1. Technical Approaches for 3GPP2 Evolution Dr. Byung K Yi Chair, TSG-C LG Electronics bkyi@lge.com

2. 1 Executive Summary Background Spectral Efficiency –Spatial Processing –Interference Reduction Higher Data Rate –Multi-carrier DV/HRPD –New Air Interfaces Multiple Antenna Technologies Other Features Summarizing Remarks Technical Contributions Outline

3. 2 Significant support has been expressed for cdma2000 evolution Air Interface Evolution (AIE) Technical Experts Meeting (TEM) for 3GPP2 Evolution was held during 10-11 March 2005 in Denver, CO, USA. AIE TEM workshop was intended to share the views of the future 3GPP2 Evolution. 10 Requirement and 11 Technical contributions were presented. Phased approaches for evolution were proposed and discussed. This presentation summarizes proposed technical solutions for phased evolution. Executive Summary

4. 3 Proposed specifications for future wireless cellular systems included : –Increased spectral efficiency :  4 bps/Hz –Higher peak data rates and system capacity Long-term targets for peak data rate –FL : 100 Mbps ~ 1 Gbps –RL : 50 ~ 100 Mbps The following analyses and approaches were suggested. Background

5. 4 To achieve higher data rate and reduced cost per bit, higher spectral efficiency (  4 bps/Hz) is required Spatial signal processing has opened another domain in addition to time and frequency domain to provide higher spectral efficiency  Space Domain. In cellular environments, inter-cell interference is a major hurdle for higher spectral efficiency. Spectral Efficiency (1/5)

6. 5 Trend of cellular systems indicates that higher spectral efficiency and lower Eb/No are required in future systems [1]. Spectral Efficiency (2/5) 0.01 0.1 1 10 Spectral Efficiency [bit/s/Hz] 100203040 Eb/No [dB] IS-95 CDMA 1x GSM AMPS EVDO Requirement : 4 [bit/s/Hz] FL receiver performance requirements (fading ch.) [3] Based on voice user capacity reported at CDG website[2]

7. 6 Further increase of spectral efficiency with less Eb/No is very hard as the theoretical limit is approached. Spectral efficiency is increased by increasing Eb/No in 1xEV-DO [1]. Spectral Efficiency (3/5) Requirement : 4 [bit/s/Hz] 0.01 0.1 1 10 Spectral Efficiency [bit/s/Hz] 100203040 Eb/No [dB] IS-95 GSM AMPS FL receiver performance requirements (fading ch.) [3] FL receiver performance requirements (AWGN) [3] Based on voice user capacity reported at CDG website[2] CDMA 1x EVDO Shannon limit EVDO (~Peak rate)

8. 7 Not all users achieve higher spectral efficiency due to another constraint imposed by interference [1]. Spectral Efficiency (4/5) FL receiver performance requirements (fading ch.) [3] FL receiver performance requirements (AWGN) [3] Based on voice user capacity reported at CDG website[2] Shannon limit Requirement : 4 [bit/s/Hz] 0.01 0.1 1 10 Spectral Efficiency [bit/s/Hz] 100203040 Eb/No [dB] IS-95 GSM AMPS CDMA 1x EVDO EVDO (~Peak rate) Interference bound (Freq. reuse = 1)

9. 8 Addition of space domain and reduction of interference are key factors for higher spectral efficiency in future cellular systems. Spectral Efficiency (5/5) Requirement : 4 [bit/s/Hz] 0.01 0.1 1 10 Spectral Efficiency [bit/s/Hz] 100203040 Eb/No [dB] IS-95 GSM AMPS CDMA 1x EVDO EVDO (~Peak rate) 2: Interference Reduction 1: Spatial Multiplexing Target

10. 9 Exploiting the spatial dimension in signal processing for cellular communication networks to improve : –Coverage –Signal Quality –Spectral Efficiency Higher spectral efficiency comes by means of spatial multiplexing. –Multiple spatial data pipes between TX and RX Spatial Processing (1/4)

11. 10 5% outage / 95% reliability vs. SNR as a function of the number of TX and RX antennas. Bandwidth is 200 KHz : Source : Paulraj, Stanford University Capacity Gain Spatial Processing (2/4)

12. 11 SDMA with fixed beams –Low complexity  Beam selection only –Max. 6 spatial multiplexing using overlapped 12beams (12 antennas) Spatial Processing (3/4) Directional Gain [dB] 0 -5 -10 -15 -20 -25 -30 -35 -40 -150 -120 -90 -60 -300 30 60 90 120 150 Angle [degree] #a #b#c#d#e#f #g #h#i#j#k#l Beam IDs

13. 12 Spatial Multiplexing (SM) Technologies –Multiple antenna technique for achieving higher data rate efficiently –Independent data streams transmitted on each antenna –Requires multiple receive antennas and sophisticated SM receiver processing –Works best in scattering channels Spatial Processing (4/4)

14. 13 BS cooperation approach to reduce inter-cell interference : Each MS measures and reports which beam cause inter-cell interference. BSs make schedules in cooperation to avoid beam collision. Advanced Signal Processing Techniques –Enhanced forward link equalizer –Interference Cancellation –MUD Interference Reduction (1/2) BS1 BS2 Receive data from BS2-beam3 without interference Receive data from BS1-beam4 without interference Interference due to beam collision Exchange beam schedule 1 2 3 4 1 2 3 4 MS1 MS2 MS3

15. 14 Achievable envelope of spectral efficiency by varying the degrees of spatial multiplexing and interference reduction [1] Spatial Multiplexing + Interference Reduction x12 x6 x3 x2 x1 0.1 1 10 100 Spectral Efficiency [bit/s/Hz] 40100203040 Eb/No [dB] 3dB 6dB 10dB 14dB 20dB Requirement : 4 [bit/s/Hz]

16. 15 To satisfy ever increasing service demands requiring even higher transmission rate : –Suggested short-term targets for peak data rate FL : up to 15 x 3.1 Mbps ~ (up to 46.5 Mbps) RL : up to 15 x 1.8 Mbps ~ (up to 27 Mbps) –Suggested long-term targets for peak data rate FL : 100 Mbps ~ 1 Gbps RL : 50 Mbps ~ 1200 Mbps Higher Data Rate

17. 16 N x cdma2000 : Phase I –Maximize Return on Investment (ROI) by maintaining backward compatibility for short-term –Fast time-to-market to maintain a market leadership –Number of 1.25 MHz carriers, N, 15  N  1 –Both symmetric and asymmetric FL/RL assignments Minimum N = 1 for backward compatibility Multi-carrier cdma2000 (1/5)

18. 17 Symmetric and asymmetric carrier assignments. Example of asymmetric assignment is FTP download [11]. Multi-carrier cdma2000 (2/5)

19. 18 N x cdma2000 : Phase II Enhancements of existing Multi-carrier cdma2000 : –Backward compatibility –Rapid time-to-market for broadband services –Technologies under consideration : Interference Cancellation Enhanced FL Equalizer Advanced FEC Antenna Techniques Multi-carrier cdma2000 (3/5)

20. 19 Coexistence of new modulation over existing multi-carrier HRPD : –Providing improved spectrum utilization and peak data rates while maintaining backward compatibility –New modulation : OFDM –OFDM symbols in cdma2000 slots –Value-added Technologies : MIMO SDMA Multi-carrier cdma2000 (4/5)

21. 20 Example : 1xEV-DO, NxEV-DO, and broadband OFDM coexist in the same N = 3 carriers [10]. Multi-carrier cdma2000 (5/5)

22. 21 Bandwidth up to 20 MHz or more Peak data rates –FL : 100 Mbps ~ 1 Gbps –RL : 50 Mbps ~ 100 Mbps Criteria for new AI –Ease of scalable bandwidth operation –Excellent performance in frequency-selective channels –Reduced handset complexities –Easy accommodation of value-added technologies like MIMO New Air Interfaces (1/5)

23. 22 Possible Candidate Multiplexing Technologies : –OFDM Bandwidth scalability with orthogonal frequency separation Full utilization of frequency selectiveness High performance in a multipath channel Narrow sidelobes –MC-CDMA CDMA + OFDM –DS-CDMA with higher chip rate –Single carrier with cyclic prefix and frequency domain equalizer Comparable performance to OFDM Reduced peak-to-average power ratio (PAPR) New Air Interfaces (2/5)

24. 23 Graphical representation of OFDM in time and frequency domain [10] New Air Interfaces (3/5)

25. 24 Example : OFDM + CDMA [9] –One time slot (2048 chips) is divided into 4 OFDM-CDMA symbols –One carrier has 512 tones –Each chip is mapped to one tone New Air Interfaces (4/5)

26. 25 System level comparison of OFDM and 1xEV-DV with rake reception in 1.25 MHz based on Evaluation Methodology Document (EMD) [12] New Air Interfaces (5/5)

27. 26 Use of multiple antennas at the transmitter and receiver (MIMO) –Improves SNR through beamforming array gain –Reduces CCI or MAI Improves coverage, capacity, and data rate –Enhances spatial diversity Improves signal quality –Increases spectral efficiency by means of spatial multiplexing Multiple Antenna Technologies (1/3)

28. 27 MIMO is a key technology for broadband wireless communications [12]. Multiple Antenna Technologies (2/3)

29. 28 Spatial Processing : –MIMO –Spatial multiplexing –Space Time Codes (STC) –Beamforming SDMA –12 overlapping fixed beams : Hitachi –BS cooperation to avoid beam collision : Hitachi –Secondary pilot : Lucent –Tx/Rx Diversity, Antenna Arrays : Motorola, Ericsson Multiple Antenna Technologies (3/3)

30. 29 Support of higher-order modulation (64 QAM) : Lucent Advanced reception with equalization and interference cancellation : LGE, Qualcomm, Motorola, Lucent Enhanced broadcast and multicast services (BCMCS) : Via Telecom –Cellular Digital Multimedia Broadcast (CDMB) Compatible with 1x and Nx CMDA channels Other Features

31. 30 Common Objectives for 3GPP2 Evolution –Increase data rate to maintain a market leadership over other wideband systems –Latency reduction –Backward compatibility for near-term Two step phased approaches for evolution were proposed to leverage investments while exploiting the promising technologies for each phase Phase I –Cost effective and straightforward migration to provide higher transmission rates and spectral efficiency –Nx CDMA systems (1xEV-DV Rev. D and HRPD) Summarizing Remarks (1/2)

32. 31 –Peak data rates : FL Peak Data Rate: at least 3 x HRPD Rev A FL (3.01 Mbps) up to 50 Mbps RL Peak Data Rate : at least 3 x HRPD Rev A RL (1.8 Mbps) up to 29 Mbps Phase II –Further enhancements beyond Phase I by providing higher data rates and spectral efficiency –Peak data rates greater than 100 Mbps –Candidate Technologies : CDMA with Equalizer or Interference Cancellation OFDM(A) IFDMA MIMO, SDMA Advanced Modulation and Coding Summarizing Remarks (2/2)

33. 32 1.C00AIE-20050310-021R2, “ Hitachi Technical Approaches for Future RAN Evolution ”, Hitachi, March 2005 2.http://www.cdg.org/technology/cdma_technology/capacity/capac ity_comparison_paper.asp, CDMA Development Grouphttp://www.cdg.org/technology/cdma_technology/capacity/capac ity_comparison_paper.asp 3.C.S0010-C, “ Recommended Minimum Performance Standards for cdma2000 ® Spread Spectrum Base Station Release C ”, January 2005 4.C00AIE-20050310-020, “ cdma2000 Air Interface Evolution ”, Ericsson, March 2005 5.C00AIE-20050310-022R1, “ LGE ’ s View on 3G Evolution ”, LG Electronics, March 2005 6.C00AIE-20050310-023R1, “ NxHRPD Architecture and High Level Design ”, Lucent, March 2005 Technical Contributions (1/2) cdma2000 ® is the trademark for the technical nomenclature for certain specifications and standards of the Organizational Partners (OPs) of 3GPP2. Geographically (and as of the date of publication), cdma2000 ® is a registered trademark of the Telecommunications Industry Association (TIA-USA) in the United States.

34. 33 7. C00AIE-20050310-023AR1, “ HRPD Evolution Technology Enhancements ”, Lucent, March 2005 8. C00AIE-20050310-024, “ Motorola ’ s View on cdma2000 Air Interface Evolution ”, Motorola, March 2005 9.C00AIE-20050310-025, “ A Look at Evolving cdma2000 Technical Approaches ”, Nokia, March 2005 10.C00AIE-20050310-026, “ 3GPP2 Air Interface Evolution ”, Nortel, March 2005 11.C00AIE-20050310-027R1, “ cdma2000 Evolution Technical Summary ”, Qualcomm, March 2005 12.C00AIE-20050310-028R1, “ Key Technologies for cdma2000 Evolution ”, Samsung, March 2005 13.C00AIE-20050310-029, “ CDMB-Cellular Digital Multimedia Broadcast ”, Via Telecom, March 2005 Technical Contributions (2/2)