Suche senden
Hochladen
Wcdma systems 003
•
Als PPT, PDF herunterladen
•
1 gefällt mir
•
347 views
Basil John
Folgen
wcdma ppt
Weniger lesen
Mehr lesen
Ingenieurwesen
Diashow-Anzeige
Melden
Teilen
Diashow-Anzeige
Melden
Teilen
1 von 72
Jetzt herunterladen
Empfohlen
Wcdma systems 003
Wcdma systems 003
Kaushal Kumar
3gpp architecture evolution
3gpp architecture evolution
philip habib
3 gpp – overview
3 gpp – overview
Virendra Uppalwar
Lte continuing the evolution of mobile broadband networks
Lte continuing the evolution of mobile broadband networks
Rafael Junquera
Coexistence or Convivence PMR-LTE Technology
Coexistence or Convivence PMR-LTE Technology
Aitor Sanchoyerto Martínez
Tetraquickguide
Tetraquickguide
Deepak Sharma
LTE-Advanced Enhancements and Future Radio Access Toward 2020
LTE-Advanced Enhancements and Future Radio Access Toward 2020
Praveen Kumar
Tetra Ppt 6604 Edited
Tetra Ppt 6604 Edited
mamach4
Empfohlen
Wcdma systems 003
Wcdma systems 003
Kaushal Kumar
3gpp architecture evolution
3gpp architecture evolution
philip habib
3 gpp – overview
3 gpp – overview
Virendra Uppalwar
Lte continuing the evolution of mobile broadband networks
Lte continuing the evolution of mobile broadband networks
Rafael Junquera
Coexistence or Convivence PMR-LTE Technology
Coexistence or Convivence PMR-LTE Technology
Aitor Sanchoyerto Martínez
Tetraquickguide
Tetraquickguide
Deepak Sharma
LTE-Advanced Enhancements and Future Radio Access Toward 2020
LTE-Advanced Enhancements and Future Radio Access Toward 2020
Praveen Kumar
Tetra Ppt 6604 Edited
Tetra Ppt 6604 Edited
mamach4
New ppt
New ppt
Sumit Singh Panwar
Tetra\Tetra
Tetra\Tetra
Deepak Sharma
Lte principles overview
Lte principles overview
Ndukwe Amandi
Lte presentation at und
Lte presentation at und
Zahirul Islam
Tetra Series Product
Tetra Series Product
Hytera Communications(UK)Co.,Ltd.
Lte presentation
Lte presentation
Gabriel Cristian Goman
IRJET- DRM: An Emerging Radio Technology and its Impact on India
IRJET- DRM: An Emerging Radio Technology and its Impact on India
IRJET Journal
Lte Tutorial
Lte Tutorial
Pengpeng Song
LTE Basic
LTE Basic
neerav_adhikari
Huawei Workshop LTE Spectrum Strategic Opportunities
Huawei Workshop LTE Spectrum Strategic Opportunities
Adrian Hall
Introduction to LTE
Introduction to LTE
Nadisanka Rupasinghe
Lte tutorial april 2009 ver1.1
Lte tutorial april 2009 ver1.1
Gerti Windhuber
Long term evolution (lte) technology
Long term evolution (lte) technology
konan23
Voip basics
Voip basics
krishna112
lte advanced
lte advanced
Vikas Gandhi
LTE and LTE Advanced Introduction
LTE and LTE Advanced Introduction
BP Tiwari
Lte key technologies
Lte key technologies
Abdulqader Al-kaboudei
Lte tdd-the-global-solution-for-unpaired-spectrum
Lte tdd-the-global-solution-for-unpaired-spectrum
Muhammad Rauf Akram
LTE Fundamentals Training and Certification by TELCOMA Global
LTE Fundamentals Training and Certification by TELCOMA Global
Gaganpreet Singh Walia
3 gpp – sum,it pdf
3 gpp – sum,it pdf
Sumit Singh Panwar
From educational controlling to learning value management
From educational controlling to learning value management
scil CH
Hrm1
Hrm1
Basil John
Weitere ähnliche Inhalte
Was ist angesagt?
New ppt
New ppt
Sumit Singh Panwar
Tetra\Tetra
Tetra\Tetra
Deepak Sharma
Lte principles overview
Lte principles overview
Ndukwe Amandi
Lte presentation at und
Lte presentation at und
Zahirul Islam
Tetra Series Product
Tetra Series Product
Hytera Communications(UK)Co.,Ltd.
Lte presentation
Lte presentation
Gabriel Cristian Goman
IRJET- DRM: An Emerging Radio Technology and its Impact on India
IRJET- DRM: An Emerging Radio Technology and its Impact on India
IRJET Journal
Lte Tutorial
Lte Tutorial
Pengpeng Song
LTE Basic
LTE Basic
neerav_adhikari
Huawei Workshop LTE Spectrum Strategic Opportunities
Huawei Workshop LTE Spectrum Strategic Opportunities
Adrian Hall
Introduction to LTE
Introduction to LTE
Nadisanka Rupasinghe
Lte tutorial april 2009 ver1.1
Lte tutorial april 2009 ver1.1
Gerti Windhuber
Long term evolution (lte) technology
Long term evolution (lte) technology
konan23
Voip basics
Voip basics
krishna112
lte advanced
lte advanced
Vikas Gandhi
LTE and LTE Advanced Introduction
LTE and LTE Advanced Introduction
BP Tiwari
Lte key technologies
Lte key technologies
Abdulqader Al-kaboudei
Lte tdd-the-global-solution-for-unpaired-spectrum
Lte tdd-the-global-solution-for-unpaired-spectrum
Muhammad Rauf Akram
LTE Fundamentals Training and Certification by TELCOMA Global
LTE Fundamentals Training and Certification by TELCOMA Global
Gaganpreet Singh Walia
3 gpp – sum,it pdf
3 gpp – sum,it pdf
Sumit Singh Panwar
Was ist angesagt?
(20)
New ppt
New ppt
Tetra\Tetra
Tetra\Tetra
Lte principles overview
Lte principles overview
Lte presentation at und
Lte presentation at und
Tetra Series Product
Tetra Series Product
Lte presentation
Lte presentation
IRJET- DRM: An Emerging Radio Technology and its Impact on India
IRJET- DRM: An Emerging Radio Technology and its Impact on India
Lte Tutorial
Lte Tutorial
LTE Basic
LTE Basic
Huawei Workshop LTE Spectrum Strategic Opportunities
Huawei Workshop LTE Spectrum Strategic Opportunities
Introduction to LTE
Introduction to LTE
Lte tutorial april 2009 ver1.1
Lte tutorial april 2009 ver1.1
Long term evolution (lte) technology
Long term evolution (lte) technology
Voip basics
Voip basics
lte advanced
lte advanced
LTE and LTE Advanced Introduction
LTE and LTE Advanced Introduction
Lte key technologies
Lte key technologies
Lte tdd-the-global-solution-for-unpaired-spectrum
Lte tdd-the-global-solution-for-unpaired-spectrum
LTE Fundamentals Training and Certification by TELCOMA Global
LTE Fundamentals Training and Certification by TELCOMA Global
3 gpp – sum,it pdf
3 gpp – sum,it pdf
Andere mochten auch
From educational controlling to learning value management
From educational controlling to learning value management
scil CH
Hrm1
Hrm1
Basil John
Biderketa taulak
Biderketa taulak
Joserra Abarretegui
9.references
9.references
Basil John
Jayan - IT Manager, Project Manager, ITSM
Jayan - IT Manager, Project Manager, ITSM
Jayan Varghese
Fuzzy logic
Fuzzy logic
Basil John
BIZITZAREN HISTORIA ZURE GORPUTZA SM-IKASMINA SAN MARTIN ESKOLAN EGOKITUA
BIZITZAREN HISTORIA ZURE GORPUTZA SM-IKASMINA SAN MARTIN ESKOLAN EGOKITUA
Joserra Abarretegui
Leaders as learning facilitators: learnscapes, prerequisites & field of action
Leaders as learning facilitators: learnscapes, prerequisites & field of action
scil CH
5 g communication
5 g communication
Basil John
Evaluation question 3
Evaluation question 3
Attraction-mov ThrillerOpen
Mm case 2 ref
Mm case 2 ref
Basil John
Class7
Class7
Basil John
Wi max
Wi max
Basil John
Basil john mm field assignment jan2016
Basil john mm field assignment jan2016
Basil John
Urdaneta comic
Urdaneta comic
Joserra Abarretegui
3.table of contents
3.table of contents
Basil John
An efficient vertical handoff mechanism for future mobile network
An efficient vertical handoff mechanism for future mobile network
Basil John
Persona global newsletter issue iv
Persona global newsletter issue iv
Pedro Martin
LEGAL LEASE DOCUMENT
LEGAL LEASE DOCUMENT
Basil John
Business Law
Business Law
Basil John
Andere mochten auch
(20)
From educational controlling to learning value management
From educational controlling to learning value management
Hrm1
Hrm1
Biderketa taulak
Biderketa taulak
9.references
9.references
Jayan - IT Manager, Project Manager, ITSM
Jayan - IT Manager, Project Manager, ITSM
Fuzzy logic
Fuzzy logic
BIZITZAREN HISTORIA ZURE GORPUTZA SM-IKASMINA SAN MARTIN ESKOLAN EGOKITUA
BIZITZAREN HISTORIA ZURE GORPUTZA SM-IKASMINA SAN MARTIN ESKOLAN EGOKITUA
Leaders as learning facilitators: learnscapes, prerequisites & field of action
Leaders as learning facilitators: learnscapes, prerequisites & field of action
5 g communication
5 g communication
Evaluation question 3
Evaluation question 3
Mm case 2 ref
Mm case 2 ref
Class7
Class7
Wi max
Wi max
Basil john mm field assignment jan2016
Basil john mm field assignment jan2016
Urdaneta comic
Urdaneta comic
3.table of contents
3.table of contents
An efficient vertical handoff mechanism for future mobile network
An efficient vertical handoff mechanism for future mobile network
Persona global newsletter issue iv
Persona global newsletter issue iv
LEGAL LEASE DOCUMENT
LEGAL LEASE DOCUMENT
Business Law
Business Law
Ähnlich wie Wcdma systems 003
3GPP Standards for the Internet-of-Things
3GPP Standards for the Internet-of-Things
Eiko Seidel
Lte àà¿ë ±â¼ú ±³à°
Lte àà¿ë ±â¼ú ±³à°
Birendra Yadav
4 td lte(ᶺà¿-) (1)
4 td lte(ᶺà¿-) (1)
mnajib171
Edge hspa and_lte_broadband_innovation_powerpoint_sept08
Edge hspa and_lte_broadband_innovation_powerpoint_sept08
Muhammad Ali Basra
LTE Introduction - Hello World to LTE
LTE Introduction - Hello World to LTE
Sachidananda Sahu
Lte epc ieee_comsoc_rao_april_8_2010
Lte epc ieee_comsoc_rao_april_8_2010
Supachok Sappasri
Just Fact: Using 4G mobile and fixed services on a dual mode WiMAX/LTE network
Just Fact: Using 4G mobile and fixed services on a dual mode WiMAX/LTE network
BSP Media Group
GSA-Evolution_to_LTE_report_October_2016
GSA-Evolution_to_LTE_report_October_2016
Sitha Sok
2018-04-17_GA-booth__3gppNR_compressed.ppt
2018-04-17_GA-booth__3gppNR_compressed.ppt
ssuser38e5dc1
6. itu 4 g regulation
6. itu 4 g regulation
Kheng Heng
Comparison lte wi_max_ball_ew2007
Comparison lte wi_max_ball_ew2007
Muhammad Ali Basra
1 tmo18023 umts overview
1 tmo18023 umts overview
DhairYash Kotwani
2011 Broadband Tech Update to Electronic Engineers in the Philippines
2011 Broadband Tech Update to Electronic Engineers in the Philippines
Francisco "Cocoy" Claravall
Different Generations Of Mobile Technologies
Different Generations Of Mobile Technologies
3G4G
LTE- Long Term Evolution
LTE- Long Term Evolution
Razib Bondu
4G LTE full tutorial
4G LTE full tutorial
Afzaal Anwar
Ppt2
Ppt2
Deepa s
4G to 5G Evolution
4G to 5G Evolution
Manoj Singh
Low-Power Wide Area - Overview
Low-Power Wide Area - Overview
M2M Alliance e.V.
3gpp lte
3gpp lte
Apitan Kongcharoen
Ähnlich wie Wcdma systems 003
(20)
3GPP Standards for the Internet-of-Things
3GPP Standards for the Internet-of-Things
Lte àà¿ë ±â¼ú ±³à°
Lte àà¿ë ±â¼ú ±³à°
4 td lte(ᶺà¿-) (1)
4 td lte(ᶺà¿-) (1)
Edge hspa and_lte_broadband_innovation_powerpoint_sept08
Edge hspa and_lte_broadband_innovation_powerpoint_sept08
LTE Introduction - Hello World to LTE
LTE Introduction - Hello World to LTE
Lte epc ieee_comsoc_rao_april_8_2010
Lte epc ieee_comsoc_rao_april_8_2010
Just Fact: Using 4G mobile and fixed services on a dual mode WiMAX/LTE network
Just Fact: Using 4G mobile and fixed services on a dual mode WiMAX/LTE network
GSA-Evolution_to_LTE_report_October_2016
GSA-Evolution_to_LTE_report_October_2016
2018-04-17_GA-booth__3gppNR_compressed.ppt
2018-04-17_GA-booth__3gppNR_compressed.ppt
6. itu 4 g regulation
6. itu 4 g regulation
Comparison lte wi_max_ball_ew2007
Comparison lte wi_max_ball_ew2007
1 tmo18023 umts overview
1 tmo18023 umts overview
2011 Broadband Tech Update to Electronic Engineers in the Philippines
2011 Broadband Tech Update to Electronic Engineers in the Philippines
Different Generations Of Mobile Technologies
Different Generations Of Mobile Technologies
LTE- Long Term Evolution
LTE- Long Term Evolution
4G LTE full tutorial
4G LTE full tutorial
Ppt2
Ppt2
4G to 5G Evolution
4G to 5G Evolution
Low-Power Wide Area - Overview
Low-Power Wide Area - Overview
3gpp lte
3gpp lte
Mehr von Basil John
Class 5 ipr trips - trims
Class 5 ipr trips - trims
Basil John
Overcoming communication Barriers
Overcoming communication Barriers
Basil John
Luxottica
Luxottica
Basil John
AADHAR Card- Database Creation
AADHAR Card- Database Creation
Basil John
Walmart f500
Walmart f500
Basil John
Umts
Umts
Basil John
Interworking of wi_max_and_3gpp_networks_-slides
Interworking of wi_max_and_3gpp_networks_-slides
Basil John
Cloud computing
Cloud computing
Basil John
Fuzzy logic - copy
Fuzzy logic - copy
Basil John
An advanced handoff algoritm in mobile communication network using fuzzy deci...
An advanced handoff algoritm in mobile communication network using fuzzy deci...
Basil John
Handoff survey
Handoff survey
Basil John
Neural networks
Neural networks
Basil John
An efficient vertical handoff mechanism
An efficient vertical handoff mechanism
Basil John
1. front page
1. front page
Basil John
8.conclusion
8.conclusion
Basil John
4. list of figures
4. list of figures
Basil John
2.acknowledgement
2.acknowledgement
Basil John
7.chapter
7.chapter
Basil John
6.abstract
6.abstract
Basil John
5.list of abbreviations
5.list of abbreviations
Basil John
Mehr von Basil John
(20)
Class 5 ipr trips - trims
Class 5 ipr trips - trims
Overcoming communication Barriers
Overcoming communication Barriers
Luxottica
Luxottica
AADHAR Card- Database Creation
AADHAR Card- Database Creation
Walmart f500
Walmart f500
Umts
Umts
Interworking of wi_max_and_3gpp_networks_-slides
Interworking of wi_max_and_3gpp_networks_-slides
Cloud computing
Cloud computing
Fuzzy logic - copy
Fuzzy logic - copy
An advanced handoff algoritm in mobile communication network using fuzzy deci...
An advanced handoff algoritm in mobile communication network using fuzzy deci...
Handoff survey
Handoff survey
Neural networks
Neural networks
An efficient vertical handoff mechanism
An efficient vertical handoff mechanism
1. front page
1. front page
8.conclusion
8.conclusion
4. list of figures
4. list of figures
2.acknowledgement
2.acknowledgement
7.chapter
7.chapter
6.abstract
6.abstract
5.list of abbreviations
5.list of abbreviations
Kürzlich hochgeladen
Cara Menggugurkan Sperma Yang Masuk Rahim Biyar Tidak Hamil
Cara Menggugurkan Sperma Yang Masuk Rahim Biyar Tidak Hamil
Cara Menggugurkan Kandungan 087776558899
Call Girls in South Ex (delhi) call me [🔝9953056974🔝] escort service 24X7
Call Girls in South Ex (delhi) call me [🔝9953056974🔝] escort service 24X7
9953056974 Low Rate Call Girls In Saket, Delhi NCR
Online food ordering system project report.pdf
Online food ordering system project report.pdf
Kamal Acharya
Learn the concepts of Thermodynamics on Magic Marks
Learn the concepts of Thermodynamics on Magic Marks
Magic Marks
HOA1&2 - Module 3 - PREHISTORCI ARCHITECTURE OF KERALA.pptx
HOA1&2 - Module 3 - PREHISTORCI ARCHITECTURE OF KERALA.pptx
SCMS School of Architecture
Computer Lecture 01.pptxIntroduction to Computers
Computer Lecture 01.pptxIntroduction to Computers
MairaAshraf6
Thermal Engineering Unit - I & II . ppt
Thermal Engineering Unit - I & II . ppt
DineshKumar4165
Employee leave management system project.
Employee leave management system project.
Kamal Acharya
Rums floating Omkareshwar FSPV IM_16112021.pdf
Rums floating Omkareshwar FSPV IM_16112021.pdf
smsksolar
"Lesotho Leaps Forward: A Chronicle of Transformative Developments"
"Lesotho Leaps Forward: A Chronicle of Transformative Developments"
mphochane1998
Standard vs Custom Battery Packs - Decoding the Power Play
Standard vs Custom Battery Packs - Decoding the Power Play
Epec Engineered Technologies
Generative AI or GenAI technology based PPT
Generative AI or GenAI technology based PPT
bhaskargani46
School management system project Report.pdf
School management system project Report.pdf
Kamal Acharya
AIRCANVAS[1].pdf mini project for btech students
AIRCANVAS[1].pdf mini project for btech students
vanyagupta248
Engineering Drawing focus on projection of planes
Engineering Drawing focus on projection of planes
RAJNEESHKUMAR341697
S1S2 B.Arch MGU - HOA1&2 Module 3 -Temple Architecture of Kerala.pptx
S1S2 B.Arch MGU - HOA1&2 Module 3 -Temple Architecture of Kerala.pptx
SCMS School of Architecture
notes on Evolution Of Analytic Scalability.ppt
notes on Evolution Of Analytic Scalability.ppt
MsecMca
Online electricity billing project report..pdf
Online electricity billing project report..pdf
Kamal Acharya
COST-EFFETIVE and Energy Efficient BUILDINGS ptx
COST-EFFETIVE and Energy Efficient BUILDINGS ptx
JIT KUMAR GUPTA
HAND TOOLS USED AT ELECTRONICS WORK PRESENTED BY KOUSTAV SARKAR
HAND TOOLS USED AT ELECTRONICS WORK PRESENTED BY KOUSTAV SARKAR
KOUSTAV SARKAR
Kürzlich hochgeladen
(20)
Cara Menggugurkan Sperma Yang Masuk Rahim Biyar Tidak Hamil
Cara Menggugurkan Sperma Yang Masuk Rahim Biyar Tidak Hamil
Call Girls in South Ex (delhi) call me [🔝9953056974🔝] escort service 24X7
Call Girls in South Ex (delhi) call me [🔝9953056974🔝] escort service 24X7
Online food ordering system project report.pdf
Online food ordering system project report.pdf
Learn the concepts of Thermodynamics on Magic Marks
Learn the concepts of Thermodynamics on Magic Marks
HOA1&2 - Module 3 - PREHISTORCI ARCHITECTURE OF KERALA.pptx
HOA1&2 - Module 3 - PREHISTORCI ARCHITECTURE OF KERALA.pptx
Computer Lecture 01.pptxIntroduction to Computers
Computer Lecture 01.pptxIntroduction to Computers
Thermal Engineering Unit - I & II . ppt
Thermal Engineering Unit - I & II . ppt
Employee leave management system project.
Employee leave management system project.
Rums floating Omkareshwar FSPV IM_16112021.pdf
Rums floating Omkareshwar FSPV IM_16112021.pdf
"Lesotho Leaps Forward: A Chronicle of Transformative Developments"
"Lesotho Leaps Forward: A Chronicle of Transformative Developments"
Standard vs Custom Battery Packs - Decoding the Power Play
Standard vs Custom Battery Packs - Decoding the Power Play
Generative AI or GenAI technology based PPT
Generative AI or GenAI technology based PPT
School management system project Report.pdf
School management system project Report.pdf
AIRCANVAS[1].pdf mini project for btech students
AIRCANVAS[1].pdf mini project for btech students
Engineering Drawing focus on projection of planes
Engineering Drawing focus on projection of planes
S1S2 B.Arch MGU - HOA1&2 Module 3 -Temple Architecture of Kerala.pptx
S1S2 B.Arch MGU - HOA1&2 Module 3 -Temple Architecture of Kerala.pptx
notes on Evolution Of Analytic Scalability.ppt
notes on Evolution Of Analytic Scalability.ppt
Online electricity billing project report..pdf
Online electricity billing project report..pdf
COST-EFFETIVE and Energy Efficient BUILDINGS ptx
COST-EFFETIVE and Energy Efficient BUILDINGS ptx
HAND TOOLS USED AT ELECTRONICS WORK PRESENTED BY KOUSTAV SARKAR
HAND TOOLS USED AT ELECTRONICS WORK PRESENTED BY KOUSTAV SARKAR
Wcdma systems 003
1.
1 WCDMA, HSPA and
advanced receivers Timo Nihtil , Ph.Lic. (Ph.D. def.)ä Senior Research Scientist Magister Solutions Ltd.
2.
TLT-5606 Spread © Timo
Nihtilä2 Readings related to the subject • General readings – WCDMA for UMTS– HarriHolma, AnttiToskala – HSDPA/HSUPA for UMTS –Harri Holma, Antti Toskala • Network planning oriented – Radio NetworkPlanning and Optimisationfor UMTS– Janna Laiho, Achim Wacker, Tomás Novosad – UMTS Radio Network Planning, Optimizationand QoS Management For PracticalEngineering Tasks –Jukka Lempiäinen, Matti Manninen
3.
TLT-5606 Spread © Timo
Nihtilä3 Outline • Background • Key concepts – Code multiplexing – Spreading • Introduction to Wideband Code Division Multiple Access (WCDMA) • WCDMA Performance Enhancements – High Speed Packet Access (HSDPA/HSUPA) – Advanced featuresfor HSDPA
4.
4 Background •Why new radio
access system •FrequencyAllocations •Standardization •WCDMA background and evolution •Evolution of Mobile standards •Current WCDMA markets
5.
TLT-5606 Spread © Timo
Nihtilä5 Why new radio access system • Need for universal standard (Universal Mobile Telecommunication System) • Support for packet data services – IP data incore network – Wireless IP • New services in mobile multimedia need faster data transmission and flexible utilization of the spectrum • FDMA and TDMA are not efficient enough – TDMA wastestime resources – FDMA wastes frequencyresources • CDMA can exploit the whole bandwidth constantly • Wideband CDMA was selected for a radio access system for UMTS (1997) – (Actuallythe superiorityof OFDMwas not fullyunderstood bythen)
6.
TLT-5606 Spread © Timo
Nihtilä6 Frequency allocations for UMTS • Frequency plans of Europe, Japan and Korea are harmonized • US plan is incompatible, the spectrum reserved for 3G elsewhere is currently used for the US 2G standards • IMT-2000 band in Europe: – FDD 2x60MHz Expected air interfaces and spectrums, source: “WCDMA for UMTS”
7.
TLT-5606 Spread © Timo
Nihtilä7 Standardization • WCDMA was studied in various research programs in the industry and universities • WCDMA was chosen besides ETSI also in other forums like ARIB (Japan) as 3G technology in late 1997/early 1998. • During 1998 parallel work proceeded in ETSI and ARIB (mainly), with commonalities but also differences – Work was also on-going in USA and Korea
8.
TLT-5606 Spread © Timo
Nihtilä8 Standardization • At end of 1998 different standardization organizations got together and created 3GPP, 3rd Generation Partnership Project. – 5 Founding members: ETSI, ARIB+TTC (Japan), TTA (Korea), T1P1 (USA) – CWTS (China) joined later. • Different companies are members through their respective standardization organization. E T S I M e m b e r s E T S I A R I B M e m b e r s A R I B T T A M e m b e r s T T A T 1 P 1 M e m b e r s T 1 P 1 T T C M e m b e r s T T C C W T S M e m b e r s C W T S 3 G P P
9.
TLT-5606 Spread © Timo
Nihtilä9 WCDMA Background and Evolution • First major milestone wasRelease ‘99, 12/99 – Full set of specifications by 3GPP – Targeted mainly on access part of the network • Release 4, 03/01 – Core network was extended – markets jumped over Rel 4 • Release 5, 03/02 – High Speed Downlink Packet Access (HSDPA) • Release 6, end of 04/beginning of 05 – High Speed Uplink Packet Access (HSUPA) • Release 7, 06/07 – Continuous Packet connectivity (improvement for e.g. VoIP), advanced features for HSDPA (MIMO, higher order modulation)
10.
TLT-5606 Spread © Timo
Nihtilä10 WCDMA Background and Evolution 2000 2002 2004 2006 2007200520032001 3GPP Rel -99 12/99 3GPP Rel 4 03/01 3GPP Rel 5 (HSDPA) 03/02 3GPP Rel 6 (HSUPA) 2H/04 3GPP Rel 7 HSPA+ 06/07 Further Releases Japan Europe (pre-commercial) Europe (commercial) HSDPA (commercial) HSUPA (commercial)
11.
TLT-5606 Spread © Timo
Nihtilä11 Evolution of Mobile standards EDGE GPRS GSM HSCSD cdmaOne (IS-95) WCDMA FDD HSDPA/ HSUPA cdma2000 TD-SCDMA TDD LCR cdma2000 1XEV - DO cdma2000 1XEV - DV TD-CDMA TDD HCR HSDPA/ HSUPA LTE
12.
TLT-5606 Spread © Timo
Nihtilä12 Current WCDMA markets • Graph of the technologiesadopted bythe wireless users worldwide: • Over 3.5 billionwireless users worldwide • GSM+WCDMA share currentlyover 88 % (www.umts-forum.org) • CDMA share isdecreasing every year GSM (80.9%) CDMA (12%) WCDMA (4.6%) iDEN (0.9%) PDC(0.8%) US TDMA (0.8%)
13.
TLT-5606 Spread © Timo
Nihtilä13 Current WCDMA markets • Over 200 millionWCDMA subscribers globally(04/08) (www.umts-forum.org) – 10 % HSDPA/HSUPA users • Number of subscribers isconstantlyincreasing Millionsubscribers
14.
14 Key concepts •CDMA •Spread Spectrum •Direct
Sequence spreading •Spreading and Processing gain
15.
TLT-5606 Spread © Timo
Nihtilä15 Multiple Access Schemes • FrequencyDivision Multiple Access(FDMA), different frequencies for different users – example Nordic Mobile Terminal (NMT) systems • Time DivisionMultiple Access (TDMA), same frequencybut different timeslots for different users, – example Global System for Mobile Communication (GSM) – GSM also uses FDMA • Code Division Multiple Access(CDMA), same frequencyand time but users are separated from each other with orthogonalcodes Code Frequency Time 1 2 N … TDMAFDMA CDMA
16.
TLT-5606 Spread © Timo
Nihtilä16 Spread Spectrum • Means that the transmission bandwidth is much larger than the information bandwidth i.e. transmitted signal is spread to a wider bandwidth – Bandwidthis not dependent onthe informationsignal • Benefits – More secure communication – Reducesthe impact of interference (and jamming) due toprocessing gain • Classification – Direct Sequence (spreading with pseudo noise (PN) sequence) – Frequency hopping (rapidly changing frequency) – Time Hopping (large frequency, short transmission bursts) • Direct Sequence is currently commercially most viable
17.
TLT-5606 Spread © Timo
Nihtilä17 Spread Spectrum • Where does spread spectrum come from – First publications, late 40s – First applications: Militaryfrom the 50s – Rake receiver patent 1956 – Cellular applicationsproposed late 70s – Investigations for cellular use 80s – IS-95 standard 1993 (2G) – 1997/1998 3G technologychoice – 2001/2002 Commerciallaunchof WCDMA technology
18.
TLT-5606 Spread © Timo
Nihtilä18 Direct Sequence • In direct sequence (DS) user bits are coded with unique binary sequence i.e. with spreading/channelization code – The bits of the channelizationcode are called chips – Chip rate (W) is typicallymuchhigher than bit rate (R) – Codes need to be insome respect orthogonalto eachother (cocktail partyeffect) • Length of a channelization code – defineshow manychips are used tospread a single informationbit and thus determines the end bit rate – Shorter code equals to higher bit rate but better Signal to Interference and Noise Ratio (SINR) is required • Also the shorter the code, the fewer number of codes are available – Different bit rates have different geographical areascovered based on the interference levels
19.
TLT-5606 Spread © Timo
Nihtilä19 Direct Sequence • Transmission (Tx) side with DS – Information signal is multiplied with channelizationcode => spread signal • Receiving (Rx) side with DS – Spread signal ismultiplied withchannelizationcode – Multiplied signal (spread signalx code) isthenintegrated (i.e.summed together) • If the integration results in adequately high (or low) values, the signal is meant for the receiver
20.
TLT-5606 Spread © Timo
Nihtilä20 Direct Sequence
21.
TLT-5606 Spread © Timo
Nihtilä21 Direct Sequence
22.
TLT-5606 Spread © Timo
Nihtilä22 Processing gain and Spreading Frequency Despread narrowband signal Spread wideband signal W R Powerdensity(Watts/Hz)Powerdensity(Watts/Hz) Frequency Transmitted signal before spreading Received signal before despreading Interference for the part we are interested in
23.
TLT-5606 Spread © Timo
Nihtilä23 Processing gain and Spreading Frequency Powerdensity(Watts/Hz)Powerdensity(Watts/Hz) Frequency Received signal after despreading but before filtering Received signal after despreading and after filtering Transmitted signal Interference
24.
TLT-5606 Spread © Timo
Nihtilä24 Processing gain and Spreading • Spread spectrum systems reduce the effect of interference due to processing gain • Processing gainisgenerallydefined as follows: – G[dB]=10*log10(W/R), where ’W’ is the chip rate and ’R’ is the user bit rate • The number of userstakes negative effect onthe processing gain. The lossis defined as: – Lp = 10*log10k, where ’k’ is the amount of users • Processing gainwhenthe processing loss is takeninto account is – Gtot=10*log10(W/kR) • Highbit rate means lower processing gainand higher power OR smaller coverage • The processing gainis different for different services over 3G mobile network(voice, web browsing, videophone) due to different bit rates – Thus, the coverage area and capacity might be different for different services depending on the radio network planning issues
25.
TLT-5606 Spread © Timo
Nihtilä25 Processing gain and Spreading • Processing gain is what gives CDMA systems the robustness against self-interference that is necessary in order to reuse the available 5 MHz carrier frequency over geographically close distances. • Examples: Speech service with a bit rate of 12.2 kbps – processing gain 10 log10(3.84e6/12.2e3) = 25 dB – For speechservice the required SINR istypicallyinthe order of 5.0 dB, sothe required wideband signal-to-interference ratio (alsocalled “carrier- to-interference ratio, C/I) is therefore “5.0 dB minusthe processing” = -20.0 dB. – In other words, the signal power can be 20 dB under the interference or thermalnoise power, and the WCDMA receiver canstilldetect the signal. – Notice: inGSM, a good qualityspeechconnectionrequires C/I= 9–12 dB.
26.
26 Introduction to Wideband
Code Division Multiple Access (WCDMA) •Overview •Codes inWCDMA •QoS support •NetworkArchitecture •Radio propagationand fading •RAKE receiver •Power Control inWCDMA •Diversity •Capacityand coverage
27.
TLT-5606 Spread © Timo
Nihtilä27 WCDMA System • WCDMA is the most common radio interface for UMTS systems • Wide bandwidth, 3.84 Mcps (Megachips per second) – Maps to 5 MHz due to pulse shaping and smallguard bandsbetweenthe carriers • Users share the same 5 MHz frequency band and time – ULand DL have separate 5 MHz frequencybands • High bit rates – WithRelease ’99 theoretically 2 Mbps bothUL and DL – 384 kbps highest implemented • Fast power control (PC) => Reduces the impact of channel fading and minimizes the interference
28.
TLT-5606 Spread © Timo
Nihtilä28 WCDMA System • Soft handover – Improves coverage, decreases interference • Robust and low complexityRAKEreceiver – Introduces multipath diversity • Variable spreading factor – Support for flexible bit rates • Multiplexing of different services ona single physical connection – Simultaneous support of services with different QoS requirements: • real-time – E.g. voice,video telephony • streaming – streaming videoand audio • interactive – web-browsing • background – e-mail download
29.
TLT-5606 Spread © Timo
Nihtilä29 Codes in WCDMA • ChannelizationCodes (=short code) – Codes from different branches of the code tree are orthogonal – Length is dependent on the spreading factor – Used for • channel separation from the single source in downlink • separation of dataandcontrol channelsfrom each other in the uplink – Same channelization codes in every cell / mobiles and therefore the additional scrambling code is needed • Scrambling codes (=long code) – Very long (38400 chips = 10 ms =1 radio frame), many codes available – Does not spread the signal – Uplink: to separate different mobiles – Downlink: to separate different cells – The correlation between two codes (two mobiles/NodeBs) is low • Not fully orthogonal
30.
TLT-5606 Spread © Timo
Nihtilä30 Codes in WCDMA • For instance, the relationbetweendownlinkphysical layer bit rates and codes Spreading Factor (SF) Channel symbol rate (ksps) Channel bit rate (kbps) DPDCH channel bit rate range (kbps) Maximum user data rate with ½- rate coding (approx.) 512 7.5 15 3–6 1–3 kbps 256 15 30 12–24 6–12 kbps 128 30 60 42–51 20–24 kbps 64 60 120 90 45 kbps 32 120 240 210 105 kbps 16 240 480 432 215 kbps 8 480 960 912 456 kbps 4 960 1920 1872 936 kbps 4, with 3 parallel codes 2880 5760 5616 2.3 Mbps Half rate speech Full rate speech 144 kbps 384 kbps 2 Mbps Symbol_rate = Chip_rate/SF Bit_rate = Symbol_rate*2 Control channel (DPCCH) overhead User bit rate with coding = Channel_bit_rate/2
31.
TLT-5606 Spread © Timo
Nihtilä31 QoS Support • Key Factors: – Simultaneous support of services with different QoS requirements: • up to 210 Transport Format Combinations, selectable individually for every radio frame (10 ms) • going towards IP core networks greatly increases the usage of simultaneous applications requiring different quality, e.g. real time vs. non-real time – Optimized usage of different transport channels for supporting different QoS
32.
TLT-5606 Spread © Timo
Nihtilä32 QoS support Example: Downlink Shared Channel Downlink Dedicated Channels USER 1 .... 10 ms USER 2 USER 3 USER 1 USER 1 USER 4 Data Rate 2 Mbps Code 5 Code 4 Code 3 Code 2 Code 1USER 1 USER 2 USER 3 USER 4 USER 2 Time
33.
TLT-5606 Spread © Timo
Nihtilä33 UMTS Terrestrial Radio Access Network (UTRAN) Architecture • New Radio Access network needed mainly due to new radio access technology • Core Network (CN) is based on GSM/GPRS • Radio Network Controller (RNC) corresponds roughly to the Base Station Controller (BSC) in GSM • Node B corresponds roughly to the Base Station in GSM – Term “Node B”is a relic from the first 3GPP releases RNC NodeB NodeB NodeB UE CN RNC UE Uu interface Iub interface Iur interface UTRAN
34.
TLT-5606 Spread © Timo
Nihtilä34 UMTS Terrestrial Radio Access Network (UTRAN) Architecture • Radio network controller (RNC) – Ownsand controls the radio resources inits domain – Radio resource management (RRM) tasks include e.g. the following • Mapping of QoS Parameters into the air interface • Air interface scheduling • Handover control • Outer loop power control • Call Admission Control • Setting of initial powers and SIR targets • Radio resource reservation • Code allocation • Load Control
35.
TLT-5606 Spread © Timo
Nihtilä35 UMTS Terrestrial Radio Access Network (UTRAN) Architecture • Node B – Mainfunctiontoconvert the data flow betweenUu and Iub interfaces – Some RRM tasks: • Measurements • Inner loop power control
36.
TLT-5606 Spread © Timo
Nihtilä36 Radio propagation and fading • A transmitted radio signal goes through several changes while traveling via air interface to the receiver – reflections, diffractions, phase shifts and attenuation • Due to length difference of the signal paths, multipath components of the signal arrive at different times to the receiver and can be combined either destructively or constructively – Depends onthe phases of the multipathcomponents
37.
TLT-5606 Spread © Timo
Nihtilä37 Radio propagation and fading • Example of the fast fading channel of a function of time • Opposite phases of two random multipath components arriving at the same time cancel each other out – Resultsina fade • Coherent phases are combined constructively
38.
TLT-5606 Spread © Timo
Nihtilä38 • Every multipath component arriving at the receiver more than one chip time (0.26 μs) apart can be distinguished by the RAKE receiver – 0.26 μs corresponds to 78 m inpath lengthdifference • RAKE assigns a “finger” to each received component (tap) and alters their phases based on a channel estimate so that the components can be combined constructively Finger #1 Finger #2 Finger #3 RAKE receiver Transmitted symbol Received symbol at each time slot Phase modified using the channel estimate Combined symbol
39.
TLT-5606 Spread © Timo
Nihtilä39 Power Control in WCDMA • The purpose of power control (PC) is to ensure that each user receives and transmits just enough energy to have service but to prevent: – Blocking of distant users (near-far-effect) – Exceeding reasonable interference levels UE1 UE2 UE3 UE1 UE2 UE3 UE1 UE2 UE3 Without PC received power levels would be unequal With ideal PC received power levels are equal
40.
TLT-5606 Spread © Timo
Nihtilä40 Power Control in WCDMA 1. Open loop power control • Onlyfor the initial power setting of the MS • Based on distance attenuationestimationfrom the downlinkpilot signal 1. Inner loop transmitter power control (CL TPC) at a rate of 1500 Hz • Mitigates fading processes (fast and slow fading) • Tx power is adjusted up/down to reachSIR target • BothinULand DL • Usesqualitytargets in MS /BS 1. Outer loop PC at the rate of 100 Hz • Sets the qualitytarget used bythe inner loop PC • Compensates the changes inthe propagationconditions • Adjusts the qualitytarget • BothinULand DL
41.
TLT-5606 Spread © Timo
Nihtilä41 Power Control in WCDMA • Inner loop power control in the uplink – Outer loop PC (running inthe radio network controller, RNC) definesSIR target for the BS. – If the measured SIR at BS is lower thanthe SIR-target, the MSis commanded to increases its transmit power. Otherwise MS is commanded todecrease its power – Power controldynamics at the MS is 70 dB
42.
TLT-5606 Spread © Timo
Nihtilä42 Power Control in WCDMA • Inner loop power control in downlink: – Outer loop PC (running inthe MS) defines SIR target for the MS – If the measured SIR at the MS is lower thanthe SIR-target, the BSis commanded to increasesits transmit power for that MS. Otherwise, BS iscommanded to decrease its power. – Power controlrate 1500 Hz – Power controldynamics is dependent onthe service – There’s no near-far problem inDL due to one-to-manyscenario.However, it is desirable to provide a marginalamount of additional power to mobile stations at the cell edge, astheysuffer from increased other-cell interference.
43.
TLT-5606 Spread © Timo
Nihtilä43 Power Control in WCDMA • Example of inner loop power control behavior: • With higher velocities channel fading is more rapid and 1500 Hz power control may not be sufficient
44.
TLT-5606 Spread © Timo
Nihtilä44 Power Control in WCDMA • Inner loop power controltries to keep the received SIR as close to the target SIR aspossible. • However, the constant SIR alone does not actually guarantee the required frame error rate (FER) which canbe considered as the qualitycriteria of the link/service. – There’s no unique SIR that automatically gives a certain FER – FER is a function of SIR, but also depends on mobility and propagation environment. • Therefore, the frame reliabilityinformationhas to be delivered toouter loop control, whichcantune the SIR target if necessary.
45.
TLT-5606 Spread © Timo
Nihtilä45 Diversity • Transmitting ona single pathonlycanlead to seriousperformance degradationdue tofading • As fading is independent betweendifferent times and spacesit is reasonable to use the available diversityof them todecrease the probability of a deep fade – The more there are paths to choose from, the less likely it is that all of them have a poor energy level • There existsdifferenttypes of diversitywhichcan be used to improve the quality, e.g.: – Multipath • RAKE receiver exploitstaps arrivingat different times – Macro • Different Node Bs sendthe same information – Site Selection Transmit Diversity (SSTD) • Maintain alist of available base stationsand choose the best one, from which the transmission isreceivedandtell the others not totransmit
46.
TLT-5606 Spread © Timo
Nihtilä46 Diversity – Time • Same information is transmitted in different times – Receive antenna • Transmission is received with multiple antennas • Power gain and diversity gain – Transmit antenna • Transmission is sent with multiple antennas
47.
TLT-5606 Spread © Timo
Nihtilä47 WCDMA Handovers • WCDMA handovers can be categorized into three different types • Intra-frequency handover – WCDMA handover withinthe same frequencyand system. Soft, softer and hard handover supported • Inter-frequency handover – Handover betweendifferent frequencies (carriers) but within the same system – E.g. from one WCDMA operator to another – Onlyhard handover supported • Inter-system handover – Handover betweenWCDMA and another system, e.g.from WCDMA to GSM – Onlyhard handover supported
48.
TLT-5606 Spread © Timo
Nihtilä48 WCDMA Handovers • Soft handover – Handover betweendifferent Node Bs – Several Node Bstransmit the same signalto the UE whichcombines the transmissions • Advantages: lower Tx power needed for each Node B and UE – lower interference, battery saving for UE • Disadvantage: resources (code, power) need to be reserved for the UE in each Node B – Excess soft handovers limit the capacity – No interruptionindata transmission – Needs RNC duplicating frame transmissions to two Node Bs
49.
TLT-5606 Spread © Timo
Nihtilä49 WCDMA Handovers • Softer handover – Handover betweentwo sectors of the same Node B • Special case of a soft handover • No need for duplicate frames • Hard handover – The source isreleased first and then new one is added – Short interruption indata flow
50.
TLT-5606 Spread © Timo
Nihtilä50 WCDMA Handovers • Some terminology – Active set (AS), represents the Node Bs to whichthe UEis in soft handover – Neighbor set (NS), representsthe links that UE monitorsbut whichare not already in active set Received signal strength BS1 BS2 Threshold_1 Triggering time_1 Threshold_2 Triggering time_2 BS2 from the NS reaches the threshold to be added to the AS BS2 is still after the triggering time above threshold and thus added to the AS BS1 from the AS reaches the threshold to be dropped from the AS BS1 dropped from the AS
51.
TLT-5606 Spread © Timo
Nihtilä51 Capacity and coverage • In WCDMA coverage and capacity are tight together: – When the load increases, the interference levels increases, too, and therefore also increased transmit powers are needed inorder to keep constant quality. – Due to finite power resources, the more users Node B servesthe less power it has for eachUE coverage willdecrease • This leads to cell breathing: the coverage area changes as the load of the cell changes. • Therefore, the coverage and the capacity have to be planned simultaneously • Radio resource management (RRM) is needed in WCDMA to effectively control cell breathing.
52.
TLT-5606 Spread © Timo
Nihtilä52 Capacity and coverage • Received power of one user as a function of users per cell • Due to finite maximum Tx power of the UE coverage is usually limited by the uplink • Node B does not have this problem – There is enough Tx power to transmit veryfar to a single user if necessary – However, downlinkTx power isdivided betweenall users and thus capacityis limited bythe downlink
53.
53 WCDMA evolution •HighSpeed DownlinkPacket
Access (HSDPA) •HighSpeed Uplink Packet Access(HSUPA) •Advanced receivers withHSDPA •Advanced HSDPA scheduling •Femto cells withHSDPA
54.
TLT-5606 Spread © Timo
Nihtilä54 High Speed Downlink Packet Access (HSDPA) • The High Speed Downlink Packet Access (HSDPA) concept was added to Release 5 to support higher downlink data rates • It is mainly intended for non-real time traffic, but can also be used for traffic with tighter delay requirements. • Peak data rates up to 10 Mbit/s (theoretical data rate 14.4 Mbit/s) • Reduced retransmission delays • Improved QoS control (Node B based packet scheduler) • Spectrally and code efficient solution
55.
TLT-5606 Spread © Timo
Nihtilä55 HSDPA features • Agreed features in Release 5 – Adaptive Modulation and Coding (AMC) • QPSK or 16QAM – Multicode operation • Support of 1-15 code channels (SF=16) – Short frame size (TTI = 2 ms) – Fast retransmissions using Hybrid Automatic Repeat Request (HARQ) • Chase Combining • Incremental Redundancy – Fast packet scheduling at Node B • E.g.Round robin, Proportionalfair • Features agreed in Release 7 – Higher order modulation (64QAM) – Multiple Input Multiple Output (MIMO)
56.
TLT-5606 Spread © Timo
Nihtilä56 HSDPA - general principle • Fast scheduling is done directly in Node-B based on feedback information from UE and knowledge of current traffic state. Channel quality (CQI, Ack/Nack, TPC) Data Users may be time and/or code multiplexed New base station functions • HARQ retransmissions • Modulation/coding selection • Packet data scheduling (short TTI) New base station functions • HARQ retransmissions • Modulation/coding selection • Packet data scheduling (short TTI) UE 0 2 0 4 0 6 0 8 0 1 0 0 1 2 0 1 4 0 1 6 0 - 2 0 2 4 6 8 1 0 1 2 1 4 1 6 T im e [ n u m b e r o f T T Is ] Q P S K 1 / 4 Q P S K 2 / 4 Q P S K 3 / 4 1 6 Q A M 2 / 4 1 6 Q A M 3 / 4 InstantaneousEsNo[dB]
57.
TLT-5606 Spread © Timo
Nihtilä57 HSDPA functionality • Scheduling responsibility has been moved from RNC to Node B • Due to this and the short TTI length (2 ms) the scheduling is dynamic and fast • Support for several parallel transmissions – When packet A issent it starts to wait for anacknowledgement from the receiver, during which other packets canbe sent via a parallel SAW (stop-and-wait) channels Pkt A Pkt B Pkt C Pkt D Pkt E Pkt F Ack B
58.
TLT-5606 Spread © Timo
Nihtilä58 HSDPA functionality • UE informs the Node B regularly of its channel quality by CQI messages (Channel Quality Indicator)
59.
TLT-5606 Spread © Timo
Nihtilä59 HSDPA functionality • Node B can use channel state information for several purposes – In transport format (TFRC) selection • Modulation and coding scheme – Scheduling decisions • Non-blind scheduling algorithms can be utilized – HS-SCCH power control
60.
TLT-5606 Spread © Timo
Nihtilä60 HSDPA channels • User data is sent on High Speed Downlink Shared Channel (HS-DSCH) • Control information is sent on High Speed Common Control Channel (HS-SCCH) • HS-SCCH is sent two slot before HS-DSCH to inform the scheduled UE of the transport format of the incoming transmission on HS-DSCH
61.
TLT-5606 Spread © Timo
Nihtilä61 High Speed Uplink Packet Access (HSUPA) • Peak data rates increased to significantly higher than 2 Mbps; Theoretically reaching 5.8 Mbps • Packet data throughput increased, though not as high throughput as with HSDPA • Reduced delay from retransmissions. • Solutions – Layer1 hybrid ARQ – NodeB based scheduling for uplink – Frame sizes 2ms & 10 ms • Schedule in 3GPP – Part of Release 6 – First specifications version completed 12/04 – In 3GPP specs with the name Enhanced uplink DCH (E-DCH)
62.
TLT-5606 Spread © Timo
Nihtilä62 5 codes QPSK of codes# Modulation 5 codes 16-QAM 10 codes 16-QAM 15 codes 16-QAM 15 codes 16-QAM 1.8 Mbps Max data rate 3.6 Mbps 7.2 Mbps 10.1 Mbps 14.4 Mbps 2 x SF4 2 ms 10 ms of codes# TTI 2 x SF2 10 ms 2 x SF2 2 ms 2 x SF2 + 2 x SF4 2 ms 1.46 Mbps Max data rate 2.0 Mbps 2.9 Mbps 5.76 Mbps Downlink HSDPA • Theoretical up to 14.4 Mbps • Initial capability1.8 – 3.6 Mbps Uplink HSUPA • Theoretical up to 5.76 Mbps • Initial capability1.46 Mbps HSPA Peak Data Rates
63.
63 Performance of advanced
HSDPA features
64.
TLT-5606 Spread © Timo
Nihtilä64 Advanced receivers with HSDPA • UE receiver experiences significant interference from different sources – In a reflective environment the signalinterferes itself – Neigboring base stationsignals interfere eachother – One solutionto decrease mainlyownbase stationsignal interference is touse anequalizer before despreading Own cell interference Other cell interference Own signal
65.
TLT-5606 Spread © Timo
Nihtilä65 Advanced receivers with HSDPA • In a frequency-selective channel there is a significant amount of interfering multipaths • Linear Minimum Mean Squared Error (LMMSE) equalizer can be used to make an estimate of the original transmitted chip sequence before despreading – The interfering multipathcomponentsare removed – The channelbecomes flat again
66.
TLT-5606 Spread © Timo
Nihtilä66 Advanced receivers with HSDPA • LMMSE equalizer (Equ in the figure) offers a very good performance for the user especially near the base station • Using antenna diversity (1x2) the throughput can be doubled compared to a single antenna • Both techniques increase the cost of a mobile unit
67.
TLT-5606 Spread © Timo
Nihtilä67 Advanced HSDPA scheduling • Node B has a limited amount of scheduling opportunities • The amount of data transmitted by the network must be maximized whilst offering the best possible quality of service to all users – The scheduling canbe improved byanadvanced algorithm
68.
TLT-5606 Spread © Timo
Nihtilä68 Advanced HSDPA scheduling • An improved scheduling algorithm (Proportional Fair, PF) offers significant gain over a conventional algorithm (Round Robin, RR) • PF has a very good price-quality ratio – User equipment needs no changes – Node B’s need onlyminor changes
69.
TLT-5606 Spread © Timo
Nihtilä69 Femtocells • More and more consumers want to use their mobile devices at home, even when there’s a fixed line available – Providing full or evenadequate mobile residentialcoverage is a significant challenge for operators – Mobile operators need to seize residential minutes from fixed line providers, and compete withfixed and emerging VoIPand WiFiservices => There is trend indiscussing verysmallindoor, home and campus NodeB layouts • Femtocells are cellular access points (for limited access group) that connect to a mobile operator’s network using residential DSL or cable broadband connections • Femtocells enable capacity equivalent to a full 3G network sector at very low transmit powers, dramatically increasing battery life of existing phones, without needing to introduce WiFi enabled handsets
70.
TLT-5606 Spread © Timo
Nihtilä70 Femtocells • The study considers the system performance of an HSDPA network consisting of macro cells and very low transmit power (femto) cells • The impact of using 64QAM in addition to QPSK and 16QAM in order to benefit from the high SINR is studied • The network performance is investigated with different portions of users created in the buildings (0-100%)
71.
TLT-5606 Spread © Timo
Nihtilä71 Femtocells • Femtocells provide maximum of 15-17 % gainto networkthroughput alreadywithout dedicated indoor users • The gainis visible with high load inthe networkand comes directlyfrom the increased number of access points inthe network • Average load of a cell is decreased and users canbe scheduled more often Scheme Offered load Medium High Congested Rake 1x1 3 % 8 % 15 % Rake 1x2 -1 % 19 % 13 % Equ 1x1 -2 % 18 % 15 % Equ 1x2 -1 % 3 % 17 % Table: Network throughput gain of femto cells to macro users
72.
TLT-5606 Spread © Timo
Nihtilä72 Femtocells • When the amount of dedicated indoor users increase, the gain of femto cells explodes • Gain is in the range of hundreds of percents even with small portion of indoor users
Jetzt herunterladen