Contents

OFDMA Frame StructureAllocation of Sub-carriersAMCQoSTarger MarketFrequency Reuse ModelsCoverage PlannigMIMOAAS

OFDMA Frame StructurePower

DL Sub-frame TTG UL Sub-frame RTGLast FrameTime

Next Frame

Frame structure

DL sub-frame consists of Preamble、FCH（frame control header ）、DL_MAP and DL data burst.

UL sub-frame consists of Ranging sub-channel, UL data burst. Ranging sub-channel is used for bandwidth request from all MSs.

Number of OFDM Symbols in DL and UL for 5/10MHz BW ranges from (35, 12) to (26:21)

Asymmetric DL/UL capability is implemented by different number of DL/UL sub-channels allocation.

For each SS, the maximum number of bursts to decode in one downlink subframe is 64.

In UL, every MS is only allocated one burst.

Allocation of Sub-carrierPilot sub-carrier Data sub-carrier

Guard sub-carrierDC sub-carrier

… … …………

10MHz*(28/25)=10.94KHz*1024

Calculation Method :channel Bandwidth10MHz10*(28/25)=11.2FFT Size:1024FFT Size:102416 sub –channel for DL FUSC11.2MHz/1024=10.94KHz1/10.94KHz=91.4 microseconds91.4*1/8=11.4(Cyclic Prefix is 1/8)5millisecond/102.9 microseconds=48

Frequency domainSC S OFDMA symbol is made up of subcarriersSub-carrierDC Sub-carrier OFDMA symbol is made up of subcarriers,

the number of which determines the FFT size used.

Data subcarriers: for data transmission

Guard Sub-carrierPilot Sub-carrier Data Sub-carrier Pilot subcarriers: for various estimation purposes

Null carrier: no transmission at all, for guard bands and DC carrier

Active subcarriers are divided into subsets of subcarriers termed a subchannel

Permutation zone: PUSC, FUSC, PUSC with all subchannels, optional FUSC, AMC andwith all subchannels, optional FUSC, AMC and FUSC with all subchannels

With the OFDMA sub-carrier structure, it supports a wide range of bandwidths from 1 25

Sub-channel #1 Sub-channel #2

supports a wide range of bandwidths from 1.25 MHz to 20 MHz.

WiMAX Key Technique--AMC64QAM

16QAM

QPSK

AMC Ad ti M d l ti d C diAMC

AMC：Adaptive Modulation and Coding Modulation scheme on sub-carrier is changeable.AMC introduced by OFDMA system user different modulation and coding based on the channel condition tomodulation and coding based on the channel condition to provide robust link adaptation in mobile environments.MS under good channel condition can get more higher data rate and average system throughput is also improvedrate and average system throughput is also improved.Channel measurement in 802.16 is based on RSSI and CINR.Mobile WiMAX supports AMC in both downlink and uplink with variable packet size.with variable packet size.

AMC• AMC

– Adaptive Modulation and Coding

AMC

p g• Purpose:

– To select the suitable modulation and coding gmodes according to different channel qualities

16QAM QPSK64QAM

• Through the combination of modulation and• Through the combination of modulation and coding, the network can provide different transmission rate.Th t f h l lit i b d• The measurement of channel quality is based on RSSI and CINR in 802.16e.

• Higher data rate of single user and the higherHigher data rate of single user and the higher average transmission rate of whole network

• Lower interferences.

The selection principle• Good channel quality: combination of high• Good channel quality: combination of high

efficiency modulation mode• Bad channel quality: combination of low

ffi i d l ti defficiency modulation mode

Different Result Based on Different Edge Rate Requirement

>10Mb

Rate Requirement

>1Mbps>10Mbps

>5Mbps500Kbps

VoIP

• The Area close to the BTS, can get high data rateThe Area close to the BTS, can get high data rate• It is not everywhere have a high data rate, in the data coverage planning

It is prefer to deploy the site in the central of the subscribersIt is prefer to deploy the site in the central of the subscribers.

Modulation and Coding Mode inModulation and Coding Mode in WiMAX

Supported Modulations and Codings

DL ULModulation Types

DL UL

QPSK、16QAM、64QAM

QPSK、16QAM、64QAM

CC 1/2, 2/3, 3/4, 5/6 1/2, 2/3, 3/4, 5/6

CTC 1/2 2/3 3/4 5/6 1/2 2/3 3/4 5/6CTC 1/2, 2/3, 3/4, 5/6 1/2, 2/3, 3/4, 5/6

Repetition x2, x4, x6 x2, x4, x6

QoS Guarantee

Mobile WiMAX can meet QoS requirements for a wide range of data q gservices and applications.

In the Mobile WiMAX MAC layer, QoS is provided via service flows.

The QoS parameters define the transmission ordering and scheduling on the air interface. The connection-oriented QoS therefore, can provide accurate control over the air interface.

QoS-Based Services

Unsolicited Grant Service (UGS) – VoIP (without silence suppression)Unsolicited Grant Service (UGS) – VoIP (without silence suppression)

Extended Real-time Polling Service (ertPS) – VoIP with silence

suppression

Real-time Polling Service (rtPS) – MPEG video

Non-real-time Polling Service (nrtPS) – FTP service

Best Effort (BE) – network browse, e-mail

Services WiMAX Supported

WiMAX forum put forward following service need to support:

pp

p g pp

• Interactive games among multiple person

• VoIP and video meeting

• Media streaming downloading

• Web browse and instant messages

• Media matter downloading

Target Market

• Nomadic• Fixed • Simple Mobility

• Portable • Full Mobility

Fixed Nomadic Portable Simple Mobility Full MobilityFixed（16d/16e）

Nomadic（16e）

Portable（16e）

Simple Mobility（16e）

Full Mobility（16e）

ApplicationEnterprise access Backhaul、high-level family outdoor access

Family indoor access and personal terminal access（not support handover）

Family outdoor access and personal terminal access（ support handover ）

Middle-rate mobile personal terminal

access

High-rate mobile personal terminal access

Terminal Outdoor Indoor, PCMCIAIndividual CPE，PCMCIA,Embedded portable terminal

Individual CPE，PCMCIA ，Personal handing terminal ，Embedded handing terminal

Mobility N/A Not support >5Km/h， >60Km/h >120Km/h

Frequency Reuse Model

N×S×K

The network is divided into clusters of N cells, S sector per cell, and K different frequency allocations per cell

The 1x3x1 case has higher interference than the 1x3x3The 1x3x1 case has higher interference than the 1x3x3

PUSC 1*3*1PUSC : There is 1 frequency point F1 in the whole network The DL and UL uses

11 11

PUSC : There is 1 frequency point F1 in the whole network. The DL and UL uses PUSC permutation models.

F1F133

2233

22

Only 1 Frequency Point for whole network, easy for Soft-Handover

Lower Frequency Efficiency11

33

q y yLarger CoverageEasy Deployment

More Interference Consideration22 More Interference Consideration

Reuse = 3

PUSC with all SC 1*3*3/FUSC 1*3*3PUSC with all SC/FUSC: There are 3 frequency points F1, F2, F3. Each sector of site with 3 sectors uses one frequency respectively. The DL uses FUSC/PUSC with all SC, and UL uses PUSC with all SC permutation models.

F1F1 F1F1 High Capacity per SiteLower Interference

F3F3F2F2

F3F3F2F2

F1F1

Lower InterferenceLarger CoverageEasy Deployment

F1F1

F3F3F2F2

Need Frequency Resource

F3F3

FFR 1*3*1FFR: Fractional Frequency Reuse, The PUSC will be used in the area beyond BS to ensure the coverage and the core area of the cells will use the PUSC with all SC permutation to enhance the throughput

Only 1 Channel for whole network, easy for Soft-Handovereasy for Soft Handover

Higher Frequency efficiencyLarger throughput per sector

Higher Frequency Efficiency

Different Result Based on Different Morphology

Dense UrbanCit t d CBD hi h d it lti l

Morphology

City center and CBD, high density multiple dwelling residential units, challenging propagation environment

UrbanSurrounding the city center, moderate to high density, Squally challenging propagation environment

SuburbanSuburbanLower density, favorable propagation environment

RuralMoving further from the city center, homes are g y ,further apart resulting in significantly lower population density with scattered small businesses

Coverage Planning Case StudyLink Budget

• Morphology: Dense Urbanp gy• Terminal: Indoor PCMCIA• Edge modulation: QPSK1/2• Frequency:2.5G• BS height: 30m• BS height: 30m• Propagation:Cost231-Hata ( HW )• MIMO: Matrix A• Antenna: UL 1T2R/DL 2T1R• Result: UL 0.55km/DL 0.47km• WiMAX radius is limited by UL

Capacity Planning Steps

Traffic model analysis/ requirement analysis/ requirement analysis

Single-user Customer resourceSingle user capacity

Customer resourcenetworking analysis

Single-sitecapacity

Total throughput

Number of sites

Significance of radio Propagation Models

The propagation models are the basis of coverage planning. Good models ensure the

i i f l iprecision of planning.The radio propagation modules are affected

by the system working frequency. Different models have different working frequency ranges, and the ranges differ for indoor propagation models and outdoor propagation models.

When using the propagation models, pay attention to the value set for each parameter.attention to the value set for each parameter.

What is MIMO?• MIMO： Multiple input and

multiple outputmultiple output

Multiple Antenna Technologies Analysis MIMO Matrix-A

User1

STT

Supported to provide transmit diversity and reduce fading margin by 2-8 dB depending on the environment &terminal

UL DL SS 1

Dthe environment &terminal antenna number

1T2R 2T2R

• Compare with SISO,MIMO 2×2 can improve the coverage radius by 50%~90% (Huawei simulation result)

I BS t th h t i di tl1T1R

800 MHZ

1T2R 2T2R • Improve BS system throughput indirectly(20%,Huawei simulation result)

• Support fixed and mobile service

• One dual-polarization antenna can support 2T2R

1T1R

• One dual-polarization antenna can support 2T2R MIMO

• Can support single or dual antenna terminal

Multiple Antenna Technologies Analysis MIMO Matrix-B

S ti l M lti l i

User1

Spatial Multiplexing

With 2x2 MIMO, the DL user and sector peak data rate are User1

SS 1

ptheoretically doubled. But 1.6times than SISO is realizable.

• SM: Each signal may convey different data to the same or different users, increasing the capacity. Rx antenna can not be less than Tx antenna. For terminal must have 2 Rx antennas

• Sector throughput, peak data rate and spectrum efficiency can be improved

• UL collaborative SM (Virtual MIMO) can not increase the peak data rate of users, but can improve the UL sector throughput (about 33%, compare with 1T2R, from WiMAX Forum)

Working Mode of MIMO• Diversity mode（Matrix A）

T it th d t i diff t t

g

– Transmit the same data in different antennas

– Enhance the capacity indirectly

Th b f i i t b l th th– The number of receiving antenna can be less than the number of transmitting antennas

• Spatial Multiplexing mode (Matrix B)Spatial Multiplexing mode (Matrix B)

– Transmit different data in different antennas

– Enhance the capacity directlyEnhance the capacity directly

– The number of receiving antenna can not be less than the number of transmitting antennas

Multiple Antenna Technologies Analysis MIMO-BF

• Based on not only DOA, but also spatial signature of different users

• Can use not only in urban but also in suburban & rural

• Use non-correlation antenna array, can be applied to NLOS area

MIMO M t i A/B/C d t MIMO BF• MIMO Matrix A/B/C can upgrade to MIMO-BF

• MIMO-BF 2*2 can obtain additional 3dB coverage gain compare with MIMO-Matrix A , and MIMO-BF 4*4 can obtain 6dB (Huawei theory research result)

What is AAS?• AAS: Adaptive/Advanced Antenna

S

What is AAS?

System

Omni antenna Directional antenna AAS

Types of AAS

• Switched Beam

Types of AAS

Antennas– Cell is covered by

some fixed beams

• Adaptive A t AAntenna Arrays– Beam can trace

th ’ itithe user’s position automatically

Improvement to performance

Increase the SNR and the sensitivity of BS

Improvement to performance

Decrease the error bit of systemDecrease the system interferenceyEnhance the coverageImprove the spectrum efficiency.p p y

Multiple Antenna Technologies Analysis Adaptive Antenna System (AAS)

UserUser

Switched Beam systemAdaptive Array systemBecause of Muti path in Urban AAS

• Based on DOA (Direction Of Arrival)• AAS include switched beam system and adaptive array system

Because of Muti-path in Urban, AAS coverage gain is lower than LOS

• Increase coverage and capacity by beamforming

• AAS can obtain 3.5dB coverage gain in rural, 3dB in suburban and only 2.55dB in urban

• AAS does not deal well with mobility at higher speeds