Toward 4G IP-based Wireless Systems:
A Proposal for the Uplink.
Chalmers U. of Technology
Uppsala University and
Chalmers U. of Technology.
Wireless World Research Forum Workshop,
Phoenix, Arizona, March 2002 and London,
The Wireless IP project within the PCC program studies
problems that are crucial in the evolution of UMTS towards high
data rates, as well as in future 4G technologies aimed at
rapidly mobile terminals. The goal is to attain higher
througputs for packet data in particular in downlinks,
without bandwidth expansion and while providing acceptable
quality of service for various classes of traffic.
A packet switched wireless
cellular system with wide area
coverage and high throughput is proposed.
The system is designed to be cost
effective and to provide high spectral
It makes use of a combination
of tools and concepts:
Smart antennas both at base stations
and mobiles, provide antenna gain and
improve the signal to interference ratio.
The fast fading is predicted
in both time and frequency
and a slotted OFDM radio interface is used,
in which time-frequency slots are allocated
adaptively to different mobile users, based on
their predicted channel quality. This enables
among sectors and users as well as fast
adaptive modulation and power control.
We here outline the uplink of
the radio interface. Calculations based on
simplifying assumptions illustrate how the
channel capacity grows with the number of
simultaneous users and the number of antenna
A~high capacity can be attained already for
moderate numbers of users and
base station/terminal antennas.
The downlink of this
system proposal, presented at WWRF Dec 2001, Paris.
Licenciate Thesis by Nilo C. Ericsson
on predictive scheduling combined with adaptive modulation.
Licenciate Thesis by Sorour Falahati, Feb. 2000.
on channel prediction over 1-10 ms horizons.
for the downlink 4G systems similar to the one discussed here
(FTC 2001, Beijing).
An overview of the Wireless IP Project, NRS 01.