It sppts the same the same eates as the eates as the dLdL-ScH.-ScH.

Radom Acce Cael (RACh)

The rAcH is a vey spei taspt hael, it aies limite tl imati ig the

vey ealiest stages  eti establishmet. This a mm plik hael theee thee

is the isk  llisis ig uE tasmissi.

(44)

LTE Transport Channels

D

o

w

n

l

i

n

k

T

r

a

n

s

p

o

r

t

C

h

a

n

e

l

s

U

p

l

i

n

k

T

r

a

n

s

p

o

r

t

C

h

a

n

e

l

s

Broadcast Channel (BCH)

•

• xed, pre-dened transport format;xed, pre-dened transport format;

•

• broadcast in the entire coverage areabroadcast in the entire coverage area

of the cell.

Downlink Shared Channel (DL-SCH)

•

• HARQ;HARQ;

•

• dynamic link adaptation by varyingdynamic link adaptation by varying

the modulation, coding and transmit

power;

•

• broadcast in the entire cell;broadcast in the entire cell;

•

• beamforming;beamforming;

•

• dynamic and semi-static resourcedynamic and semi-static resource

allocation;

•

• UE discontinuous reception (DRX) toUE discontinuous reception (DRX) to

enable UE power saving;

•

• MBMS transmission.MBMS transmission.

Paging Channel (PCH)

•

• UE discontinuous reception (DRX) toUE discontinuous reception (DRX) to

enable UE power saving

•

of the cell;

•

• mapped to physical resources whichmapped to physical resources which

can be used dynamically also for

trafc/other control channels.

Multicast Channel (MCH)

•

of the cell;

•

• MBSFN combining of MBMSMBSFN combining of MBMS

transmission on multiple cells;

•

• support for semi-static resourcesupport for semi-static resource

allocation e.g. with a time frame of a

long cyclic

Uplink Shared Channel (UL-SCH)

•

• beamformingbeamforming

•

• dynamic link adaptation by varyingdynamic link adaptation by varying

the transmit power and potentially

modulation and coding;

•

• HARQ;HARQ;

•

• dynamic and semi-static resourcedynamic and semi-static resource

allocation.

Random Access Channel (RACH)

•

• limited control information;limited control information;

•

• collision risk;collision risk;