MIT Department of Electrical Engineering & Computer Science

OFDM-Based Multi-Antenna Systems for Broadband Wireless Communications

Helmut Bolcskei
Stanford University

Monday, March 27, 2000
2:15 PM (refreshments 2:00)
Grier Room, Room 34-401A
EECS Special Seminar

Abstract

The use of multiple antennas at both the transmitter and the receiver has recently been shown to have the potential of achieving extraordinary bit rates. So far, most of the research in this context has been restricted to narrow-band channels and single-carrier modulation.

In this talk, we focus on a broadband wireless Orthogonal Frequency Division Multiplexing (OFDM)-based multi-antenna system. We present a new spatial channel model, compute the corresponding channel capacity, and study the influence of propagation parameters on capacity.

We then introduce space-frequency Trellis codes and we prove that they achieve full diversity gain (i.e., spatial diversity and frequency diversity) in a multi-antenna delay spread channel. We study the performance degradation of space-frequency Trellis codes due to spatial fading correlation (caused by small antenna spacing or small angle spread) both analytically and by means of computer simulations. In particular, we establish an upper bound on the error probability of space-frequency Trellis codes as a function of the propagation parameters. Simulation results will be demonstrated throughout the talk.

This is a joint work with A. Paulraj and D. Gesbert.