4 th August, 2012

1. As Part of Pedagogy Activity in EC Department, 2011, 2012 Simulation and Analysis of 3G Air interface Wideband Coded Division Multiple Access working in Downlink FDD 4th August, 2012 Presented By:Prof. Amit Degada amit.degada@nirmauni.ac.in Electronics and Communication Department,Institute of Technology,Nirma University,Ahmedabad-382481.

2. ज्ञानंज्ञेयंपरिज्ञातात्रिविधाकर्म च यत्तुदना।करणंकर्मकर्तेतित्रिविधःकर्मसंग्रहः॥१८- १८॥ Meaning Knowledge, the Object of knowledge, and the knower are the three factors that motivate the action; the senses, the work, and the doer are the three constituents of action --The Bhagavad Gita(18.18)

3. Presentation Outline • The Objective • Standardization Body • Motivation to work • WCDMA Parameters • CDMA Transmitter and Receiver: A General Approach • Air Interface Architecture • WCDMA Channels • WCDMA Transmitter

4. The Objective of the Lecture • How the Technology has evolved. • Various Air Interfaces of 3G • Physical Layer of WCDMA Working In Downlink FDD

5. First Mobile Radio Telephone

6. Today’s Mobile Source:www.gsmarena.com

7. Presentation Outline • The Objective • Standardization Body • Motivation to work • WCDMA Parameters • CDMA Transmitter and Receiver: A General Approach • Air Interface Architecture • WCDMA Channels • WCDMA Transmitter

8. Migration to 3G

9. Migration to 3G Source: univ.zte.com/cn

10. 3GPP- A Global Initiative 3GPP - Third Generation Partnership Project ARIB - Association of Radio Industries and Businesses CWTS - China Wireless Telecommunication Standard group ETSI - European Telecommunications Standards Institute T1 - Standards Committee T1 Telecommunications TTA - Telecommunications Technology Association TTC - Telecommunication Technology Committee IETF - Internet Engineering Task Force ITU-R - International Telecommunication Union -Radiocommunication ITU-T - International Telecommunication Union - Telecommunication Standardization Source: univ.zte.com/cn

11. IMT-2000 Vision Includes Source: www.itu-t.com

12. UMTS General Architecture Figure : General Architecture User Equipment: Mobile Equipment : Radio Transmission & contains applications. Mobile Termination, Terminal Equipment USIM : Data and Procedures which unambiguously and securely identify itself in Smart Card.

13. 3GPP Rel.6 Objectives • Migration from GSM based Network to 3G standard WCDMA • Scope and definition in progress • IP Multimedia Services, phase 2 • „IMS messaging and group management • Wireless LAN interworking • Speech enabled services • „ Distributed speech recognition (DSR) • Number portability • Other enhancements

14. 3GPP2 Defines • 3rd Generation Partnership Project “Two”„ • Separate organization, as 3GPP closely tied to GSM and UMTS„ • Goal of ultimate merger (3GPP + 3GPP2) remains

15. Various Air interfaces of 3G WCDMA CDMA2000 3G TD-SCDMA CDMA 2000 standards UWC CDMA is the main technology of 3G

16. Presentation Outline • The Objective • Standardization Body • Motivation to work • WCDMA Parameters • CDMA Transmitter and Receiver: A General Approach • Air Interface Architecture • WCDMA Channels • WCDMA Transmitter

17. Architecture of channel Adaptive Hybrid ARQ/FEC

18. CDMA Vs. WCDMA

19. Concepts We have to know • Simplex Vs. Duplex • Circuit Switching Vs. packet switching • TDD Vs. FDD • Symmetric Vs. Asymmetric Transmission • TDMA Vs FDMA • Spread Spectrum

20. Simplex Vs. Duplex Fig. Simplex Scenario

21. Simplex Vs. Duplex Fig. Duplex Scenario While in Duplex we have access to both transmitter and receiver Simultaneously. Mobile can Send and receive data Simultaneously

22. Circuit Switching Vs. packet Switching Traditional Connection for Voice Communication requires that a Physical path Connecting the users at the end of the line and that path stays open until the Conversation ends. This is Called Circuit Switching. • Most Modern Technology Defers from this Traditional Model because they uses packet data. • Chopped into pieces • Given a destination address • Mixed with other data from other Source • Transmitted over channel with other data • Reconstructed at other end Packet Data was originally developed for Internet.

23. FDD and TDD systems frequency allocation frequency FDD Guard frequency MS BS Guard time TDD Time Source: Information and Communication university. WCDMA • Works in Two mode

24. FDD - WCDMA • Improved performance over 2G systems: • Improved Capacity and coverage • Coherent uplink using a user-dedicated pilot • Fast power control in the downlink • Seamless inter-frequency handover High degree of service flexibility: • Multi-rate service : with maximums of 144-384 Kb/s for full coverage and 2 Mb/s for limited coverage • Packet access mode High degree of operator flexibility: • Support ofasynchronous inter-base-station • Support of different deployment scenarios, including hierarchical cell structure (HCS) and hot-spot scenarios • Support of new technologies like multi-user detection (MUD) and adaptive antenna arrays (SDMA)

25. Symmetric vs. Asymmetric Transmission Same Data rate for Uplink and downlink Different Data Rate

26. Presentation Outline • The Objective • Standardization Body • Motivation to work • WCDMA Parameters • CDMA Transmitter and Receiver: A General Approach • Air Interface Architecture • WCDMA Channels • WCDMA Transmitter

27. WCDMA Parameters Source: [21]

28. Presentation Outline • The Objective • Standardization Body • Motivation to work • WCDMA Parameters • CDMA Transmitter and Receiver: A General Approach • Air Interface Architecture • WCDMA Channels • WCDMA Transmitter

29. Selection of Code is Utmost Important CDMA Transmitter And Receiver Fig. Block diagram of the mobile transmitter Fig. Block diagram of the base station receiver

30. an an-1 an-2 an-r c1 c2 c3 cr Spreading in WCDMA Pseudo Random (PN) sequence:A bit stream of ‘1’s and ‘0’s occurring randomly, or almost randomly, with some unique properties. Linear shift register

31. Spreading and Scrambling in WCDMA Spreading: To multiply the input information bits by a PN code and get processing gain, the chip level signal’s bandwidth is much wider than that of input information bits. It maintains the orthogonality among different physical channels of each user. Scrambling: To separate the signals from the different users. It doesn’t change the signal bandwidth. Each cell has a unique scrambling code in the system. Fig. Relation between spreading and scrambling [11] Fig. Spreading for all downlink physical channels except SCH [11] Suppressing interference Selecting codes high autocorrelation low cross correlation WCDMA

32. C4,1=1 1 1 1 C4,3=1 -1 1 -1 C2,1=1 1 C4,2=1 1 -1 -1 C4,4=1 -1 -1 1 C1,1= 1 C2,2=1 -1 Fig. Auto-correlation and cross correlation between the OVSF codes of length 128 Spreading in WCDMA • OVSF Code and Gold Code OVSF Code: Purpose: Spreading Generation Methedology: Code-Tree Gold Code: Purpose: Scrambling Generation: modulo-2 sum of 2 m-sequences Fig. Auto and cross correlation of Gold Code

33. OVSF Code Fig OVSF code Matrix of 8 ×8 length. Fig OVSF code Matrix of 4 ×4 length. Fig OVSF code plot for code number 6 from 128 ×128 OVSF code Matrix

34. Gold Code Fig Scrambling code generation

35. Gold Code • A set of Gold codes can be generated with the following steps. • Pick two maximum length sequences of the same length    such that their absolute cross-correlation is less than or equal to where   is the size of the LFSR used to generate the maximum length sequence (Gold '67).

36. Presentation Outline • The Objective • Standardization Body • Motivation to work • WCDMA Parameters • CDMA Transmitter and Receiver: A General Approach • Air Interface Architecture • WCDMA Channels • WCDMA Transmitter

37. Air Interface Protocol Architecture Physical Channels Source: [6]

38. Presentation Outline • The Objective • Standardization Body • Motivation to work • WCDMA Parameters • CDMA Transmitter and Receiver: A General Approach • Air Interface Architecture • WCDMA Channels • WCDMA Transmitter

39. Control Channel (CCH) Broadcast Control Channel (BCCH) Paging Control Channel (PCCH) Dedicated Control Channel (DCCH) Common Control Channel (CCCH) Shared Channel Control Channel (SHCCH) ODMA Dedicated Control Channel (ODCCH) ODMA Common Control Channel (OCCCH) Logical Channel Traffic Channel (TCH) Dedicated Traffic Channel (DTCH) ODMA Dedicated Traffic Channel (ODTCH) Common Traffic Channel (CTCH)

40. Transport Channel • Dedicated channels. • Common channels. Broadcast Channel (BCH) Forward Access Channel (FACH) Paging channel (PCH) Random Access Channel (RACH) Common Packet Channel (CPCH) Downlink Shared Channel (DSCH)

41. Dedicated physical Channel Common physical Channel Downlink Dedicated Physical Channel (DPCH) Physical Downlink Shared Channel (DSCH) Primary and Secondary Common Pilot Channels (CPICH) Primary and Secondary Common Control Physical Channels (CCPCH) Synchronization Channel (SCH) Physical Channel • Uplink Channels • Downlink Channels

42. Mapping of Transport channel into Physical Channel Source: [3] • The Transport Channels are Channel Coded and matched to the data • rate offered by physical Channels.

43. Downlink Physical Channels • The length of a radio frame is 10 ms and one frame consists of 15 time slots. • The number of bits per time slot depends on the physical channel. • There is one downlink dedicated physical channel, one shared and five common control channels • Dedicated Downlink physical channel (DPCH) • Physical downlink shared channel (DSCH) • Primary and secondary common pilot channels (CPICH) • Primary and secondary common control physical channels (CCPCH) • Synchronization channel (SCH)

44. Dedicated Downlink Physical Channel (DPCH) Source: [25]

45. DPDCH and DPCCH Field Source: [25]

46. Downlink Dedicated Physical channel (DPCH) Fig. Data After Spreading Fig Data after Scrambling

47. Simulation of Downlink Channels Methodology. Generation of Data Mapped to I and Q branch Adjust into Frame by Adding TPC, TFCI bits…… Spreading & Scrambling Divide to Real and Imag branch Modulation

48. DPCH According to 3GPP standards, one slot (10ms/15 = .666 ms) layout is as follows: |--Data1--|--TPC--|--TFCI--|--Data2--|--pilot--| | 248 | 8 | 8 | 1000 | 16 | Total bits = 1280, SF=4 ==>num_chips=1280*4=5120chips/slot Channel rate is 1280(bit/slot)*15(slot) =1920 kbps. To form a slot and then a frame we need to break our data stream into 248-1000-248-1000.........according to Data1 and Data2(format#0).

49. Common Downlink Physical channel • Common Pilot Channel (CPICH) • P-CPICH • S-CPICH Fig Common Pilot Channel (CPICH) [25]

50. Common Control Physical Channel • Primary-CCPCH • Secondary-CCPCH Fig Primary-CCPCH [25] Fig Secondary-CCPCH [25]