Towards a 4G IP-based Wireless System Proposal.

Tony Ottosson, Chalmers U. of Technology
Mikael Sternad, Uppsala University
Anders Ahlén, Uppsala University
Arne Svensson, Chalmers U. of Technology and
Anna Brunström, Karlstad University

Radiovetenskap och Kommunikation RVK 02, Stockholm, June 2002.

Outline:

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.

Abstract:

A packet switched wireless cellular system with wide area coverage, high throughput and high spectral efficiency is proposed. Smart antennas at both base stations and mobiles improve the antenna gain and improve the signal to interference ratio. The small-scale fading is predicted in both time and frequency and a slotted OFDM radio interface is used, in which time-frequency bins are allocated adaptively to different mobile users, based on their predicted channel quality. This enables efficient scheduling among sectors and users as well as fast adaptive modulation and power control.

We here estimate the spectral efficiency of the suggested downlink. The resulting channel capacity grows with the number of simultaneous users and with the number of antenna elements in terminals. A high efficiency, around 4 bits/s/Hz, is attained already for moderate numbers of users and terminal antennas. An outline is given of research pursued within the PCC Wireless IP Project to improve and investigate this type of system.

Related publications:

The uplink of this system proposal, presented at WWRF March 2002, Phoenix, Arizona.

Licenciate Thesis by Nilo C. Ericsson (June 2001), on predictive scheduling combined with adaptive modulation.

Licenciate Thesis by Sorour Falahati, Feb. 2000.

VTC01spring-paper on channel prediction over 1-10 ms horizons.

Scheduling and adaptive transmission for the downlink 4G systems similar to the one discussed here (FTC 2001, Beijing).

An overview of the Wireless IP Project, NRS 01.

Some other presentations by Wireless IP at RVK02:

An overview of the Wireless IP Project

Improved Channel Power Prediction, by using unbiased predictors and advanced regressor noise reduction.

Optimizing adaptive modulation, by taking the power prediction error into account.

Simulating TCP/IP traffic over wireless links in real time.

Source:

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