Reference Signal for LTE-Advanced

Reference Signalfor LTE-Advanced

Arumjeni Mitayani

Prologue

Reference Signal

• Downlink– Cell-specific reference signals– MBSFN reference signals– UE-specific reference signal (evo)– Positioning reference signal– CSI reference signal (evo)

• Uplink– Generation of the reference signal sequence– Demodulation reference signal (evo)– Sounding reference signal (evo)

Cell-specific RS

• Rel. 8– Non-MBSFN transmission

• Rel. 9– PDSCH transmission

• Rel.10– PDSCH transmission

Cell-specific RS (2)

0l0R

0R

0R

0R

6l 0l0R

0R

0R

0R

6l

One

ant

enna

por

tT

wo

ante

nna

port

s

Resource element (k,l)

Not used for transmission on this antenna port

Reference symbols on this antenna port

0l0R

0R

0R

0R

6l 0l0R

0R

0R

0R

6l 0l

1R

1R

1R

1R

6l 0l

1R

1R

1R

1R

6l

0l0R

0R

0R

0R

6l 0l0R

0R

0R

0R

6l 0l

1R

1R

1R

1R

6l 0l

1R

1R

1R

1R

6l

Four

ant

enna

por

ts

0l 6l 0l

2R

6l 0l 6l 0l 6l2R

2R

2R

3R

3R

3R

3R

even-numbered slots odd-numbered slots

Antenna port 0

even-numbered slots odd-numbered slots

Antenna port 1

even-numbered slots odd-numbered slots

Antenna port 2

even-numbered slots odd-numbered slots

Antenna port 3

Cell-specific RS (3)

• Generation

12,...,1,0 ,)12(212

1)2(21

2

1)( DLmax,

RB, s Nmmcjmcmr nl

CPcellID

cellIDs

10init 2121172 NNNlnc

Input:- N max DL RB- N cell ID- N CP- n sOutput:- CRS (3 dimension)

Cell-specific RS (4)

• Mapping

)'(s,

)(, mra nlplk

DLRB

DLmax,RB

DLRB

DLsymb

shift

12,...,1,0

3,2 if1

1,0 if3,0

6mod6

NNmm

Nm

p

pNl

vvmk

Input:- N max DL RB- N DL RB- N cell ID- n s- CRS

3 if)2mod(33

2 if)2mod(3

0 and 1 if0

0 and 1 if3

0 and 0 if3

0 and 0 if0

s

s

pn

pn

lp

lp

lp

lp

v

6modcellIDshift Nv

Output:- Slot (3 dimension)

MBSFN-RS

• Only supported in extended cyclic prefix mode

0l 5l 0l 5l

even-numbered slots odd-numbered slots

Antenna port 4

4R

4R

4R

4R

4R

4R

4R

4R

4R

4R

4R

4R

4R

4R

4R

4R

4R

4R Using antenna port 4

MBSFN-RS (2)

• Generation

16,...,1,0 ,)12(212

1)2(21

2

1)( DLmax,

RB, s Nmmcjmcmr nl

MBSFNID

MBSFNID

9init 121172 NNlnc s

Input:- N max DL RB- N MBSFN ID- n sOutput:- MBSFNRS (3 dimension)

MBSFN-RS (3)

• Mapping

)(s,

)(, mra nlplk

DLRB

DLmax,RB

DLRB

s

s

s

s

3

16,...,1,0

kHz 5.7 and 12mod if2,0

kHz 5.7 and 02mod if1

kHz 15 and 12mod if4,0

kHz 15 and 02mod if2

kHz 5.7 and 0 if24

kHz 5.7 and 0 if4

kHz 15 and 0 if12

kHz 15 and 0 if2

NNmm

Nm

fn

fn

fn

fn

l

flm

flm

flm

flm

k

Input:- n s- N max DL RB- N DL RB- MBSFNRSOutput:- Slot (3 dimension)

UE-specific RS

• Purpose– Enable channel estimation for demodulation– Allows reduced RS overhead– Obtain more accurate interference estimates in

partial loading scenarios• 1• 2• 3

UE-specific RS (2)

0leven-numbered slots odd-numbered slots

Antenna port 5

5R

5R

5R

5R

5R

5R

5R

5R

5R

5R

5R

5R

0l 6l6l

UE-specific RS (3)

0l 6l 0l 6l

Spe

cial

sub

fram

e, c

onfi

gura

tion

1, 2

, 6 o

r 7

Spe

cial

sub

fram

e, c

onfi

gura

tion

3, 4

or

8

0l 6l 0l 6l 0l 6l 0l 6l

0l 6l 0l 6l 0l 6l 0l 6l

All

oth

er d

ownl

ink

subf

ram

es

0l 6l 0l 6l 0l 6l 0l 6l

even-numbered slots odd-numbered slots

Antenna port 7

even-numbered slots odd-numbered slots

Antenna port 8

even-numbered slots odd-numbered slots

Antenna port 9

even-numbered slots odd-numbered slots

Antenna port 10

7R 7R 7R 7R

7R7R7R7R

7R 7R 7R 7R 8R 8R 8R 8R

8R 8R 8R 8R

8R 8R 8R 8R

9R 9R 9R 9R

9R 9R 9R 9R

9R 9R 9R 9R

10R 10R 10R 10R

10R 10R 10R 10R

10R 10R 10R 10R

7R 7R

7R7R

7R 7R

7R 7R

7R7R

7R 7R 8R 8R

8R 8R

8R 8R

8R 8R

8R 8R

8R 8R

7R 7R

7R7R

7R 7R

7R 7R

7R7R

7R 7R 8R 8R

8R 8R

8R 8R

0l 6l 0l 6l

8R 8R

8R 8R

8R 8R

0l 6l 0l 6l 0l 6l 0l 6l

0l 6l 0l 6l 0l 6l 0l 6l

9R 9R

9R 9R

9R 9R

9R 9R

9R 9R

9R 9R

10R 10R

10R 10R

10R 10R

10R 10R

10R 10R

10R 10R

9R 9R

9R 9R

9R 9R

9R 9R

9R 9R

9R 9R

10R 10R

10R 10R

10R 10R

10R 10R

10R 10R

10R 10R

UE-specific RS (4)

• Generation 11210 ,)12(21

2

1)2(21

2

1)( PDSCH

RBs N,...,,mmcjmcmrn

RNTI16cell

IDsinit 21212 nNnc

prefix cyclic extended11610

prefix cyclic normal11210 ,)12(21

2

1)2(21

2

1)(

DLmax,RB

DLmax,RB

N,...,,

N,...,,mmcjmcmr

SCID16cell

IDsinit 21212/ nNnc

Input:- N PDSCH RB- N cell ID- n RNTI- N max DL RB- n SCID

Output:- DMRS for port 5

(2 dimension)- DMRS for others

(3 dimension)

UE-specific RS (5)

• Mapping)'3( PDSCH

RB)(

, smNlra n

plk

13,...,1,0'

12mod if2,3

02mod if1,0

35

22

16

03

6,5 if4mod)2(4m'

3,2 if'4

mod)(

PDSCHRB

s

s

shift

shift

PRBRBsc

RBsc

Nm

n

nl

l

l

l

l

l

lv

lvmk

nNNkk

Input:- N PDSCH RB- n s- N sc RB- n PRB- DMRSOutput:- Slot (3 dimension)

3modcellIDshift Nv

UE-specific RS (6)

Positioning RS

0l 6l 0l 6lF

our

PB

CH

ant

enna

por

ts

6R

6R

6R

6R

6R

6R

6R

6R

6R

6R

6R

6R

6R

6R

0l 6l 0l 6l

One

and

two

PB

CH

ant

enna

po

rts

6R

6R

6R

6R

6R

6R

6R

6R

6R

6R

6R

6R

6R

6R

6R

6R

even- numbered slots odd- numbered slots

Antenna port 6

even - numbered slots odd- numbered slots

Antenna port 6

Positioning RS (2)

• Generation

12,...,1,0 ,)12(212

1)2(21

2

1)( DLmax,

RB, s Nmmcjmcmr nl

CPcellID

cellIDs

10init 2121172 NNNlnc

Input:- N max DL RB- n s- N cell ID- N CPOutput- PRS (3 dimension)

Positioning RS (2)

• Mapping)'(

s,)(

, mra nlplk

PRSRB

DLmax,RB

PRSRB

s

s

s

shiftPRSRB

DLRB

12,,1,0

portsantennaPBCH4and12modif6,5,3,2

portsantennaPBCH2or1and12modif6,5,3,2,1

02modif6,5,3

6mod66

NNmm

Nm

n

n

n

l

vlNNmk

6modcellIDshift Nv

Input:- N DL RB- N PRS RB- N max DL RB- N cell ID- PRSOutput:- Slot (3 dimension)

CSI-RS

• Purpose– To support 8-layer spatial multiplexing– Replace legacy data symbols on CSI-RS REs – Better support of coordinated multipoint (CoMP)

• 1• 2

CSI-RS (2)

even-numbered slots odd-numbered slots even-numbered slots odd-numbered slots even-numbered slots odd-numbered slots even-numbered slots odd-numbered slots

0l 6l 0l 6l 0l 6l 0l 6l 0l 6l 0l 6l 0l 6l 0l 6l

0l 6l 0l 6l 0l 6l 0l 6l 0l 6l 0l 6l 0l 6l 0l 6l

15R 15R 16R 16R

17R 17R 18R 18R

19R 19R 20R 20R

21R 21R 22R 22R

CSI-RS (3)

• Generation

1,...,1,0 ,)12(212

1)2(21

2

1)( DLmax,

RB, s Nmmcjmcmr nl

CPcellID

cellIDs

10init 2121172 NNNlnc

Input:- N max DL RB- N cell ID- N CP- n s

Output:- CSIRS (3 dimension)

CSI-RS (4)

• Mapping )'(s,"

)(, mrwa nllplk

2

DLRB

DLmax,RB'

1DLRB,...,1,0

1,0"

22,20,18,16"

1

21,19,17,151

prefix cyclic extended 27,-0 ionsconfigurat signal reference CSI"

prefix cyclic normal 31,-20 ionsconfigurat signal reference CSI"2

prefix cyclic normal 19,-0 ionsconfigurat signal reference CSI"

'

prefix cyclic extended,22,21for 9

prefix cyclic extended,20,19for 6

prefix cyclic extended,18,17for 3

prefix cyclic extended,16,15for 0

prefix cyclic normal,22,21for 7

prefix cyclic normal,20,19for 1

prefix cyclic normal,18,17for 6

prefix cyclic normal,16,15for 0

12'

NNmm

Nm

l

pl

plw

l

l

l

ll

p

p

p

p

p

p

p

p

mkk

Input:- N DL RB- N max DL RB- P- CSI config- N CP- CSIRS

Output:- Slot (3

dimension)

CSI-RS (5)

Demodulation RS

• To reduce downlink signaling overhead, 3 bit field is used to signal combination of CS and OCC

Evolution

• LTE Release 8– SRS is based on the extended ZC sequence

• LTE Release 10– Aperiodic SRS (A-SRS)

• 2

Sounding Reference Signal