Class of Full-Rank Space-Time Codes Combining Orthogonal Designs With Delay Diversity

This paper considers a new class of full-diversity space-time (ST) codes for multiple-transmit-antenna wireless systems. These codes, relying on partitioning the transmit antennas into groups, consist of a combination of delay transmit diversity with orthogonal ST block codes and specially designed symbol mappings of information bits into channel symbols. Due to the orthogonality of the ST block codes, which guarantees each antenna group composed signal to have full rank, and the blockwise delay diversity, which guarantees independence of the signals transmitted by different antenna groups at the same time, these codes achieve full diversity with relatively low decoding complexity. A computer search has been employed to determine the channel symbol mappings for codes with quaternary phase-shift keying (QPSK) and eight-phase PSK modulation that maximize the asymptotic coding advantages. For 16-phase quadrature amplitude modulation (16 QAM), we present a novel hand-designed code. These codes yield performance gains in terms of both frame error rate and bit error rate with respect to many known full-diversity codes over quasi-static and block-fading Rayleigh channels, with decoding of reasonable complexity.