TY - JOUR

T1 - A unified construction of space-time codes with optimal rate-diversity tradeoff

AU - Lu, Hsiao-Feng

AU - Kumar, P. Vijay

PY - 2005/5/1

Y1 - 2005/5/1

N2 - The problem of constructing space-time (ST) block codes over a fixed, desired signal constellation is considered. In this situation, there is a tradeoff between the transmission rate as measured in constellation symbols per channel use and the transmit diversity gain achieved by the code. The transmit diversity is a measure of the rate of polynomial decay of pairwise error probability of the code with increase in the signal-to-noise ratio (SNR). In the setting of a quasi-static channel model, let nt denote the number of transmit antennas and T the block interval. For any nt ≤ T, a unified construction of (nt × T) ST codes is provided here, for a class of signal constellations that includes the familiar pulse-amplitude (PAM), quadrature-amplitude (QAM), and 2K-ary phase-shift-keying (PSK) modulations as special cases. The construction is optimal as measured by the rate-diversity tradeoff and can achieve any given integer point on the rate-diversity tradeoff curve. An estimate of the coding gain realized is given. Other results presented here include i) an extension of the optimal unified construction to the multiple fading block case, ii) a version of the optimal unified construction in which the underlying binary block codes are replaced by trellis codes, iii) the providing of a linear dispersion form for the underlying binary block codes, iv) a Gray-mapped version of the unified construction, and v) a generalization of construction of the ℘-ary case corresponding to constellations of size ℘K. Items ii) and iii) are aimed at simplifying the decoding of this class of ST codes.

AB - The problem of constructing space-time (ST) block codes over a fixed, desired signal constellation is considered. In this situation, there is a tradeoff between the transmission rate as measured in constellation symbols per channel use and the transmit diversity gain achieved by the code. The transmit diversity is a measure of the rate of polynomial decay of pairwise error probability of the code with increase in the signal-to-noise ratio (SNR). In the setting of a quasi-static channel model, let nt denote the number of transmit antennas and T the block interval. For any nt ≤ T, a unified construction of (nt × T) ST codes is provided here, for a class of signal constellations that includes the familiar pulse-amplitude (PAM), quadrature-amplitude (QAM), and 2K-ary phase-shift-keying (PSK) modulations as special cases. The construction is optimal as measured by the rate-diversity tradeoff and can achieve any given integer point on the rate-diversity tradeoff curve. An estimate of the coding gain realized is given. Other results presented here include i) an extension of the optimal unified construction to the multiple fading block case, ii) a version of the optimal unified construction in which the underlying binary block codes are replaced by trellis codes, iii) the providing of a linear dispersion form for the underlying binary block codes, iv) a Gray-mapped version of the unified construction, and v) a generalization of construction of the ℘-ary case corresponding to constellations of size ℘K. Items ii) and iii) are aimed at simplifying the decoding of this class of ST codes.

KW - Diversity gain advantage

KW - Multiple antennas

KW - Multiple-input multiple-output (MIMO)

KW - Rate-diversity tradeoff

KW - Space-time (ST) codes

KW - Unified construction

UR - http://www.scopus.com/inward/record.url?scp=18544371645&partnerID=8YFLogxK

U2 - 10.1109/TIT.2005.846403

DO - 10.1109/TIT.2005.846403

M3 - Article

AN - SCOPUS:18544371645

VL - 51

SP - 1709

EP - 1730

JO - IEEE Transactions on Information Theory

JF - IEEE Transactions on Information Theory

SN - 0018-9448

IS - 5

ER -