The pairwise-error probability upper bounds of space-time codes (STCs) in independent Rician fading channels are derived. Based on the performance analysis, novel code design criteria for slow and fast Rayleigh fading channels are developed. It is found that, in fading channels, the STC design criteria depend on the value of the possible diversity gain of the system. In slow fading channels, when the diversity gain is smaller than four, the code error performance is dominated by the minimum rank and the minimum determinant of the codeword distance matrix. However, when the diversity gain is larger than, or equal to, four, the performance is dominated by the minimum squared Euclidean distance. Based on the proposed design criteria, new codes are designed and evaluated by simulation.

This paper presents the design of space-time turbo trellis coded modulation (ST turbo TCM). We introduce new recursive space-time trellis coded modulation (STTC) which outperform feedforward STTC proposed by Tarokh, Seshadri and Calderbank (see Trans. Inform. Theory, vol.44, no.2, p.744-65, 1998) and by Baro, Bauch and Hansmann (see IEEE Trans. Commun. Letters, vol.4, no.1, p.20-22, 2000) . A substantial improvement in performance can be obtained by constructing parallel concatenation of recursive STTC and making use of iterative decoding. The new recursive STTCs can be used directly in this scheme. ST turbo TCM outperforms the best known STTC by about 2 dB on slow fading channels and by up to 8 dB on fast fading channels.

A layered space-time architecture has been proposed to realize the tremendous increase in capacity which is offered by rich scattering wireless channels in comparison with a single transmit and single receive antenna case. We analyze the performance of horizontally (HLST) and diagonally (DLST) layered space-time architectures on slow and fast Rayleigh fading channels. Based on the analysis, we derive the code design criteria for the constituent codes for each architecture.

Novel code design criteria for space-time codes on slow Rayleigh fading channels are presented. It is shown that the code performance is dominated by the minimum rank r and the minimum determinant of the codeword distance matrix when the product of the minimum rank r and the number of receive antennas n/sub R/ is less than 4. However, when r/spl middot/n/sub R/ is greater than or equal to 4, the code error performance is dominated by the minimum trace of the codeword distance matrix. Furthermore, we present recursive spacetime trellis coded modulation (STTC) which outperforms feedforward STTC on slow and fast fading channels. A substantial increase in performance can be obtained by constructing spacetime turbo trellis coded modulation (ST turbo TCM) which consists of concatenated recursive STTC, decoded by iterative decoding algorithm. The proposed recursive STTC are used as constituent codes in this scheme. The proposed ST turbo TCM significantly outperforms the best known STTC on both slow and fast fading channels.