TY - JOUR

T1 - Optimal diversity-multiplexing tradeoff and code constructions of some constrained asymmetric MIMO systems

AU - Lu, Francis

AU - Hollanti, Camilla

PY - 2010/5

Y1 - 2010/5

N2 - In multiple-inputmultiple-output (MIMO) communications, the notion of asymmetric channel refers to the situation when the number of transmit antennas is strictly larger than the number of receive antennas. Such channels can often be found in MIMO downlink transmissions. While existing cyclic-division-algebra (CDA)-based codes can still be employed to achieve the optimal diversitymultiplexing tradeoff (DMT) at high signal-to-noise ratio (SNR) regime, such codes cannot be directly decoded using, for example, the pure sphere decoding method. Although other means of decoding methods such as minimum mean square error generalized decision feedback equalizer (MMSE-GDFE) with lattice search and regularized lattice decoding are available, an alternative approach is to constrain the number of active transmit antennas in each channel use to be no larger than the number of receive antennas. The resulting system is coined constrained asymmetric MIMO system. Two general types of asymmetrical channels are considered in this paper, namely, 1) when there are two receive antennas and the number of transmit antennas is arbitrary, and 2) when the number of transmit antennas is one larger than the number of receive antennas. Explicit optimal transmission schemes as well as the corresponding code constructions for such constrained asymmetric MIMO channels are presented, and are shown to achieve the same DMT performance as their unconstrained counterparts.

AB - In multiple-inputmultiple-output (MIMO) communications, the notion of asymmetric channel refers to the situation when the number of transmit antennas is strictly larger than the number of receive antennas. Such channels can often be found in MIMO downlink transmissions. While existing cyclic-division-algebra (CDA)-based codes can still be employed to achieve the optimal diversitymultiplexing tradeoff (DMT) at high signal-to-noise ratio (SNR) regime, such codes cannot be directly decoded using, for example, the pure sphere decoding method. Although other means of decoding methods such as minimum mean square error generalized decision feedback equalizer (MMSE-GDFE) with lattice search and regularized lattice decoding are available, an alternative approach is to constrain the number of active transmit antennas in each channel use to be no larger than the number of receive antennas. The resulting system is coined constrained asymmetric MIMO system. Two general types of asymmetrical channels are considered in this paper, namely, 1) when there are two receive antennas and the number of transmit antennas is arbitrary, and 2) when the number of transmit antennas is one larger than the number of receive antennas. Explicit optimal transmission schemes as well as the corresponding code constructions for such constrained asymmetric MIMO channels are presented, and are shown to achieve the same DMT performance as their unconstrained counterparts.

KW - Constrained asymmetric multiple-input-multiple-output (MIMO) channels

KW - Cyclic-division algebra

KW - Diversity-multiplexing tradeoff

KW - Space-time codes.

KW - Transmit antenna selection schemes

UR - http://www.scopus.com/inward/record.url?scp=77951589597&partnerID=8YFLogxK

U2 - 10.1109/TIT.2010.2043779

DO - 10.1109/TIT.2010.2043779

M3 - Article

AN - SCOPUS:77951589597

SN - 0018-9448

VL - 56

SP - 2121

EP - 2129

JO - IEEE Transactions on Information Theory

JF - IEEE Transactions on Information Theory

IS - 5

M1 - 9

ER -