TY - GEN

T1 - Outage probability of OSTBC

T2 - 2006 IEEE International Conference on Acoustics, Speech and Signal Processing, ICASSP 2006

AU - Jorswieck, Eduard A.

AU - Sezgin, Aydin

AU - Boche, Holger

PY - 2006

Y1 - 2006

N2 - Orthogonal space-time block codes (OSTBC) are an efficient mean in order to exploit the diversity offered by the wireless multiple-input multiple-output (MIMO) channel. It was shown that the Alamouti scheme, an OSTBC for n T = 2 transmit antennas, achieves the capacity of such MIMO channels with nR = 1 receive antenna. However, by increasing the number of transmit antennas, the transmission rate of the OSTBC is monotonically decreasing. Recently, this rate reduction was characterized completely. Using a recent result on the properties of Gaussian quadratic forms, we show two key results: Assume the transmitter has not channel state information. We show that for given rate and SNR it is optimal to use a subset of all available antennas with equal power allocation. Further on, we show that an OSTBC for an odd number of transmit antennas is always outperformed by an OSTBC for either the next lower or the next higher even number of transmit antennas. Finally, the impact of spatial correlation with uninformed transmitter is characterized. We illustrate the theoretical results by numerical simulations. The theoretical and simulation results show the suboptimality of the OSTBC for an odd number of antennas with respect to the outage probability minimization.

AB - Orthogonal space-time block codes (OSTBC) are an efficient mean in order to exploit the diversity offered by the wireless multiple-input multiple-output (MIMO) channel. It was shown that the Alamouti scheme, an OSTBC for n T = 2 transmit antennas, achieves the capacity of such MIMO channels with nR = 1 receive antenna. However, by increasing the number of transmit antennas, the transmission rate of the OSTBC is monotonically decreasing. Recently, this rate reduction was characterized completely. Using a recent result on the properties of Gaussian quadratic forms, we show two key results: Assume the transmitter has not channel state information. We show that for given rate and SNR it is optimal to use a subset of all available antennas with equal power allocation. Further on, we show that an OSTBC for an odd number of transmit antennas is always outperformed by an OSTBC for either the next lower or the next higher even number of transmit antennas. Finally, the impact of spatial correlation with uninformed transmitter is characterized. We illustrate the theoretical results by numerical simulations. The theoretical and simulation results show the suboptimality of the OSTBC for an odd number of antennas with respect to the outage probability minimization.

UR - http://www.scopus.com/inward/record.url?scp=33947645785&partnerID=8YFLogxK

M3 - Conference contribution

AN - SCOPUS:33947645785

SN - 142440469X

SN - 9781424404698

T3 - ICASSP, IEEE International Conference on Acoustics, Speech and Signal Processing - Proceedings

SP - IV177-IV180

BT - 2006 IEEE International Conference on Acoustics, Speech, and Signal Processing - Proceedings

Y2 - 14 May 2006 through 19 May 2006

ER -