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Academic Year 2010/2011            ELECTRICAL AND COMPUTER ENGINEERING            THE INSTITUTE OF TELECOMMUNICATIONS     ...
ELABORATION OF LABORATORY EXPERIMENTS FOR TEACHING PURPOSES IN THE AREA OF LTE, WIMAX NETWORKS PLANNING, SON NETWORKS.    ...
OPRACOWANIE ĆWICZEŃ LABORATORYJNYCH  W ZAKRESIE TECHNOLOGII LTE, PLANOWANIA           SIECI WIMAX, SIECI SON.             ...
Jarosław Medwid                                                 Date of birth: 15.06.1987r.                               ...
Sincere thanks for SupervisorMirosław Słomiński, Associate Professor                 for help in elaboration              ...
Official thanks to IS-WirelessWe would like to thank the staff and the President of IS-Wireless (brand of InnovativeSoluti...
Table of Contents1. Introduction ............................................................................................
Figures list:Fig. 1 eNB Transmitter block scheme involved in the downlink investigations[38] ............... 25Fig. 2 Samp...
Tables list:Tab. 1 Coordinates of particular network units ..................................................................
Abbreviations:E-UTRAN – Evolved UMTS Terrestial Radio Access NetworkOFDM – Orthogonal Frequency Division MultiplexingOFDMA...
RRC – Radio Resource ControlNAS – Non-Access StratumWiMAX – Worldwide Interoperability for Microwave AccessWi-Fi – tradema...
1. IntroductionMobile wireless Internet access is very perspective branch, which is one of the maindevelopment directions ...
amount of throughput. But there are also services like Skype or YouTube which demand highspeed Internet connection. Operat...
trying to increase signal quality of 3G. Comparing to 4G implementation process is cheap incase of 3G and it assures incom...
1.2 ComplementarityDesigned thesis is complementary to [15]. It includes elaborated laboratory exercises fornewly-formed c...
experiment. At the end of each chapter there is summary of the abilities which can be gainedby the students and overall co...
2. Analysis of the available software tools utilized further inthe laboratory experimentsFirst objective of the thesis ref...
It is worth to underline that LTE PHY Lab tool structure is very granular what allows for highflexibility of simulations. ...
2.2.2 WiMAX Networks planning utilizing selected method   A. WiMAX PHY LabWiMAX PHY Lab tool is a Matlab toolbox allowing ...
allows for better optimization of the designed networks. Tool is very intuitive what facilitatesits usability.   D. Radio ...
Such optimizations facilitate network implementation what is connected with minimization ofthe operation costs of running ...
3. Laboratory experiments organizationOn the beginning of the laboratory experiment students will get familiar with the ma...
   summary of each part of simulation with description of achieved aim   answers for the questions asked in the laborato...
4. Laboratory no 1 – investigations of the downlink physicalchannels of the LTE Technology with utilization of the LTEPHY ...
Task 1:First task refers to the investigations of the data allocations for downlink model in LTEtransmission.             ...
comfortable for students to learn the role of particular elements in the whole downlinktransmission operation.In the secon...
sizeFFT = 512;outputSamples = LTELinkLevelSimulateDL(inputDataBlock,...                        numPDCCH,numsPRB, modOrder,...
   Specify the number of OFDMA symbols.       Describe the role of the particular elements. Each figure with necessary de...
b) Investigate how particular channel looks like for different subframe (numSubframevariable).b) Select randomly the bytes...
Sample scatterplots can be seen below:On the first scatterplots we can find sample downlink frame which is the result of t...
Using own knowledge and tutorial notes students should mark particular channels in the waypresented on the figure 16. Each...
4.1 Selected issues of LTE TechnologyIn this section there are presented essential issues of the LTE Technology with which...
Fig. 6 Frame type 1, timing and symbol allocations shown for FDD with normal cyclic prefix (CP) [13]LTE frame structure of...
Resource Elements, Resource BlockLTE introduces also different units referring to the both time and frequency aspects apar...
Fig. 9 Resource grid scheme [14]Reference SignalsLTE introduces a concept of special Reference Signals (RS) interspersed a...
Fig. 10 LTE Reference Symbols distribution among the Reference Elements [14]4.1.3 LTE downlink channels and signals typesI...
Fig. 11 Map of Downlink frame using FDD and normal CP shows the relative location of the various physical          channel...
Physical Downlink Control Channel (PDCCH)  Physical Downlink Control Channel is allocating both uplink and downlink resour...
Cell-specific Reference SignalsCell-specific Reference Signals occurrence refers to the cells which are supporting the non...
Downlink Transport Channels  Broadcast Channel (BCH)  Downlink Broadcast Channel is allowing the devices accessing to the ...
downlink direction. It is also visible the number of assigned RE for the PDCCH channel. Suchinformation are delivered by t...
Downlink Logical Channels  Downlink Control and Traffic channels:  Broadcast Control Channel (BCCH)  Broadcast Control Cha...
Accordingly to the previous mapping of downlink physical and transport channelscooperation LTE adds next layer of logical ...
Fig. 16 3D view toggle inside the figure windowFully detailed user guide instruction provided by Innovative Solutions can ...
The main objective of the laboratory session is to combine gained LTE knowledge with theresults of the simulation and to m...
5. Laboratory no 2 – investigations of the uplink physicalchannels of the LTE Technology with utilization of the LTEPHY La...
provided under each of them. The simulation shows spectrogram (also in 3D view). Users canmanipulate the 3D view to observ...
Elaboration of Laboratory Experiments for Teaching Purposes in the area of LTE, WiMAX Networks Planning, SON Networks
Elaboration of Laboratory Experiments for Teaching Purposes in the area of LTE, WiMAX Networks Planning, SON Networks
Elaboration of Laboratory Experiments for Teaching Purposes in the area of LTE, WiMAX Networks Planning, SON Networks
Elaboration of Laboratory Experiments for Teaching Purposes in the area of LTE, WiMAX Networks Planning, SON Networks
Elaboration of Laboratory Experiments for Teaching Purposes in the area of LTE, WiMAX Networks Planning, SON Networks
Elaboration of Laboratory Experiments for Teaching Purposes in the area of LTE, WiMAX Networks Planning, SON Networks
Elaboration of Laboratory Experiments for Teaching Purposes in the area of LTE, WiMAX Networks Planning, SON Networks
Elaboration of Laboratory Experiments for Teaching Purposes in the area of LTE, WiMAX Networks Planning, SON Networks
Elaboration of Laboratory Experiments for Teaching Purposes in the area of LTE, WiMAX Networks Planning, SON Networks
Elaboration of Laboratory Experiments for Teaching Purposes in the area of LTE, WiMAX Networks Planning, SON Networks
Elaboration of Laboratory Experiments for Teaching Purposes in the area of LTE, WiMAX Networks Planning, SON Networks
Elaboration of Laboratory Experiments for Teaching Purposes in the area of LTE, WiMAX Networks Planning, SON Networks
Elaboration of Laboratory Experiments for Teaching Purposes in the area of LTE, WiMAX Networks Planning, SON Networks
Elaboration of Laboratory Experiments for Teaching Purposes in the area of LTE, WiMAX Networks Planning, SON Networks
Elaboration of Laboratory Experiments for Teaching Purposes in the area of LTE, WiMAX Networks Planning, SON Networks
Elaboration of Laboratory Experiments for Teaching Purposes in the area of LTE, WiMAX Networks Planning, SON Networks
Elaboration of Laboratory Experiments for Teaching Purposes in the area of LTE, WiMAX Networks Planning, SON Networks
Elaboration of Laboratory Experiments for Teaching Purposes in the area of LTE, WiMAX Networks Planning, SON Networks
Elaboration of Laboratory Experiments for Teaching Purposes in the area of LTE, WiMAX Networks Planning, SON Networks
Elaboration of Laboratory Experiments for Teaching Purposes in the area of LTE, WiMAX Networks Planning, SON Networks
Elaboration of Laboratory Experiments for Teaching Purposes in the area of LTE, WiMAX Networks Planning, SON Networks
Elaboration of Laboratory Experiments for Teaching Purposes in the area of LTE, WiMAX Networks Planning, SON Networks
Elaboration of Laboratory Experiments for Teaching Purposes in the area of LTE, WiMAX Networks Planning, SON Networks
Elaboration of Laboratory Experiments for Teaching Purposes in the area of LTE, WiMAX Networks Planning, SON Networks
Elaboration of Laboratory Experiments for Teaching Purposes in the area of LTE, WiMAX Networks Planning, SON Networks
Elaboration of Laboratory Experiments for Teaching Purposes in the area of LTE, WiMAX Networks Planning, SON Networks
Elaboration of Laboratory Experiments for Teaching Purposes in the area of LTE, WiMAX Networks Planning, SON Networks
Elaboration of Laboratory Experiments for Teaching Purposes in the area of LTE, WiMAX Networks Planning, SON Networks
Elaboration of Laboratory Experiments for Teaching Purposes in the area of LTE, WiMAX Networks Planning, SON Networks
Elaboration of Laboratory Experiments for Teaching Purposes in the area of LTE, WiMAX Networks Planning, SON Networks
Elaboration of Laboratory Experiments for Teaching Purposes in the area of LTE, WiMAX Networks Planning, SON Networks
Elaboration of Laboratory Experiments for Teaching Purposes in the area of LTE, WiMAX Networks Planning, SON Networks
Elaboration of Laboratory Experiments for Teaching Purposes in the area of LTE, WiMAX Networks Planning, SON Networks
Elaboration of Laboratory Experiments for Teaching Purposes in the area of LTE, WiMAX Networks Planning, SON Networks
Elaboration of Laboratory Experiments for Teaching Purposes in the area of LTE, WiMAX Networks Planning, SON Networks
Elaboration of Laboratory Experiments for Teaching Purposes in the area of LTE, WiMAX Networks Planning, SON Networks
Elaboration of Laboratory Experiments for Teaching Purposes in the area of LTE, WiMAX Networks Planning, SON Networks
Elaboration of Laboratory Experiments for Teaching Purposes in the area of LTE, WiMAX Networks Planning, SON Networks
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Elaboration of Laboratory Experiments for Teaching Purposes in the area of LTE, WiMAX Networks Planning, SON Networks

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This thesis presents the concept of laboratory experiments realized for teaching purposes at the Warsaw University of Technology. The addressed technical areas include simulations for LTE Technology, WiMAX Network Planning and deployment of Self-Organizing Networks.

The majority of the proposed lab experiments have been implemented in a MATLAB-based link level simulator from IS-Wireless, which is part of 4G University Suite. For more information about 4G University Suite, please have a look http://is-wireless.com/4g-university-suite/

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Elaboration of Laboratory Experiments for Teaching Purposes in the area of LTE, WiMAX Networks Planning, SON Networks

  1. 1. Academic Year 2010/2011 ELECTRICAL AND COMPUTER ENGINEERING THE INSTITUTE OF TELECOMMUNICATIONS FACULTY OF ELECTRONICS AND INFORMATION TECHNOLOGY WARSAW UNIVERSITY OF TECHNOLOGY MASTER OF SCIENCE THESIS ELABORATION OF LABORATORY EXPERIMENTS FOR TEACHING PURPOSES IN THE AREA OF LTE, WIMAX NETWORKS PLANNING, SON NETWORKS. Jarosław MEDWID Supervisor: Mirosław SŁOMIŃSKI, Associate Professor........................................................... Evaluation........................................................... Signature of the Head of Examination Committee Warsaw, September 2011
  2. 2. ELABORATION OF LABORATORY EXPERIMENTS FOR TEACHING PURPOSES IN THE AREA OF LTE, WIMAX NETWORKS PLANNING, SON NETWORKS. AbstractMy Master of Science Thesis presents a concept of laboratory experiments for teachingpurposes in the area of simulations utilizing LTE Technology, WiMAX Network Planningand Self-Organizing Networks. Elaborated laboratory experiments concepts referring directlyto the issues that will be described on the newly-formed course based on the modern wirelesstechnologies. Thesis includes theoretical introductions, task descriptions and utilized toolsinstructions for each of the elaborated laboratory experiments. Software tools were selectedafter investigations of the set of tools available on the software market. Elaborated laboratoryexperiments are combining selected software tools with the demands of the examined subjectfor particular investigation area.
  3. 3. OPRACOWANIE ĆWICZEŃ LABORATORYJNYCH W ZAKRESIE TECHNOLOGII LTE, PLANOWANIA SIECI WIMAX, SIECI SON. StreszczenieMoja Praca Magisterska prezentuje koncepcje ćwiczeń laboratoryjnych dla celówdydaktycznych w zakresie symulacji wykorzystujących technologię LTE, planowania sieciwykorzystujących technologię WiMAX oraz sieci SON. Opracowane ćwiczenia laboratoryjneodnoszą się bezpośrednio do zagadnień, które będą opisywane na nowo-stworzonymprzedmiocie bazującym na tematyce nowoczesnych technologii bezprzewodowych. Pracazawiera wprowadzenie teoretyczne, opisy zadań oraz instrukcje do wykorzystywanychnarzędzi programistycznych podczas każdego z przeprowadzonych ćwiczeń. Narzędziaprogramistyczne zostały wybrane po badaniach zestawu narzędzi dostępnych na rynkuoprogramowania. Opracowane ćwiczenia laboratoryjne łączą wybrane narzędzia zwymaganiami badanych zagadnień dla wybranego obszaru badań.
  4. 4. Jarosław Medwid Date of birth: 15.06.1987r. Curriculum VitaeEducation:  10.2010 – 09.2011 Warsaw University of Technology, Faculty of Electronics and Information Technology, Electrical and Computer Engineering, M.Sc.  10.2006 – 09.2010 Warsaw University of Technology, Faculty of Electronics and Information Technology, Electrical and Computer Engineering, B.Sc.  09.2003 – 06.2006 Liceum Ogólnokształcące im.B.Prusa w SkierniewicachWork experience:  10.2011 – actually Nokia Siemens Networks, Senior Software Testing Engineer  11.2009 – 09.2011 Psiloc, Mobile Software Solutions, Quality Assurance Specialist  09.2009 – 11.2009 Telekomunikacja Polska S.A., Technical Service Department, Practices  07.2008 – 10.2008 Zatra S.A., Sales and Marketing SpecialistSkills:  Knowledge in the area of Network management and planning (WiMAX and WiFI Technologies), Routing protocols, Internet protocols  Experience in mobile software development on platforms Android, iOS, Windows Phone, Symbian, Maemo, Java, Web solutions  Experience over the testing, integration and verification areas  Programming languages basic knowledge: Python, C++, C, Assembler, Visual Basic, HTML/XML/CSS  Basic knowledge of SQL databasesLanguages:  English – fluently  Deutsch – intermediate …………………………. Signature of the student
  5. 5. Sincere thanks for SupervisorMirosław Słomiński, Associate Professor for help in elaboration Master of Science Thesis
  6. 6. Official thanks to IS-WirelessWe would like to thank the staff and the President of IS-Wireless (brand of InnovativeSolutions) creators of LTE PHY LAB, for helping during laboratory scenario research andgranting us a trial license for their tool. The tool is a simulator of LTE physical layer inMatlab and the IS-Wireless has acquired the status of the Mathworks partner programconnections. Due to the fact that it is a professional tool, it has the greatest potential of allused. For this reason, we increase its share in our laboratories. As many as four of the eightlaboratories use this tool. With this tool, students can observe, and most importantly, changewhat you normally see only in books, namely, the physical signal of LTE. Can thus learn thefoundation of LTE, namely OFDMA and SC-FDMA. Technologies that are now the basis formost of the major radio technologies.Their help and suggestions have proved as important as the license itself. Through theseconsultations, the scenarios correspond to the real demands and are a great educationalmaterial. LTE PHY LAB certainly would be a great help in conducting theoretical lecture,which could lead to support the theory of real examples, with the simulation in real-timemode. In this case, the lecturer can present the relevant features and technologies, in differentcases, and conducts theoretical lecture more interactive, confronting theory with practicalexamples in various cases.Working with IS-Wireless is a great example of the western model of education, where thecompany is actively involved in creating educational programs. Specialist with the IS-Wireless gave us a clear and concrete suggestions on what we should put focus on andanswered all our questions, with excellent knowledge of the topic, market and customerneeds.Especially we would like to thank CEO Dr. Sławomir Pietrzyk for giving us this opportunityand Mr. Marcin Dryjański for help and support during development of this work.
  7. 7. Table of Contents1. Introduction .......................................................................................................................... 12 1.1 Work objectives.............................................................................................................. 14 1.2 Complementarity ............................................................................................................ 15 1.3 Structure of the work ...................................................................................................... 152. Analysis of the available software tools utilized further in the laboratory experiments ...... 17 2.1 Preface for newly-formed teaching course ..................................................................... 17 2.2 Software tool selection ................................................................................................... 17 2.2.1 LTE simulation utilizing selected method .............................................................. 17 2.2.2 WiMAX Networks planning utilizing selected method .......................................... 19 2.2.3 Self-Organizing Networks....................................................................................... 203. Laboratory experiments organization................................................................................... 22 3.1 Laboratory experiments rules ......................................................................................... 224. Laboratory no 1 – investigations of the downlink physical channels of the LTETechnology with utilization of the LTE PHY Lab Matlab tool. .............................................. 24 4.1 Selected issues of LTE Technology ............................................................................... 32 4.1.1 LTE Technology introduction ................................................................................. 32 4.1.2 Frame structures ...................................................................................................... 32 4.1.3 LTE downlink channels and signals types .............................................................. 36 4.2 LTE PHY Lab tool instruction ....................................................................................... 43 4.3 Summary and conclusions .............................................................................................. 445. Laboratory no 2 – investigations of the uplink physical channels of the LTE Technologywith utilization of the LTE PHY Lab Matlab tool. .................................................................. 46 5.1 Selected issues of LTE Technology ............................................................................... 56 5.1.1 LTE uplink channels and signals types ................................................................... 56 5.2 Summary and conclusions .............................................................................................. 596. Laboratory no 3 – investigations of the WiMAX Technology with use of theWiMAXProjekt tool ................................................................................................................. 60 6.1 Selected issues of WiMAX Technology ........................................................................ 63 6.1.1 Duplexing techniques .............................................................................................. 63 6.1.2 Adaptive modulation ............................................................................................... 63 6.1.3 Overbooking ............................................................................................................ 63 6.2 WiMAXProjekt tool instruction ..................................................................................... 64 6.3 Summary and conclusions .............................................................................................. 697. Laboratory no 4 – investigations of the SON with use of the PKSA Planner tool .............. 71 7.1 Selected issues of SON .................................................................................................. 77 7.1.1 Self-Organizing Networks introduction .................................................................. 77 7.1.2 Primary and additional paths ................................................................................... 77 7.1.3 Methods of reconfiguration ..................................................................................... 78 7.1.4 Important definitions ............................................................................................... 79 7.2 PKSA Planner tool instruction ....................................................................................... 79 7.3 Summary and conclusions .............................................................................................. 818. Conclusions .......................................................................................................................... 829. References ............................................................................................................................ 84 9.3 CD contents .................................................................................................................... 85 9.4 Appendix A .................................................................................................................... 85 7
  8. 8. Figures list:Fig. 1 eNB Transmitter block scheme involved in the downlink investigations[38] ............... 25Fig. 2 Sample downlink subframe ............................................................................................ 30Fig. 3 Sample downlink subframe – 3D view of the previous scatterplot ............................... 30Fig. 4 Sample downlink subframe 0 presenting way of scatterplots description expected in thestudents’ reports ....................................................................................................................... 31Fig. 5 Sample downlink frame with overall view on each subframe ...................................... 31Fig. 6 Frame type 1, timing and symbol allocations shown for FDD with normal cyclic prefix(CP) [13] ................................................................................................................................... 33Fig. 7 Frame type 2 – special fields are shown in subframes 1 and 6. Guard period separatesthe Downlink and Uplink. This TDD example represents a 5ms switch point. A 10ms switchpoint would not have the special fields in subframe 6. [13]..................................................... 33Fig. 8 Relationship between a slot, symbols and Resource Blocks. N(dl/rb) is the symbol usedto indicate the maximum number of downlink Resource Blocks for a given bandwidth. [35] 34Fig. 9 Resource grid scheme [14]............................................................................................. 35Fig. 10 LTE Reference Symbols distribution among the Reference Elements [14] ................ 36Fig. 11 Map of Downlink frame using FDD and normal CP shows the relative location of thevarious physical channels. Frames in systems using extended CP or TDD would be slightlydifferent. [35] ........................................................................................................................... 37Fig. 12 Primary and Secondary Synchronization Signals allocations [13] .............................. 39Fig. 13 Mapping of downlink transport and physical channels cooperation [13] .................... 40Fig. 14 LTE downlink frame map (10ms length, Δf=15 kHz, normal CP) [37] ...................... 41Fig. 15 Mapping of uplink logical and transport channels cooperation [13] ........................... 42Fig. 16 3D view toggle inside the figure window .................................................................... 44Fig. 17 UE Transmitter block scheme involved in the uplink investigations[38].................... 47Fig. 18 Sample uplink subframe .............................................................................................. 52Fig. 19 Sample uplink subframe – 3D view of the previous scatterplot .................................. 53Fig. 20 Sample uplink subframe with SRS presence ............................................................... 53Fig. 21 Sample uplink subframe with PRACH presence ......................................................... 54Fig. 22 Sample uplink subframe with PUSCH in format 3 presence ....................................... 54Fig. 23 Sample uplink frame consisting of all subframes ........................................................ 55Fig. 24 Map of Uplink subframe withNormal Cyclic Prefix [35] ............................................ 56Fig. 25 Random access preamble structure [37] ...................................................................... 57Fig. 26 Mapping of uplink transport and physical channels cooperation [13] ......................... 58Fig. 27 Mapping of uplink logical and transport channels cooperation [37] ........................... 58Fig. 28 Application main view ................................................................................................. 64Fig. 29 Single terminal addition ............................................................................................... 65Fig. 30 Hardware and radio parameters selection .................................................................... 66Fig. 31 Primary localization of the terminals [2] ..................................................................... 67Fig. 32 Manual optimization of the terminals localizations [2] ............................................... 67Fig. 33 View of the modulation range for two 90 degrees antennas and 4 client terminals [2].................................................................................................................................................. 68Fig. 34 Terrain cross-section points geographic coordinates [2] ............................................. 68Fig. 35 Checking LOS condition and terrain cross-section view ............................................. 69Fig. 36 Sample network topology model ................................................................................. 75Fig. 37 Link-based method failure reconfiguration scenario ................................................... 78Fig. 38 End-to-end method failure reconfiguration scenario ................................................... 78Fig. 39 PKSA Planner visual window ...................................................................................... 80 8
  9. 9. Tables list:Tab. 1 Coordinates of particular network units ........................................................................ 61Tab. 2 Downlink and uplink configurations including overbooking factor ............................. 62Tab. 3 Initial data table with Primary Paths and Secondary Paths dedicated to the samplemodel from Figure 1 ................................................................................................................. 72Tab. 4 Primary Paths configuration table ................................................................................. 73Tab. 5 Secondary Paths configuration table using end-to-end method .................................... 74 9
  10. 10. Abbreviations:E-UTRAN – Evolved UMTS Terrestial Radio Access NetworkOFDM – Orthogonal Frequency Division MultiplexingOFDMA – Orthogonal Frequency Division Multiple AccessFDMA – Frequency Division Multiple AccessSC – Single CarrierSC-FDMA – Single Carrier Multiple AccessMIMO – Multiple Input Multiple OutputSISO – Single Input Single OutputRF – Radio FrequencySAE – System Architecture EvolutionUE – User EquipmenteNB – eNodeBMME – Mobility Management EntitySGW – Serving GatewayPGW – PDN GatewayPCRF – Policy and Charging Rules FunctionRNC – Radio Network ControllersCP – Cyclic PrefixDwPTS – Downlink Pilot Time SlotGP – Guard PeriodUpPTS – Uplink Pilot Time SlotPBCH – Physical Broadcast ChannelPCFICH – Physical Control Format Indicator ChannelPDCCH – Physical Downlink Control ChannelPHICH – Physical Hybrid ARQ Indicator ChannelPDSCH – Physical Downlink Shared ChannelPMCH – Physical Multicast ChannelPUCCH – Physical Uplink Control ChannelPUSCH – Physical Uplink Shared ChannelPRACH – Physical Random Access ChannelBCH – Broadcast ChannelDL-SCH – Downlink Shared ChannelPCH – Paging ChannelMCH – Multicast ChannelUL-SCH – Uplink Shared ChannelRACH – Random Access ChannelBCCH – Broadcast Control ChannelPCCH – Paging Control ChannelCCCH – Common Control ChannelMCCH – Multicast Control ChannelDCCH – Dedicated Control ChannelDTCH – Dedicated Traffic ChannelMTCH – Multicast Traffic ChannelPHY – Physical layerMAC – Medium Access ControlRLC – Radio Link ControlPDCP – Packet Data Convergence Protocol 10
  11. 11. RRC – Radio Resource ControlNAS – Non-Access StratumWiMAX – Worldwide Interoperability for Microwave AccessWi-Fi – trademark of Wi-Fi AllianceWMN – Wireless Mesh NetworkIEEE – Institute of Electrical and Electronics Engineers3G – Third Generation of Cellular Wireless Standards4G – Fourth Generation of Cellular Wireless StandardsHSPA – High-Speed Packet AccessLTE – Long Term EvolutionWAN – Wide Area NetworkLAN – Local Area NetworkSS – Subscriber StationBS – Base StationBTS – Base Terminal StationAP – Access PointTDD – Time Division DuplexFDD – Frequency Division DuplexSNR – Signal to Noise RatioAMSL – Above Mean Sea LevelDWDM – Dense Wavelength Division MultiplexingUWDM – Ultra Dense Wavelength Division MultiplexingQoS – Quality of ServiceSLA – Service Level AgreementLOS – Line-of-sightNLOS – Non-line-of-sightSON – Self-Organizing NetworkSHN – Self-Healing NetworkCR – Cognitive RadioUGS – Unsolicited Grant ServicesCG – Continuous GrantrtPS – Real–Time Polling ServicesErtPS – Extended Real–Time Polling ServicenrtPS – Non–Real–Time Polling ServicesBE – Best EffortMRTR – Minimum Reserved Traffic RateMSTR – Sustained Maximum Traffic RateML – Maximum LatencyTJ – Tolerated JitterTP – Traffic PriorityR / TP – Request / Transmission PolicyMAC – Media Access Control addressMAC-PDU – MAC Protocol Data UnitOEC – Office of Electronic CommunicationsVLAN – Virtual LANVPN – Virtual Private NetworkIP – Internet ProtocolVoIP – Voice over Internet ProtocolQPSK – Quadrature Phase-Shift KeyingQAM – Quadrature Amplitude Modulation 11
  12. 12. 1. IntroductionMobile wireless Internet access is very perspective branch, which is one of the maindevelopment directions in telecommunication. The idea is to provide as high as possibletransmission quality to portable devices for convenience of Internet usage everywhere.High-Speed Packet Access (HSPA) technology as a current standard in cell networks can beprovided as an example of modern mobile systems. Offered throughput depends on therelease and region where it is implemented. In Polish cell networks like Orange, T-Mobile orPlus, HSPA provides throughput at the level of 7.2 Mbit/s, but there are also known releaseswith 21.6 Mbit/s of theoretical throughput. This solution is still evolving and now under thename of HSPA+ can provides multiplied throughput of HSPA dependently on the release.Mobile Worldwide Interoperability for Microwave Access (mobile WiMAX) standard IEEE802.16e [34] is a mobile edition of WiMAX IEEE 802.11d. It allows for usage in movement.As an example of this edition, South Korean network under name WiBro can be given. Basestation of this standard offers an aggregate data throughput at the level of 30 to 50 Mbit/s percarrier and covering radius of 1–5 km. It allows for portable internet usage in mobility formoving devices up to 120 km/h.Long Term Evolution (LTE) Technology is actually bringing the highest amount ofinvestments by huge, worldwide operators like T-Mobile, Orange or Vodafone. It isunderstandable taking under consideration the level of service offered by this technology [34].Technology is very efficient in mobile usage as it improved the handover mechanism whichnow allows for better handling this issue and stay connected even inside moving car or train.Along progressive introduction of information society development assumptions, aims will begradually filling. Technological awareness is increasing together with each new generation. Itis visible in growing amount of high level of education staff in IT sector at the academic level.It is only a matter of time when things will happen.In this year sales of the smartphones and tablets exceeded the amount of ‘typical’ phones sale[18]. That indicates the proper way of telecommunication development and underlinedemands for mobile solutions. Actually not only the business market want to be constantlyconnected to the Internet to receive e-mails and communicate with offices, consumer markethas shown that demands for mobile solutions refers also to this social area. Nowadays, peopledoesn’t want only to receive e-mails, they also want to transfer some file, listen to Internetradio, watch live relation from football match, what requires large amounts of data to betransmitted and thus higher throughput from the operators.Moreover, people want to use Internet in the places where in a few years ago they only coulddream about, mountains, beaches and so on, are now waiting for the Internet users. Thatforced operators to extend network coverage outside typical Internet regions usage.Constant development of the Internet services raises new challenges for mobile networkoperators. Influence of the social services like Facebook or Twitter has great impact on themobile market, because millions of people are using them and everyone wants to be ‘intouch’. This led to the moment that operators are offering free Internet access in the mobilephones for usage with selected services, mostly social one since it doesn’t require high 12
  13. 13. amount of throughput. But there are also services like Skype or YouTube which demand highspeed Internet connection. Operators need to extend their networks and invest in the modernwireless technologies which met the requirements of modern Internet services.It is necessary to underline that actual throughput of the modern 3G and 4G technologies isallowing to use even High-Definition television (HDTV) in mobility. This is a part of thetelecommunication market which is expected to be developing rapidly in the next few years,so also investments of the operators in video technologies transmissions are obvious toforecast. Lots of services have their mobile versions including video materials which are sodesirable by end users of mobile devices. There is also visible the trend of Internet ProtocolTelevision (IPTV) [40] intensified interest. People simply want to bring to their mobiledevices entertainment and information.Constant developmentAll mobile systems are understood as development stages moving towards 4G solutionsincluding usage in mobility. Mobile WiMAX, so as LTE are known as ‘pre 4G’, because theyallow for mobile usage, but they are not fulfilling all requirements of 4G standard. It isexpected that by the end of 2011 standard called LTE Advanced will be released ([17], [18]).At the moment that standard is submitted as a candidate to 4G systems, because it introducesenhancements to the LTE standard which are aimed to fulfill all 4G requirements.WiMAX Forum is also going to introduce their second release WiMAX 2 aimed to fulfillrequirements of 4G specification [39]. The standard known as IEEE 802.16m is planned to beready by the end of 2011. Despite the fact that actual release of Mobile WiMAX has beendefeated by the LTE, it is still being developed in some countries. Implementation of WiMAXis good for some regions and it is even better than LTE from the point of implementationcosts. WiMAX brings more coverage on single Base Terminal Station (BTS), so it requiresless units than LTE to cover particular region. That is why many sources doesn’t defineWiMAX as a competitor of LTE because both technologies are dedicated for different part ofthe telecommunication market. However, WiMAX 2 is planned to raise the stationarythroughput up to 1 Gb/s and portable up to 100 Mb/s. New release is going to use OrthogonalFrequency Division Multiplexing (OFDM) and Multiple Input Multiple Output (MIMO)technologies and will be backward compatible with previous generation of devices utilizingWiMAX in the first release. First implementations of WiMAX confirmed the specification’sdata defining dowlink rate at 120 Mb/s and uplink at 60 Mb/s. BTS tests confirmed range ofabout 70 km2.Simultaneously with the final release of WiMAX 2, LTE is planned to be widely spreading allover the world. Basing on first implementations and responses from the telecommunicationmarket, more and more operators are becoming certain that they need to implement LTE.There is apprehension that WiMAX 2 will be released too late to compete with LTE, simplybecause when operators decide to invest in the LTE which is planned, as the name said, longterm solution, it will be very hard to turn them into the WiMAX 2 direction.Despite the fact of 4G technologies development operators are still investing into HSPA andHSPA+ technologies. For most of nowadays typical users speeds offered by 3G HSPA areaffordable and they fulfilling their demands. It is conscious movement of operators becauseimplementation of the 4G technologies within the country is a long time and very expensiveprocess. Until most of the country will be covered by the 4G network signal, operators are 13
  14. 14. trying to increase signal quality of 3G. Comparing to 4G implementation process is cheap incase of 3G and it assures incomes in the next 3-5 years. Simultaneously operators will beinvesting into 4G backbone creation inside countries and at the moment when it will be ready4G competition of the consumer market will grow rapidly.Moreover, as it was said during Mobile World Congress in Barcelona 2011[41], also HSPA isstill planned to be improved to double actual downlink throughput to the level of 84 Mb/s.Such improvements like sophisticated encoding techniques with multiple subcarriers areplanned to bring mentioned efficiency increment.1.1 Work objectivesPresented Master of Science Thesis is aimed for elaboration of laboratory experiments forteaching purposes in the area of simulations utilizing LTE Technology, WiMAX Networkplanning and Self-Organizing Networks (SON). Laboratories concepts cover issues connecteddirectly with the concepts described on the newly-formed course based on the modernwireless technologies like WiMAX, LTE and issues of Self-Organizing Networks, CognitiveNetworks, etc.First objective referred to the selection of the proper area of investigations of particulartechnologies during the laboratory experiments. This choice was essential because itdetermined the way of student’s learning process. Elaborated laboratory experiments put thehighest focus on the LTE Technology, because actually it is the most desirable technology inthe telecommunication market. In the next order of importance WiMAX Technology is beinginvestigated as for the last few years it was the main competitor in the ‘battle of 4Gtechnologies’. Despite the fact that most of the market turns into the LTE, WiMAX is stillbeing developed and it is still attractive technology for some solutions. The last laboratoryexperiment subject concerns SON.In my opinion conducted selections are logical taking under consideration telecommunicationmarket trends and to demands for particular technologies. From the development support ofmentioned areas selected subject are also up to date.Second main goal of the project refers to the selection of the software tools which could beutilized during laboratory experiments. There was a need to examine each of tools and to findthe best one which will fit to the investigated laboratory experiments subjects.Third general aim was to combine selected software tool with the demands of the examinedsubject for particular investigation area. Along with that, there was also need to design theway of execution the lab. Planned laboratory tasks constitute an internal part of the newsubject or group of subjects dedicated to the modern wireless technologies. Designed thesisincludes also creation of instruction sets for each particular laboratory exercise. Structure ofinstructions consists of two parts – theoretical and practical. The first one contains allnecessary theory knowledge that students will be required to get to known before eachlaboratory session. This part includes also the user guide for the tools used on the exercises.The second part of instruction determines the set of practical tasks, steps explaining the wayof working and tips necessary to make familiar with the utilized tools. 14
  15. 15. 1.2 ComplementarityDesigned thesis is complementary to [15]. It includes elaborated laboratory exercises fornewly-formed course concerning modern wireless technologies.There are planned eight laboratory sessions which will cover related content with utilizationof the different tools and checking different abilities.There are planned:  Four laboratory sessions concerning LTE simulations,  Two laboratory sessions concerning WiMAX Network planning,  One laboratory session concerning Self-Organizing Networks,  One laboratory session concerning Cognitive Radio.Selection of the tools issue is described in the section 2.3.Laboratory sessions schedule: 1. Investigation of the LTE Technology simulation – Generation of uplink transmission frames – with usage of the LTE PHY Lab tool. 2. Investigation of the LTE Technology simulation – Simulation of the influence of the transmit-receive mismatches on the received signal – with usage of the LTE PHY Lab tool. 3. Investigation of the LTE Technology simulation – Generation of PDSCH symbols – with usage of the LTE PHY Lab tool. 4. Investigation of the LTE Technology simulation – Generation of downlink transmission frames – with usage of the LTE PHY Lab tool. 5. Investigation of the WiMAX Network planning with usage of the WiMAXProjekt – part 1. 6. Investigation of the WiMAX Network planning with usage of the WiMAXProjekt – part 2. 7. Investigation of the Self-Organizing Networks with usage of the PKSA Planner tool. 8. Investigation of the Cognitive Radio.1.3 Structure of the workThesis consists of the several sections including both practical and theoretical work. In theChapter 1 there are presented objectives of the thesis with introduction explaining the reasonof selection such topic for investigations.Chapter 2 refers to the investigations of the available tools which can be utilized duringparticular laboratory experiments. This section includes brief descriptions of each particulartool.Chapter 3 refers to the description of laboratory experiments sessions organization and rules.Chapters 4, 5, 6, 7 are dedicated to the particular laboratory experiments. Each chapterincludes description of the laboratory tasks and overall schedule of the tasks. There are alsotheoretical introductions of essential knowledge which students are obliged to know beforethe laboratory. Each chapter has also included instruction of the tool utilized in the particular 15
  16. 16. experiment. At the end of each chapter there is summary of the abilities which can be gainedby the students and overall conclusions.Conclusions referring to whole work are located in the Chapter 8.Chapter 9 is dedicated to the references and additional notes. 16
  17. 17. 2. Analysis of the available software tools utilized further inthe laboratory experimentsFirst objective of the thesis refers to the investigation of the available software tools coveringthe area of the LTE, WiMAX technologies and SON method. This section presentsdescriptions of the tools fulfilling demands for teaching purposes.2.1 Preface for newly-formed teaching courseElaborated laboratory experiments concepts will cover issues connected directly with theconcepts described on the newly-formed course based on the modern wireless technologieslike WiMAX, LTE and issues of SON, Cognitive Networks. During course students will learnthe fundamentals and more specialized matters of mentioned technologies and methods.2.2 Software tool selectionThis section is referring to the selection of the software tools which was taken underconsideration to be the part of the laboratory experiments conducted within the newly-formedcourse.2.2.1 LTE simulation utilizing selected methodIn the Master of Science Thesis investigations referring to LTE Technology the LTE PHYLab Tool will be utilized, regarding WiMAX Technology the WiMAXProjekt will be utilized.However, there are also other tools like LTE Suite or WiMAX PHY Lab available. The mainproblem with the selection of the simulation tools is its hard availability due to their high cost.The alternative is the free or low cost Matlab equivalents, but their quality and accuracy arereally low comparing to the commercial ones.In the area of SON students will be using the PKSA Planner tool [10]. A. LTE PHY LabLTE PHY Lab tool is a Matlab toolbox allowing for investigations of the LTE physical layer[17]. Structure of this tool allows to utilize it by professionals during each stage of LTEsoftware or hardware development since research and prototype processes to simulation of thefully designed system.LTE PHY Lab is implemented according to TS 36.211-870, TS 36.212-870 and TS 36.213-870 specifications.It provides ability to simulate downlink and uplink chains of the LTE PHY layer. Users gainpossibility to set essential simulation parameters of modulation, OFDMA, SC-FDMA orMIMO and observe deeply the resource mapping. It allows for creation a complete models ofeNodeB (eNB) and User Equipment (UE). 17
  18. 18. It is worth to underline that LTE PHY Lab tool structure is very granular what allows for highflexibility of simulations. Such customization allows to investigate the role of every singlecomponent block inside designed experiment. It is very beneficial especially in the education.The problem with LTE PHY Lab tool is that it is not freeware. B. LTE SuiteLteSuite is compliant to the 3GPP Release-8 LTE standard specification [29]. It providesability to simulate the LTE L1/L2 layers with utilization of MIMO and OFDMA.LTE Suite is divided into 4 standalone applications: o LTE GridBasic component allowing to generate LTE resource grid using appropriate setting of thesimulation parameters. Users gain possibility to manage parameters like Cell id, transmissionbandwidth or number of antenna ports. o LTE WaveSeparate component allowing to simulate and observe LTE waveforms. User gain possibilityto see how particular signal processing techniques is resulting on the final plots. It is possibleto observe such effects like filtering or PAPR clipping. Basing on the provided observations,user can analyze the LTE waveforms in the form of spectral analysis, EVM measurements orchannel estimation accuracy. o LTE LinkThis component of the LTE Suite is a toolbox for Matlab allowing for investigations of thedownlink transmission in the LTE L1 layer. Toolbox provides ability to use duringsimulations such techniques like SISO, spatial multiplexing, HARQ control or channel codingand decoding. o LTE SystemThis component of the LTE Suite is a toolbox for Matlab allowing for investigations of theUE simulations. It provides feedback mechanism, link-adaptation and multi-user scheduling.The problem with LTE Suite is that it is not freeware. Only feature limited version is availablefor free. For full one, user has to purchase the product. C. Matlab tools (option)Other Matlab tools connected with issue of LTE planning, taken from the [33]. 18
  19. 19. 2.2.2 WiMAX Networks planning utilizing selected method A. WiMAX PHY LabWiMAX PHY Lab tool is a Matlab toolbox allowing for investigations of the mobile WiMAXphysical layer [17]. Structure of this tool allows to utilize it by professionals during each stageof WiMAX software or hardware development since research and prototype processes tosimulation of the fully designed system.WiMAX PHY Lab is implemented according to IEEE 802.16e-2005 (and 802.16d-2004where necessary) and WiMAX Forum Mobile System Profile Specification Release 1.5.It provides ability to simulate downlink and uplink chains of the WiMAX PHY layer. Usersgain possibility to set essential simulation parameters of modulation, OFDMA or MIMO andobserve deeply the resource mapping. It allows for creation a complete models of BaseStations (BS) and Mobile Stations (MS).It is worth to underline that WiMAX PHY Lab tool structure is very granular what allows forhigh flexibility of simulations. Such customization allows to investigate the role of everysingle component block inside designed experiment. It is very beneficial especially in theeducation.The problem with WiMAX PHY Lab tool is that it is not freeware. B. WiMAX ProjektIt is a tool used for assistance with planning wireless nomadic networks in standard IEEE802.16 [2]. This tool makes easier to select the location of BTS station and proper sectoradjustment. It is collaborating with widely used tools –Google Earth. Thanks to that it offersuseful features as:  Altitude maps with terrain cross-section  Iterative Covering Algorithm which helps with positioning BTS stations  Possibility for selection specified sets of network parameters and features as types of antennas, transmitters capacities, height of objects positions, others  Allows for cells size calculation for different modulationsBy realization of some different running examples I familiarized with this tool and itsfeatures. Optimization of the network using this tool may be really profitable. Afterdetermination the final concepts, assumptions and data for my project I will use this tool tooptimize it. C. PTP Link PlannerMotorola’s PTP Link Planner is allowing to create and configure point-to-point network links[30]. It allows to simulate behavior of the network under particularly set parameters likegeographical location, distances between stations, antenna height, transmitting power. Usersgain possibility to change parameters of simulations and to optimize performance of theirdesigned networks basing on the observations of simulations. It is also quite intelligent what 19
  20. 20. allows for better optimization of the designed networks. Tool is very intuitive what facilitatesits usability. D. Radio MobileRadio Mobile is a freeware tool which is allowing to predict the performance of a radiosystem [31]. Basing on the digital terrain elevation and environmental data, application is ableto automatize path selection between an emitter and receiver of the network inside terrainmodel. User gain possibility to observe 3D, stereoscopic and animation views of the plannedterrain. Moreover, obtained results can be merged with map, satellite photo or military ADRGfor better detailed view of the terrain.Huge advantage of this tool is the fact that it is freeware. E. WLAN Link PlannerSimple tool which could be utilized in case of WLAN planning [32]. F. Matlab tools (option)Other Matlab tools connected with issue of WiMAX planning, taken from the [19].2.2.3 Self-Organizing Networks A. PKSA PlannerDuring laboratory session concerning the Self-Organizing Networks students will be using thePKSA Planner tool [10]. It allows for investigation of the network topology, checking theavailability of the network resources, creation of the basic and additional configurations forplans 1+1, 1:1, 1:N, handling failure scenarios and network reconfiguration process,optimization of required resources and analysis of reconfiguration process performance.Application allows also for visualization of the planned network topology, also with thealgorithmic way of configuration the basic and additional paths for methods End-to-end andLink-based. B. Motorola’s SONMotorola’s SON is a tool which allows for planning and optimizing SON parameters of theLTE network [30]. Taking under such parameters like network coverage, capacity, cell size,topology, frequency allocation and bandwidth user can observe network behavior. It ispossible to observe problems like interferences, which can be faced by parametersoptimization. It is also possible to face other problems like weak signal strength or highnetwork traffic in some locations. 20
  21. 21. Such optimizations facilitate network implementation what is connected with minimization ofthe operation costs of running a network. Conducting network planning and parametersoptimization by simulations decrease possibility for bad implementation of the real network. C. Matlab tools (option)Other Matlab tools connected with issue of SON, taken from the [33]. 21
  22. 22. 3. Laboratory experiments organizationOn the beginning of the laboratory experiment students will get familiar with the mainfunctions which will be investigated during it. Before the lab students are obliged to get toknown the theoretical instruction which explains the concept of necessary area ofexaminations on LTE and WiMAX Technologies and Self-Organizing Networks.Regarding LTE laboratory students get the basic function for generation of the downlink anduplink transmissions which they need to extend by putting an additional blocks with necessarydata. Students have to base on their theoretical knowledge and on the list of additionalfunctions which they can use for investigations of the topic.Each task has its own basic Matlab example for students’ investigations.Materials and guides given for the students and laboratory supervisors:1. Full, detailed sample scenario for particular tasks. The scenarios will be also prepared andresolved by the laboratory supervisors to compare the results.2. Detailed user guide instruction of the LTE PHY Lab Tool for Matlab including descriptionof all input and output parameters and propositions for their settings. User guide instructionwill be based on the tool’s documentation and experience with simulations with its usage.3. Detailed user guide instruction of the WiMAXProjekt tool including description of theparticular functions necessary during laboratory experiment investigations. User guideinstruction will be based on the tool’s documentation and experience with simulations with itsusage.4. Detailed user guide instruction of the PKSA Planner for Matlab including description of allinput and output parameters and propositions for their settings. User guide instruction will bebased on the tool’s documentation and experience with simulations with its usage.5. Theoretical instructions including all necessary knowledge for the laboratory experimentinvestigations.3.1 Laboratory experiments rules1. Students should expect that each laboratory experiment laboratory supervisor can orderthem to answer 1 or 2 short questions as the preliminary test. Students’ answers will beevaluated accordingly to the scoring proposals for particular laboratory experiment.2. Each laboratory session is planned to last 3 hours, but for the extreme situations, thereshould be reserved 1 more hour. There can occur situation when simulation applications canoperate too slowly to let students finish their reports in the defined time. Such situation canoccur especially in case of the WiMAXProjekt which is not so optimized in the operationspeed area.3. Students can create two person teams, but they are not obliged to do so.4. Each student’s team has to prepare laboratory report including:  results of simulations with clear explanation and descriptions of its particular elements  necessary comments describing the way to achieve team’s results 22
  23. 23.  summary of each part of simulation with description of achieved aim answers for the questions asked in the laboratory experiment conclusions summarizing and comparing results, advantages and disadvantages of particular method, solution, etc. will be recognized as an additional contribution and evaluated with additional points 23
  24. 24. 4. Laboratory no 1 – investigations of the downlink physicalchannels of the LTE Technology with utilization of the LTEPHY Lab Matlab tool.Laboratory number 1 refers to the investigations of the downlink physical channel of the LTETechnology with utilization of the LTE PHY Lab Matlab tool. During laboratory sessionstudents will get possibility to observe how LTE network operates during downlinktransmission taking under consideration the structure of the LTE radio frame and particularsubframes. Students will be able to see the role of the particular LTE channels and signals andprinciples of the OFDMA operation.Investigations cover the analysis of four main areas: 1. Data allocations for downlink model of LTE. 2. Radio frame and subframe. 3. Radio frame channels and signals. 4. OFDMA.Basic settings code for downlink analysis:%Input parameters and datatxDLSCH = randint(1,300,2); %input data block of 300 bitstxBCH = randint(1,24,2); %input bits for BCH (always 24)txDCI = struct(data,{randint(1,26,2),randint(1,12,2),randint(1,14,2)},... PDCCHformat, {0, 0, 0}, ... nRNTI, {12, 0, 133}); %input info for DCI (3 DCIs)txHI = randint(1,8,2); %input bits for HI (indicators)mimoSetting = [1 0 1 0 1 0 0 0 1]; %MIMO setting (here SISO)modOrder = 4; %modulation order (QPSK – 4 symbols)numSubframe = 0; %subframe numbersizeFFT = 256; %FFT size (corresponding to BW 3MHz)numPDCCH = 3; %3 OFDMA symbols allocated for Control regionnumsPRB = [2 3 7]; %Resource allocation for data: PRB number 2, 3 and 7nF = 0; %frame numberN_cell_ID = 123; %physical cell IDtrBlkSize = 600; %transport block sizeRVidx = 0; %redundancy version index%Processing – calling the transmitter functiontxOFDMSymbols = LTEDLPhyTransmitter(txDLSCH, txBCH, ... txDCI,txHI,mimoSetting, modOrder, numSubframe, sizeFFT, ... numPDCCH, numsPRB, N_cell_ID, nF, trBlkSize, RVidx);%Plotting the spectrogramspectrogram(ifft(fftshift(fft(txOFDMSymbols))),200,100,1024);%We need to perform fftshift operation to shift the subcarrier zero intothe center of the picturePresented settings code for downlink analysis is only for help purposes and for moreadvanced students who would like to simulate something exceeding the laboratory exercisesprogram. Students are encouraged to use the particular elements from presented code for theirsimulations in the following tasks. Codes dedicated for the particular laboratory tasks areprovided under each of them. 24
  25. 25. Task 1:First task refers to the investigations of the data allocations for downlink model in LTEtransmission. Fig. 1 eNB Transmitter block scheme involved in the downlink investigations[38]Students are encouraged to try to combine eNB Transmiter block scheme on Fig.13 withsimulation observations and to conclude dependence of particular scheme blocks, channelsand signals onto each other. Students have to differentiate physical from transport and controlchannels and to clearly understand the role of particular elements.This simulation example helps students for better understanding of the downlink modeltransmissions in LTE Technology.Students should focus on the operation of PDCCH and their data blocks which are influencingwhole transmission. Second important issue is to observe changes in the downlinktransmission map resources made by changing PRBs number and their data blocks.Observations of resource map behavior are essential in this laboratory experiment. Basing onthem, it is possible to forecast the occurrence of particular resource elements and resourceblocks in particular locations inside the resource map. Elements like RSs can be then easilylocated what makes whole operation more understandable for the person who is going to learnoperation principles of the whole technology. Moreover, some elements which are appearingonly in the defined way or situation are now more predictable. As an example can be taken P-SS, S-SS and PBCH which are appearing only in some subframes. In this way in is more 25
  26. 26. comfortable for students to learn the role of particular elements in the whole downlinktransmission operation.In the second task more focus has been directed into investigations of the role of particularchannels during downlink transmission. In this area of examinations students should put theirattention to the role of particular parameters of the simulation data. Such parameters likeselected channel, antennas number and input byte stream vector of user data are the mostessential during such simulations.LTE PHY Lab as Matlab application brings large amount of Matlab’s facilitations duringsimulations. For example 3D manipulation which changes the vision angle on the simulatedresulting plots offers more accessible data during investigations. This feature is most useful inthe case when we need to differentiate some particular resource element from the other.Basing on the observations done over the tool, this feature makes simulations morecomfortable and results are becoming more understandable.Another feature which is really important facilitation is a well-developed support ‘help’ insidethe application. It brings the clean, comprehensive description of particular functions givenfor the user in the intelligent way. Particular commands come with bright and widespecification including default data which can be utilized during the simulations. Eachparameter of the data is provided with clear explanation of its role. Moreover, it hasdescription of the way of its proper utilization inside particular functions. Such facilitation isvery important for the students who would desire instant explanations of particular functions.This function also allows to perform testing of new functionalities more easily.Students are asked to indicate particular elements of the system, to differentiate them and toshow their way of understanding roles of them. Their knowledge will be examined basing onthe practical and real simulation cases performed during the laboratory experiment. Importantissue concerns the ability to combine logical thinking with analysis of the whole system.Basic settings code for downlink data allocations analysis:function lab3_1_DL_Data_Allocations%DL transmission%inputDataBlock = struct of data bytes to be placed into radio frame %(must be size(10,x)) where x is not restricted. %Each row is transmitted over different %subframe on the PRBs corresponding to the numsPRB %valuesinputDataBlock = struct(data, {[1:15], [1:15], [1:15], [1:31], [1:31],... [1:31], [1:56], [1:56], [1:15], [1:56]});%numPDCCH = vector of number of the PDCCH Symbols per subframe of %length(10) (value = 1,2 or 3)numPDCCH = [2 2 3 3 3 2 2 2 3 3];%numsPRB = matrix of PRB numbers where the data is mapped on, must be in %ascending order size(10, x), where 1<x<max num PRB.For %this version of the simulator all vectors must be the %same sizenumsPRB = struct(PRB,{[0 1 2], [3], [5 6], [7 8 9], [9 10],... [11 12 13], [11 14 15], [16 17 18], [19 20 21], [22 23 24]});%modOrder = vector of modulation orders per subframe, length(10), %(values: 4 for QPSK, 16 for 16QAM, 64 for 64QAM)modOrder = [16 16 16 16 16 16 16 16 16 16];%sizeFFT = number corresponding to the fft size (related to the system % BW), (values: 256, 512) 26
  27. 27. sizeFFT = 512;outputSamples = LTELinkLevelSimulateDL(inputDataBlock,... numPDCCH,numsPRB, modOrder, sizeFFT);endPresented code allows for simulation of the downlink radio frame allocation of the user data.Simulation is presenting each subframes from 0 to 9 and after that the whole frame. User haveto remember that available FFT sizes are 256 and 512 which corresponds to the 3 and 5 MHzbandwidth channels and 15 and 25 Resource Blocks (RBs) respectively. User must not exceedthose limits in the configuration code. The simulation shows spectrogram (also in 3D view).Users can manipulate the 3D view to observe simulation from other perspectives.Laboratory experiment code file is lab3_1_DL_Data_Allocations.m1. Investigation of the simulation data:a) Build the input data block (inputDataBlock variable).b) Select proper number and format of Physical Downlink Control Channel (numPDCCHvariable). Remember that proper structure creating the frame has includes 10 subframes.c) Build proper structure and format of allocation PRB (numsPRB variable).d) Try to change modulation for each block of the allocation structure PRB (modOrdervariable).e) Try to change FFT sizes (sizeFFT variable).2.Run the simulation, observe the results and comment them:a) Observe how look each particular subframe, remember that switching between followingsubframes can be done using ‘space’ key.b) Observe how look full allocations of the subframes in the whole frame for particularsimulation.c) Manipulate the 3D plots to observe their appearance from different perspectives.d) Investigate the allocation of the particular blocks in the frames in each of previous points.e) Comment the influence of particular initial data parameters on simulation results.3. Repeat simulations three times for different sets of data, comment the results andconclude your observations. Describe the connections between particular elements ofsimulations and influences between each other.4. Answer the questions:a) How inputDataBlock structures are influencing the resulting plots? Which elements areinfluenced by it and how they are being changed?b) How numsPRB influence on the resulting plots? Which elements influence on them andhow they change their look?c) Save simulation figures presenting mapping of characteristic subframes 0, 6 and twosubframes selected by you. Clearly mark on the picture each element (if any):  RS,  P-SS – in which subframes it can be seen?  S-SS – in which subframes it can be seen?  PBCH – in which subframes it can be seen?  OFDMA symbols with control region (PDCCH, PHICH, PCFICH),  PRB – specify the numbers of them,  Specify bandwidth, 27
  28. 28.  Specify the number of OFDMA symbols. Describe the role of the particular elements. Each figure with necessary description has to be placed in the laboratory exercise report.d) What is presented on the last DL Radio Frame simulation figure? Describe particular partsof it.Task 2:Second task refers to the physical downlink channels investigations for downlink model inLTE transmission.Basic settings code for downlink physical channels analysis:function lab3_2_DL_Channels% channel = choice of the particular channel to be plotted/allocated:% 1 - RS, 2 - PSS, 3 - SSS, 4 - PBCH, 5 - PCFICH, 6 - PHICH,% 7 - PDCCH, 8 - PDSCHchannel = 1;% numAntennas = number of antennas in the systemnumAntennas = 1;% txBytes = the input byte stream vector of user datatxBytes = randint(1,100,63);%modOrder = vector of modulation orders per subframe, length(10), %(values: 4 for QPSK, 16 for 16QAM, 64 for 64QAM)modOrder = 4;% numSubframe = the number of the subframe in the LTE radio frame (0-9)numSubframe = 1;%sizeFFT = number corresponding to the fft size (related to the system % BW), (values: 256, 512)sizeFFT = 256;%numPDCCH = vector of number of the PDCCH Symbols per subframe of %length(10) (value = 1,2 or 3)numPDCCH = 2;%numsPRB = matrix of PRB numbers where the data is mapped on, must be in %ascending order size(10, x), where 1<x<max num PRB.For %this version of the simulator all vectors must be the %same sizenumsPRB = [2 3 4];whitebg(k) txOFDMSymbolsRS = LTEDLPhyTransmitterCA(channel, numAntennas,... txBytes, modOrder, numSubframe, sizeFFT, numPDCCH,numsPRB); spectrogram(txOFDMSymbolsRS,256,128,1024,3840000), title(Selectedchannel for 1 antenna); pause();endPresented code allows for simulation of the downlink physical channels like RS, P-SS, S-SS,PBCH, PCFICH, PHICH, PDCCH, PDSCH. The simulation shows scatterplot, spectrogram(also in 3D view) and time frequency allocation (also in 3D view). Users can manipulate the3D view to observe simulation from other perspectives. During laboratory experimentsinvestigations students should analysis only scatterplots and spectrograms, withoutinvestigations of time frequency allocations.Laboratory experiment code file is lab3_2_DL_ Channels.m1. Investigation of the simulation data:a) Select investigated channel. 28
  29. 29. b) Investigate how particular channel looks like for different subframe (numSubframevariable).b) Select randomly the bytes for downlink transmission (txBytes).b) Select proper number and format of Physical Downlink Control Channel (numPDCCHvariable).c) Build proper structure of allocation PRB (numsPRB variable).d) Try to change modulation (modOrder variable).e) Try to change FFT sizes (sizeFFT variable).2. Run the simulation, observe the results and comment them:a) Observe the channels: RS, PSS, SSS, PBCH, PCFICH, PHICH, PDCCH, PDSCH on thescatterplot, spectrogram in 3D and in time-frequency allocation in 3D.b) Manipulate the 3D plots to observe their appearance from different perspectives.c) Investigate the allocation of the particular blocks in the frames in each of previous points.d) Comment the influence of particular initial data parameters on simulation results.3. Repeat simulations three times for different sets of data, comment the results andconclude your observations. Describe the connections between particular elements ofsimulations and influences between each other.4. Answer the questions:a) Does any channel looks different in some particular subframe number? Describe thedifferences and explain why.b) Describe how selected modulation influences the resulting channel mappings.c) Describe the role of each physical uplink channels in each possible mode. Select foursimulation figures presenting mapping of physical downlink channels and save them. Clearlymark on the picture each selected physical channel (from set: RS, PSS, SSS, PBCH, PCFICH,PHICH, PDCCH, PDSCH) Resource Blocks and elements:  Specify bandwidth,  Specify the number of OFDMA symbols. Describe the role of the particular elements. Each figure with necessary description has to be placed in the laboratory exercise report. Use the sample scatterplots to get to know the scheme showing the way to describe the way of reporting the laboratory experiment results. 29
  30. 30. Sample scatterplots can be seen below:On the first scatterplots we can find sample downlink frame which is the result of thesimulation. During the experiments students will be dealing with such matter ofinvestigations. It is necessary for them to differentiate particular REs, RBs, etc. and toindicate their function in the transmission process. Fig. 2 Sample downlink subframeIn the second scatterplot it is visible the same result of simulation but the angle of the visionhas been changed from 2D to 3D. Such view facilitates the examination of the received resultsand moreover it facilitates way of understanding the whole transmission process. Fig. 3 Sample downlink subframe – 3D view of the previous scatterplot 30
  31. 31. Using own knowledge and tutorial notes students should mark particular channels in the waypresented on the figure 16. Each element on the scheme has to be indicated and brieflydescribed. Students should also describe features and roles of them. The most essential part isto combine received results with gained knowledge and to describe relationships andinfluences between particular elements. Fig. 4 Sample downlink subframe 0 presenting way of scatterplots description expected in the students’ reportsAt the end of the simulation students will get full downlink frame constructed from thepreviously obtained subframes. Important and desirable ability is connected with matchingresults obtained for particular subframe with the general observations of the final full frame.Conclusions concerning influence of particular subframes on the full frame are the mostessential at this point. Fig. 5 Sample downlink frame with overall view on each subframe 31
  32. 32. 4.1 Selected issues of LTE TechnologyIn this section there are presented essential issues of the LTE Technology with which studentshave to be familiar before the laboratory session. This introduction is common for laboratorysessions 3 and 4.4.1.1 LTE Technology introductionFollowing theoretical introduction states that students know the basics of the LTE Technologyand it is not required to quote them. Moreover it is a supplement to [15] LTE theoreticalintroduction as each thesis is an internal part of the course and they are mutuallycomplementary.Presented introduction includes the most essential information concerning issues examinedduring the laboratory exercises. For more information students should refer to the mentionedsources.4.1.2 Frame structuresLTE systems have characteristic kind of frames and subframe structures that have beendefined to manage the synchronization of the whole system and exchange of different types ofinformation. In both downlink and uplink transmissions, dependently on the duplex modeTDD or FDD there are two LTE frame structures, which are utilized accordingly to theservices and their priorities which are being introduced in the operating networks, i.e. VoIPservices will rather introduce FDD mode due to the fact that they better operate in that mode.LTE introduces two types of frame structures:  Type 1 – utilized in the systems operating in the FDD mode,  Type 2 – utilized in the systems operating in the TDD mode.LTE frame structure of Type 1LTE frame structure of Type 1 is utilized in systems operating in the FDD mode. Each frameconsists of 10 subframes of 1 ms each resulting in total of overall 10 ms frame length. Eachsubframe is created by two 0.5 ms slots, what means that in whole frame we have 20 slots.Each slot consists of 6 or 7 OFDM symbols depending on the type of selected CP, 6 whenextended and 7 when normal(short) CP is being introduced. The basic unit dedicated for timecounting in LTE is Sample Time (Ts) which defines the amount of time allocated for eachOFDM sample. Ts is defined as Ts=1/(15000*2048) second or near 32.6 nanoseconds. 32
  33. 33. Fig. 6 Frame type 1, timing and symbol allocations shown for FDD with normal cyclic prefix (CP) [13]LTE frame structure of Type 2LTE frame structure of Type 2 is utilized in systems operating in the TDD mode. Each frameconsists of 2 half frames of 5 ms consisting of 5 subframes of 1 ms. Each subframe, just likein the LTE Type 1 frame, is divided into two slots of 0.5 ms each. In this subframe type it isessential that at least one half frame includes a special subframe carrying three fields ofswitch information:  DwPTS – Downlink Pilot Time Slot,  GP – Guard Period,  UpPTS – Uplink Pilot Time Slot.Second type of LTE frame can have two switching time, at 5 ms and at 10 ms. In the first caseswitching information occurs in both half frames, firstly in the subframe one and secondly inthe subframe six. In the second case switching information occurs only in the subframe one.For the downlink transmission LTE reserves subframes 0 and 5 and DwPTS. Uplinktransmission reserves UpPTS and the subframe following it. Other subframes can be utilizedin both downlink and uplink transmission modes. Special subframes can be configuredindividually in the terms of length, however the length of them all have to be equal 1 ms intotal.Fig. 7 Frame type 2 – special fields are shown in subframes 1 and 6. Guard period separates the Downlink and Uplink. This TDD example represents a 5ms switch point. A 10ms switch point would not have the special fields in subframe 6. [13] 33
  34. 34. Resource Elements, Resource BlockLTE introduces also different units referring to the both time and frequency aspects apartfrom the time-domain viewpoint. Resource Element (RE) is defined as one symbol in timeversus one subcarrier in the frequency and it is known as the smallest structure in the LTEPHY notation system. Resource Elements are further aggregated into Resource Blocks (RB).Dependently on the selected CP the number of symbols in RB is changing. Typically, fornormal (short) CP the RB contains 7 symbols. But in case of extreme delay spread ormultimedia broadcast modes usage the extended CP is being used causing that RB containsonly 6 symbols.There are two types of Resource Blocks selected accordingly to selected CP:  6 symbols by 12 subcarriers for extended (long) CP,  7 symbols by 12 subcarriers for normal (short) CP.Resource Elements and Resource Block structure containing 7 symbols by 12 subcarriers(normal CP) is presented on the Figure 20.Fig. 8 Relationship between a slot, symbols and Resource Blocks. N(dl/rb) is the symbol used to indicate the maximum number of downlink Resource Blocks for a given bandwidth. [35]Transmitted downlink signal consists of downlink Resource Blocks for a duration of the6 or 7 OFDM symbols (accordingly to the selected CP). If normal CP is utilized then one slotcan be defined as a RB consisting of 7 symbols by 12 subcarriers including 84 RE per RB.Frame which consists of 20 slots corresponds to 1680 RE of 20 slots by 84 REs each. Suchconfiguration is presented on the Figure 21 containing resource grid. It is necessary tounderline that MIMO utilizes separate resource grids for each transmitting antenna. 34
  35. 35. Fig. 9 Resource grid scheme [14]Reference SignalsLTE introduces a concept of special Reference Signals (RS) interspersed among REs andtransmitted every sixth subcarrier. Accordingly to the utilized CP the RSs are transmitteddifferently. In case of normal CP, RSs are transmitted during the first and fifth OFDMsymbols of each slot. While extended CP is used, RSs occupies the first and fourth OFDMsymbols. Further, RSs are distributed over the time and frequency. On the subcarriers bearingthe RSs the channel response can be computed directly, while the rest of subcarriers needinterpolation for channel response estimation. 35
  36. 36. Fig. 10 LTE Reference Symbols distribution among the Reference Elements [14]4.1.3 LTE downlink channels and signals typesIn order to keep the data transmission arrangement LTE utilizes channels and signals.Different kinds of channels allows for communication with higher layers within LTEprotocol. Channels are also facilitating segregation of the different types of data. LTEstandard describes exact positions in the frame of physical signals and channels in terms ofsubcarriers and symbols.There are three main categories of channels in LTE:  Physical channels acting as transmission channels carrying user data and control messages.  Transport channels offering information transfer to the Medium Access Control (MAC) and higher order layers.  Logical channels providing services for MAC layer.Downlink Physical channelsDownlink Physical Channel refers to the RE carrying information originating from higherlayers and its interfaces. 36
  37. 37. Fig. 11 Map of Downlink frame using FDD and normal CP shows the relative location of the various physical channels. Frames in systems using extended CP or TDD would be slightly different. [35]Physical Downlink Shared Channel (PDSCH)Physical Downlink Shared Channel is responsible for carrying downlink user data. Thespecified number of RBs is being associated via OFDMA with particular users defininguser data rate. Physically, PDSCH is a RB of 1 ms length and 180 kHz width. LTEterminal basing on the Channel Quality Indicator (CQI) information is allocating theresources within the eNB base station. The shared channel PDSCH is time shared with thecontrol channel PDCCH in the first timeslot of each subframe. It is allocated in the secondtimeslot for which the subframe does not transmit broadcast (PBCH), PrimarySynchronization (PSS) or Secondary Synchronization (SSS). PDSCH is desired for highdata rates. It can operate with QPSK, 16-QAM, and 64-QAM modulation modes. PDSCHexclusively uses spatial multiplexing. In the PDSCH channel RSs are allocated regularlyenabling channel estimation and minimizing overhead.Physical Broadcast Channel (PBCH)Physical Broadcast Channel is utilized to send cell-specific system identification andaccess control parameters, like Random Access (RACH) parameters, every 4th frame (40ms) using QPSK modulation. PBCH structure is independent of the actually utilizedsystem bandwidth because it is always provided with 1.08 MHz bandwidth. In case with1.4 MHz system bandwidth, there are no RBs on either side of the PBCH in the frequencydomain in use, so the meet the spectrum mask requirements only 6 RBs are usedeffectively.Physical Control Format Indicator Channel (PCFICH)Physical Control Format Indicator Channel is indicating the num ber of OFDM symbolsreserved for control information in PDCCH in a subframe. For each subframe PCFICH canindicate them from 1 to 3. Dynamic signaling offered by PCFICH is beneficial due to thefact that system can support two different modes of user data, when large number of lowdata rate users and when higher data rates are used by fewer active users to providesufficiently low signaling overhead. PCFICH utilizes QPSK modulation mode. 37
  38. 38. Physical Downlink Control Channel (PDCCH) Physical Downlink Control Channel is allocating both uplink and downlink resource scheduling. PDCCH utilizes QPSK modulation mode. PDCCH maps Downlink Control Information (DCI) having different formats and depending on its size it is transmitted in one or more Control Channel Elements (CCEs). They refers to 9 RE groups consisting of 4 RE each. PDCCH having shared information (PDSCH) often is being referred to as the downlink assignment. During providing downlink resource allocation information related to the Primary Synchronization (PSS) to the downlink assignment gets information concerning:  RB allocation  Downlink user data modulation and coding scheme  HARQ process number  Power control commands for PUCCH Physical Multicast Channel (PMCH) Physical Multicast Channel is providing multimedia broadcast information. Multicast information can be sent to multiple wireless devices simultaneously. PMCH can operate using QPSK, 16-QAM, or 64-QAM modulation modes. Physical Hybrid ARQ Indicator Channel (PHICH) Physical Hybrid ARQ Indicator Channel indicates in downlink whether an uplink packet was correctly received using ACK/NACKs acknowledgment indicators. If packet was not received then PHICH inquires for packet retransmission. Necessary information are received from PDCCH. ACK/NACKs are implemented inside HARQ mechanism.Downlink Physical Signals Reference Signal (RS) Reference Signal in downlink is used for channel estimation by wireless devices. RS allows to determine the Channel Impulse Response (CIR). RSs are generated as the symbol-by-symbol product of a two-dimensional orthogonal sequence and a two-dimensional pseudo-random sequence. LTE specification determines 510 sequences of RSs since there are 3 different two-dimensional orthogonal sequences and 170 available two-dimensional sequences for the Pseudorandom Number (PRN). In case of normal CP, RSs are transmitted during the first and fifth OFDM symbols of each slot. While extended CP is used, RSs occupies the first and fourth OFDM symbols. Further, RS’ are distributed over the time and frequency. There are three types of downlink RSs defined:  Cell-specific RSs utilizing non-multimedia broadcast Multicast Service Single Frequency Network (MBSFN) transmission  MBSFN RSs utilizing MBSFN transmission  UE-specific RSs 38
  39. 39. Cell-specific Reference SignalsCell-specific Reference Signals occurrence refers to the cells which are supporting the non-MBSFN transmissions in the downlink subframes. Cell-specific RSs can be used also fortransmissions utilizing MBSFN, in such case only two first OFDM symbols of thesubframe can be utilized. All of the cell-specific RSs for transmission utilize ports from 0to 3 of one or several antennas.MBSFN Reference SignalsMBSFN Reference Signals occurrence refers to the cells which are suporting MBSFNtransmission. MBSFN RSs for transmission utilize port 4 of the antenna.UE Specified Reference SignalsUE Specific Reference Signals are utilized during downlink transmission of PDSCH.During PDSCH demodulation UE gets specific RSs answer, if it confirms it to be validthen UE receives information. UE is being informed constantly about the occurrence ofspecific RSs by higher layers of the system transmission. UE specific RSs are utilizing port5 of the antenna.Primary and Secondary Synchronization Signal (PSS and SSS)Primary Synchronization Signal is utilized in cell search and within it operates for timingand frequency acquisition. More precisely, it keeps slot timing synchronization and bringsa part of the cell ID. It operates using one of the three available Zadoff-Chu sequences.Secondary Synchronization Signal is also utilized in cell search where it is providing frametiming synchronization and the remainder of the cell ID. It operates using BPSKmodulation and two 31-binary sequences.PSS and SSS synchronization signals took 6 RBs and are allocated on 62 from 72 reservedsubcarriers. They occur on the 0 and 10 slots where PSS are located on 6th symbol andSSS on the 5th one. They occupy 1.08 MHz of frequency bandwidth. Fig. 12 Primary and Secondary Synchronization Signals allocations [13] 39
  40. 40. Downlink Transport Channels Broadcast Channel (BCH) Downlink Broadcast Channel is allowing the devices accessing to the system to enable them by broadcasting parameters of the system. It is also used for operators identification. Downlink Shared Channel (DL-SCH) Downlink Shared Channel took part in the point to point downlink connections where it is carrying the user data or highrt order level information submitted for particular user, UE or multiple devices. For transmissions involving one UE, DL-SCH is able to use physical layer retransmission and dynamic link adaptation which are increasing the quality and reliability of the transmission. Paging Channel (PCH) Paging Channel is informing the device operating in the downlink direction to change its state from the idle mode to the connected state. Thanks to PCH it is possible to initiate downlink transmission. Multicast Channel (MCH) Multicast Channel is transferring multicast service content to the UE in the downlink direction.Mapping of downlink transport and physical channels cooperationTo illustrate the cooperation connections between transport and physical channels in thedownlink direction it is necessary to present few links. The first informs that the PCH ismapped to the PDSCH. The second link refers to the information that BCH is mapped to thePBCH, but it is worth to remember that only parts of the broadcasted parameters are on BCHwhile the actual System Information Blocks (SIBs) are then on DL-SCH. The DL-SCH ismapped to the PDSCH and MCH is mapped to the PMCH. Fig. 13 Mapping of downlink transport and physical channels cooperation [13]LTE Downlink MapThe map of the LTE downlink frame is providing visible and understandable two dimensionalresource allocation map. Resources are dynamically allocated basing on the user’s dataprofile. Map allows for reasonable understanding of LTE PHY layer system operation. It ispossible to differentiate particular channels, resource elements, resource blocks and so on.Looking on the resource map from the left hand side, it is visible that at the beginning of eachsubframe there are located the downlink control channels managing the transmission in the 40
  41. 41. downlink direction. It is also visible the number of assigned RE for the PDCCH channel. Suchinformation are delivered by the control format indicator channel PCFICH.At the beginning of TS1 or the second timeslot on the first subframe one can see the broadcastchannel PBCH. This allows UE to get base station state information.Map diagram is showing also how and when primary and secondary synchronization channels(P-SCH and S-SCH) are carrying PSS and SSS respectively. It is visible on the latter symbolsof TS0 and TS10 occupying 1.08 MHz bandwidth at the center of the transmission band.Using monitoring of the downlink signal of the 1.08 MHz bandwidth for the 5 ms UE is ableto get synchronized with the base station. Fig. 14 LTE downlink frame map (10ms length, Δf=15 kHz, normal CP) [37]Investigation of such downlink map is crucial during the laboratory exercises concerning LTEPHY layer. 41
  42. 42. Downlink Logical Channels Downlink Control and Traffic channels: Broadcast Control Channel (BCCH) Broadcast Control Channel is taking part in the operation of accessing to the system by broadcasting information with parameters required to perform such operation. Paging Control Channel (PCCH) Paging Control Channel is allowing the device to enable to the network by sending the paging information. In this way such device is being attached to the Paging Channel servicing whole operation. Common Control Channel (CCCH) Common Control Channel is enabling the downlink transfer of the control information between the network and the UE when there is no RRC connection between them. It is mapped to the DL-SCH in the transport channels. Dedicated Control Channel (DCCH) Dedicated Control Channel operates as a point to point carrier of control information between the UE and the network in the downlink direction. It is mapped to the DL-SCH in the transport channels. Dedicated Traffic Channel (DTCH) Dedicated Traffic Channel operates as a point to point carrier of all user’s data in the downlink direction. It is mapped to the DL-SCH in the transport channels. Multicast Control Channel (MCCH) Multicast Control Channel operates as a point to multipoint carrier of the multicast control information between the network and UE in the downlink direction (it is worth to compare it with the Multimedia Broadcast Multicast Service MBMS part of the WCDMA, because their operations are similar). Multicast Traffic Channel (MTCH) Multicast Traffic Channel operates as a point to multipoint carrier of the multicast data in the downlink direction.Mapping of downlink logical and transport channels cooperation Fig. 15 Mapping of uplink logical and transport channels cooperation [13] 42
  43. 43. Accordingly to the previous mapping of downlink physical and transport channelscooperation LTE adds next layer of logical channels.4.2 LTE PHY Lab tool instructionThis instruction is common for laboratory sessions 3 and 4 as they refer to the samesimulation tool.LTE PHY Lab tool is a Matlab Toolbox implementation of the 3GPP Release 8 EUTRAphysical layer. It is able to simulate behavior of the LTE system network at every stages ofimplementation of software, hardware, researching and development. Tool is very granularwhat makes it universal and able to meet the requirements of precise measurements of LTEnetwork environment.UsageDuring laboratory students will receive files dedicated to Matlab containing the laboratoryexercises basic source codes. Students are obliged to follow the tool usage instruction.1. Please make sure if the hardware key is inserted into the USB port. Simulation willnot start without it.2. Start Matlab3. Specify the direction path of the LTE PHY Lab in the Matlab’s navigation line.4. Please write the command ‘LTEpaths’ into the Matlab’s console.5. Open Matlab file dedicated for the particular laboratory exercise.6. Follow instruction of the particular laboratory.HelpStudents are allowed and encouraged to use the configuration examples for investigatedfunctions. To call them it is necessary to put ‘help’ connected with the name of the functioninside Matlab’s command line, so such quote should looks like ‘help function_name’.Materials and configurations gathered from help function should be adapted to the needs andrequirements of the particular laboratory.3D view toggleUser can switch between 2D and 3D view using toggle marked on the picture below. 3D viewcan be rotated by movements of the mouse. 43
  44. 44. Fig. 16 3D view toggle inside the figure windowFully detailed user guide instruction provided by Innovative Solutions can be found in theAppendix A. It includes description of each function used during the laboratory experimentsas well as the step by step instruction of tool usage.4.3 Summary and conclusionsLaboratory number 1 concerning investigation of the downlink physical channel allowstudents to gain practical abilities and knowledge concerning structures of LTE downlinkframes and subframes.Structure of the laboratory session requires from students not only technical knowledge butalso force to use logical thinking. Students are asked to observe the results of simulations fordifferent sets of data and multiple parameters options during each step of the laboratory. Itallows for practical understanding of the whole operation and to observe changes made byparticular adjustments. 44
  45. 45. The main objective of the laboratory session is to combine gained LTE knowledge with theresults of the simulation and to match received information. Basing on the considerationunder examined matter students are required to bring conclusions concerning performedoperations, results of the adjustments and influence of particular simulation parameters on theresults.Described laboratory session is quite complicated and requires good understanding ofparticular elements of LTE downlink frame starting from resource elements and resourceblocks, their locations inside the frame slot, finishing on the physical and logical channels andsignals.By understanding this particular laboratory, student gain also possibility to extend knowledgeabout principles of LTE OFDMA system operation. Hence OFDMA is a base of manybroadband radio access systems, it may be said that student learn universal knowledge whichmay be used in investigations of other systems.Experience gained during the laboratory session is combining knowledge concerning LTEprinciples of operation with logical thinking. Such profile of experience is appreciated byfuture employers and actually it is the most desirable. Candidates are asked not only about theparticular definitions or to describe some techniques, they are also asked to design somethingbasing on own knowledge what refers to combining it with practical abilities. 45
  46. 46. 5. Laboratory no 2 – investigations of the uplink physicalchannels of the LTE Technology with utilization of the LTEPHY Lab Matlab tool.Laboratory number 2 refers to the investigations of the uplink physical channel of the LTETechnology with utilization of the LTE PHY Lab Matlab tool. During laboratory sessionstudents will get possibility to observe how LTE network operates during uplink transmissiontaking under consideration the structure of the LTE radio frame and particular subframes.Students will be able to see the role of the particular LTE channels and signals and principlesof the SC-FDMA operation.Investigations cover the analysis of four main areas: 1. Data allocations for uplink model of LTE. 2. Radio frame and subframe. 3. Radio frame channels and signals. 4. SC-FDMA.Basic settings code for uplink analysis:%Input parameters and datatxULSCH = -1; %we use the PUCCH so ULSCH is emptytxCQI = -1; %we use the PUCCH format 1a so CQI is emptytxHI = [1 0]; %Input bits for HItxRI = -1; %we use the PUCCH format 1a so RI is emptyisHI_RI = 1; %we transmit only HI this timemodOrder = -1; %we use PUCCH so we do not modulate the PUSCH datanumSubframe = 0; %subframe numbersizeFFT = 128; %FFT size (128 corresponds to BW 1.4MHz)RIV = [0 1]; %we use PUCCH but something must be inside RIVisSRS = 0; %we do not use SRS here so we put 0isPRACH = 0; %we do not use PRACH here so we put 0isPUSCH = 0; %this is the switch between PUCCH and PUSCH (if 0 then PUCCH)PUCCHformat = 2; %PUCCH format (2 corresponds to format 1a)N_cell_ID = 1; %physical cell IDnRNTI = 2; %UE IDtrBlkSize = 0; %we do not use PUSCH so no transport blockRVidx = 0; %we do not use PUSCH so no redundancy version%Processing – calling the transmitter functiontxSCFDMASymbols=LTEULPhyTransmitter(txULSCH, txCQI, txHI, txRI, isHI_RI,...modOrder, numSubframe, sizeFFT, RIV, isSRS, isPRACH, isPUSCH,PUCCHformat,N_cell_ID, nRNTI, trBlkSize, RVidx);%Plotting the spectrogramspectrogram(ifft(fftshift(fft(txSCFDMASymbols))),200,100,1024);%We need to perform fftshift operation to shift the subcarrier zero intothe center of the picturePresented settings code for uplink analysis is only for help purposes and for more advancedstudents who would like to simulate something exceeding the laboratory exercises program.Students are encouraged to use the particular elements from presented code for theirsimulations in the following tasks. Codes dedicated for the particular laboratory tasks are 46
  47. 47. provided under each of them. The simulation shows spectrogram (also in 3D view). Users canmanipulate the 3D view to observe simulation from other perspectives.Laboratory experiment code file is lab4_1_UL_ Data_Allocations.mTask 1:First task refers to the investigations of the data allocations for uplink model in LTEtransmission. Fig. 17 UE Transmitter block scheme involved in the uplink investigations[38]Students are encouraged to try to combine UE Transmiter block scheme on Fig.14 withsimulation observations and to conclude dependence of particular scheme blocks, channelsand signals onto each other. Students have to differentiate physical from transport and controlchannels and to clearly understand the role of particular elements.This simulation example helps students for better understanding of the uplink modeltransmissions in LTE Technology.In the uplink case students should focus on the operation of four basic data blocks PUSH,PRACH, SRS and RIV matrix. Format of each of them is really essential during wholesimulation, they have the biggest influence on the resulting plots of the whole transmissionoperation. Effects made by changes of their environment can be easily found on the uplinkresource maps visible during the simulation operation. It is worth to underline that parametersformat in this point should be provided really carefully. 47

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