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Wireless Technology Beyond 3G In Japan. Dave Smith. Technology Evolution. Datarate is the Goal. Requirement 100Mb/s Wide area By 2010 How? USA – WLAN Europe – convergence Japan – new air interface. What are key technologies ?. Telecommunications Council Report 2001 New air interface
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Wireless Technology Beyond 3G In Japan Dave Smith
Datarate is the Goal • Requirement • 100Mb/s • Wide area • By 2010 How? • USA – WLAN • Europe – convergence • Japan – new air interface
What are key technologies? • Telecommunications Council Report 2001 • New air interface • Software Defined Radio • Adaptive Array Antennas • High level modulation schemes • Dynamic link adaptation
What are the key technologies? • Telecommunications Council Report 2001 • New air interface • Software Defined Radio • Adaptive Array Antennas • High level modulation schemes • Dynamic link adaptation • MIMO • Direct Conversion receivers
Access Scheme • 4-5 GHz • NTT DoCoMO defined access scheme • (referenced 4 year study) • OFDMA vs MC –CDMA
2002 c NTT DoCoMo Current Multiple Access Technologies ・ For Seamless Area Coverage, Multi-cell Structure is necessary. CDMA can achieve the best spectrum efficiency. ・ For High Throughput, Single-cell Structure is suitable because it can avoid inter-cell interference. OFDM can achieve the best spectrum efficiency. But ・・・・・ - Each scheme is not best in the other cell structure. - For the flexible area coverage and service deployment with lower cost, both Multi-cell and Single-cell environments should be supported with maximum throughput. Look for New Wireless Access Scheme that coversboth environments. 7
Variable Spreading Factor MC CDMA Spreading and Scrambling #Cmux Code Multiplexing #2 Code #1 f SF SF SF OFCDMA And the winner is …….. OFCDMA is MC CDMA. If the spreading factor = 1, MC-CDMA OFDMA.
Smart antennas • Considered “Indispensable” • All labs have active programmes • Trial antenna at KDDI • Status: • Probably lag Europe e.g. NTTDoCoMo array RLS processor
Tx Tx Processing DeMux Encoding, Modulation, Rx Processing Demodulation Decoding, Mux, Tx Tx Tx Rx Rx Rx Rx MIMO CHANNEL é ù h h L 11 1 N ê ú T O M ê ú ê ú M h h L ë û M 1 M N R R T MIMO • Multi-element array antenna at both ends of link. • Space-time coding • Highly computationally intensive • Status: • All Japanese R&D labs have a programme • No obvious advance over European knowledge • “USA well ahead of rest of the world”
Will this achieve 100Mb/s? • No calculation to confirm this yet. • Real transmit power issues • Battery technology • Testbed under construction: • Summer 2002 • 200m range LoS • 100 Mb/s Downlink, 40 Mb/s uplink • Note BLAST work in USA: • spectral efficiency of 20-40bit/s, • But real life?
Terminals • 3G is here • NTTDoCoMo – FOMA W-CDMA terminals from NEC and Matsushita • KDDI – CDMA 2000 – multiple suppliers
2001 c NTT DoCoMo FOMA -Terminals Visual Standard (i-mode) Data Card FOMA P2401 FOMA N2001/2002 FOMA P2101V /D2101V 384k Packet, 64k Data, 64k Real-time Video, Voice, 384k Packet/ i-mode Voice, 384k Packet/ i-mode, 64k Data, Multi Access 13
KDDI • Pics and projections
4G terminal concepts • Voice recognition • Wearable communicators/computers • Status: • Early days
4G terminal concepts • Voice recognition • Wearable communicators/computers • Status: • Early days
Direct conversion • Quoted as necessary for 4G by NTT, KDDI, Fujitsu and Matsushita • Single chip solution • Reduced cost
Software Defined Radio • IEICE SDR study group • Considered ‘key’ • Unclear strategy for terminals or basestations
Summary • 100 Mb/s is a target for 4G research • Need new air interface to achieve it. • Not in tune with Europe or USA • If right, Japanese research programme will provide a technical and market lead in next 10 years • If wrong ….