4G cellular

http://www.comsoc.org/ci/private/2000/jul/powerpoint/sld003.htm

4G Wireless
  • A "wireless cable modem"
    1. Asymmetric access
    2. WOFDM downlinks & EDGE uplinks
  • High-speed service to advanced handsets, laptops, PDAs, body-computers with heads-up displays, dash-board computers,….
    • Complements 2G/3G Wireless
  • Targets spectrum from 500 MHz to 3 GHz
AT&T Labs-Research Work on 4G:
  • Smart antennas
  • Multiple-Input-Multiple-Output Systems
  • Space-Time Coding
  • Dynamic Packet Assignment
  • Wideband OFDM
OFDM for 4G Wireless
OFDM is being increasingly used in high -speed information transmission systems:
  • European HDTV
  • Digital Audio Broadcast (DAB)
  • Digital Subscriber Loop (DSL)
  • IEEE 802.11 Wireless LAN
Mobile OFDM parameters: ex.
  • 5 MHz channels
    1. 6 KHz tones
    2. 13/26 MHz sample rate
  • 2048 FFT size (160 usec OFDM blocks)
  • 256/512 sample OFDM block guard time
  • QPSK & 16-QAM modulation adaptive modulation/coding
  • 1 to 2 msec time-slots in 20 to 40 msec frames
  • Mobile OFDM parameters: ex.
Key Features of 4G W-OFDM:
  • IP packet data centric
  • Support for streaming, simulcasting & generic data
  • Peak downlink rates of 5 to 10 Mbps
  • Full macro-cellular/metropolitan coverage
  • Asymmetric with 3G uplinks (EDGE)
  • Variable bandwidth - 1 to 5 MHz
  • Adaptive modulation/coding
  • Smart/adaptive antennas supported
  • MIMO/BLAST/space-time coding modes
  • Frame synchronized base stations using GPS
  • Network assisted dynamic packet assignment
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Copyright © 2004, Jonathan D. Torbert. All rights reserved.
Last Modified 11-17-04 11:00 am
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