chapter 11 wireless systems and standards -...

Chapter 11 Wireless Systems and standards

1

11.1 AMPS and ETACS Air Interface AMPS ETACS AMPS ETACS FDMA FDMA FDD FDD 30kHz 25kHz /RF 1 1 824~849MHz 890~915MHz 869~894MHz 935~960MHz FM FM /

kHz12 kHz8

kHz10 kHz4.6

BCH(40,28) BCH(48,36)

BCH(40,28) BCH(48,36)

/ 10kbps 8kbps 0.33bps/Hz 0.33bps/Hz 832 1000

2

11.2

IP

2G 2.5G 2.75G 3G 3.5G 3.75G 3.9G

GPRS EDGE

HSDPAR5

HSUPAR6MBMS 4G

MBMS

CDMA 2000 1X EV-DO

802.16 e 802.16 m

HSDPA

HSPA+R7 FDD/TDD

4G

GSM

TD-SCDMA

WCDMAR99

802.16 d

CDMAIS95

CDMA2000 1x

LTE

EV-DORev. A

EV-DORev. B

HSUPA HSPA+R7

11.3 Global System for Mobile (GSM) Most popular 2G , Features:

First cellular system using digital modulation Improved Networks archietecture Subscriber Identity Module (SIM). on-the-air privacy (MoU) Data service 9.6kbps

4

11. 3.1 GSM System Architecture It consists of three major interconnected

subsystems: BSS, NSS, and OSS.

BTS

BTS

BTS

BSC

BTS

BTS

BTS

BSC HLR VLR AUC

MSC

OMC

PSTN

ISDN

GSM

Abis

A SS7

5

GSM 890-915MHz 935~960MHzARFCN 0~124 975~1023

XX RT

XX RT 45MHz 3

270.833333kbps 4.615ms 8 576.9 s 3.692 s 0.3GMSK ARFCN 200kHz 40ms 13.4kbps

885-909/930-9541710-1720/1805-1815,:909-915/954-9601745-1755/1840-1850 6

11.3.3 GSM Channel Types Channel( both the forward and reverse

link) TS number ARFCN

Each physical channel in a GSM system can be mapped into different logical channels at different times.

There are two types of logic channel: TCH (traffic channel) CCH (control channel)

7

11.3.3.1 GSM Traffic ChannelsTCH Full-Rate TCH (user data is contained within one

TS per frame) Full-Rate Speech ChannelTCH/FS:13kbps/22.8kbps

Full- Rate Data Channel for 9.6kbps (TCH/F9.6) Full-Rate Data Channel for 4.8kbps (TCH/F4.8)Full-Rate Data Channel for 2.4kbps (TCH/F2.4} Half-Rata TCH (user data is mapped onto the same

TS, but is sent alternate frames) Half-Rata Speech Channel (TCH/HS):

6.5kbps/11.2kbps Half-Rata Data Channel for 4.8kbps (TCH/H4.8)Half-Rata Data Channel for 2.4bps (TCH/H2.4)

8

1TS0TS 2TS 4TS 5TS 6TS 7TS3TS

0T 1T 10T 11T 14T 15T 22T 23T 24T

576.92 (156.25 )s 86

13T2T

:nTS n

:nT n TCH S:I:

S IS

11.3.3.2 Radio Frame

9

11.3.3.3 GSM Control Channels (CCH GSM Control Channel: BCH, CCCH, DCCH. BCH: operates on the forward link of a

specific ARFCN within each cell, in the TS0 of certain frames. BCCH: be used to broadcast information such as cell and

network identity, operating characteristics and a list of channels that are currently in use within the cell.

FCCH (frequency correlation channel): it occupies TS0 for the every first GSM frame and is repeated every ten frames within a control channel multiframe.

SCH: Is used to identify the serving BS, frame number (FN), BS identity code (BSID). It is transmitted once every ten frames within the control channel multiframe.

10

CCCH: On the BCH ARFCN, occupying TS0 of every GSM frame that is not used by the BCH or the Idle frame. PCH: it provides paging signals, and notifies a specific

mobile of an incoming call. The PCH transmits the IMSI of the target MS, along with a request for ACK from the MS on the RACH.

RACH: It uses a slotted ALOHA access scheme. It is used by a MS to ACK a page from the PCH and is also used by users to originate a call.

AGCH (Access Grant channel)It used to instructs mobile to operate in a particular physical channel (TS and ARFCN), and also used by the BS to respond to a RACH sent in previous CCCH frame.

11

DCCH: there are three types. They are bi-directional and may exist in any TS and any ARFCN except TS0 of the BCH ARFCN. SDCCH (stand-alone dedicated): it carries signaling data

following the connection of the mobile with the BS, and just before a TCH assignment is issued by the BS.

SACCH: it is always associated with a traffic channel or a SDCCH and maps onto the same physical channel. It carries general information between MS and BTS. It is transmitted during the 13 frame of every speech/DCCH multiframe.

FACCH: it carries urgent messages, contains essentially the same type of inform. as the SDCCH.

12

0F

1S

3B

2B

5B

6C

7C

8C

9C

10F

11S

13C

20F

14C

4B

...21S

22C

...39C

40F

41S

42C

...12C

49C

50I

=51DMA235ms

0R

1R

2R

3R

4R

5R

6R

.............46R

47R

48R

49R

50R

=51DMA235ms

(a)

(b)

FFCCHBCHSSCHBCHBBCHBCHCPCH/AGCHCCCHI

13

11.3.4 Frame Structure for GSM These data bursts may have one of five

specific formats.

58

3

26

58

3

8.25

3

1423

8.25

3

39

41

39

3

8.25

8

64

36

3

68.25

3

58

26

58

3

8.25

FCCH

SCH

RACH

14

The data structure of a normal burst: During a frame, a user uses one TS to transmit,

one TS to receive, and may use the six spare TSs to measure signal strength on adjacent BSs as well as its own BS.

The 13th or 26th frame are not used for traffic, but for control purposes.

Each of the normal speech frames are grouped into larger structures called multi-frames (26 frames ) which in turn are grouped into super-frames (51 multi-frames ) and hyper-frames (2048 super-frames or 2715648 frames).

15

6.12s

120ms

0 21 3 4 5 6 7

4.615ms

3 57 1 26 1 57 3 8.25

576.92 s

51

26

8

156.25bits

16

11.3.5 Signal Processing in GSM

17

Speech Coding : RELP. TCH/FSSACCHFACCH channel Coding

Channel Coding for Data Channels: TCH/F9.6 is based on handling 60bits of user data at 5ms intervals, (240bit4tail), r=1/2, k=5, punctured conv. code, 32 bits are not transmitted, and the data is separated into 4*114bit data bursts.

50Ia

132Ib

78II

50 3 132 4

378 78

20ms456

1/25

18

Channel Coding for Control Channels: message are defined to be 184 bits long, and are encoded using a shortened binary cyclic fire code, followed by a half-rate convolutional coder. The fire code uses the generator polynominal:

Interleaving : These eight sub-blocks (57bit) which make up a single speech frame are spread over eight consecutive TCH time slots.

23 17 3 40 26 23 17 35 ( ) 1 1 1G x x x x x x x x x

0a 4b 1a 5b 2a 6b 3a 4a7b 0b 5a 1b 6a 2b 7a 3b

i+0 i+1 i+2 i+3 i+4 i+5 i+6 i+7

114bits

114bits

TCH/SACCH/FACCH88

19

Ciphering : A3 and A5 ciphering modifies. A3 algorithm is used to authenticate each

mobile by verifying passcode within the SIM with the cryptographic key at the MSC.

A5 algorithm provides the scrambling for the data.

Burst Formatting: adds binary data to the ciphered block, to help synchronization and equalization.

Modulation: 0.3GMSK. FH: Slow FH may be implemented to

combat the multipath or interference effects in that cell. FH is carried out on a frame-by-frame basis.

20

Equalization: is performed with the help of the training sequence. The type is not specified.

Demodulation: To a particular user is determined by the assigned TS and ARFCN.

The appropriate TS is demodulated with aid of synchronization data provided by the burst formatting.

21

11.3.6 Example of a GSM Call The MS must be synchronized to a nearby BS as it

monitors the BCH. The user dials, transmits a burst of RACH data, using

the same ARFCN as the BS to which it is locked. The BS responds with an AGCH message on the CCCH

which assigns the user to a new channel for SDCCH connection.

The user would receive its ARFCN and TS assignment from the AGCH and would immediately tune to the new ARFCN and TS (SDCCH).

The subscriber waits for the SACCH frame to be transmitted, which informs the mobile of any required timing advance and transmitter power command.

22

The user is now able to transmit normal burst message as required for speech traffic.

While the PSTN connects the dialed party to the MSC, and the MSC switches the speech path to the serving BS. The SDCCH sends messages between the mobile user and the BS, taking care of authentication and user validation.

The mobile unit is commanded by the BS via the SDCCH to retune to a new ARFCH and new TS for the TCH assignment.

The call is successfully underway, and the SDCCH is vacated.

23

11.4 CDMA Digital Cellular Standard (IS-95)

In March, 1993, a US digital cellular system based on CDMA was standardized as (IS-95) by TIA.

IS-95 is fully compatible with the IS-41 network standard described .

The user data rate changes in real-time, depending on the voice activity and requirements in the network.

IS-95 uses a different modulation and spreading techniques for the forward and reverse links.

24

11.4.1 Frequency and Channel Specifications reverse link operation in the 824~849MHz band and

869~894MHz for the forward link. A PCS version of IS-95 use in the 1800-2000MHz bands.

A forward and reverse channel is separated by 45MHz. The maximun user data rate is 9.6kbps. User data is spread to a channel chip rate of

1.2288Mcps. Number of channels: sixty-four orthogonal spreading

channels/carrier frequency. The spreading process is different for forward and

reverse links. RAKE receivers are used in both BS and MS. To provide BS diversity during soft handoff.

25

11.4.2 Forward CDMA Channelall "0" bits Pilot

Channel

Walsh 0

I-phasesequence

Q-phasesequence

SyncChannel

1.2kbps 4.8ksps

Walsh 32

PagingChannel

9.6kbps 19.2ksps 19.2ksps

Walsh i(0 < i < 8)

ForwardTrafficChannel

Walsh j(0 < j < 64, j!=32,i )

Conv. Encr=1/2 k=9

2.4ksps Sym. RepInterleaver

Conv. Encr=1/2 k=9

Sym. RepInterleaver

4.8ksps 9.6kbps

DecimatorLong CodeGenerator

1.2288Mcps

19.2ksps

9.6kbps 19.2ksps 19.2kspsConv. Encr=1/2 k=9

Sym. RepInterleaver

4.8ksps 9.6kbps

DecimatorLong CodeGenerator

1.2288Mcps

19.2ksps

2.4ksps1.2kbps

4.8ksps2.4ksps

Mux

800bpsPowerControlbits

1.2288M

1.2288M

1.2288M

26

It consists of a pilot channel, a synchronization channel, up to 7 paging channels and up to 63 traffic channels.

Convolutional Encoder: r=1/2, k=9, (753)8 and (561)8.

Repetition and Block Interleaver: to keep a constant baseband symbol rate of 19.2kbps, each symbol is repeat. After convolution coding and repetition, symbols are sent to a 20 ms block interleaverwhich a 24 by 16 array.

27

Long PN sequence: direct sequence is used for data scrambling.the LC is uniquely assigned to each user is a periodic with 242-1 chips.

Each PN chip is generated by the modulo 1 inner product of a 42 bit mask and the 42 bit state vector.

Two types of masks are used in the LC generator: a public mask for the MSs ESN and private mask for the MIN.

f x x x x x x x x x x xx x x x x x x x x x

( )

42 35 33 31 27 26 25 22 21 19

18 17 16 10 7 6 5 3 2 1 1

28

All CDMA calls are initiated using the public mask. Transition to the private mask is carried out after authentication is performed.

The public long code is specified as followsM41-M32 is set to 1100011000and M31-M0 is set to a permutation of the mobile stations ESN bitsESN=(E31,E30,E0)Permuted ESN=(E0,E31,E22,E13,E5,E27,E18,E9).

29

The private long code mask is specified so M41 and M40 are set to 0, 1, and M39-M0 are set by a private procedure.

1100011000 ESN

0 1

41M

41M 0M

0M

30

Data screambler: the 1.2288MHz PN sequence is applied to a decimator, which keeps only the 1st chip out of every 64 consecutive PN chip. The data screambling is performed by modulo 2 addition.

Orthogonal covering: each forward CDMA channel is spread with a Walsh function at a fixed chip rate of 1.2288Mcps. The 6464 Walsh function matrix:

1 2 2

0 00, ,

0 0N N

NN N

H HH H H

H H

31

Quadrature Modulation: After the orthogonal covering, symbols are spread in quadrature. A short binary spreading sequence, with a period 2 15-1 chip, is used for easy acquisition and synchronization at each mobile receiver and is used for modulation.

I Sequence: X = X X X X X X X X X X

Q Sequence: X = X X X X X X X X X X X

2 6 7 8 10 15 1 2 3 14

3 4 5 9 10 11 12 15 1 2 14

32

PC Subchannel: PC bits are transmitted by using puncturing.

1 2 3

0 1 2 3 4 5 6 97 8 10 11 12 13 14 15

0 1 2 3 4 5 6 97 8 10 11 12 13 14 15

20ms=16

0 2 3 4 5 6 97 8 10 11 12 13 14 151

2

1 0 11

=11=

1.25ms=24

IS-95 33

11.4.3 Reverse CDMA Channel

I-phasesequence

Q-phasesequence

AccessChannel

14.4ksps 28.8kspsConv. Encr=1/3 k=9

Sym. RepInterleaver

4.8ksps

Long CodeGenerator

1.2288Mcps

64-aryModu.

307.2ksps

ReverseTrafficChannel

28.8kspsConv. Encr=1/3 k=9

Sym. RepInterleaver

1.2ksps

Long CodeGenerator

1.2288Mcps

64-aryModu.

307.2ksps2.4ksps4.8ksps9.6ksps

3.6ksps7.2ksps

14.4ksps28.8ksps ChannelSelection

Delay T

34

Channel Coding: Convolutional Encoder: r=1/3, k=9, (557)8, (663) 8and (711)8.

Block interleaver: spans 20ms, and is an array with 32rows and 18 columns. Code symbols are written into the matrix by columns and read out by rows.

Orthogonal modulation: A 64-ary orthogonal modulation is used for reverse CDMA channel. One of sixty-four possible Walsh functions is transmitted for each group of six coded bits.Within a Walsh function, sixty-four Walsh chips are transmitted. The particular Walsh function is selected according to the following formula.

Walsh chips are transmitted at a rate of 307.2kcps0 1 2 3 4 5Walsh function number 2 4 8 16 32c c c c c c

28.8 (64Walsh chips) /(6coded bits) 307.2kbps kbps

35

1112 13 114 15 0 2 3 4 5 6 7 8 9 10 11 12 1413 15

1112 13 114 15 0 2 3 4 5 6 7 8 9 10 11 12 1413 15

1112 13 114 15 0 2 3 4 5 6 7 8 9 10 11 12 1413 15

1112 13 114 15 0 2 3 4 5 6 7 8 9 10 11 12 1413 15

9600bps

4800bps

2400bps

1200bps

1.25ms={12=36=6= 1

20ms={192=576=96=16

b0b1b2b3b4b5b6b7b8b9

b10

b12

b11

b13

PN

PCG14 PCG15

14PN 0 1 13, ,... 00101101100100b b b

36

Reverse IS-95 channel variable data rate transmission example is as above figure.

Direct sequence spreading: the reverse traffic channel is spread by the long PN sequence which operates at a rate of 1.2288Mcps.

The long code is generated as for the forward channel.

Each Walsh chip is spread by 4 long code PN chips.

Quadrature Modulation: prior to transmission, the reverse traffic channel is spread by I and Q channel pilot PN sequence which are identical to those used in the forward CDMA channel process.

37

11.5 World-wide used 3G TechnologyWCDMA

Radio interface architecture The Physical Layer(L1) the data link layer (L2)

Medium Access Control (MAC) Radio Link Control (RLC) Packet Data Convergence Protocol (PDCP) Broadcast/Multicast Control (BMC)

network layer (L3). Radio Resource Control (RRC)

38

11.5.1 Radio interface architecture

L3co

ntro

l

cont

rol

cont

rol

cont

rol

LogicalChannels

TransportChannels

C-plane signalling U-plane information

PHY

L2/MAC

L1

RLC

DCNtGC

L2/RLC

MAC

RLCRLC

RLCRLC

RLCRLC

RLC

Duplication avoidance

UuS boundary

BMC L2/BMC

control

PDCPPDCP L2/PDCP

DCNtGC

RadioBearers

RRC

39

Ref. 3GPP25.301

11.5.2 logical ChannelBroadcast Control Channel (BCCH)

Paging Control Channel (PCCH)

Dedicated Control Channel (DCCH)

Common Control Channel (CCCH)

Control Channel

Dedicated Traffic Channel (DTCH) Traffic Channel

Common Traffic Channel (CTCH)

Shared Channel Control Channel (SHCCH)

MBMS point-to-multipoint Control Channel (MCCH)

MBMS point-to-multipoint Traffic Channel (MTCH)

MBMS point-to-multipoint Scheduling Channel (MSCH)

40

11.5.3 Transport Channel Uplink

Random Access Channel (RACH) Dedicated Channel (DCH) Enhanced Dedicated Channel(E-DCH)

Downlink Broadcast Channel (BCH) Forward Access Channel (FACH) Paging Channel (PCH) High Speed Downlink Shared Channel (HS-

DSCH) Dedicated Channel (DCH)

41

Logical channels mapped onto transport channels, seen from the UE side

BCH PCH DSCH (TDD only)

FACHRACH

BCCH-SAP

DCCH-SAP

CCCH-SAP

PCCH- SAP

DCH

DTCH-SAP

Transport Channels

MAC SAPs

USCH (TDD only)

CTCH-SAP

SHCCH- SAP (TDD only)

HS-DSCHE-DCH

MSCH-SAP

MCCH- SAP

MTCH-SAP

42

11.5.4 Physical Channel Uplink

Common Uplink Physical channel PRACH

Dedicate Uplink Physical channel Downlink

Common Downlink Physical channel CPICH SCH P-CCPCH AICH

Dedicate Downlink Physical channel

S-CCPCH PICH PDSCH

43

Transport Channels

DCH

RACH

BCH

FACH

PCH

Physical Channels

Dedicated Physical Data Channel (DPDCH)

Dedicated Physical Control Channel (DPCCH)

Physical Random Access Channel (PRACH)

Common Pilot Channel (CPICH)

Primary Common Control Physical Channel (P-CCPCH)

Secondary Common Control Physical Channel (S-CCPCH)

Synchronisation Channel (SCH)

Acquisition Indicator Channel (AICH)

Paging Indicator Channel (PICH)

HS-DSCH-related Shared Control Channel (HS-SCCH)

HS-DSCH High Speed Physical Downlink Shared Channel (HS-PDSCH)

Dedicated Physical Control Channel (uplink) for HS-DSCH (HS-DPCCH)

Transport channels mapped onto physical channels

44

11.5.5.1 Data Flow in U-Plane : example I

45Ref. 3GPP25.301

Higher Layer

L1

Higher Layer PDU

RLC SDU

MAC SDU

Transport block (MAC PDU)

CRC

RLCheader

RLCheader

MAC SDU

Transport block (MAC PDU)

CRC

MACheader

MACheader

L2 MAC(non-transparent)

L2 RLC(non-transparent) Segmentation &

concatenation

reassembly

Higher Layer PDU

RLC SDU

Typical Data flow for non-transparent RLC and MAC

Data Flow in U-Plane: example II

46Ref. 3GPP25.301

Higher Layer

L1

Higher Layer PDU

RLC SDU

MAC-d SDU

MAC-d PDU

RLC RLC

MAC-d SDU

MAC-d PDU

CRC

MAC-d MAC-d L2 MAC-d

(non-transparent)

L2 RLC

(non-transparent)

Segmentation

&

Concatenation

Reassembly

Higher Layer PDU

RLC SDU

MAC-hs SDU MAC-hs SDU MAC-hs L2 MAC-hs (non-transparent)

Transport Block (MAC-hs PDU)

Data flow for non-transparent RLC and MAC mapped to HS-DSCH (MAC-hs configured),

11.5.5.2 Interactions between RRC and lower layers in the C plane

47

Ref. 3GPP25.301

R R C R R C

R L C R L C

Radio ResourceAssignment[Code, Frequency,TS, TF Set, Mapping,etc.]

Measurement Report

RLC retransmissioncontrol

L 1 L 1

U T R A N U E

Con

trol

Mea

sure

men

ts

Con

trol

Mea

sure

men

ts

Con

trol

Mea

sure

men

ts

Con

trol

Mea

sure

men

ts

M A C M A C

Con

trol

Con

trol

11.5.6 Physical channel frame structure

10ms/ radio frame 15 time slot/ radio frame Time slot length = 2560 chips Power control period 15 times/10ms HSPA: 2ms/subframe

48

11.5.6.1 PRACH

Pilot Npilot bits

DataNdata bits

Slot #0 Slot #1 Slot #i Slot #14

Tslot = 2560 chips, 10*2k bits (k=0..3)

Message part radio frame TRACH = 10 ms

Data

ControlTFCI

NTFCI bits

Structure of the random-access message part radio frame

K corresponds to a spreading factor of 256, 128, 64, and 32 respectively for the message data part.

49

Uplink Modulation

The binary control and data parts are spread to the chip rate by the channelisation code cc and cd respectively.the real-valued spread signals are weighted by gain factors, bc for the control part and bd for the data partThis complex-valued signal is then scrambled by the complex-valued scrambling code Sr-msg,n

S

Im{S}

Re{S}

cos(t)

Complex-valuedchip sequencefrom spreadingoperations

-sin(t)

Splitreal &imag.parts

Pulse-shaping

Pulse-shaping

Uplink spreading and modulation - PRACH

50

One access slot

p-a

p-mp-p

Pre-amble

Pre-amble Message part

Acq.Ind.AICH access

slots RX at UE

PRACH accessslots TX at UE

Structure of the random-access transmission

Message partPreamble

4096 chips10 ms (one radio frame)

Preamble Preamble

Message partPreamble

4096 chips 20 ms (two radio frames)

Preamble Preamble

Timing relation between PRACH and AICH as seen at the UE

51

11.5.6.2 Dedicated uplink physical channels

Frame structure for uplink DPDCH/DPCCH

TFCI: transport-format combination indicatorFBI: feedback information,TPC: transmit power-control

Pilot Npilot bits

TPC NTPC bits

DataNdata bits


Tslot = 2560 chips, 10 bits

1 radio frame: Tf = 10 ms

DPDCH

DPCCHFBI

NFBI bitsTFCI

NTFCI bits

Tslot = 2560 chips, Ndata = 10*2k bits (k=0..6)

52

Spreading for uplink DPCCH, DPDCHs and HS-DPCCH

I

j

cd,1 d

Sdpch,n

I+jQ

DPDCH1

Q

cd,3 d

DPDCH3

cd,5 d

DPDCH5

cd,2 d

DPDCH2

cd,4 d

cc c

DPCCH

S

chs HS-DPCCH (If Nmax-dpdch mod 2 = 1)

DPDCH4

chs HS-DPCCH (If Nmax-dpdch mod 2 = 0)

hs

hs

cd,6 d

DPDCH6

DPDCH Maximum Spreading factor:

256,{256,128,64,32,16,8,4}

DPCCH spreading factor: 256

53

11.5.6.3 synchronization channels

PrimarySCH

SecondarySCH

256 chips

2560 chips

One 10 ms SCH radio frame

acsi,0

acp

acsi,1

acp

acsi,14

acp

Slot #0 Slot #1 Slot #14

PSC is the same for every cell in the system.Secondary SCH consists of repeatedly transmitting a length 15 sequence of modulated codes of length 256 chips, 64 groups

54

Combining of downlink physical channels

Different downlink Physical channels

G1

G2

GP

GS

S-SCH

P-SCH

(point T in Figure 11)

55

11.5.6.4 Dedicated downlink physical channels

Frame structure for downlink DPDCH/DPCCHOne radio frame, Tf = 10 ms

TPC NTPC bits



Data2Ndata2 bits

DPDCHTFCI

NTFCI bitsPilot

Npilot bitsData1

Ndata1 bits

DPDCH DPCCH DPCCH

56

T

Im{T}

Re{T}

cos(t)

Complex-valuedchip sequencefrom summingoperations

-sin(t)

Splitreal &imag.parts

Pulse-shaping

Pulse-shaping

I

downlink physical channel

SP

Cch,SF,m

j

Sdl,n

Q

I+jQ S ModulationMapper

Downlink spreading and modulation

Spreading, I/Q branch use same channelization code.

modulation 57

11.5.6.5 Common Pilot Channel (CPICH)

Frame structure for Common Pilot Channel

P-CPICH: SF=256, fixed channelization code, time reference in a cellS-CPICH: SF=256, any channelization code , time reference for sccpch & dl-dpch

Pre-defined bit sequence


Tslot = 2560 chips , 20 bits


58

11.5.6.6 P-CCPCH

Frame structure for Primary Common Control Physical Channel

Data Ndata1=18 bits


Tslot = 2560 chips , 20 bits


(Tx OFF)

256 chips

Carry BCH,SF=256. Dont transmit during first 256 chip (SCH transmission)

59

11.5.6.7 S-CCPCH

Frame structure for Secondary Common Control Physical Channel



Pilot Npilot bits

Data Ndata1 bits


TFCI NTFCI bits

Carry FACH & PCH,SF: dynamic.

60

11.5.6.8 Shared Control Channel (HS-SCCH)

Subframe structure for the HS-SCCH

Slot #0 Slot#1 Slot #2

Tslot = 2560 chips, 40 bits

DataNdata1 bits

1 subframe: T f = 2 ms

The HS-SCCH is a fixed rate (60 kbps, SF=128) downlink physical channel used to carry downlink signalling related to HS-DSCH transmission 61

11.5.6.9 High Speed Physical Downlink Shared Channel (HS-PDSCH)

Subframe structure for the HS-PDSCH

Slot #0 Slot#1 Slot #2

Tslot = 2560 chips, M*10*2 k bits (k=4)

Data Ndata1 bits

1 subframe: Tf = 2 ms

An HS-PDSCH may use QPSK or 16QAM modulation symbols. M is the number of bits per modulation symbols i.e. M=2 for QPSK and M=4 for 16QAM 62

Step 1: Slot synchronisationDuring the first step of the cell search procedure the UE uses the SCHs primary synchronisation code to acquire slot synchronisation to a cell. This is typically done with a single matched filter (or any similar device) matched to the primary synchronisation code which is common to all cells. The slot timing of the cell can be obtained by detecting peaks in the matched filter output.

11.5.6.10 Cell search procedure

63

Step 2: Frame synchronisation and code-groupidentificationThe UE uses the SCHs secondary synchronisation code to find frame synchronisation and identify the code group of the cell found in the first step.(This is done by correlating the received signal with all possible secondary synchronisation code sequences, and identifying the maximum correlation value). Since the cyclic shifts of the sequences are unique the code group as well as the frame synchronisation is determined.

8192 scrambling code, 512 scrambling code primary , 64 group * 8,

64

Step 3: Scrambling-code identificationDuring the third and last step of the cell search procedure, the UE determines the exact primary scrambling code used by the found cell. The primary scrambling code is typically identified through symbol-by-symbol correlation over the P-CPICH with all codes within the code group identified in the second step. After the primary scrambling code has been identified, the Primary CCPCH can be detected. And the system and cell specific BCH information can be read.

65

11.6 LTE

Radio Resource Control (RRC)

Medium Access Control

Transport channels

Physical layer

Con

trol /

Mea

sure

men

tsLayer 3

Logical channelsLayer 2

Layer 1

1

10ms10 0.5ms Ts=1/(15000*2048)

#0

1 Tf = 307200 TS = 10 ms

1 Tslot=15360TS=0.5ms

#1

1

#2 #17 #18 #19

2

10ms25ms41

3DwPTSGPUpPTS1ms 5ms10ms 05DwPTS

1

#5

DwPTSGP

UpPTS

#9

1 153600 TS = 5 ms

1

#0

DwPTSGP

UpPTS

30720TS

#4

1Tslot=15360TS

1 Tf = 307200 Ts = 10 ms

Uplink-downlink

configuration

Downlink-to-Uplink

Switch-point periodicity

Subframe number

0 1 2 3 4 5 6 7 8 9

0 5 ms D S U U U D S U U U

1 5 ms D S U U D D S U U D

2 5 ms D S U D D D S U D D

3 10 ms D S U U U D D D D D

4 10 ms D S U U D D D D D D

5 10 ms D S U D D D D D D D

6 5 ms D S U U U D S U U D

D

U SDwPTSGPUpPTS

DwPTSUpPTSDwPTSGPUpPTS1ms

ConfigurationNormal cyclic prefix Extended cyclic prefix

DwPTS GP UpPTS DwPTS GP UpPTS

0 3 10

1 OFDMsymbols

3 8

1 OFDMsymbols

1 9 4 8 3

2 10 3 9 2

3 11 2 10 1

4 12 1 3 72 OFDMsymbols

5 3 9

2 OFDMsymbols

8 2

6 9 3 9 1

7 10 2 - - -

8 11 1 - - -

DwPTS

PSSDwPTS DwPTSPDCCH OFDM3

DwPTS9

TD-SCDMADwPTS

UpPTS

UpPTSRACHSRSSounding

RACHSRS

OFDMUpPTS

TD-SCDMAUpPTSUppch

= x RB x RB

= 15KHz RB = 12

(MHz) 1.4 3 5 10 15 20

RB 6 15 25 50 75 100

(MHz) 1.08 2.7 4.5 9 13.5 18

RE (Resource Element)

11

(k, l)

RB ( Resource Block)

112

LTE /

BCCH PCCH CCCH DCCH DTCH MCCH

MTCH

PCH DL-SCH MCHBCH

PBCH PDSCH PMCH

CCCH DCCH DTCH

UL-SCH

PRACH PUSCH

RACH

PUCCH

MACRLC

CCHTCHLTELTE BCCHBCCH

PCCH DCCH

MCCHMTCH DTCH

MTCHMBMS

MAC

LTE BCHBCCH PCHPCCH DL-SCHLTE

HARQLTEHSPACPC (Continuous Packet Conectivity)DL-SCHTTI1ms

MCHMBMS UL-SCHDL-SCH

PUSCH PUCCH PRACH

Reference

SignalRS

PDSCH: PBCH PMCH PCFICH PDCCH PHICH

Synchronization

Signal Reference Signal

RE

LTE PBCH PDSCH PCFICH

OFDM PDCCH PHICHHARQACK/NACK PMCH RS SCH

LTE PRACH PUSCH PUCCHHARQCQI

DMRS PUSCHPUCCH SRS PUSCH

PUCCH

UL-SCH

DL-SCH M

AC

sch

edul

erM

AC

sch

edul

er

RS1 2

1

0.5ms1

1ms

(SRS Channel sounding reference signal)

Step1PSCH5msID Step2SSCH10msID Step3BCH UEPBCHPCHRACH

SCH1.25MHzUEIDCPBCH

PRACHRACH

preamble UEPDCCH

PDSCHUE

UEPUSCH

eNBPDSCH

2

UE eNB

Msg1: preamble on PRACH

Msg2: RA response on PDCCH and PDSCH

min delay2ms

1

Msg3: connection requirement, ect3

Delay about5ms

Msg4: contention resolution 4

DelayBased on eNB

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