Title :
Switching between diversity and multiplexing in MIMO systems
Author :
Heath, Robert W., Jr. ; Paulraj, Arogyaswami J.
Author_Institution :
Dept. of Electr. & Comput. Eng., Univ. of Texas, Austin, TX, USA
fDate :
6/1/2005 12:00:00 AM
Abstract :
Multiple-input multiple-output (MIMO) wireless communication systems can offer high data rates through spatial multiplexing or substantial diversity using transmit diversity. In this letter, switching between spatial multiplexing and transmit diversity is proposed as a simple way to improve the diversity performance of spatial multiplexing. In the proposed approach, for a fixed rate, either multiplexing or diversity is chosen based on the instantaneous channel state and the decision is conveyed to the transmitter via a low-rate feedback channel. The minimum Euclidean distance at the receiver is computed for spatial multiplexing and transmit diversity and is used to derive the selection criterion. Additionally, the Demmel condition number of the matrix channel is shown to provide a sufficient condition for multiplexing to outperform diversity. Monte Carlo simulations demonstrate improvement over either multiplexing or diversity individually in terms of bit error rate.
Keywords :
MIMO systems; Monte Carlo methods; channel coding; diversity reception; error statistics; feedback; multiplexing; radio receivers; space-time codes; telecommunication channels; BER; MIMO system; Monte Carlo simulation; bit error rate; channel coding; feedback channel; instantaneous channel state; matrix channel; minimum Euclidean distance; multiple-input multiple-output wireless communication system; space-time coding; spatial multiplexing; transmit diversity; Communication switching; Cultural differences; Error probability; Euclidean distance; MIMO; Receiving antennas; State feedback; Transmitters; Transmitting antennas; Wireless communication; Multiple-input multiple-output (MIMO) systems; space-time coding; transmit diversity;
Journal_Title :
Communications, IEEE Transactions on
DOI :
10.1109/TCOMM.2005.849774