Multiuser MIMO-OFDM for Next-Generation Wireless Systems-Proceedings of IEEE 2007.pdf

INVITED
PAPER
Multiuser MIMO-OFDM
for Next-Generation
Wireless Systems
Multiple-Input Multiple-Output (MIMO) wireless systems using OFDM promise to
provide the needed performance for future consumer products. This paper reviews
existing MIMO-OFDM systems, discusses their limitations, and examines the
use of ic Algorithms (GAs) as a tool to handle large numbers of users.
By Ming Jiang, Member IEEE,andLajosHanzo,Fellow IEEE
ABSTRACT | This overview portrays the 40-year evolution of for employment in multiuser MIMO OFDM. In order to stimulate
orthogonal frequency division multiplexing (OFDM) research. new research, we demonstrate that the family of GA-aided
The amelioration of powerful multicarrier OFDM arrangements MUDs is capable of achieving a near-optimum performance at
with multiple-input multiple-output (MIMO) systems has nu- the cost of a significantly plexity than
merous benefits, which are detailed in this treatise. We that imposed by their optimum maximum-likelihood (ML) MUD
continue by highlighting the limitations of conventional aided counterparts. The paper is concluded by outlining a
detection and channel estimation techniques designed for range of future research options that may find their way into
multiuser MIMO OFDM systems in the so-called rank-deficient next-generation wireless systems.
scenarios, where the number of users supported or the number
of transmit antennas employed exceeds the number of receiver
KEYWORDS | Channel estimation; ic algorithm (GA);
antennas. This is often encountered in practice, unless we limit
multiple-input multiple-output (MIMO); multiuser detection/
the number of users granted access in the base station’s or
detector (MUD); orthogonal frequency division multiplexing
radio port’s coverage area. Following a historical perspective
(OFDM); space division multiple access (SDMA)
on the associated design problems and their state-of-the-art
solutions, the second half of this treatise details a ra